Decreased cortical bone density and mechanical strength with associated elevated bone turnover markers at peri-pubertal peak height velocity: a cross-sectional and longitudinal cohort study of 396 girls with adolescent idiopathic scoliosis.

Decreased cortical bone density and bone strength at peak height velocity (PHV) were noted in girls with adolescent idiopathic scoliosis (AIS). These findings could provide the link to the previously reported observation that low bone mineral density (BMD) could contribute as one of the prognostic factors for curve progression that mostly occurs during PHV in AIS. INTRODUCTION: As part of the studies related to aetiopathogenesis of AIS, we assessed bone qualities, bone mechanical strength and bone turnover markers (BTMs) focusing at the peri-pubertal period and PHV in AIS girls. METHODS: 396 AIS girls in two separate cohorts were studied. Skeletal maturity was assessed using the validated thumb ossification composite index (TOCI). Bone qualities and strength were evaluated with high-resolution peripheral quantitative computed tomography (HR-pQCT) and finite element analysis (FEA). RESULTS: Cohort-A included 179 girls (11.95 ± 0.95 years old). Girls at TOCI-4 had numerically the highest height velocity (0.71 ± 0.24 cm/month) corresponding to the PHV. Subjects at TOCI-4 had lower cortical volumetric BMD (672.36 ± 39.07 mg/mm3), cortical thickness (0.68 ± 0.08 mm) and apparent modulus (1601.54 ± 243.75 N/mm2) than: (a) those at TOCI-1-3 (724.99 ± 32.09 mg/mm3 (p < 0.001), 0.79 ± 0.11 mm (p < 0.001) and 1910.88 ± 374.75 N/mm2 (p < 0.001), respectively) and (b) those at TOCI-8 (732.28 ± 53.75 mg/mm3 (p < 0.001), 0.84 ± 0.14 mm (p < 0.001), 1889.11 ± 419.37 N/mm2 (p < 0.001), respectively). Cohort-B included 217 girls (12.22 ± 0.89 years old). Subjects at TOCI-4 had higher levels of C-terminal telopeptide of type 1 collagen (1524.70 ± 271.10 pg/L) and procollagen type 1 N-terminal propeptide (941.12 ± 161.39 µg/L) than those at TOCI-8 (845.71 ± 478.55 pg/L (p < 0.001) and 370.08 ± 197.04 µg/L (p < 0.001), respectively). CONCLUSION: AIS girls had decreased cortical bone density and bone mechanical strength with elevated BTMs at PHV. Coupling of PHV with decreased cortical and FEA parameters could provide the link to the previously reported observation that low BMD could contribute as one of the prognostic factors for curve progression that mostly occurs during PHV in AIS.

Engineered RebH Halogenase Variants Demonstrating a Specificity Switch from Tryptophan towards Novel Indole Compounds.

Activating industrially important aromatic hydrocarbons by installing halogen atoms is extremely important in organic synthesis and often improves the pharmacological properties of drug molecules. To this end, tryptophan halogenase enzymes are potentially valuable tools for regioselective halogenation of arenes, including various industrially important indole derivatives and similar scaffolds. Although endogenous enzymes show reasonable substrate scope towards indole compounds, their efficacy can often be improved by engineering. Using a structure-guided semi-rational mutagenesis approach, we have developed two RebH variants with expanded biocatalytic repertoires that can efficiently halogenate several novel indole substrates and produce important pharmaceutical intermediates. Interestingly, the engineered enzymes are completely inactive towards their natural substrate tryptophan in spite of their high tolerance to various functional groups in the indole ring. Computational modelling and molecular dynamics simulations provide mechanistic insights into the role of gatekeeper residues in the substrate binding site and the dramatic switch in substrate specificity when these are mutated.

Association of serum 25(OH)Vit-D levels with risk of pediatric fractures: a systematic review and meta-analysis.

The association between the risk of fractures and suboptimal vitamin D (Vit-D) status remains controversial in children. This meta-analysis suggested that serum 25(OH)Vit-D levels were lower in pediatric cases with fractures. 25-hydroxyvitamin D (25(OH)Vit-D) levels less than 50 nmol/L were associated with increased fracture risk in children. INTRODUCTION: This study aimed to assess the association between serum 25(OH)Vit-D and the risk of fractures in children, and to explore the sources of heterogeneity and investigate their impact on results. METHODS: Systematic review and meta-analysis were conducted for observational studies comparing serum 25(OH)Vit-D levels between fracture and non-fracture pediatric cases. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS). RESULTS: Analysis on 17 case-control and 6 cross-sectional studies (2929 fracture cases and 5000 controls) suggested that 25(OH)Vit-D was lower in fracture cases than in controls (pooled mean difference (MD) = - 3.51 nmol/L; 95% confidence interval (CI): - 5.60 to - 1.42) with a heterogeneity (I2) of 73.9%. The sensitivity analysis which merged the case-control studies that had a NOS score ≥ 4 showed a pooled MD of - 4.35 nmol/L (95% CI: - 6.64 to - 2.06) with a heterogeneity (I2) of 35.9%. Pooled odds ratio of fracture in subjects with 25(OH)Vit-D ≤ 50 nmol/L compared to subjects with 25(OH)Vit-D > 50 nmol/L was 1.29 (95% CI: 1.10 to 1.53; I2 < 1%). CONCLUSION: This study indicated that serum 25(OH)Vit-D levels were lower in pediatric patients with fractures. 25(OH)Vit-D ≤ 50 nmol/L was associated with increased fracture risk in children.

Ninety-day and one-year healthcare utilization and costs after knee arthroplasty.

OBJECTIVES: This study examined ninety-day and one-year postoperative healthcare utilization and costs following total knee arthroplasty (TKA) from the health sector and patient perspectives. DESIGN: This study relied on: 1) patient-reported medical resource utilization data from diaries in the Knee Arthroplasty Pain Coping Skills Training (KASTPain) trial; and 2) Medicare fee schedules. Medicare payments, patient cost-sharing, and patient time costs were estimated. Generalized linear mixed models were used to identify baseline predictors of costs. RESULTS: In the first ninety days following TKA, patients had an average of 29.7 outpatient visits and 6% were hospitalized. Mean total costs during this period summed to $3,720, the majority attributed to outpatient visit costs (84%). Over the year following TKA, patients had an average of 48.9 outpatient visits, including 33.2 for physical therapy. About a quarter (24%) of patients were hospitalized. Medical costs were incurred at a decreasing rate, from $2,428 in the first six weeks to $648 in the last six weeks. Mean total medical costs across all patients over the year were $8,930, including $5,328 in outpatient costs. Total costs were positively associated with baseline Charlson comorbidity score (P < 0.01). Outpatient costs were positively associated with baseline Charlson comorbidity score (P = 0.03) and a bodily pain burden summary score (P < 0.01). Mean patient cost-sharing summed to $1,342 and time costs summed to $1,346. CONCLUSIONS: Costs in the ninety days and year after TKA can be substantial for both healthcare payers and patients. These costs should be considered as payers continue to explore alternative payment models.

Alkene Carboarylation through Catalyst-Free, Visible Light-Mediated Smiles Rearrangement.

A light-mediated Truce-Smiles arylative rearrangement is described that proceeds in the absence of any photocatalyst. The protocol creates two C-C bonds from simple starting materials, with the installation of an aryl ring and a difluoroacetate moiety across unactivated alkenes. The reaction proceeds via a radical mechanism, utilizing a light-mediated reduction of ethyl bromodifluoroacetate by N,N,N',N'-tetramethylethylenediamine (TMEDA) to set up intermolecular addition to an unactivated alkene, followed by Truce-Smiles rearrangement.

Recent metformin adherence and the risk of hypoglycaemia in the year following intensification with a sulfonylurea.

AIM: To evaluate whether recent low adherence to metformin monotherapy is associated with hypoglycaemia after addition of a sulfonylurea. METHODS: We assembled a retrospective cohort of veterans who filled a new prescription for metformin between 2001 and 2011 and intensified treatment with a sulfonylurea after ≥1 year of metformin use. We calculated metformin adherence from pharmacy data using the proportion of days covered in the 180-day period before intensification. The primary outcome was hypoglycaemia, defined as a hospitalization or emergency department visit for hypoglycaemia or an outpatient blood glucose measurement <3.3 mmol/l in the year following intensification. Cox proportional hazards models were used to compare the risk of hypoglycaemia between participants with low (<80%) and high (≥80%) adherence. Adherence was also modelled as a continuous variable using restricted cubic splines. RESULTS: Of 187 267 participants who initiated metformin monotherapy, 49 424 added a sulfonylurea after ≥1 year. The median (interquartile range) rate of treatment adherence was 87 (50-100)% and 43% had adherence <80%. Hypoglycaemia rates per 1000 person-years were 23.1 (95% CI 21.1-25.4) and 24.5 (95% CI 22.7-26.4) in participants with low and high adherence, respectively (adjusted hazard ratio 0.95, 95% CI 0.84-1.08). The risk of hypoglycaemia was similar across all levels of adherence when adherence was modelled as a continuous variable. CONCLUSIONS: We found no evidence that past low adherence to metformin monotherapy was associated with hypoglycaemia after intensification with a sulfonylurea.

Cobalt-Catalyzed Cross-Coupling Reactions of Aryl Triflates and Lithium Arylborates.

A catalyst system comprising CoCl2/IAd·HBF4 enables the Suzuki-Miyaura cross-coupling reaction of a broad range of aryl triflates and arylboronic esters that are activated by n-butyllithium.

Differences in health outcomes associated with initial adherence to oral antidiabetes medications among veterans with uncomplicated Type 2 diabetes: a 5-year survival analysis.

AIM: To determine the association of adherence to oral antidiabetes medication with macrovascular and microvascular complications, time to insulin therapy, revascularization, admissions, and death among veterans with uncomplicated diabetes. METHODS: This was a retrospective cohort study using the Veterans Affairs Corporate Data Warehouse to examine 159 032 veterans diagnosed with uncomplicated diabetes during 2002-2014 and starting oral antidiabetes therapy for the first time. The first uncomplicated diabetes diagnosis was identified and confirmed by subsequent oral antidiabetes therapy initiation. Adherence was calculated from outpatient pharmacy records using the proportion of days covered over the first year of therapy. Health outcomes were observed up to 5 years beyond the first oral antidiabetes agent fill, and compared according to adherence status using Cox proportional hazards models adjusted for baseline demographic and clinical characteristics. RESULTS: During the first 5 years of oral antidiabetes treatment, people initially non-adherent to oral antidiabetes therapy were more likely to experience myocardial infarction (hazard ratio 1.14, 95% CI 1.03-1.27) and ischaemic stroke (hazard ratio 1.22, 95% CI 1.05-0.1.42), or to die (hazard ratio 1.21; 95% CI 1.15-1.28). Veterans with <20% adherence to oral antidiabetes therapy in the first year had particularly high hazards for ischaemic stroke (hazard ratio 1.78, 95% CI 1.27-2.49) and all-cause death (hazard ratio 1.33, 95% CI 1.17-151). Adherent people were more likely to be diagnosed with a microvascular complication or chronic kidney disease. CONCLUSIONS: People who are non-adherent to treatment were more likely to experience detrimental health outcomes within the first 5 years of antidiabetes therapy. Adherence is paramount to disease management and this should be stressed from the time at which treatment is initiated.

Overall survival and oncological outcomes after partial nephrectomy and radical nephrectomy for cT2a renal tumors: A collaborative international study from the French kidney cancer research network UroCCR.

BACKGROUND: Partial nephrectomy (PN) is recommended as first-line treatment for cT1 stage kidney tumors because of a better renal function and probably a better overall survival than radical nephrectomy (RN). For larger tumors, PN has a controversial position due to lack of evidence showing good cancer control. The aim of this study was to compare the results of PN and RN in cT2a stage on overall survival and oncological results. METHOD: A retrospective international multicenter study was conducted in the frame of the French kidney cancer research network (UroCCR). We considered all patients aged≥18 years who underwent surgical treatment for localized renal cell carcinoma (RCC) stage cT2a (7.1-10cm) between 2000 and 2014. Cox and Fine-Gray models were performed to analyze overall survival (OS), cancer specific survival (CSS) and cancer-free survival (CFS). Comparison between PN and RN was realized after an adjustment by propensity score considering predefined confounding factors: age, sex, tumor size, pT stage of the TNM classification, histological type, ISUP grade, ASA score. RESULTS: A total of 267 patients were included. OS at 3 and 5 years was 93.6% and 78.7% after PN and 88.0% and 76.2% after RN, respectively. CSS at 3 and 5 years was 95.4% and 80.2% after PN and 91.0% and 85.0% after RN. No significant difference between groups was found after propensity score adjustment for OS (HR 0.87, 95% CI: 0.37-2.05, P=0.75), CSS (HR 0.52, 95% CI: 0.18-1.54, P=0.24) and CFS (HR 1.02, 95% CI: 0.50-2.09, P=0.96). CONCLUSION: PN seems equivalent to RN for OS, CSS and CFS in cT2a stage kidney tumors. The risk of recurrence is probably more related to prognostic factors than the surgical technique. The decision to perform a PN should depend on technical feasibility rather than tumor size, both to imperative and elective situation. LEVEL OF EVIDENCE: 4.

Generating allergen-specific human IgEs for immunoassays by employing human ε gene knockin mice.

BACKGROUND: Antigen-specific human IgEs are important reagents in immunoassays to quantify antigen-specific IgEs in allergic patients, but they are not easy to prepare. METHODS: We constructed a knockin homozygous mouse strain, referred to as HεκKI strain, whose gene segment encoding γ1 constant region has been replaced by that encoding human ε constant region and gene segment encoding κ constant region replaced by that encoding human κ constant region. The mice were tested for their ability to produce antigen-specific chimeric human IgE (with mouse variable regions) upon the immunization with ovalbumin and papain. Subsequently, the spleen cells from the immunized mice were used as the source of B cells for the preparation of hybridomas, which secreted monoclonal human IgE antibodies specific for the antigens. RESULTS: The HεκKI mice expressed human IgE (ε, κ) in serum at levels 10- to 30-fold higher than those of mouse IgE. Upon immunization with an antigen, the mice yielded splenic B cells for preparing hybridomas that secrete chimeric human IgE specific for the antigen. Purified IgEs from those hybridomas could activate a basophilic cell line to undergo degranulation upon the stimulation with their respective antigens. CONCLUSIONS: We have developed a human ε gene and κ gene knockin mouse strain, which is useful for producing various antigen-specific chimeric human IgEs for potential use as standards in immunoassays.

Evaluation of seasonal feeding patterns of West Nile virus vectors in Bernalillo county, New Mexico, United States: implications for disease transmission.

Many mosquito species take bloodmeals predominantly from either birds or mammals. Other mosquito species are less host-specific and feed readily on both. Furthermore, some species tend to alter their feeding patterns over the course of the year; early in the mosquito season such species may feed primarily on a particular host type, and subsequently take an increasingly larger proportion of their bloodmeals from an alternative host type as the season progresses. We have examined the feeding patterns of the three mosquito species found in Bernalillo County, NM: Culex quinquefasciatus (Say), Culex tarsalis (Coquillett), and Aedes vexans (Meigen). Specifically, we seek to determine if any of these species displays a seasonal shift in terms of its host utilization pattern. Our analysis focuses on these three species because they are all considered to be competent vectors for the West Nile virus (WNV). Our current data for Cx. quinquefasciatus suggest that unlike elsewhere in its range, this species increases its proportion of avian bloodmeals as the season progresses. Alternatively, Ae. vexans feeds primarily on mammals, whereas Cx. tarsalis appears to feed on both mammals and birds throughout the mosquito season. A more complete understanding of the feeding habits of these three mosquito species may help to clarify the transmission dynamics of WNV in Bernalillo County.

Association between varicocele and hypogonadism, or erectile dysfunction: A systematic review and meta-analysis.

OBJECTIVE: To assess the association between varicocele and hypogonadism, or erectile dysfunction. METHODS: We searched MEDLINE, EMBASE, LILACS, CENTRAL, and other sources. We included cohort, case-control, and cross-sectional studies. The primary outcome was the association between varicocele and hypogonadism, or erectile dysfunction, and the secondary outcome included semen analysis. We assessed the risk of bias with the Newcastle-Ottawa Scale. We performed statistical analysis in Review Manager 5.3 and reported information about the Odds Ratio (OR) with a 95% confidence interval. We produced a forest plot for the primary outcome. RESULTS: We included ten studies in qualitative analysis and six studies in quantitative analysis. Most of the cross-sectional studies showed a low risk of bias, not so for the two case-control studies, which represented a high risk of bias. Most of the reports described a correlation between having varicocele and presenting low testosterone levels: the meta-analysis showed that there is a significant association between varicocele and hypogonadism (OR 3.27 95% CI 1.23 to 8.68). Regarding varicocele and erectile, only one study showed a significant difference in erectile function in comparison to varicocele patients and men without varicocele. CONCLUSION: There is an association between varicocele presence and hypogonadism, although more studies are needed. Besides, not much is reported about an association between varicocele and erectile dysfunction, but impairment can occur through hormone disturbances.

The discovery of [Ni(NHC)RCN]2 species and their role as cycloaddition catalysts for the formation of pyridines.

The reaction of Ni(COD)(2), IPr, and nitrile affords dimeric [Ni(IPr)RCN](2) in high yields. X-ray analysis revealed these species display simultaneous η(1)- and η(2)-nitrile binding modes. These dimers are catalytically competent in the formation of pyridines from the cycloaddition of diynes and nitriles. Kinetic analysis showed the reaction to be first order in [Ni(IPr)RCN](2), zeroth order in added IPr, zeroth order in nitrile, and zeroth order in diyne. Extensive stoichiometric competition studies were performed, and selective incorporation of the exogenous, not dimer bound, nitrile was observed. Post cycloaddition, the dimeric state was found to be largely preserved. Nitrile and ligand exchange experiments were performed and found to be inoperative in the catalytic cycle. These observations suggest a mechanism whereby the catalyst is activated by partial dimer-opening followed by binding of exogenous nitrile and subsequent oxidative heterocoupling.

Copper-catalyzed alkene arylation with diaryliodonium salts.

Alkenes and arenes represent two classes of feedstock compounds whose union has fundamental importance to synthetic organic chemistry. We report a new approach to alkene arylation using diaryliodonium salts and Cu catalysis. Using a range of simple alkenes, we have shown that the product outcomes differ significantly from those commonly obtained by the Heck reaction. We have used these insights to develop a number of new tandem and cascade reactions that transform readily available alkenes into complex arylated products that may have broad applications in chemical synthesis.

Halogenation of Peptides and Proteins Using Engineered Tryptophan Halogenase Enzymes.

Halogenation of bioactive peptides via incorporation of non-natural amino acid derivatives during chemical synthesis is a common strategy to enhance functionality. Bacterial tyrptophan halogenases efficiently catalyze regiospecific halogenation of the free amino acid tryptophan, both in vitro and in vivo. Expansion of their substrate scope to peptides and proteins would facilitate highly-regulated post-synthesis/expression halogenation. Here, we demonstrate novel in vitro halogenation (chlorination and bromination) of peptides by select halogenase enzymes and identify the C-terminal (G/S)GW motif as a preferred substrate. In a first proof-of-principle experiment, we also demonstrate chemo-catalyzed derivatization of an enzymatically chlorinated peptide, albeit with low efficiency. We further rationally derive PyrH halogenase mutants showing improved halogenation of the (G/S)GW motif, both as a free peptide and when genetically fused to model proteins with efficiencies up to 90%.

Indole and azaindole halogenation catalyzed by the RebH enzyme variant 3-LSR utilizing co-purified E. coli reductase.

Biocatalytic C-H halogenation is becoming increasingly attractive due to excellent catalyst-controlled selectivity and environmentally benign reaction conditions. Significant efforts have been made on enzymatic halogenation of industrial arenes in a cost-effective manner. Here we report an unprecedented enzymatic halogenation of a panel of industrially important indole, azaindole and anthranilamide derivatives using a thermostable RebH variant without addition of any external flavin reductase enzyme. The reactions were catalyzed by the RebH variant 3-LSR enzyme with the help of a co-purified E. coli reductase identified as alkyl hydroperoxide reductase F (AhpF).

Potential Muscle-Related Biomarkers in Predicting Curve Progression to the Surgical Threshold in Adolescent Idiopathic Scoliosis-A Pilot Proteomic Study Comparing Four Non-Progressive vs. Four Progressive Patients vs. A Control Cohort.

Previous studies have reported abnormal muscle morphology and functions in patients with adolescent idiopathic scoliosis (AIS). To answer whether such abnormalities could be reflected in their circulation and their clinical implication for predicting curve progression to the surgical threshold, this preliminary study explored the presence of baseline muscle-related proteins and their association with curve progression. Plasma samples were collected at the first clinical visit for AIS, with patients divided into non-progressive or progressive groups (N = four and four) according to their Cobb angle in six-year follow-ups, with age- and sex-matched healthy subjects (N = 50). Then, the samples were subjected to isobaric tags for relative and absolute quantitation (iTRAQ) for global comparison of untargeted protein expression. Seventy-one differentially expressed proteins (DEPs) were found elevated in progressive AIS. Functional analysis showed that 18 of these are expressed in muscles and play an essential role in muscle activities. Among the muscle-related DEPs, α-actin had the highest fold change in progressive/non-progressive groups. This preliminary study firstly suggested higher circulating levels of muscle structural proteins in progressive AIS, indicating the likelihood of structural damage at the microscopic level and its association with progression to the surgical threshold. Further studies with larger sample sizes are warranted to validate these novel candidates for early diagnosis and predicting progression.

Fabrication of Highly Sensitive Pt-black Electrochemical Sensors for GABA Detection.

GABA (Gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the central nervous system of mammals. It is known to be related with various neurological disorders. GABA plays a crucial role in normal neuronal activity, information processing and plasticity, and neuronal network synchronization. To date, microdialysis has been widely used to monitor the level of GABA but the temporal and spatial resolution is limited. Besides, electrochemical sensors for neurotransmitter measurement, having high temporal and spatial resolution, overcome this problem. Here, using a cost-effective method of electrodeposition of platinum black (Pt-black), a highly sensitive, GABA specific, amperometric electrochemical sensor is fabricated. Nanostructured Pt-black increases the active surface area of the electrode contributing to higher sensitivity. Along with that, a self-referencing site and an exclusion layer are integrated to increase the selectivity and the signal-to-noise ratio (SNR) of the biosensor. This provides a prototype for a highly sensitive GABA sensor that could later be used to study various neurological disorders related to GABA concentrations.Clinical Relevance- This electrochemical sensor allows real-time monitoring of major inhibitory neurotransmitter (GABA) with high sensitivity which can be used for studying various neurological disorders.

Smartwatch inertial sensors continuously monitor real-world motor fluctuations in Parkinson's disease.

Longitudinal, remote monitoring of motor symptoms in Parkinson's disease (PD) could enable more precise treatment decisions. We developed the Motor fluctuations Monitor for Parkinson's Disease (MM4PD), an ambulatory monitoring system that used smartwatch inertial sensors to continuously track fluctuations in resting tremor and dyskinesia. We designed and validated MM4PD in 343 participants with PD, including a longitudinal study of up to 6 months in a 225-subject cohort. MM4PD measurements correlated to clinical evaluations of tremor severity (ρ = 0.80) and mapped to expert ratings of dyskinesia presence (P < 0.001) during in-clinic tasks. MM4PD captured symptom changes in response to treatment that matched the clinician's expectations in 94% of evaluated subjects. In the remaining 6% of cases, symptom data from MM4PD identified opportunities to make improvements in pharmacologic strategy. These results demonstrate the promise of MM4PD as a tool to support patient-clinician communication, medication titration, and clinical trial design.