Determination of an Optimal Standardized Uptake Value of Fluorodeoxyglucose for Positron Emission Tomography Imaging to Assess Pathological Volumes of Cervical Cancer: A Prospective Study

Purpose

To determine the optimal standardized uptake value (SUV) of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) for positron emission tomography (PET) imaging, at which the PET-defined gross tumor volume (GTV_PET) best matches with the pathological volume (GTV_PATH) in the cervical cancer.

Materials and Methods

Ten patients with the cervical cancer who underwent surgery were enrolled in this study. The excised specimens were processed for whole-mount serial sections and H-E staining. The tumor borders were outlined in sections under a microscope, histopathological images were scanned and the GTV_PATH calculated. The GTV_PET was delineated automatically by using various percentages relative to the maximal SUV and absolute SUV. The optimal threshold SUV was further obtained as the value at which the GTV_PET best matched with the GTV_PATH.

Results

An average of 85±10% shrinkage of tissue was observed after the formalin fixation. The GTV_PATH was 13.38±2.80 cm³ on average. The optimal threshold on percentile SUV and absolute SUV were 40.50%±3.16% and 7.45±1.10, respectively. The correlation analysis showed that the optimal percentile SUV threshold was inversely correlated with GTV_PATH (p<0.05) and tumor diameter (p<0.05). The absolute SUV was also positively correlated with SUV_max (p<0.05).

Conclusion

The pathological volume could provide the more accurate tumor volume. The optimal SUV of FDG for PET imaging by use of GTV_PATH as standard for cervical cancer target volume delineation was thus determined in this study, and more cases are being evaluated to substantiate this conclusion.     

Genetic Variants of LRRK2 in Taiwanese Parkinson’s Disease

Genetic variants of leucine-rich repeat kinase 2 (LRRK2) were reported to alter the risk for Parkinson’s disease (PD). However, the genetic spectrum of LRRK2 variants has not been clearly disclosed yet in Taiwanese population. Herein, we sequenced LRRK2 coding region in 70 Taiwanese early onset PD patients (age at onset ≤ 50), and found six amino acid-changing single nucleotide polymorphisms (SNPs, N551K, R1398H, R1628P, S1647T, G2385R and M2397T), one reported (R1441H) and 2 novel missense (R767H and S885N) mutations. We examined the frequency of identified LRRK2 variants by genotyping 573 Taiwanese patients with PD and 503 age-matched control subjects. The results showed that PD patients demonstrated a higher frequency of G2385R A allele (4.6%) than control subjects (2.1%; odds ratio = 2.27, 95% confidence interval: 1.38–3.88, P = 0.0017). Fewer PD patients (27.7%) carried the 1647T-2397T haplotype as compared with the control subjects (33.0%; odds ratio = 0.80, 95% confidence interval: 0.65–0.97, P = 0.0215). However, the frequency of 1647T-2385R-2397T haplotype (4.3%) in PD patients was still higher than in control subjects (1.9%, odds ratio: 2.15, 95% confidence interval: 1.27–3.78, P = 0.0058). While no additional subject was found to carry R767H and R1441H, one more patient was observed to carry the S885N variant. Our results indicate a robust risk association regarding G2385R and a new possible protective haplotype (1647T-2397T). Gene-environmental interaction and a larger cohort study are warranted to validate our findings. Additionally, two new missense mutations (R767H and S885N) regarding LRRK2 in PD patients were identified. Functional studies are needed to elucidate the effects of these LRRK2 variants on protein function.     

Oxidative damage in Parkinson disease: Measurement using accurate biomarkers

Oxidative damage has been implicated in the pathogenesis of Parkinson disease (PD) but the literature data are confusing. Using products of lipid and DNA oxidation measured by accurate methods, we assessed the extent of oxidative damage in PD patients. The levels of plasma F₂-isoprostanes (F₂-IsoPs), hydroxyeicosatetraenoic acid products (HETEs), cholesterol oxidation products, neuroprostanes (F₄-NPs), phospholipase A₂ (PLA₂) and platelet activating factor–acetylhydrolase (PAF-AH) activities, urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG), and serum high-sensitivity C-reactive protein were compared in 61 PD patients and 61 age-matched controls. The levels of plasma F₂-IsoPs, HETEs, 7β-and 27-hydroxycholesterol, 7-ketocholesterol, F₄-NPs, and urinary 8-OHdG were elevated, whereas the levels of plasma PLA₂ and PAF-AH activities were lower, in PD patients compared to controls (p <  0.05). The levels of plasma F₂-IsoPs, HETEs, and urinary 8-OHdG were higher in the early stages of PD (p trend <  0.05). There was a significant negative correlation between the cumulative intake of levodopa and urinary 8-OHdG (r =  ?0.305, p =  0.023) and plasma total HETEs (r =  ?0.285, p =  0.043). Oxidative damage markers are systemically elevated in PD, which may give clues about the relation of oxidative damage to the onset and progression of PD.     

Antidiabetic activities of oligosaccharides of Ophiopogonis japonicus in experimental type 2 diabetic rats

The aim of the present study is to investigate the antidiabetic properties of oligosaccharides of Ophiopogonis japonicus (OOJ) in experimental type 2 diabetic rats. OOJ was administered orally in doses of 225 and 450mg/kg body weight to high-fat diet and low-dose streptozotocin (STZ)-induced type 2 diabetic rats for 3 weeks. The results showed that OOJ treatment could increase body weight, decrease organ related weights of liver and kidney, reduce fasting blood glucose level, and improve oral glucose tolerance in diabetic rats. Moreover, increased glycogen content in liver and skeletal muscle, reduced urinary protein excretion, higher hepatic GCK enzyme activity, lower hepatic PEPCK enzyme activity, enhanced GLP-1 level, decreased glucagon level and alleviated histopathological changes of pancreas occurred in OOJ-treated diabetic rats by comparison with untreated diabetic rats. This study demonstrates, for the first time to our knowledge, that OOJ exerts remarkable antidiabetic effect in experimental type 2 diabetes mellitus, thus justifying its traditional usage.     

Association of the shuffling of Streptococcus pyogenes clones and the fluctuation of scarlet fever cases between 2000 and 2006 in central Taiwan

Background  

The number of scarlet fever occurrences reported between 2000 and 2006 fluctuated considerably in central Taiwan and throughout the nation. Isolates of Streptococcus pyogenes were collected from scarlet fever patients in central Taiwan and were characterized by emm sequencing and a standardized pulsed-field gel electrophoresis (PFGE) method. National weekly report data were collected for investigating epidemiological trends.     

Comparative Phosphoproteomics Reveals the Role of AmpC β-lactamase Phosphorylation in the Clinical Imipenem-resistant Strain Acinetobacter baumannii SK17

Nosocomial infectious outbreaks caused by multidrug-resistant Acinetobacter baumannii have emerged as a serious threat to human health. Phosphoproteomics of pathogenic bacteria has been used to identify the mechanisms of bacterial virulence and antimicrobial resistance. In this study, we used a shotgun strategy combined with high-accuracy mass spectrometry to analyze the phosphoproteomics of the imipenem-susceptible strain SK17-S and -resistant strain SK17-R. We identified 410 phosphosites on 248 unique phosphoproteins in SK17-S and 285 phosphosites on 211 unique phosphoproteins in SK17-R. The distributions of the Ser/Thr/Tyr/Asp/His phosphosites in SK17-S and SK17-R were 47.0%/27.6%/12.4%/8.0%/4.9% versus 41.4%/29.5%/17.5%/6.7%/4.9%, respectively. The Ser-90 phosphosite, located on the catalytic motif S⁸⁸VS⁹⁰K of the AmpC β-lactamase, was first identified in SK17-S. Based on site-directed mutagenesis, the nonphosphorylatable mutant S90A was found to be more resistant to imipenem, whereas the phosphorylation-simulated mutant S90D was sensitive to imipenem. Additionally, the S90A mutant protein exhibited higher β-lactamase activity and conferred greater bacterial protection against imipenem in SK17-S compared with the wild-type. In sum, our results revealed that in A. baumannii, Ser-90 phosphorylation of AmpC negatively regulates both β-lactamase activity and the ability to counteract the antibiotic effects of imipenem. These findings highlight the impact of phosphorylation-mediated regulation in antibiotic-resistant bacteria on future drug design and new therapies.Members of the genus Acinetobacter are nonmotile Gram-negative bacteria, many of which cause severe, life-threatening infections and hospital outbreaks (1). Although Acinetobacter baumannii is regarded as an opportunistic pathogen with low virulence, this species infects the soft tissues, bone, bloodstream, and urinary tract and is an important cause of pneumonia and meningitis in immune-compromised patients (2). Crude mortalities because of nosocomial pneumonia and bloodstream infections caused by A. baumannii ranged from 30–75% and 25–54%, respectively (3–5). In intensive care units (ICU), outbreaks of infection caused by multidrug-resistant A. baumannii strains exhibit a crude mortality rate as high as 91.7% (4, 5). The poor outcome in patients with invasive multidrug-resistant A. baumannii infection highlights the urgent need for new therapeutic agents and vaccines to reduce the associated morbidity and mortality.The survival of A. baumannii is enhanced by its ability to acquire foreign genes, thus increasing the number of vulnerable hosts, producing biofilms, and displaying an open pan-genome (6, 7). These abilities enable A. baumannii to persist in nosocomial environments and to survive even under antibiotic treatment. Numerous studies have reported the emergence of A. baumannii clinical isolates that are resistant to multiple antimicrobials such as carbapenems, colistin, sulbactam, and tigecycline, thus reducing the number of effective therapeutic options (8, 9). In epidemiological studies, the incidence rate of carbapenem-resistant A. baumannii in countries such as Australia, Brazil, Singapore, Canada, South Korea, Taiwan, and Thailand is in the range of 47–80% (10). A study showed that 11% of nosocomial isolates of A. baumannii were carbapenem-resistant; resulting in a morbidity and mortality rate of 52% as compared with a rate of 19% of patients infected with carbapenem-sensitive isolates (4, 11–13). Among the many carbapenem derivatives, imipenem initially was highly effective in the treatment of patients with A. baumannii infections; however, imipenem resistance has been confirmed in 53.7% of Acinetobacter nosocomial infections since the early 1990s (4, 14, 15). The most common pathways leading to carbapenem resistance are associated with the loss of outer membrane porins, overexpression of efflux pumps, and overproduction of Ambler class B metallo-β-lactamases, class D oxacillinases, and AmpC cephalosporinase (16–18). In the case of Acinetobacter-derived cephalosporinase (ADC)¹, the key upstream insertion sequence (IS) element, ISAba1, provides promoter sequences that confer bacterial resistance to broad-spectrum cephalosporins (3, 19, 20). In a study of Pseudomonas aeruginosa, the overproduction of AmpC β-lactamase exhibited weak carbapenem-hydrolyzing activity and thus contributed to carbapenem resistance in porin-deficient isolates (21). Although the study suggested a link between AmpC β-lactamase and carbapenem resistance, the regulatory mechanisms remain unclear.Kinase-induced protein phosphorylation and phosphatase-induced protein dephosphorylation are crucial for signal transduction in both prokaryotic and eukaryotic species (22–26). Hence, bacterial phosphoproteomic analysis is a promising and accurate tool to study biological networks, including the mechanisms of antibiotic resistance. In a recent comparative phosphoproteomic study of A. baumannii ATCC17978 and the multidrug-resistant clinical isolate A. baumannii Abh12O-A2, the relationship between phosphoproteins and antibiotic resistance remained unclear because of the lack of biological confirmation (27). In this study, we used two clinical isolates of A. baumannii to establish comparative phosphoproteomic maps and to conduct biological validation to explore the mechanisms of imipenem resistance (28). Phosphoproteomic analysis of A. baumannii SK17 clinical strains was carried out using a shotgun strategy combined with phosphopeptides enrichment techniques and high-performance mass spectrometry, and thus the identified phosphosites were verified by site-directed mutagenesis (23, 29–31). Our findings clearly show that AmpC β-lactamase activity is regulated by phosphorylation and is involved in imipenem resistance.     

Oenothera chloroplast DNA polymorphisms associated with plastome mutator activity

Molecular Genetics and Genomics - Oenothera plants homozygous for a recessive allele at the plastome mutator (pm) locus show non-Mendelian mutation frequencies that are 1000-fold higher than...