Results Of Minimally Invasive Vats Thymectomy In Miastenia Gravis Patients Compared With More Invasive Approaches - 10-Year Experience In A Single Center.

INTRODUCTION: Myasthenia gravis (MG) is an autoimmune, neurologic disease that causes a wide range of symptoms. While the transsternal, transcervical and thoracotomy approaches are accepted as effective, there is still debate regarding the VATS approach. MATERIALS AND METHODS: We analyzed our center's surgical experience with thymectomy for myasthenia gravis, comparing the results of patients operated on using VATS and more invasive approaches, over a period of 10 years. A search of the department's surgical database for myasthenia gravis cases between January 2010 and January 2021, revealed a total of 40 cases. Twenty-four patients were included in the final analysis and were distributed into two groups: the VATS procedure group (group A) and the open procedure group (group B). The latter included sternotomy, thoracotomy, transcervical and hemiclamshell approaches. Only radical thymectomies were included. The established outcomes were clinical improvement defined as asymptomatic remission, reduction, or discontinuation of the medication necessary to achieve optimal symptom control. RESULTS: The median follow-up time was 27 months (ranging from 4 to 75 months). Videothoracoscopy radical thymectomy was performed on 12 patients. Complete remission with no medication was achieved in 1 case (8.3%), while 2 patients (16.7%) became asymptomatic with reduced medication. An improvement (reduced symptoms or decreased medication) was observed in 8 cases (66.6%). No change in clinical outcome was noted in 1 patient (8.3%). None of the patients reported worsening symptoms. Open thymectomy was performed on 12 patients. Complete remission with no medication was achieved in 1 case (8.3%), while 2 patients (16.7%) became asymptomatic with reduced medication. An improvement was noted in 6 cases (50%). No change in clinical outcome was observed in 3 patients (25%) whereas 2 of them (16.7%) experienced slightly better symptom control but with a significant increase in medication. One patient (8.3%) described the clinical results as without any significant change. None of the patients reported worsening symptoms. CONCLUSION: The videotoracoscopic approach in the treatment of myasthenia gravis is non-inferior compared to the open approach and effective in a long-term follow-up, offering all the additional benefits of less invasive surgery.

Enhancement of Subjective Quality of Life Following Surgical Intervention in Patients With Drug-Resistant Epilepsy: A Depressive Symptom-Independent Outcome.

PURPOSE: To evaluate the impact of depressive symptoms on the subjective perception of quality of life in patients with drug-resistant epilepsy (DRE) after surgical treatment for seizures.  Methods: A case-control study with DRE patients who received surgical treatment (n=19) and matched non-operated patients (n=23). We assessed the quality of life using the Subjective Handicap of Epilepsy (SHE) scale, alongside measuring depressive symptoms using the Beck Depression Inventory (BDI). RESULTS: The mean age of the participants was 45 years, with females constituting 52.4% of the patients. A majority (73.8%) had been diagnosed with temporal lobe epilepsy. Those who had undergone surgical intervention showed significantly enhanced performance across all quality-of-life domains on the SHE scale independently of depressive symptoms. The domains of "Work and Activity," "Physical Health," and "Self-Perception" displayed the greatest improvements, with the surgical group's averages outperforming the control group by factors of 1.87, 2.53, and 2.81, respectively. Influential differences impacting the quality-of-life scores included seizure frequency, the quantity of antiepileptic drugs utilized, and the incidence of convulsive seizures. CONCLUSION: The findings suggest that surgical control of seizures in drug-resistant focal epilepsy is associated with improvement in quality of life across various domains, independently of the depressive symptoms of the patients.

Investigating SARS-CoV-2 Incidence and Morbidity in Ponce, Puerto Rico: Protocol and Baseline Results From a Community Cohort Study.

BACKGROUND: A better understanding of SARS-CoV-2 infection risk among Hispanic and Latino populations and in low-resource settings in the United States is needed to inform control efforts and strategies to improve health equity. Puerto Rico has a high poverty rate and other population characteristics associated with increased vulnerability to COVID-19, and there are limited data to date to determine community incidence. OBJECTIVE: This study describes the protocol and baseline seroprevalence of SARS-CoV-2 in a prospective community-based cohort study (COPA COVID-19 [COCOVID] study) to investigate SARS-CoV-2 infection incidence and morbidity in Ponce, Puerto Rico. METHODS: In June 2020, we implemented the COCOVID study within the Communities Organized to Prevent Arboviruses project platform among residents of 15 communities in Ponce, Puerto Rico, aged 1 year or older. Weekly, participants answered questionnaires on acute symptoms and preventive behaviors and provided anterior nasal swab samples for SARS-CoV-2 polymerase chain reaction testing; additional anterior nasal swabs were collected for expedited polymerase chain reaction testing from participants that reported 1 or more COVID-19-like symptoms. At enrollment and every 6 months during follow-up, participants answered more comprehensive questionnaires and provided venous blood samples for multiantigen SARS-CoV-2 immunoglobulin G antibody testing (an indicator of seroprevalence). Weekly follow-up activities concluded in April 2022 and 6-month follow-up visits concluded in August 2022. Primary study outcome measures include SARS-CoV-2 infection incidence and seroprevalence, relative risk of SARS-CoV-2 infection by participant characteristics, SARS-CoV-2 household attack rate, and COVID-19 illness characteristics and outcomes. In this study, we describe the characteristics of COCOVID participants overall and by SARS-CoV-2 seroprevalence status at baseline. RESULTS: We enrolled a total of 1030 participants from 388 households. Relative to the general populations of Ponce and Puerto Rico, our cohort overrepresented middle-income households, employed and middle-aged adults, and older children (P<.001). Almost all participants (1021/1025, 99.61%) identified as Latino/a, 17.07% (175/1025) had annual household incomes less than US $10,000, and 45.66% (463/1014) reported 1 or more chronic medical conditions. Baseline SARS-CoV-2 seroprevalence was low (16/1030, 1.55%) overall and increased significantly with later study enrollment time (P=.003). CONCLUSIONS: The COCOVID study will provide a valuable opportunity to better estimate the burden of SARS-CoV-2 and associated risk factors in a primarily Hispanic or Latino population, assess the limitations of surveillance, and inform mitigation measures in Puerto Rico and other similar populations. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/53837.

Single dominant lesion in capillary malformation-arteriovenous malformation (CM-AVM) RASA1 syndrome.

We report two cases with localized vascular malformations clinically resembling the "dominant lesion" seen in capillary malformation-arteriovenous malformation (CM-AVM) syndrome, however, lacking germline RASA1 variants but presenting double somatic RASA1 variants in affected tissue. Both patients presented with localized and superficial high-flow vascular malformations were treated with surgery and laser therapy and showed partial resolution. The study underscores the rarity of somatic RASA1 variants, contributes to understanding the "second-hit" pathophysiology in vascular lesions, and emphasizes the significance of clinical distinctions and genotyping for accurate diagnoses, offering implications for diagnosis, prognosis, and genetic counseling.

Phylodynamic analysis of foot-and-mouth disease virus evolution in Mar Chiquita, Argentina.

Foot-and-mouth disease is a highly contagious disease affecting cloven-hoofed animals, resulting in considerable economic losses. Its causal agent is foot-and-mouth disease virus (FMDV), a picornavirus. Due to its error-prone replication and rapid evolution, the transmission and evolutionary dynamics of FMDV can be studied using genomic epidemiological approaches. To analyze FMDV evolution and identify possible transmission routes in an Argentinean region, field samples that tested positive for FMDV by PCR were obtained from 21 farms located in the Mar Chiquita district. Whole FMDV genome sequences were obtained by PCR amplification in seven fragments and sequencing using the Sanger technique. The genome sequences obtained from these samples were then analyzed using phylogenetic, phylogeographic, and evolutionary approaches. Three local transmission clusters were detected among the sampled viruses. The dataset was analyzed using Bayesian phylodynamic methods with appropriate coalescent and relaxed molecular clock models. The estimated mean viral evolutionary rate was 1.17 × 10- 2 substitutions/site/year. No significant differences in the rate of viral evolution were observed between farms with vaccinated animals and those with unvaccinated animals. The most recent common ancestor of the sampled sequences was dated to approximately one month before the first reported case in the outbreak. Virus transmission started in the south of the district and later dispersed to the west, and finally arrived in the east. Different transmission routes among the studied herds, such as non-replicating vectors and close contact contagion (i.e., aerosols), may be responsible for viral spread.

Plant Reproductive Success Mediated by Nectar Offered to Pollinators and Defensive Ants in Terrestrial Bromeliaceae.

Most plants produce floral nectar to attract pollinators that impact pollination and seed production; some of them also secrete extrafloral nectar harvested by insects that may influence the plant reproductive success. The aim of this study was to analyze the effects of excluding pollinators and/or ants on the per-plant reproductive success in two species (Dyckia floribunda Griseb. and Dyckia longipetala Baker, Bromeliaceae) that produce floral and extrafloral nectar. The hypothesis states that both ecological processes (pollination and ant defense) involving nectar-mediated animal-plant interactions are beneficial for plant reproductive success. We expected the highest decrease in the plant fruit and seed sets when the pollinators and ants were excluded, and a moderate decrease when solely ants were excluded, compared to the control plants (those exposed to pollinators and ants). In addition, a lower natural reproductive success was also expected in the self-incompatible D. longipetala than in the self-compatible D. floribunda, as the former totally depends on animal pollination for seed production. D. floribunda and D. longipetala presented similar trends in the response variables, and the expected results for the experimental treatments were observed, with some variations between species and among populations. The ecological function of nectar is important because these two plant species depend on pollinators to produce seeds and on ants to defend flowers from the endophytic larvae of Lepidoptera. The study of multispecies interactions through mechanistic experiments could be necessary to clarify the specific effects of different animals on plant reproductive success.

Autoimmune encephalitis in a resource-limited public health setting: a case series analysis.

BACKGROUND: Autoimmune encephalitis (AE) consists of a group of acquired diseases that affect the central nervous system. A myriad of phenotypes may be present at the onset. Due to the heterogeneity of clinical presentations, it is difficult to achieve uniformity for the diagnostic and therapeutic processes and follow-up strategies. OBJECTIVE: To describe a series of patients diagnosed with AE in a resource-limited public hospital in southern Brazil and to analyze therapeutics and outcomes. METHODS: We retrospectively reviewed the electronic medical records of patients diagnosed with AE at the Hospital de Clínicas de Porto Alegre from 2014 to 2022. Data collected included clinical presentation, neuroimaging, cerebrospinal fluid testings, electroencephalogram, autoantibodies, treatments, outcomes, follow-up time, degree of neurological impairment, and mortality. RESULTS: Data from 17 patients were retrieved. Eleven cases were classified as definite AE and 6 as possible AE. Autoantibodies were identified in 9 patients. Timing for diagnosis was impacted by the high costs associated with autoantibody testing. Most patients became functionally dependent (82.4%) and most survivors remained with autoimmune-associated epilepsy (75%). Five patients died during hospitalization, and one after a 26-month of follow-up. CONCLUSION: In this resource-limited hospital, patients with AE had a worse clinical outcome than that previously described in the literature. Development of epilepsy during follow-up and mortality were greater, whilst functional outcome was inferior. Autoantibody testing was initially denied in most patients, which impacted the definitive diagnosis and the use of second-line therapies.

ANTECEDENTES: A encefalite autoimune (EA) consiste em um grupo de doenças adquiridas que afetam o sistema nervoso central. OBJETIVO: Descrever uma série de pacientes diagnosticados com EA em um contexto de atenção terciária à saúde com recursos limitados e analisar a terapêutica e os resultados. MéTODOS: Revisamos retrospectivamente os prontuários eletrônicos de pacientes diagnosticados com EA no Hospital de Clínicas de Porto Alegre de 2014 a 2022. Os dados coletados incluíram apresentação clínica, neuroimagem, exames de líquido cefalorraquidiano, eletroencefalograma, autoanticorpos, tratamentos, resultados, tempo de acompanhamento, grau de comprometimento neurológico e mortalidade. RESULTADOS: Dados de 17 pacientes foram coletados. Onze casos foram classificados como EA definitivo e seis como EA possível. Autoanticorpos foram identificados em nove pacientes. O tempo para o diagnóstico foi afetado pelos altos custos associados ao teste de autoanticorpos. A maioria dos pacientes tornou-se funcionalmente dependente (82,4%), e a maioria dos sobreviventes permaneceu com epilepsia autoimune associada (75%). Cinco pacientes faleceram durante a internação, e um após 26 meses de seguimento. CONCLUSãO: No hospital em questão, os pacientes com EA tiveram um desfecho clínico pior do que o previamente descrito na literatura. O desenvolvimento de epilepsia durante o acompanhamento e a mortalidade foram maiores, enquanto o desfecho funcional foi inferior. Os testes de autoanticorpos foram inicialmente negados para a maioria dos pacientes, o que impactou o diagnóstico definitivo e o uso de terapias de segunda linha.

Monoclonal gammopathy of renal significance: An atypical presentation of Waldenström's disease.

Waldenström's disease is a rare lymphoproliferative syndrome in the bone marrow and sometimes in lymphoid organs which secretes high amounts of monoclonal immunoglobulin M into serum. It can remain indolent for years and rarely affects the kidney, with intraglomerular rather than intratubular damage being predominant, in contrast to multiple myeloma. Different studies identified AL amyloidosis as the most frequent renal lesion, followed by cryoglobulinemic glomerulonephritis. Signs and symptoms may be unspecific, as well as renal manifestations, so collaboration between nephrologists, hematologists, and pathologists is crucial to establish the role of paraprotein in the development of renal damage. We present an atypical case of Waldenström's disease that had a minimal monoclonal peak and clinically debuted with nephritic and nephrotic syndromes. The diagnosis was cryoglobulinemic glomerulonephritis. Currently, there are numerous treatment options, without enough evidence yet to establish a standardised treatment.

Microbiological hazard identification in river waters used for recreational activities.

Pathogenic bacteria, viruses, and parasites can cause waterborne disease outbreaks. The study of coastal water quality contributes to identifying potential risks to human health and to improving water management practices. The Río de la Plata River, a wide estuary in South America, is used for recreational activities, as a water source for consumption and as a site for sewage discharges. In the present study, as the first step of a quantitative microbial risk assessment of the coastal water quality of this river, a descriptive study was performed to identify the microbial pathogens prevalent in its waters and in the sewage discharged into the river. Two sites, representing two different potential risk scenarios, were chosen: a heavily polluted beach and an apparently safe beach. Conductivity and fecal contamination indicators including enterococci, Escherichia coli, F + RNA bacteriophages, and human polyomaviruses showed high levels. Regarding enterococci, differences between sites were significant (p-values <0.001). 93.3% and 56.5% of the apparently safe beach exceeded the recreational water limits for E. coli and enterococci. Regarding pathogens, diarrheagenic E. coli, Salmonella, and noroviruses were detected with different frequencies between sites. The parasites Cryptosporidium spp. and Giardia duodenalis were frequently detected in both sites. The results regarding viral, bacterial, and parasitic pathogens, even without correlation with conventional indicators, showed the importance of monitoring a variety of microorganisms to determine water quality more reliably and accurately, and to facilitate further studies of health risk assessment. The taxonomic description of microbial pathogens in river waters allow identifying the microorganisms that infect the population living on its shores but also pathogens not previously reported by the clinical surveillance system.

Measuring quality and safety of epilepsy monitoring units in Brazil: Adoption of quality indicators.

PURPOSE: Drug-resistant epilepsy affects a substantial proportion (30-40 %) of patients with epilepsy, often necessitating video-electroencephalography (video-EEG) monitoring. In 2016, Sauro et al. introduced a set of measures aimed at improving the quality and safety indicators reported in video-EEG evaluations. This study aims to report our experience with the implementation of these measures. METHODS: We analyzed video-EEG data regarding quality and safty from a period spanning January 2016 to January 2018, involving a total of 101 patients monitored in our video-EEG unit. RESULTS: Among the patients included in the study, a definitive diagnosis was attainable for 92.1 %, with 36.6 % experiencing a change in diagnosis and 65.3 % undergoing a change in treatment as a result of the video-EEG evaluation. Additionally, the referral question was fully addressed in 60.4 % of admissions, and video-EEG was considered to be very useful or extremely useful in 66.4 % of cases. Adverse events were observed in 26.7 % of patients, with the most common being the progression of focal seizures to bilateral tonic-clonic seizures (11.9 %) and the occurrence of seizure clusters (5.9 %). CONCLUSION: Our findings support the implementation of Sauro et al.'s set of measures, as they provide valuable criteria for improving the reporting of video-EEG quality and safety indicators. However, challenges may arise due to variations in terminology across studies and the lack of standardized criteria for defining essential questions in video-EEG evaluations. Further research utilizing these measures is necessary to enhance their effectiveness and encourage consistent reporting of results from epilepsy monitoring units.

Emergence of genotype III St. Louis encephalitis virus in the western United States potentially linked to a wetland in Argentina.

St. Louis encephalitis virus (SLEV) is endemic in the Americas and its transmission networks involve Culex mosquitoes and avian species. In 2015, a human encephalitis outbreak took place in Arizona and California, indicating the re-emergence of this pathogen in the US. Viral strains isolated in that outbreak belong to genotype III SLEV previously detected only in South America. In this study, genotype III SLEV was detected in mosquitoes collected in Mar Chiquita Lagoon (Córdoba, Argentina), an overwintering site for numerous migratory bird species. The genotype III SLEV sequence detected in this site shares the closest known ancestor with those introduced in Arizona in 2015. Our results highlight the potential significance of wetlands as key sites for arbovirus maintenance and emergence.

Autoimmune encephalitis in a resource-limited public health setting: a case series analysis / Encefalite autoimune em um hospital universitário público: análise de uma série de casos

Abstract Background Autoimmune encephalitis (AE) consists of a group of acquired diseases that affect the central nervous system. A myriad of phenotypes may be present at the onset. Due to the heterogeneity of clinical presentations, it is difficult to achieve uniformity for the diagnostic and therapeutic processes and follow-up strategies. Objective To describe a series of patients diagnosed with AE in a resource-limited public hospital in southern Brazil and to analyze therapeutics and outcomes. Methods We retrospectively reviewed the electronic medical records of patients diagnosed with AE at the Hospital de Clínicas de Porto Alegre from 2014 to 2022. Data collected included clinical presentation, neuroimaging, cerebrospinal fluid testings, electroencephalogram, autoantibodies, treatments, outcomes, follow-up time, degree of neurological impairment, and mortality. Results Data from 17 patients were retrieved. Eleven cases were classified as definite AE and 6 as possible AE. Autoantibodies were identified in 9 patients. Timing for diagnosis was impacted by the high costs associated with autoantibody testing. Most patients became functionally dependent (82.4%) and most survivors remained with autoimmune-associated epilepsy (75%). Five patients died during hospitalization, and one after a 26-month of follow-up. Conclusion In this resource-limited hospital, patients with AE had a worse clinical outcome than that previously described in the literature. Development of epilepsy during follow-up and mortality were greater, whilst functional outcome was inferior. Autoantibody testing was initially denied in most patients, which impacted the definitive diagnosis and the use of second-line therapies.

Resumo Antecedentes A encefalite autoimune (EA) consiste em um grupo de doenças adquiridas que afetam o sistema nervoso central. Objetivo Descrever uma série de pacientes diagnosticados com EA em um contexto de atenção terciária à saúde com recursos limitados e analisar a terapêutica e os resultados. Métodos Revisamos retrospectivamente os prontuários eletrônicos de pacientes diagnosticados com EA no Hospital de Clínicas de Porto Alegre de 2014 a 2022. Os dados coletados incluíram apresentação clínica, neuroimagem, exames de líquido cefalorraquidiano, eletroencefalograma, autoanticorpos, tratamentos, resultados, tempo de acompanhamento, grau de comprometimento neurológico e mortalidade. Resultados Dados de 17 pacientes foram coletados. Onze casos foram classificados como EA definitivo e seis como EA possível. Autoanticorpos foram identificados em nove pacientes. O tempo para o diagnóstico foi afetado pelos altos custos associados ao teste de autoanticorpos. A maioria dos pacientes tornou-se funcionalmente dependente (82,4%), e a maioria dos sobreviventes permaneceu com epilepsia autoimune associada (75%). Cinco pacientes faleceram durante a internação, e um após 26 meses de seguimento. Conclusão No hospital em questão, os pacientes com EA tiveram um desfecho clínico pior do que o previamente descrito na literatura. O desenvolvimento de epilepsia durante o acompanhamento e a mortalidade foram maiores, enquanto o desfecho funcional foi inferior. Os testes de autoanticorpos foram inicialmente negados para a maioria dos pacientes, o que impactou o diagnóstico definitivo e o uso de terapias de segunda linha.

Memantine Improves Memory and Neurochemical Damage in a Model of Maple Syrup Urine Disease.

Maple Syrup Urine Disease (MSUD) is a metabolic disease characterized by the accumulation of branched-chain amino acids (BCAA) in different tissues due to a deficit in the branched-chain alpha-ketoacid dehydrogenase complex. The most common symptoms are poor feeding, psychomotor delay, and neurological damage. However, dietary therapy is not effective. Studies have demonstrated that memantine improves neurological damage in neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Therefore, we hypothesize that memantine, an NMDA receptor antagonist can ameliorate the effects elicited by BCAA in an MSUD animal model. For this, we organized the rats into four groups: control group (1), MSUD group (2), memantine group (3), and MSUD + memantine group (4). Animals were exposed to the MSUD model by the administration of BCAA (15.8 µL/g) (groups 2 and 4) or saline solution (0.9%) (groups 1 and 3) and treated with water or memantine (5 mg/kg) (groups 3 and 4). Our results showed that BCAA administration induced memory alterations, and changes in the levels of acetylcholine in the cerebral cortex. Furthermore, induction of oxidative damage and alterations in antioxidant enzyme activities along with an increase in pro-inflammatory cytokines were verified in the cerebral cortex. Thus, memantine treatment prevented the alterations in memory, acetylcholinesterase activity, 2',7'-Dichlorofluorescein oxidation, thiobarbituric acid reactive substances levels, sulfhydryl content, and inflammation. These findings suggest that memantine can improve the pathomechanisms observed in the MSUD model, and may improve oxidative stress, inflammation, and behavior alterations.

The Impact of Family Stress and Resilience on Child Development: a scope review.

INTRODUCTION: Children grow up spending most of their time within the family social environment, where they can experience stressful situations such as marital conflict, a non-cohesive environment, parental alcohol use disorder, parental depression, and other parental mental health issues. All these factors are associated with children's developmental delays. OBJECTIVE: We aimed to conduct a scoping review on family stress and family resilience associated with child development delays to examine familial conditions associated with child development. METHODS: We conducted a scoping review of observational studies published between January 2000 to July 2023, indexed in MEDLINE and LILACS databases. We included observational studies that evaluated the history of exposure to violence, and behavioral or emotional symptoms, or mental health problems among children aged 4-12. Data were independently extracted using a structured form. RESULTS: Database searches identified 12,990 different records. A total of 43 articles were included in the review. Three main findings emerged: (1) parental mental health problems, especially depressive symptoms in mothers, were associated with child developmental delays and mental health problems; (2) better parenting practices and cohesive home environment were positively associated with child development, and (3) Vulnerable social environments (e.g., poverty and housing insecurity) may be linked to child mental health problems. CONCLUSIONS: Studies reviewed show that promoting better family dynamics and increasing family cohesion, as well as parenting abilities, are beneficial to a child's socio-emotional development and prevention of child mental health problems. Moreover, increasing family and children's resilience improves the quality of life within family units.

Identification of a new polyomavirus in distinct human populations and tissues.

Several human polyomaviruses (HPyVs) have been described in the last 15 years. This work aimed to characterize a novel HPyV with cutaneous tropism. Swabs of healthy skin (forehead) of 75 immunocompetent individuals from Argentina were screened for HPyV through sequence amplification techniques. Publicly available metagenomic data sets were also analyzed. A previously unknown polyomavirus sequence was detected in two skin swab samples. A nearly identical sequence was detected in public data sets representing metagenomic surveys of human skin and feces. Further analyses showed that the new polyomavirus diverges from its nearest relative, human polyomavirus 6 (HPyV6), by 17.3%-17.7% (in nucleotides for the large T antigen), which meets criteria for a new species designation in the genus Deltapolyomavirus. The screening also revealed more distant HPyV6 relatives in macaque genital and chimpanzee fecal data sets. Since polyomaviruses are generally thought to cospeciate with mammalian hosts, the high degree of similarity to HPyV6 suggests the new polyomavirus species is human-tropic. Therefore, a novel polyomavirus was identified and characterized from samples of distinct populations and tissues. We suggest the common name human polyomavirus 16 (HPyV16).

Diversity, composition, and networking of saliva microbiota distinguish the severity of COVID-19 episodes as revealed by an analysis of 16S rRNA variable V1-V3 region sequences.

Studies on the role of the oral microbiome in SARS-CoV-2 infection and severity of the disease are limited. We aimed to characterize the bacterial communities present in the saliva of patients with varied COVID-19 severity to learn if there are differences in the characteristics of the microbiome among the clinical groups. We included 31 asymptomatic subjects with no previous COVID-19 infection or vaccination; 176 patients with mild respiratory symptoms, positive or negative for SARS-CoV-2 infection; 57 patients that required hospitalization because of severe COVID-19 with oxygen saturation below 92%, and 18 fatal cases of COVID-19. Saliva samples collected before any treatment were tested for SARS-CoV-2 by PCR. Oral microbiota in saliva was studied by amplification and sequencing of the V1-V3 variable regions of 16S gene using an Illumina MiSeq platform. We found significant changes in diversity, composition, and networking in saliva microbiota of patients with COVID-19, as well as patterns associated with severity of disease. The presence or abundance of several commensal species and opportunistic pathogens were associated with each clinical stage. Patterns of networking were also found associated with severity of disease: a highly regulated bacterial community (normonetting) was found in healthy people whereas poorly regulated populations (disnetting) were characteristic of severe cases. Characterization of microbiota in saliva may offer important clues in the pathogenesis of COVID-19 and may also identify potential markers for prognosis in the severity of the disease. IMPORTANCE SARS-CoV-2 infection is the most severe pandemic of humankind in the last hundred years. The outcome of the infection ranges from asymptomatic or mild to severe and even fatal cases, but reasons for this remain unknown. Microbes normally colonizing the respiratory tract form communities that may mitigate the transmission, symptoms, and severity of viral infections, but very little is known on the role of these microbial communities in the severity of COVID-19. We aimed to characterize the bacterial communities in saliva of patients with different severity of COVID-19 disease, from mild to fatal cases. Our results revealed clear differences in the composition and in the nature of interactions (networking) of the bacterial species present in the different clinical groups and show community-patterns associated with disease severity. Characterization of the microbial communities in saliva may offer important clues to learn ways COVID-19 patients may suffer from different disease severities.

Evolutionary analysis of JC polyomavirus in Misiones' population yields insight into the population dynamics of the early human dispersal in the Americas.

BACKGROUND: JC polyomavirus (JCV) has an ethno-geographical distribution across human populations. OBJECTIVE: Study the origins of the population of Misiones (Argentina) by using JCV as genetic marker. METHODS: Viral detection and characterization was conducted by PCR amplification and evolutionary analysis of the intergenic region sequences. RESULTS: 22 out of 121 samples were positive for JCV, including 5 viral lineages: MY (n = 8), Eu-a (n = 7), B1-c (n = 4), B1-b (n = 2) and Af2 (n = 1). MY sequences clustered within a branch of Native American origin that diverged from its Asian counterpart about 21,914 years ago (HPD 95% interval 15,383-30,177), followed by a sustained demographic expansion around 5000 years ago. CONCLUSIONS: JCV in Misiones reflects the multiethnic origin of the current population, with an important Amerindian contribution. Analysis of the MY viral lineage shows a pattern consistent with the arrival of early human migrations to the Americas and a population expansion by the pre-Columbian native societies.

The Lambda Variant in Argentina: Analyzing the Evolution and Spread of SARS-CoV-2 Lineage C.37.

The second wave of COVID-19 occurred in South America in early 2021 and was mainly driven by Gamma and Lambda variants. In this study, we aimed to describe the emergence and local genomic diversity of the SARS-CoV-2 Lambda variant in Argentina, from its initial entry into the country until its detection ceased. Molecular surveillance was conducted on 9356 samples from Argentina between October 2020 and April 2022, and sequencing, phylogenetic, and phylogeographic analyses were performed. Our findings revealed that the Lambda variant was first detected in Argentina in January 2021 and steadily increased in frequency until it peaked in April 2021, with continued detection throughout the year. Phylodynamic analyses showed that at least 18 introductions of the Lambda variant into the country occurred, with nine of them having evidence of onward local transmission. The spatial--temporal reconstruction showed that Argentine clades were associated with Lambda sequences from Latin America and suggested an initial diversification in the Metropolitan Area of Buenos Aires before spreading to other regions in Argentina. Genetic analyses of genome sequences allowed us to describe the mutational patterns of the Argentine Lambda sequences and detect the emergence of rare mutations in an immunocompromised patient. Our study highlights the importance of genomic surveillance in identifying the introduction and geographical distribution of the SARS-CoV-2 Lambda variant, as well as in monitoring the emergence of mutations that could be involved in the evolutionary leaps that characterize variants of concern.

Melatonin improves behavioral parameters and oxidative stress in zebrafish submitted to a leucine-induced MSUD protocol.

Maple syrup urine disease (MSUD) is an inherited metabolic disorder caused by a deficiency in branched-chain alpha-ketoacid dehydrogenase complex (BCKAC). The treatment is a standard therapy based on a protein-restricted diet with low branched-chain amino acids (BCAA) content to reduce plasma levels and, consequently, the effects of accumulating their metabolites, mainly in the central nervous system. Although the benefits of dietary therapy for MSUD are undeniable, natural protein restriction may increase the risk of nutritional deficiencies, resulting in a low total antioxidant status that can predispose and contribute to oxidative stress. As MSUD is related to redox and energy imbalance, melatonin can be an important adjuvant treatment. Melatonin directly scavenges the hydroxy radical, peroxyl radical, nitrite anion, and singlet oxygen and indirectly induces antioxidant enzyme production. Therefore, this study assesses the role of melatonin treatment on oxidative stress in brain tissue and behavior parameters of zebrafish (Danio rerio) exposed to two concentrations of leucine-induced MSUD: leucine 2 mM and 5mM; and treated with 100 nM of melatonin. Oxidative stress was assessed through oxidative damage (TBARS, DCF, and sulfhydryl content) and antioxidant enzyme activity (SOD and CAT). Melatonin treatment improved redox imbalance with reduced TBARS levels, increased SOD activity, and normalized CAT activity to baseline. Behavior was analyzed with novel object recognition test. Animals exposed to leucine improved object recognition due to melatonin treatment. With the above, we can suggest that melatonin supplementation can protect neurologic oxidative stress, protecting leucine-induced behavior alterations such as memory impairment.