Straightforward Synthesis of α-Chloromethylketimines Catalyzed by Gold(I). A Clean Way to Building Blocks.

α-Chloromethylketimines have been obtained through a gold-catalyzed hydroamination of aromatic and aliphatic 1-chloroalkynes with aromatic amines by using equimolar amounts of both reagents. This procedure has allowed the preparation and spectroscopic characterization of α-chloromethylketimines for the first time with a high degree of purity, complete conversion, and atom economy. The synthetic usefulness of the methodology has been demonstrated with the preparation of ß-chloroamines and indoles.

Added value of cerebrospinal fluid multimarker analysis in diagnosis and progression of dementia.

BACKGROUND AND PURPOSE: Recently, some emerging cerebrospinal fluid (CSF) markers have been proposed as diagnostic tools for Alzheimer disease (AD) that can have an effect on disease progression. We analyze the accuracy of these CSF markers for diagnosis of AD in reference to brain amyloid positron emission tomography (PET). We also investigated whether they help in differentiating AD from other dementias and examined their influence in tracing the progression to dementia. METHODS: Amyloid-ß (Aß) 1-42, total tau (t-tau), phosphorylated tau, Aß40 , Aß38 , beta-site amyloid precursor protein cleaving enzyme 1 (BACE-1), neurogranin (ng), phosphorylated neurofilament heavy-chain, and α-synuclein (α-syn) CSF levels were analyzed in 319 subjects, among whom 57 also underwent an amyloid PET scan. We also analyzed longitudinal clinical data from 239 subjects. RESULTS: Emerging CSF markers, especially ng/BACE-1 ratio (area under the curve = 0.77) and their combinations with core AD CSF markers (all AUCs >0.85), showed high accuracy to discriminate amyloid PET positivity. Subjects with AD had higher CSF BACE-1, ng, and α-syn levels than those with non-AD dementia. CSF t-tau/α-syn ratio was higher in subjects with dementia with Lewy bodies than in those with frontotemporal dementia. Most emerging/core AD ratios predicted a faster conversion from mild cognitive impairment (MCI) stage to AD and appeared to be helpful when core AD CSF markers were discordant. In addition, the rate of cognitive decline was associated with all CSF core AD markers, several emerging/core AD two-marker ratios, and CSF ng levels. CONCLUSIONS: These results suggest that emerging biomarkers in conjunction with core AD markers improve diagnosis of AD, are associated with the conversion from MCI into AD, and predict a faster progression of dementia.

ABO Blood Groups and Incidence of COVID-19 in the Mass Gathering Events in Borriana (Spain), March 2020: A Retrospective Cohort Study.

Our objective was to estimate the incidence of COVID-19 and the ABO blood Groups in the mass-gathering events (MGEs) during the Falles Festival in Borriana (Spain) from 6-10 March 2020. We conducted a population-based retrospective cohort study and measured anti-SARS-CoV-2 antibodies and the ABO of participants. We performed laboratory COVID-19 tests and obtained the ABO in 775 subjects (72.8% of the original exposed cohort): O-group (45.2%), A-group (43.1%), B-group (8.5%) and AB-group (3.4%). Adjusted for confounding factors, including COVID-19 exposure during the MGEs, attack rates of COVID-19 for each ABO group were 55.4%, 59.6%, 60.2%, and 63.7%. The adjusted relative risks were for O-group 0.93 (95% Confidence Interval [CI] 0.83-1.04), for A-group 1.06 (95% CI 0.94-1.18), for B-group 1.04 (95%CI 0.88-1.24), and for AB-group 1.11 (95% CI 0.81-1.51) with no significant differences. Conclusions: Our results suggest no effect of ABO on COVID-19 incidence. We observed weak but not significant protection of the O-group and not a significantly greater infection risk for the remaining groups compared with the O-group. More studies are needed to resolve the controversies regarding the association between ABO and COVID-19.

Complications Post-COVID-19 and Risk Factors among Patients after Six Months of a SARS-CoV-2 Infection: A Population-Based Prospective Cohort Study.

In October 2020, we conducted a population-based prospective cohort study to determine post-COVID-19 complications, recovery, return to usual health, and associated risk factors in 536 cases of COVID-19 outbreak in Borriana (Spain) by administering an epidemiological questionnaire via phone interviews. A total of 484 patients participated (90.3%), age mean 37.2 ± 17.1 years, and 301 females (62.2%). Mild illness was the most common COVID-19 manifestation. After six months, 160 patients (33.1%) suffered at least one complication post-COVID-19, and 47 (29.4%) of them sought medical assistance. The most frequent persistent symptoms were hair loss, fatigue, loss of smell or taste, and headache. Risk factors associated with a complication were female sex (adjusted relative risk, [aRR] = 1.93 95% confidence interval [CI] 1.41-2.65), age 35 years and above (aRR = 1.50 95% CI 1.14-1.99), B blood group (aRR = 1.51 95% CI 1.04-2.16), current smoker (RR = 1.61 95% CI 1.02-2.54), and at least a COVID-19 exposure (aRR = 2.13 95% CI 1.11-4.09). Male sex, age younger than 35 years, and low COVID-19 exposures were associated with better recovery and return to usual health. A third of patients presented persistent symptoms compatible with the long-COVID-19 syndrome. In conclusion, an active medical follow-up of post-COVID-19 patients must be implemented.

Exome-wide rare variant analysis in familial essential tremor.

INTRODUCTION: Essential tremor (ET) is one of the most common movement disorders. Despite its high prevalence and heritability, its genetic etiology remains elusive with only a few susceptibility genes identified and poorly replicated. Our aim was to find novel candidate genes involved in ET predisposition through whole exome sequencing. METHODS: We studied eight multigenerational families (N = 40 individuals) with an autosomal-dominant inheritance using a comprehensive strategy combining whole exome sequencing followed by case-control association testing of prioritized variants in a separate cohort comprising 521 ET cases and 596 controls. We further performed gene-based burden analyses in an additional dataset comprising 789 ET patients and 770 healthy individuals to investigate whether there was an enrichment of rare deleterious variants within our candidate genes. RESULTS: Fifteen variants co-segregated with disease status in at least one of the families, among which rs749875462 in CCDC183, rs535864157 in MMP10 and rs114285050 in GPR151 showed a nominal association with ET. However, we found no significant enrichment of rare variants within these genes in cases compared with controls. Interestingly, MMP10 protein is involved in the inflammatory response to neuronal damage and has been previously associated with other neurological disorders. CONCLUSIONS: We prioritized a set of promising genes, especially MMP10, for further genetic and functional studies in ET. Our study suggests that rare deleterious coding variants that markedly increase susceptibility to ET are likely to be found in many genes. Future studies are needed to replicate and further infer biological mechanisms and potential disease causality for our identified genes.

ABO Blood Groups and the Incidence of Complications in COVID-19 Patients: A Population-Based Prospective Cohort Study.

After a COVID-19 outbreak in the Falles festival of Borriana (Spain) during March 2020, a cohort of patients were followed until October 2020 to estimate complications post-COVID-19, considering ABO blood groups (ABO). From 536 laboratory-confirmed cases, 483 completed the study (90.1%) carried by the Public Health Center of Castelló and the Emergency and Microbiology and Clinical Analysis of Hospital de la Plana Vila-real. The study included ABO determination and telephone interviews of patients. The participants had a mean age of 37.2 ± 17.1 years, 300 females (62.1%). ABO were O (41.4%), A (45.5%), B (9.1%), and AB (3.9%). We found no difference in the incidence of COVID-19 infections. A total of 159 (32.9%) patients reported one or more post-COVID-19 complications with divergent incidences after adjustment: O (32.3%), A (32.6%), B (54.1%), and AB (27.6%); B groups had more complications post-COVID-19 when compared with O group (adjusted relative risk [aRR] 95% confidence interval [CI] 1.68, 95% CI 1.24-2.27), and symptoms of fatigue (1.79, 95% CI 1.08-2.95), myalgia (2.06, 95% CI 1.10-3.84), headache (2.61, 95% CI 1.58-4.31), and disorder of vision (4.26 95% CI 1.33-13.60). In conclusion, we observed significant differences in post-COVID-19 complications by ABO, with a higher incidence in B group. Additional research is justified to confirm our results.

"Mass gathering events and COVID-19 transmission in Borriana (Spain): A retrospective cohort study".

OBJECTIVE: Mass gathering events (MGEs) are associated with the transmission of COVID-19. Between 6 and 10 March 2020, several MGEs related to the Falles festival took place in Borriana, a municipality in the province of Castellon (Spain). The aim of this study was to estimate the incidence of COVID-19 and its association with these MGEs, and to quantify the potential risk factors of its occurrence. METHODS: During May and June 2020, a population-based retrospective cohort study was carried out by the Public Health Center of Castelló and the Hospital de la Plana in Vila-real. Participants were obtained from a representative sample of 1663 people with potential exposure at six MGEs. A questionnaire survey was carried out to obtain information about attendance at MGEs and COVID-19 disease. In addition, a serologic survey of antibodies against SARS-Cov-2 was implemented. Inverse probability weighted regression was used in the statistical analysis. RESULTS: A total of 1338 subjects participated in the questionnaire survey (80.5%), 997 of whom undertook the serologic survey. Five hundred and seventy cases were observed with an attack rate (AR) of 42.6%; average age was 36 years, 62.3% were female, 536 cases were confirmed by laboratory tests, and 514 cases were found with SARS-CoV-2 total antibodies. Considering MGE exposure, AR was 39.2% (496/1264). A dose-response relationship was found between MGE attendance and the disease, (adjusted relative risk [aRR] = 4.11 95% confidence interval [CI]3.25-5.19). Two MGEs with a dinner and dance in the same building had higher risks. Associated risk factors with the incidence were older age, obesity, and upper and middle class versus lower class; current smoking was protective. CONCLUSIONS: The study suggests the significance of MGEs in the COVID-19 transmission that could explain the subsequent outbreak in Borriana.

Association between the missense alcohol dehydrogenase rs1229984T variant with the risk for Parkinson's disease in women.

BACKGROUND/OBJECTIVE: Several meta-analyses including retrospective case-control studies have shown that the risk of developing Parkinson's disease (PD) correlates inversely with alcohol consumption and (PD), although the results of prospective longitudinal studies are far from being conclusive. The reasons for this inverse association are not well-known. Because alcohol dehydrogenase is one of the most important alcohol-detoxification enzymes, we tried to replicate a putative association of the risk of developing PD with two missense gene variations affecting the alcohol dehydrogenase 1B (ADH1B) gene (one of them related with aversive effects to alcohol). METHODS: In a cohort composed of 629 PD patients and 865 age- and gender-matched healthy individuals, we analyzed genotypes and allele frequencies for two common missense ADH1B single nucleotide polymorphisms (SNPs), namely rs1229984 (His48Arg) and rs6413413 (Thr60Ser) using specifically designed TaqMan assays. RESULTS: The frequency of individuals carrying rs1229984T alleles in homozygosity or in heterozygosity was higher in PD than in controls in the whole study cohort (P < 0.001 and P = 0.005, respectively), and in women (P < 0.001 and P < 0.001, respectively). The genotypes for rs6413413 were similar in PD patients and control subjects. Age at onset of PD patients was not statistically related to rs1229984 or rs6413413 genotypes. CONCLUSIONS: The missense variant rs1229984T is statistically associated with the risk of developing PD mainly in women, which could explain differences in alcohol consumption in this gender.

Clinic-Based Validation of Cerebrospinal Fluid Biomarkers with Florbetapir PET for Diagnosis of Dementia.

BACKGROUND: Cerebrospinal fluid (CSF) biomarker studies have shown variable accuracy for diagnosis of Alzheimer's disease (AD); therefore, internal validation is recommended. OBJECTIVE: To investigate the correlation between CSF biomarkers and cerebral 18-Florbetapir positron emission tomography (Amyloid-PET) and calculate their sensitivity and specificity to obtain the optimal clinical cut-off points to diagnose the etiology of cognitive impairment. METHODS: We performed Amyloid-PET scans and CSF biomarker levels analyses in 68 subjects (50 with mild cognitive impairment, 11 with AD dementia, and 7 with non-AD dementia). Visual examination of Amyloid-PET scans was performed. CSF analyses were performed using standard sandwich ELISA. RESULTS: Amyloid-PET was positive in 36 subjects, negative in 26, and inconclusive in 6. Optimal clinical cut-off points for CSF markers were the following: amyloid-ß 1-42 (Aß42) = 629 pg/ml, total tau (t-tau) = 532 pg/ml, phosphorylated tau (p-tau) = 88 pg/ml, and t-tau/Aß42 ratio = 0.58. T-tau/Aß42 ratio showed the best sensitivity and specificity (92 and 84%, respectively). T-tau and p-tau CSF levels (r2 = 0.867) followed by the t-tau and t-tau/Aß42 CSF ratio (r2 = 0.666) showed the strongest inter-marker correlation. Interestingly, subjects with inconclusive Amyloid-PET showed intermediate values for all CSF markers between negative and positive Amyloid-PET groups. CONCLUSIONS: CSF t-tau/Aß42 ratio appears to be the most accurate AD CSF marker. The presence of intermediate values for CSF markers among the subjects with inconclusive Amyloid-PET suggests the presence of other dementias associated with AD pathology or intermediate phenotypes.

Pooled-DNA target sequencing of Parkinson genes reveals novel phenotypic associations in Spanish population.

Eighteen loci and several susceptibility genes have been related to Parkinson's disease (PD). However, most studies focus on single genes in small PD series. Our aim was to establish the genetic background of a large Spanish PD sample. Pooled-DNA target sequencing of 7 major PD genes (SNCA, PARK2, PINK1, DJ-1, LRRK2, GBA, and MAPT) was performed in 562 PD cases. Forty-four variants were found among 114 individuals (20.28%, p<0.05). Among these variants, 30 were found in Mendelian genes (68.18%) and 14 in PD susceptibility genes (31.82%). Seven novel variants were identified. Interestingly, most variants were found in PARK2 and PINK1 genes, whereas SNCA and DJ-1 variants were rare. Validated variants were also genotyped in Spanish healthy controls (n = 597). Carriers of heterozygous PARK2 variants presented earlier disease onset and showed dementia more frequently. PD subjects carrying 2 variants at different genes (1.42%) had an earlier age of onset and a predominantly akinetic-rigid PD phenotype (55.6%, p < 0.05), suggesting that the accumulation of genetic risk variants could modify PD phenotype.

Target-enriched sequencing of chromosome 17q21.31 in sporadic tauopathies reveals no candidate variants.

The main genetic risk factors for progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are located at chromosome 17q21.31. The identification of risk H1 subhaplotypes suggests that disease-specific variants can be identified by resequencing the 17q21.31 region (1.4 Mb) in carriers of risk H1 subhaplotypes. We hypothesized that PSP/CBD H1 subhaplotype carriers could have undergone a mutational event absent among unaffected carriers leading to the disease risk. We performed this strategy in definite PSP subjects, definite CBD subjects, and healthy controls and tried to replicate the findings in a larger PSP/CBD case-control series. In the resequencing process, 40 candidate variants were identified, but an association between PSP and rs76970862 was replicated only using an unadjusted model. Gene expression association analysis of this variant suggested no potential functional effect. Although our results failed to identify disease-associated variants, it is still possible that the risk of PSP/CBD at chromosome 17 is driven by rare variants, even in PSP/CBD H1 cases or variants located outside the capture regions.

Protein-bound tyrosine oxidation, nitration and chlorination by-products assessed by ultraperformance liquid chromatography coupled to tandem mass spectrometry.

BACKGROUND: Free radicals cause alterations in cellular protein structure and function. Oxidized, nitrated, and chlorinated modifications of aromatic amino acids including phenylalanine and tyrosine are reliable biomarkers of oxidative stress and inflammation in clinical conditions. OBJECTIVE: To develop, validate and apply a rapid method for the quantification of known hallmarks of tyrosine oxidation, nitration and chlorination in plasma and tissue proteins providing a snapshot of the oxidative stress and inflammatory status of the organism and of target organs respectively. MATERIAL AND METHODS: The extraction and clean up procedure entailed protein precipitation, followed by protein re-suspension and enzymatic digestion with pronase. An Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (UPLC-MS/MS) method was developed to quantify protein released ortho-tyrosine (o-Tyr), meta-tyrosine (m-Tyr), 3-nitrotyrosine (3NO2-Tyr) and 3-chlorotyrosine (3Cl-Tyr) as well as native phenylalanine (Phe) and tyrosine (p-Tyr) in plasma and tissue from a validated hypoxic newborn piglet experimental model. RESULTS: In plasma there was a significant increase in the 3NO2-Tyr/p-Tyr ratio. On the other hand m-Tyr/Phe and 3Cl-Tyr/p-Tyr ratios were significantly increased in liver of hypoxic compared with normoxic animals. Although no significant differences were found in brain tissue, a clear tendency to increased ratios was observed under hypoxic conditions. CONCLUSIONS: UPLC-MS/MS has proven suitable for the analysis of plasma and tissue samples from newborn piglets. The analysis of biomarkers of protein oxidation, nitration and chlorination will be applied in future studies aiming to provide a deeper insight into the mechanisms of oxidation-derived protein modification caused during neonatal asphyxia and resuscitation.