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This study investigates age-specific prostate-specific antigen (PSA) distributions in Taiwanese men and recommends reference ranges for this population after comparison with other studies. From January 1999 to December 2016, a total of 213,986 Taiwanese men aged above 19 years old without history of prostate cancer, urinary tract infection, or prostate infection were recruited from the Taiwan MJ cohort, an ongoing prospective cohort of health examinations conducted by the MJ Health Screening Center in Taiwan. Participants were divided into seven age groups. Simple descriptive statistical analyses were carried out and quartiles and 95th percentiles were calculated for each group as reference ranges for serum PSA in screening for prostate cancer in Taiwanese men. Serum PSA concentration correlated with age (r = 0.274, p<0.001). The median serum PSA concentration (5th to 95th percentile) ranged from 0.7 ng/ml (0.3 to 1.8) for men 20–29 years old (n = 6,382) to 1.6 ng/ml (0.4 to 8.4) for men over 79 years old (n = 504). The age-specific PSA reference ranges are as follows: 20–29 years, 1.80 ng/ml; 30–39 years, 1.80 ng/ml; 40–49 years, 2.0 ng/ml; 50–59 years, 3.20 ng/ml; 60–69 years, 5.60 ng/ml; 70–79 years, 7.40 ng/ml; over 80 years, 8.40 ng/ml. Almost no change occurred in the median serum PSA value in men 50 years old or younger, while a gradual increase was observed in men over 50. Taiwanese men aged 60 years above showed higher 95th percentile serum PSA values compared to Caucasian men and men in other Asian countries but were closer to those of Asian American and African American men. Results indicate significantly different PSA levels correlating to different ethnicities, suggesting that Oesterling's age-specific PSA reference ranges might not be appropriate for Taiwanese men. Our results should be further studied to validate the age-specific PSA reference ranges for Taiwanese men presented in this study. [ABSTRACT FROM AUTHOR]

Background: The effects of oxybutynin, solifenacin and tolterodine on dementia risk in patients with diabetes mellitus (DM) remain unknown. We investigated the effects of oxybutynin, solifenacin and tolterodine on dementia risk in patients with DM. Methods: We conducted a cohort study by using the diabetes dataset of the Taiwan National Health Insurance Research Database from 1 January, 2002 to 31 December, 2013. We included 10,938 patients received one type of oxybutynin, solifenacin, or tolterodine, while 564,733 had not. We included a comparable number of patients not receiving oxybutynin, solifenacin, or tolterodine as controls through systematic random sampling matching by age, gender, and the year of the index date with 1 to 1 ratio. The dementia risk was estimated through multivariate Cox proportional hazard regression after adjustment for several confounding factors. Results: The dementia event rates were 3.9% in the oxybutynin group, 4.3% in the solifenacin group, 2.2% in the tolterodine group and 1.2% in the control group (P<0.001). The adjusted HRs compared to nonusers of anticholinergic drugs were 2.35 (95% CI, 1.96 to 2.81), 2.16 (95% CI, 1.81 to 2.58), and 2.24 (95% CI, 1.85 to 2.73), respectively, for patients receiving oxybutynin, solifenacin, or tolterodine. Conclusion: Our study indicates an association between taking oxybutynin, solifenacin and tolterodine and the subsequent diagnosis of dementia in DM patients. Moreover, the patients using oxybutynin had highest risk. The impact of these three drugs on risk of dementia in non-diabetic populations is warrant. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae is the predominant pathogen isolated from liver abscesses of diabetic patients in Asian countries. However, the effects of elevated blood glucose levels on the virulence of this pathogen remain largely unknown. Type 3 fimbriae, encoded by the mrkABCDF genes, are important virulence factors in K. pneumoniae pathogenesis. In this study, the effects of exogenous glucose and the intracellular cyclic AMP (cAMP) signaling pathway on type 3 fimbriae expression regulation were investigated. The production of MrkA, the major subunit of type 3 fimbriae, was increased in glucose-rich medium, whereas cAMP supplementation reversed the effect. MrkA production was markedly increased by cyaA or crp deletion, but slightly decreased by cpdA deletion. In addition, the mRNA levels of mrkABCDF genes and the activity of PmrkA were increased in Δcrp strain, as well as the mRNA levels of mrkHIJ genes that encode cyclic di-GMP (c-di-GMP)-related regulatory proteins that influence type 3 fimbriae expression. Moreover, the activities of PmrkHI and PmrkJ were decreased in ΔlacZΔcrp strain. These results indicate that CRP-cAMP down-regulates mrkABCDF and mrkHIJ at the transcriptional level. Further deletion of mrkH or mrkI in Δcrp strain diminished the production of MrkA, indicating that MrkH and MrkI are required for the CRP regulation of type 3 fimbriae expression. Furthermore, the high activity of PmrkHI in the ΔlacZΔcrp strain was diminished in ΔlacZΔcrpΔmrkHI, but increased in the ΔlacZΔcrpΔmrkJ strain. Deletion of crp increased the intracellular c-di-GMP concentration and reduced the phosphodiesterase activity. Moreover, we found that the mRNA levels of multiple genes related to c-di-GMP metabolism were altered in Δcrp strain. These indicate that CRP regulates type 3 fimbriae expression indirectly via the c-di-GMP signaling pathway. In conclusion, we found evidence of a coordinated regulation of type 3 fimbriae expression by the CRP-cAMP and c-di-GMP signaling pathways in K. pneumoniae. [ABSTRACT FROM AUTHOR]

Background: This nationwide population-based study investigated the risk of cardiovascular diseases after 5-alpha-reductase inhibitor therapy for benign prostate hyperplasia (BPH) using the National Health Insurance Research Database (NHIRD) in Taiwan. Methods: In total, 1,486 adult patients newly diagnosed with BPH and who used 5-alpha-reductase inhibitors were recruited as the study cohort, along with 9,995 subjects who did not use 5-alpha-reductase inhibitors as a comparison cohort from 2003 to 2008. Each patient was monitored for 5 years, and those who subsequently had cardiovascular diseases were identified. A Cox proportional hazards model was used to compare the risk of cardiovascular diseases between the study and comparison cohorts after adjusting for possible confounding risk factors. Results: The patients who received 5-alpha-reductase inhibitor therapy had a lower cumulative rate of cardiovascular diseases than those who did not receive 5-alpha-reductase inhibitor therapy during the 5-year follow-up period (8.4% vs. 11.2%, P=0.003). In subgroup analysis, the 5-year cardiovascular event hazard ratio (HR) was lower among the patients older than 65 years with 91 to 365 cumulative defined daily dose (cDDD) 5-alpha-reductase inhibitor use (HR=0.63, 95% confidence interval (CI) 0.42 to 0.92; P=0.018), however there was no difference among the patients with 28 to 90 and more than 365 cDDD 5-alpha-reductase inhibitor use (HR=1.14, 95% CI 0.77 to 1.68; P=0.518 and HR=0.83, 95% CI 0.57 to 1.20; P=0.310, respectively). Conclusions: 5-alpha-reductase inhibitor therapy did not increase the risk of cardiovascular events in the BPH patients in 5 years of follow-up. Further mechanistic research is needed. [ABSTRACT FROM AUTHOR]

IscR, an Fe–S cluster-containing transcriptional factor, regulates genes involved in various cellular processes. In response to environmental stimuli such as oxidative stress and iron levels, IscR switches between its holo and apo forms to regulate various targets. IscR binding sequences are classified into two types: the type 1 IscR box that is specific for holo-IscR binding, and the type 2 IscR box that binds holo- and apo-IscR. Studying Klebsiella pneumoniae CG43S3, we have previously shown that iron availability regulates capsular polysaccharide (CPS) biosynthesis and iron-acquisition systems. The present study investigated whether IscR is involved in this regulation. Compared with that in CG43S3, the amount of CPS was decreased in AP001 (ΔiscR) or AP002 (iscR3CA), a CG43S3-derived strain expressing mutated IscR mimicked apo-IscR, suggesting that only holo-IscR activates CPS biosynthesis. Furthermore, a promoter-reporter assay verified that the transcription of cps genes was reduced in AP001 and AP002. Purified IscR::His6, but not IscR3CA::His6, was also found to bind the predicted type 1 IscR box specifically in the cps promoter. Furthermore, reduced siderophore production was observed in AP004 (Δfur-ΔiscR) but not in AP005 (Δfur-iscR3CA), implying that apo-IscR activates iron acquisition. Compared with those in AP004, mRNA levels of three putative iron acquisition systems (fhu, iuc, and sit) were increased in AP005, and both purified IscR::His6 and IscR3CA::His6 bound the predicted type 2 IscR box in the fhuA, iucA, and sitA promoters, whereas IscR3CA::His6 displayed a lower affinity. Finally, we analyzed the effect of external iron levels on iscR expression. The transcription of iscR was increased under iron-depleted conditions as well as in AP001 and AP002, suggesting an auto-repression exerted by apo-IscR. Our results show that in K. pneumoniae, IscR plays a dual role in the regulation of CPS biosynthesis and iron-acquisition systems in response to environmental iron availability. [ABSTRACT FROM AUTHOR]

Cytopathic effects (CPEs) in mosquito cells are generally trivial compared to those that occur in mammalian cells, which usually end up undergoing apoptosis during dengue virus (DENV) infection. However, oxidative stress was detected in both types of infected cells. Despite this, the survival of mosquito cells benefits from the upregulation of genes related to antioxidant defense, such as glutathione S transferase (GST). A second defense system, i.e., consisting of antiapoptotic effects, was also shown to play a role in protecting mosquito cells against DENV infection. This system is regulated by an inhibitor of apoptosis (IAP) that is an upstream regulator of caspases-9 and -3. DENV-infected C6/36 cells with double knockdown of GST and the IAP showed a synergistic effect on activation of these two caspases, causing a higher rate of apoptosis (>20%) than those with knockdown of each single gene (∼10%). It seems that the IAP acts as a second line of defense with an additional effect on the survival of mosquito cells with DENV infection. Compared to mammalian cells, residual hydrogen peroxide in DENV-infected C6/36 cells may signal for upregulation of the IAP. This novel finding sheds light on virus/cell interactions and their coevolution that may elucidate how mosquitoes can be a vector of DENV and probably most other arboviruses in nature. Author Summary: This study demonstrated an idea that mosquito cells can survive dengue virus (or other arboviruses) infection through antioxidant defense and an additional effect by induction of IAP expression for protection of infection. It makes mosquito eligible to support virus replication efficiently, leading to a goal which is important to explain how mosquitoes can be a vector even when they have been seriously infected by the virus. Our findings opened an avenue for studies on virus/vector co-evolution that benefits for both virus replication and its transmission to humans or susceptible hosts. [ABSTRACT FROM AUTHOR]

Cytopathic effects (CPEs) in mosquito cells are generally trivial compared to those that occur in mammalian cells, which usually end up undergoing apoptosis during dengue virus (DENV) infection. However, oxidative stress was detected in both types of infected cells. Despite this, the survival of mosquito cells benefits from the upregulation of genes related to antioxidant defense, such as glutathione S transferase (GST). A second defense system, i.e., consisting of antiapoptotic effects, was also shown to play a role in protecting mosquito cells against DENV infection. This system is regulated by an inhibitor of apoptosis (IAP) that is an upstream regulator of caspases-9 and -3. DENV-infected C6/36 cells with double knockdown of GST and the IAP showed a synergistic effect on activation of these two caspases, causing a higher rate of apoptosis (.20%) than those with knockdown of each single gene (,10%). It seems that the IAP acts as a second line of defense with an additional effect on the survival of mosquito cells with DENV infection. Compared to mammalian cells, residual hydrogen peroxide in DENV-infected C6/36 cells may signal for upregulation of the IAP. This novel finding sheds light on virus/cell interactions and their coevolution that may elucidate how mosquitoes can be a vector of DENV and probably most other arboviruses in nature. [ABSTRACT FROM AUTHOR]