No abstract

An enzyme that hydrolyzes cyclic ',5'-adenosine monophosphate to 5'-adenosine monophosphate was found in the culture medium of the cellular slime mold Dictyostelium discoidum. The enzymatic activity shows a pH optimum of 7.5, and magnesium is required for maximum activity. The enzyme is not inhibited by caffeine. It has a Michaelis-Menten constant of 2 x 10(-3)M and its molecular weight is around 300,000.

Background The Nelson mortality results were presented in September 2018. Four other randomized control trials (RCTs) were also reported the latest mortality outcomes in 2018 and 2019. We therefore conducted a meta-analysis to update the evidence and investigate the benefits and harms of low-dose computed tomography (LDCT) in lung cancer screening. Methods Detailed electronic database searches were performed to identify reports of RCTs that comparing LDCT to any other type of lung cancer screening. Pooled risk ratios (RRs) were calculated using random effects models. Results We identified nine RCTs ( n = 97,244 participants). In pooled analyses LDCT reduced lung cancer mortality (RR 0.83, 95% CI 0.76–0.90, I 2 = 1%) but had no effect on all-cause mortality (RR 0.95, 95% CI 0.90–1.00). Trial sequential analysis (TSA) confirmed the results of our meta-analysis. Subgroup defined by high quality trials benefitted from LDCT screening in reducing lung cancer mortality (RR 0.82, 95% CI 0.73–0.91, I 2 = 7%), whereas no benefit observed in other low quality RCTs. LDCT was associated with detection of a significantly higher number of early stage lung cancers than the control. No significant difference (RR 0.64, 95% CI 0.30–1.33) was found in mortality after invasive procedures between two groups. Conclusions In meta-analysis based on sufficient evidence demonstrated by TSA suggests that LDCT screening is superiority over usual care in lung cancer survival. The benefit of LDCT is expected to be heavily influenced by the risk of lung cancer in the different target group (smoking status, Asian) being screened. Electronic supplementary material The online version of this article (10.1186/s12890-019-0883-x) contains supplementary material, which is available to authorized users.

We examined clinical presentations, neuropsychological findings, and perfusion patterns of (99m)Tc-ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) in patients with early stage dementia with Lewy bodies (DLB) (n = 17) and Parkinson's disease (PD) (n = 16), with age-matched healthy controls (n = 10). Seven paired regions of interest (ROIs) were drawn manually including inferior frontal, temporal, parietal, occipital, parieto-occipital junction, striatum and thalamus for semiquantitative measurement. Neuropsychological tests were applied for clinical correlation. The SPECT results showed significant hypoperfusion in DLB group in frontal, parietal, thalamus, temporal ROIs compared with controls (P < 0.01) whilst signals in temporal areas was significantly reduced compared with PD group (P < 0.05). Neuropsychological tests showed that DLB patients had deficits in mental manipulation, short-term memory, abstract thinking, drawing and semantic verbal fluencies (P < 0.05, compared with control). In addition, DLB group had lower scores than those with PD in mental manipulation, drawing and semantic verbal fluency (P < 0.05). Our study showed that even in early stages of DLB, neuropsychological and perfusion patterns were evident and may be different from PD group, despite they shared certain similarities both in neuropsychological and image findings compared with age-matched controls.

Hunter syndrome (mucopolysaccharidosis II; MPS II) is caused by a defect of the iduronate-2-sulfatase (IDS) gene. Few studies have reported integrated mutation data of Taiwanese MPS II phenotypes. In this study, we summarized genotype and phenotype correlations of confirmed MPS II patients and asymptomatic MPS II infants in Taiwan. Regular polymerase chain reaction and DNA sequencing were used to identify genetic abnormalities of 191 cases, including 51 unrelated patients with confirmed MPS II and 140 asymptomatic infants. IDS activity was analyzed in individual novel IDS variants using in vitro expression studies. Nineteen novel mutations were identified, in which the percentages of IDS activity of the novel missense mutations c.and c.1403G>A were significantly decreased (p < 0.001), c.254C>T and c.1025A>G were moderately decreased (p < 0.01), and c.851C>T was slightly decreased (p < 0.05) comparing with normal enzyme activity. The activities of the other six missense mutations were reduced but were insignificant. The results of genomic studies and their phenotypes were highly correlated. A greater understanding of the positive correlations may help to prevent the irreversible manifestations of Hunter syndrome, particularly in infants suspected of having asymptomatic MPS II. In addition, urinary glycosaminoglycan assay is important to diagnose Hunter syndrome since gene mutations are not definitive (could be non-pathogenic).Sequencing data were obtained by scanning through the data to identify anomalies using Applied Biosystems Sequence Scanner Software v2.0 Sequence Trace Viewer and Editor (Applied Biosystems Co., CA, USA) and manual progressive alignment. A total of 51 mutations of the IDS gene from the 191 cases, including the confirmed patients (n = 51) and infants suspected of having MPS II (n = 140) that were identified. The suspected MPS II infants were classified into two groups: Those with either 1) "positive" uGAG biochemistry examinations, reduction in leukocyte IDS enzyme activity, and identified IDS variations (n = 7); or 2) "negative" uGAG biochemistry examinations, reduction in leukocyte IDS enzyme activity and identified IDS variations (n = 133). The 51 mutations of the IDS gene included 32 missense (62.7%), 3 nonsense (5.9%), 2 silent (3.9%), 6 splicing (11.8%), 4 small deletions (7.8%), 3 gross deletions (5.9%), and 1 complex inversion (2%) ( Table 1). Of these mutations, 35 were reported and verified as being pathogenic for MPS II with varying degrees of severity or non-pathogenic , and the other 16 were novel mutations (Figure 1), which needed to be verified according to individual IDS activity by using in vitro expression studies.