| 1. |
- Chen, Xiao, et al.
(författare)
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Changes in bone mineral density 10 years after marked reduction of cadmium exposure in a Chinese population.
- 2009
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Ingår i: Environmental research. - : Elsevier BV. - 1096-0953 .- 0013-9351. ; 109:7, s. 874-9
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Tidskriftsartikel (refereegranskat)abstract
- The main focus of this study was to evaluate the long-term effects of Cd on forearm bone mineral density after the cessation of the ingestion of Cd-polluted rice. A total of 458 persons (294 women, 164 men) from three Cd exposure areas (low, moderately, and heavy) participated in this study. Those living in the moderate and heavy exposure areas ceased ingesting Cd-polluted rice (0.51 and 3.7mg/kg, respectively) in 1996 (10 years prior to present analysis). The participants completed a questionnaire and bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at the proximal radius and ulna. The changes and change percentage in forearm bone density and the prevalence of osteoporosis between 1998 and 2006 were used as markers of bone recovery. The Cd concentrations in urine (UCd) and blood (BCd) in 1998 were used as Cd exposure markers. The values of the BMD change and change percentage of groups in which UCd was above 5microg/g creatinine (microg/g crea) and BCd was above 10microg/L were significantly higher than those of the low-exposure groups (in women, p<0.001; in men, p>0.05). The BMD change and change percentage correlated positively with the UCd and BCd (in women, p<0.01; in men, p>0.05). Analysis of the Z-score revealed that the prevalence of osteoporosis in 2006 was higher than that in 1998 and increased along with the level of UCd and BCd in both women and men, especially for those subjects with the higher BCd [BCd>5microg/L, OR=3.45 (0.95-13.6); BCd>10microg/L, OR=4.51(1.57-13.54)] and UCd [UCd>10microg/g crea, OR=4.74 (1.82-12.81)] in women. It is concluded that decreasing dietary cadmium exposure at the population level is not associated with bone recovery at the individual level, and the adverse bone effects of Cd exposure persisted after the main source of Cd exposure had been blocked, especially in women.
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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes
- 2008
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Ingår i: Autophagy. - : Landes Bioscience. - 1554-8627 .- 1554-8635. ; 4:2, s. 151-175
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Forskningsöversikt (refereegranskat)abstract
- Research in autophagy continues to accelerate,1 and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.2,3 There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.
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| 3. |
- O'Connor, Daniel T., et al.
(författare)
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Heritability and genome-wide linkage in US and australian twins identify novel genomic regions controlling chromogranin a : implications for secretion and blood pressure
- 2008
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 118:3, s. 247-57
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Chromogranin A (CHGA) triggers catecholamine secretory granule biogenesis, and its catestatin fragment inhibits catecholamine release. We approached catestatin heritability using twin pairs, coupled with genome-wide linkage, in a series of twin and sibling pairs from 2 continents. METHODS AND RESULTS: Hypertensive patients had elevated CHGA coupled with reduction in catestatin, suggesting diminished conversion of precursor to catestatin. Heritability for catestatin in twins was 44% to 60%. Six hundred fifteen nuclear families yielded 870 sib pairs for linkage, with significant logarithm of odds peaks on chromosomes 4p, 4q, and 17q. Because acidification of catecholamine secretory vesicles determines CHGA trafficking and processing to catestatin, we genotyped at positional candidate ATP6N1, bracketed by peak linkage markers on chromosome 17q, encoding a subunit of vesicular H(+)-translocating ATPase. The minor allele diminished CHGA secretion and processing to catestatin. The ATP6N1 variant also influenced blood pressure in 1178 individuals with the most extreme blood pressure values in the population. In chromaffin cells, inhibition of H(+)-ATPase diverted CHGA from regulated to constitutive secretory pathways. CONCLUSIONS: We established heritability of catestatin in twins from 2 continents. Linkage identified 3 regions contributing to catestatin, likely novel determinants of sympathochromaffin exocytosis. At 1 such positional candidate (ATP6N1), variation influenced CHGA secretion and processing to catestatin, confirming the mechanism of a novel trans-QTL for sympathochromaffin activity and blood pressure.
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| 4. |
- Xiao, Kai, et al.
(författare)
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Photoelectrical characteristics of a C/CNx multiwalled nanotube
- 2007
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 17:15, s. 2842-2846
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Tidskriftsartikel (refereegranskat)abstract
- A nanotube diode fabricated from a single C/CNx multiwalled nanotube exhibits a large photocurrent and a large photovoltage under illumination. The current-voltage (I-V) characteristics of the diode indicate a clear rectification effect. By comparing the I-V characteristics of C, CNx, and C/CNx nanotube diodes, we show that the rectifying characteristics of the C/CNx diode arises from the molecular junction formed at the C/CNx interface where the C and CNx segments are chemically bonded. External radiation photochernically generates electrons and holes in the C/CNx nanotube, producing a large photocurrent because of the influence of the strong electric field in the vicinity of the C/CNx junction. These unique photoresponsive characteristics of C/CNx, nanotube junction diodes points to potential applications such as photovoltaic devices and photodiodes.
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| 5. |
- Zhu, Lei, et al.
(författare)
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Proximity ligation measurement of the complex between prostate specific antigen and alpha1-protease inhibitor
- 2009
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 55:9, s. 1665-1671
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Prostate specific antigen (PSA)-alpha1-protease inhibitor complex (PSA-API) is a minor form of PSA in serum. It may be useful for prostate cancer (PCa) diagnosis, but its specific detection is hampered by nonspecific background. To avoid this, we developed an immunoassay for PSA-API based on proximity ligation. METHODS: We used a monoclonal antibody (mAb) to total PSA (tPSA) to capture PSA, while using another anti-tPSA mAb together with an anti-API mAb as probes. We measured PSA-API by quantification of amplified DNA strands conjugated to the probes. We measured serum PSA-API in 84 controls and 55 men with PCa who had PSA concentrations of 4.0-10 microg/L. RESULTS: The detection limit of the assay was 6.6 ng/L. The proportion of PSA-API to tPSA (%PSA-API) tended to be lower in men with PCa (2.8%) than without cancer (3.3%) but was not statistically significant (P = 0.363). When used alone, %PSA-API [area under the curve (AUC) 0.546] did not improve detection of PCa, whereas %fPSA (AUC 0.710) and the sum of %fPSA and %PSA-API (AUC 0.723) did. At 90% diagnostic sensitivity, the diagnostic specificity for cancer was not significantly better for %f PSA + %PSA-API than for %fPSA alone (36% vs 30%). CONCLUSIONS: Proximity ligation eliminated nonspecific background, enabling accurate measurement of PSA-API in serum specimens with moderately increased tPSA. The combined use of %PSA-API and %fPSA provided a modest improvement for PCa detection, but based on the current study cohort, it is uncertain whether the improvement has clinical utility.
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