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1.
Rapid Commun Mass Spectrom ; 38(1): e9650, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38073197

RESUMO

The analysis of the nitrogen (N) isotopic composition of organic matter bound to fossil biomineral structures (BB-δ15 N) using the oxidation-denitrifier (O-D) method provides a novel tool to study past changes in N cycling processes. METHODS: We report a set of methodological improvements to the O-D method, including (a) a method for sealing the reaction vials in which the oxidation of organic N to NO3 - takes place, (b) a recipe for bypassing the pH adjustment step before the bacterial conversion of NO3 - to N2 O, and (c) a method for storing recrystallized dipotassium peroxodisulfate (K2 S2 O8 ) under Ar atmosphere. RESULTS: The new sealing method eliminates the occasional contamination and vial breakage that occurred previously while increasing sample throughput. The protocol for bypassing pH adjustment does not affect BB-δ15 N, and it significantly reduces the processing time. Storage of K2 S2 O8 reagent under Ar atmosphere produces stable oxidation blanks over more than 3.5 years. We report analytical blanks, accuracy, and precision for this methodology from eight users over the course of ~3.5 years of analyses at the Max Planck Institute for Chemistry. Our method produces analytical blanks characterized by low N content (0.30 ± 0.13 nmol N, 1σ, n = 195) and stable δ15 N (-2.20 ± 3.13‰, n = 195). The analysis of reference amino acid standards USGS 40 and USGS 65 indicates an overall accuracy of -0.23 ± 0.35‰ (1σ, n = 891). The analysis of in-house fossil standards gives similar analytical precision (1σ) across a range of BB-δ15 N values and biominerals: zooxanthellate coral standard PO-1 (6.08 ± 0.21‰, n = 267), azooxanthellate coral standard LO-1 (10.20 ± 0.28‰, n = 258), foraminifera standard MF-1 (5.92 ± 0.28‰, n = 243), and tooth enamel AG-Lox (4.06 ± 0.49‰, n = 78). CONCLUSIONS: The methodological improvements significantly increase sample throughput without compromising analytical precision or accuracy down to 1 nmol of N.

2.
Am J Hum Genet ; 107(6): 1149-1156, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33186543

RESUMO

The Congenital Dyserythropoietic Anemia (CDA) Registry was established with the goal to facilitate investigations of natural history, biology, and molecular pathogenetic mechanisms of CDA. Three unrelated individuals enrolled in the registry had a syndrome characterized by CDA and severe neurodevelopmental delay. They were found to have missense mutations in VPS4A, a gene coding for an ATPase that regulates the ESCRT-III machinery in a variety of cellular processes including cell division, endosomal vesicle trafficking, and viral budding. Bone marrow studies showed binucleated erythroblasts and erythroblasts with cytoplasmic bridges indicating abnormal cytokinesis and abscission. Circulating red blood cells were found to retain transferrin receptor (CD71) in their membrane, demonstrating that VPS4A is critical for normal reticulocyte maturation. Using proband-derived induced pluripotent stem cells (iPSCs), we have successfully modeled the hematologic aspects of this syndrome in vitro, recapitulating their dyserythropoietic phenotype. Our findings demonstrate that VPS4A mutations cause cytokinesis and trafficking defects leading to a human disease with detrimental effects to erythropoiesis and neurodevelopment.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Anemia Diseritropoética Congênita/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , ATPases Vacuolares Próton-Translocadoras/genética , Adenosina Trifosfatases/metabolismo , Anemia Diseritropoética Congênita/patologia , Medula Óssea/patologia , Células da Medula Óssea/metabolismo , Criança , Pré-Escolar , Citocinese , Endossomos/metabolismo , Eritroblastos/metabolismo , Eritrócitos/citologia , Eritropoese , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Masculino , Transtornos do Neurodesenvolvimento/metabolismo , Fenótipo , Transporte Proteico , Reticulócitos/citologia
3.
Int J Mol Sci ; 24(12)2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37373396

RESUMO

The spinal cord has a poor ability to regenerate after an injury, which may be due to cell loss, cyst formation, inflammation, and scarring. A promising approach to treating a spinal cord injury (SCI) is the use of biomaterials. We have developed a novel hydrogel scaffold fabricated from oligo(poly(ethylene glycol) fumarate) (OPF) as a 0.08 mm thick sheet containing polymer ridges and a cell-attractive surface on the other side. When the cells are cultured on OPF via chemical patterning, the cells attach, align, and deposit ECM along the direction of the pattern. Animals implanted with the rolled scaffold sheets had greater hindlimb recovery compared to that of the multichannel scaffold control, which is likely due to the greater number of axons growing across it. The immune cell number (microglia or hemopoietic cells: 50-120 cells/mm2 in all conditions), scarring (5-10% in all conditions), and ECM deposits (Laminin or Fibronectin: approximately 10-20% in all conditions) were equal in all conditions. Overall, the results suggest that the scaffold sheets promote axon outgrowth that can be guided across the scaffold, thereby promoting hindlimb recovery. This study provides a hydrogel scaffold construct that can be used in vitro for cell characterization or in vivo for future neuroprosthetics, devices, or cell and ECM delivery.


Assuntos
Organofosfonatos , Traumatismos da Medula Espinal , Ratos , Animais , Hidrogéis/química , Organofosfonatos/metabolismo , Cicatriz/patologia , Ratos Sprague-Dawley , Regeneração Nervosa , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/metabolismo , Medula Espinal/metabolismo , Axônios/patologia , Alicerces Teciduais/química
4.
Glia ; 70(1): 196-214, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34716961

RESUMO

Astroglial excitatory amino acid transporter 2 (EAAT2, GLT-1, and SLC1A2) regulates the duration and extent of neuronal excitation by removing glutamate from the synaptic cleft. Hence, an impairment in EAAT2 function could lead to an imbalanced brain network excitability. Here, we investigated the functional alterations of neuronal and astroglial networks associated with the loss of function in the astroglia predominant eaat2a gene in zebrafish. We observed that eaat2a-/- mutant zebrafish larvae display recurrent spontaneous and light-induced seizures in neurons and astroglia, which coincide with an abrupt increase in extracellular glutamate levels. In stark contrast to this hyperexcitability, basal neuronal and astroglial activity was surprisingly reduced in eaat2a-/- mutant animals, which manifested in decreased overall locomotion. Our results reveal an essential and mechanistic contribution of EAAT2a in balancing brain excitability, and its direct link to epileptic seizures.


Assuntos
Epilepsia , Peixe-Zebra , Animais , Astrócitos/metabolismo , Epilepsia/metabolismo , Transportador 2 de Aminoácido Excitatório/genética , Transportador 2 de Aminoácido Excitatório/metabolismo , Ácido Glutâmico/metabolismo , Neurônios/metabolismo , Convulsões/genética , Convulsões/metabolismo , Peixe-Zebra/metabolismo
5.
Muscle Nerve ; 66(4): 479-486, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35894586

RESUMO

INTRODUCTION/AIMS: Carpal and cubital tunnel syndrome (CTS, CuTS) are common among patients with hereditary neuropathy with liability to pressure-palsies (HNPP) and Charcot-Marie-Tooth type 1A (CMT1A) and may impact quality of life. We aimed to evaluate the utility of nerve decompression surgeries in these patients. METHODS: Medical records were reviewed for patients with PMP22 mutations confirmed in Mayo Clinic laboratories from January 1999 to December 2020, who had CTS and CuTS and underwent surgical decompression. RESULTS: CTS occurred in 53.3% of HNPP and 11.5% of CMT1A, while CuTS was present in 43.3% of HNPP and 5.8% of CMT1A patients. CTS decompression occurred in 10-HNPP and 5-CMT1A patients, and CuTS decompression with/without transposition was performed in 5-HNPP and 1-CMT1A patients. In HNPP, electrodiagnostic studies identified median neuropathy at the wrist in 9/10 patients and ultrasound showed focal enlargements at the carpal and cubital tunnels. In CMT1A, median and ulnar sensory responses were all absent, and the nerves were diffusely enlarged. After CTS surgery, pain, sensory loss, and strength improved in 4/5 CMT1A, and 6/10 HNPP patients. Of clinical, electrophysiologic and ultrasound findings, only activity-provoked features significantly correlated with CTS surgical benefit in HNPP patients (odds ratio = 117.0:95% confidence interval, 1.94 > 999.99, p = 0.01). One CMT1A and one HNPP patient improved with CuTS surgery while 2 HNPP patients worsened. DISCUSSION: CTS symptom improvement post-surgery can be seen in CMT1A and (less frequent) in HNPP patients. CuTS surgery commonly worsened course in HNPP. Activity-provoked symptoms in HNPP best informed benefits from CTS surgery.


Assuntos
Doença de Charcot-Marie-Tooth , Neuropatia Hereditária Motora e Sensorial , Artrogripose , Doença de Charcot-Marie-Tooth/genética , Descompressão , Neuropatia Hereditária Motora e Sensorial/genética , Neuropatia Hereditária Motora e Sensorial/cirurgia , Humanos , Qualidade de Vida
6.
Glob Chang Biol ; 26(3): 1338-1353, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31732999

RESUMO

Historical coral skeleton (CS) δ18 O and δ15 N records were produced from samples recovered from sedimentary deposits, held in natural history museum collections, and cored into modern coral heads. These records were used to assess the influence of global warming and regional eutrophication, respectively, on the decline of coastal coral communities following the development of the Pearl River Delta (PRD) megacity, China. We find that, until 2007, ocean warming was not a major threat to coral communities in the Pearl River estuary; instead, nitrogen (N) inputs dominated impacts. The high but stable CS-δ15 N values (9‰-12‰ vs. air) observed from the mid-Holocene until 1980 indicate that soil and stream denitrification reduced and modulated the hydrologic inputs of N, blunting the rise in coastal N sources during the early phase of the Pearl River estuary urbanization. However, an unprecedented CS-δ15 N peak was observed from 1987 to 1993 (>13‰ vs. air), concomitant to an increase of NH4+ concentration, consistent with the rapid Pearl River estuary urbanization as the main cause for this eutrophication event. We suggest that widespread discharge of domestic sewage entered directly into the estuary, preventing removal by natural denitrification hotspots. We argue that this event caused the dramatic decline of the Pearl River estuary coral communities reported from 1980 to 2000. Subsequently, the coral record shows that the implementation of improved wastewater management policies succeeded in bringing down both CS-δ15 N and NH4+ concentrations in the early 2000s. This study points to the potential importance of eutrophication over ocean warming in coral decline along urbanized coastlines and in particular in the vicinity of megacities.


Assuntos
Antozoários , Poluentes Químicos da Água , Animais , China , Monitoramento Ambiental , Estuários , Isótopos de Nitrogênio , Rios
7.
J Acoust Soc Am ; 147(3): EL252, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32237800

RESUMO

The Canadian Digit Triplet Test was developed in English and French, the official languages of Canada. Four versions were developed on a common software platform using recordings produced by two fluent bilinguals, one male and one female, following procedures recommended by international guidelines. Phase I of test development focused on homogenizing digit recognition across tokens and positions within the triplets for young adults with normal hearing (n = 48). In phase II, normative data were collected for young adults with normal hearing (n = 64). Statistical properties were found to be uniform across test versions and comparable to digit triplet tests in other languages.

9.
J Acoust Soc Am ; 145(2): 749, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30823793

RESUMO

Measurement of noise exposure from communication headsets is challenging due to the need for specialized equipment, methods, and training. Canadian standard Z107.56-13 [(2013). Measurement of Noise Exposure (Canadian Standards Association, Mississauga, Canada)] introduced a calculation procedure to promote a simpler method that stakeholders in hearing loss prevention could readily apply using widely accessible sound level equipment. The original procedure specified a fixed signal-to-noise ratio (SNR) of 15 dB above the protected background noise when estimating the speech listening level through the headset communication channel. The relationship between background noise level, noise type, headset noise reduction (NR), and speech listening level is revisited in this study. In a noise simulation room, 24 participants were asked to adjust the headset volume while listening to speech and executing a visual reaction task. Results indicate that the growth in speech listening levels with noise is not adequately represented by a fixed SNR, and that one-sided listening increases speech levels by about 5-7 dB in quiet and in noise compared to two-sided listening. Moreover, use of an octave-band procedure with derating to estimate headset NR best captured the speech listening level data. A revised calculation procedure based on linear regression modeling is described with parameters adjusted separately for one-sided and two-sided headsets.

10.
J Virol ; 90(8): 3913-3928, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26842468

RESUMO

UNLABELLED: Persistent pathogens, such as herpes simplex virus 1 (HSV-1), have evolved a variety of immune evasion strategies to avoid being detected and destroyed by the host's immune system. A dynamic cross talk appears to occur between the HSV-1 latency-associated transcript (LAT), the only viral gene that is abundantly transcribed during latency, and the CD8(+)T cells that reside in HSV-1 latently infected human and rabbit trigeminal ganglia (TG). The reactivation phenotype of TG that are latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT(+)TG) is significantly higher than TG latently infected with LAT-null mutant (i.e., LAT(-)TG). Whether LAT promotes virus reactivation by selectively shaping a unique repertoire of HSV-specific CD8(+)T cells in LAT(+)TG is unknown. In the present study, we assessed the frequency, function, and exhaustion status of TG-resident CD8(+)T cells specific to 40 epitopes derived from HSV-1 gB, gD, VP11/12, and VP13/14 proteins, in human leukocyte antigen (HLA-A*0201) transgenic rabbits infected ocularly with LAT(+)versus LAT(-)virus. Compared to CD8(+)T cells from LAT(-)TG, CD8(+)T cells from LAT(+)TG (i) recognized a broader selection of nonoverlapping HSV-1 epitopes, (ii) expressed higher levels of PD-1, TIM-3, and CTLA-4 markers of exhaustion, and (iii) produced less tumor necrosis factor alpha, gamma interferon, and granzyme B. These results suggest a novel immune evasion mechanism by which the HSV-1 LAT may contribute to the shaping of a broader repertoire of exhausted HSV-specific CD8(+)T cells in latently infected TG, thus allowing for increased viral reactivation. IMPORTANCE: A significantly larger repertoire of dysfunctional (exhausted) HSV-specific CD8(+)T cells were found in the TG of HLA transgenic rabbits latently infected with wild-type HSV-1 or with LAT-rescued mutant (i.e., LAT(+)TG) than in a more restricted repertoire of functional HSV-specific CD8(+)T cells in the TG of HLA transgenic rabbits latently infected with LAT-null mutant (i.e., LAT(-)TG). These findings suggest that the HSV-1 LAT locus interferes with the host cellular immune response by shaping a broader repertoire of exhausted HSV-specific CD8(+)T cells within the latency/reactivation TG site.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Antígeno HLA-A2/imunologia , Herpesvirus Humano 1/imunologia , MicroRNAs/genética , Latência Viral , Animais , Animais Geneticamente Modificados , Epitopos de Linfócito T/imunologia , Expressão Gênica , Antígeno HLA-A2/genética , Humanos , Evasão da Resposta Imune , Contagem de Linfócitos , Coelhos , Gânglio Trigeminal/imunologia , Gânglio Trigeminal/virologia
11.
Environ Sci Technol ; 51(4): 1981-1987, 2017 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-28085273

RESUMO

The development of megalopolises in coastal areas is often linked with severe eutrophication, requiring mitigation of anthropogenic dissolved inorganic nitrogen (DIN) pollution. Yet, identifying the DIN-sources responsible for eutrophication is challenging, hampering mitigation efforts. Here, we utilize the stable nitrogen isotope ratio of endosymbiotic dinoflagellate Symbiodinium spp. (δ15Nsym) associated with the hard coral Porites to trace DIN sources in one of the most urbanized areas of the planet: the Pearl River Delta (PRD). The mean δ15Nsym value found in the coastal waters of Hong Kong (HK), located on the eastern edge of the PRD, (7.4‰ ± 1.2‰) was +2.7‰ higher than at Dongsha Atoll, a reference site unaffected by anthropogenic-DIN (4.7‰ ± 0.4‰). The isotopic enrichment suggested a consistent dominance of DIN deriving from local and regional sewage discharges on the eastern edge of HK. Furthermore, the strong depletion of the summer δ15Nsym value (-1.6‰) observed in southern HK revealed that the Pearl River plume strongly modulates the coastal DIN pool. Our results revealed the value of benthic marine organisms' δ15N for deciphering the complex dynamics of coastal eutrophication and highlighted the pivotal role of transboundary coordination in DIN-pollution mitigation.


Assuntos
Antozoários , Nitrogênio , Animais , Monitoramento Ambiental , Isótopos de Nitrogênio , Rios
12.
Glob Chang Biol ; 22(11): 3550-3565, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27414018

RESUMO

Although the impacts of nutrient pollution on coral reefs are well known, surprisingly, no statistical relationships have ever been established between water quality parameters, coral biodiversity and coral cover. Hong Kong provides a unique opportunity to assess this relationship. Here, coastal waters have been monitored monthly since 1986, at 76 stations, providing a highly spatially resolved water quality dataset including 68 903 data points. Moreover, a robust coral species richness (S) dataset is available from more than 100 surveyed locations, composed of 3453 individual colonies' observations, as well as a coral cover (CC) dataset including 85 sites. This wealth of data provides a unique opportunity to test the hypothesis that water quality, and in particular nutrients, drives coral biodiversity. The influence of water quality on S and CC was analyzed using GIS and multiple regression modeling. Eutrophication (as chlorophyll-a concentration; CHLA) was negatively correlated with S and CC, whereas physicochemical parameters (DO and salinity) had no significant effect. The modeling further illustrated that particulate suspended matter, dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) had a negative effect on S and on CC; however, the effect of nutrients was 1.5-fold to twofold greater. The highest S and CC occurred where CHLA <2 µg L-1 , DIN < 2 µm and DIP < 0.1 µm. Where these values were exceeded, S and CC were significantly lower and no live corals were observed where CHLA > 15 µg L-1 , DIN > 9 µm and DIP > 0.33 µm. This study demonstrates the importance of nutrients over other water quality parameters in coral biodiversity loss and highlights the key role of eutrophication in shaping coastal coral reef ecosystems. This work also provides ecological thresholds that may be useful for water quality guidelines and nutrient mitigation policies.


Assuntos
Antozoários , Biodiversidade , Animais , Recifes de Corais , Eutrofização , Humanos , Urbanização
13.
Noise Health ; 18(81): 62-77, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26960783

RESUMO

The measurement of noise exposure from communication headsets poses a methodological challenge. Although several standards describe methods for general noise measurements in occupational settings, these are not directly applicable to noise assessments under communication headsets. For measurements under occluded ears, specialized methods have been specified by the International Standards Organization (ISO 11904) such as the microphone in a real ear and manikin techniques. Simpler methods have also been proposed in some national standards such as the use of general purpose artificial ears and simulators in conjunction with single number corrections to convert measurements to the equivalent diffuse field. However, little is known about the measurement agreement between these various methods and the acoustic manikin technique. Twelve experts positioned circum-aural, supra-aural and insert communication headsets on four different measurement setups (Type 1, Type 2, Type 3.3 artificial ears, and acoustic manikin). Fit-refit measurements of four audio communication signals were taken under quiet laboratory conditions. Data were transformed into equivalent diffuse-field sound levels using third-octave procedures. Results indicate that the Type 1 artificial ear is not suited for the measurement of sound exposure under communication headsets, while Type 2 and Type 3.3 artificial ears are in good agreement with the acoustic manikin technique. Single number corrections were found to introduce a large measurement uncertainty, making the use of the third-octave transformation preferable.


Assuntos
Estimulação Acústica , Perda Auditiva Provocada por Ruído , Ruído Ocupacional , Ruído , Exposição Ocupacional/análise , Local de Trabalho/normas , Estimulação Acústica/instrumentação , Estimulação Acústica/métodos , Adulto , Limiar Auditivo , Comunicação , Pesquisa Comparativa da Efetividade , Desenho de Equipamento , Feminino , Perda Auditiva Provocada por Ruído/etiologia , Perda Auditiva Provocada por Ruído/prevenção & controle , Humanos , Masculino , Manequins , Pessoa de Meia-Idade , Ruído/efeitos adversos , Ruído/prevenção & controle , Ruído Ocupacional/efeitos adversos , Ruído Ocupacional/prevenção & controle , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/prevenção & controle , Espectrografia do Som/métodos
14.
Sci Total Environ ; 951: 175210, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39098414

RESUMO

Elevated sea surface temperatures are causing an increase in coral bleaching events worldwide, and represent an existential threat to coral reefs. Early studies of Mesophotic Coral Ecosystems (MCEs) highlighted their potential as thermal refuges for shallow-water coral species in the face of predicted 21st century warming. However, recent genetic evidence implies that limited ecological connectivity between shallow- and deep-water coral communities inhibits their effectiveness as refugia; instead MCEs host distinct endemic communities that are ecologically significant in and of themselves. In either scenario, understanding the response of MCEs to climate change is critical given their ecological significance and widespread global distribution. Such an understanding has so far eluded the community, however, because of the challenges associated with long-term field monitoring, the stochastic nature of climatic events that drive bleaching, and the paucity of deep-water observations. Here we document the first observed cold-water bleaching of a mesophotic coral reef at Clipperton Atoll, a remote Eastern Tropical Pacific (ETP) atoll with high coral cover and a well-developed MCE. The severe bleaching (>70 % partially or fully bleached coral cover at 32 m depth) was driven by an anomalously shallow thermocline, and highlights a significant and previously unreported challenge for MCEs. Prompted by these observations, we compiled published cold-water bleaching events for the ETP, and demonstrate that the timing of past cold-water bleaching events in the ETP coincides with decadal oscillations in mean zonal wind strength and thermocline depth. The latter observation suggests any future intensification of easterly winds in the Pacific could be a significant concern for its MCEs. Our observations, in combination with recent reports of warm-water bleaching of Red Sea and Indian Ocean MCEs, highlight that 21st century MCEs in the Eastern Pacific face a two-pronged challenge: warm-water bleaching from above, and cold-water bleaching from below.


Assuntos
Antozoários , Mudança Climática , Temperatura Baixa , Recifes de Corais , Antozoários/fisiologia , Animais , Branqueamento de Corais , Monitoramento Ambiental , Ecossistema
15.
Open Biol ; 14(7): 240140, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39079673

RESUMO

In the central nervous system of vertebrates, glutamate serves as the primary excitatory neurotransmitter. However, in the retina, glutamate released from photoreceptors causes hyperpolarization in post-synaptic ON-bipolar cells through a glutamate-gated chloride current, which seems paradoxical. Our research reveals that this current is modulated by two excitatory glutamate transporters, EAAT5b and EAAT7. In the zebrafish retina, these transporters are located at the dendritic tips of ON-bipolar cells and interact with all four types of cone photoreceptors. The absence of these transporters leads to a decrease in ON-bipolar cell responses, with eaat5b mutants being less severely affected than eaat5b/eaat7 double mutants, which also exhibit altered response kinetics. Biophysical investigations establish that EAAT7 is an active glutamate transporter with a predominant anion conductance. Our study is the first to demonstrate the direct involvement of post-synaptic glutamate transporters in inhibitory direct synaptic transmission at a central nervous system synapse.


Assuntos
Sistema X-AG de Transporte de Aminoácidos , Retina , Transmissão Sináptica , Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Retina/metabolismo , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Sistema X-AG de Transporte de Aminoácidos/genética , Proteínas de Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Ácido Glutâmico/metabolismo , Mutação , Células Bipolares da Retina/metabolismo
16.
Neurology ; 103(1): e209496, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38870464

RESUMO

BACKGROUND AND OBJECTIVES: Prolonged compound muscle action potential (CMAP) duration and preferential loss of myosin are considered the diagnostic hallmarks of critical illness myopathy (CIM); however, their correlation and prognostic values have not been studied. We aimed to investigate the correlation between CMAP duration and myosin loss and their effect on mortality by comparing between patients with CIM with and without myosin loss. METHODS: We searched the Mayo Clinic Electromyography Laboratory databases (1986-2021) for patients diagnosed with CIM on the basis of prolonged distal CMAP durations (>15 msec in fibular motor nerve studies recording over the tibialis anterior or >8 msec in other motor nerves) and needle EMG findings compatible with myopathy. Electrodiagnostic studies were generally performed within 24 hours after weakness became noticeable. We included only patients who underwent muscle biopsy. Clinical, electrophysiologic, and myopathologic data were reviewed. We conducted myosin/actin ratio analysis when muscle tissue was available. We used the Fisher exact test for categorical data comparisons and the Mann-Whitney 2-tailed test for continuous data. We applied the Kaplan-Meier technique to analyze survival rates. RESULTS: Twenty patients (13 female patients) were identified [median age at diagnosis of 62.5 years (range: 19-80 years)]. The median onset of weakness was 24 days (range: 1-128) from the first day of intensive care unit admission. Muscle biopsy showed myosin loss in 14 patients, 9 of whom had >50% of myofibers affected (high grade). Type 2 fiber atrophy was observed in 19 patients, 13 of whom also had myosin loss. Patients with myosin loss had higher frequency of steroid exposure (14 vs 3; p = 0.004); higher median number of necrotic fibers per low-power field (2.5 vs 1, p = 0.04); and longer median CMAP duration (msec) of fibular (13.4 vs 8.75, p = 0.02), tibial (10 vs 7.8, p = 0.01), and ulnar (11.1 vs 7.95, p = 0.002) nerves compared with those without. Only patients with high-grade myosin loss had reduced myosin/actin ratios (<1.7). Ten patients died during median follow-up of 3 months. The mortality rate was similar between patients with and without myosin loss. Patients with high-grade myosin loss had a lower overall survival rate than those with low-grade or no myosin loss, but this was not statistically significant (p = 0.05). DISCUSSION: Myosin loss occurred in 70% of the patients with CIM with prolonged CMAP duration. Longer CMAP duration predicts myosin-loss pathology. The extent of myosin loss marginally correlates with the mortality rate. Our findings highlight the potential prognostic values of CMAP duration and myosin loss severity in predicting disease outcome.


Assuntos
Potenciais de Ação , Estado Terminal , Eletromiografia , Músculo Esquelético , Doenças Musculares , Miosinas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Potenciais de Ação/fisiologia , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Doenças Musculares/patologia , Doenças Musculares/fisiopatologia , Doenças Musculares/metabolismo , Miosinas/metabolismo , Prognóstico , Estudos Retrospectivos , Adulto Jovem
17.
Mar Pollut Bull ; 197: 115757, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37988964

RESUMO

Most anthropogenic nitrogen (N) reaches coastal waters via rivers carrying increasing loads of sewage, fertilizer, and sediments. To understand anthropogenic N impacts, we need to understand historical N-dynamics before human influence. Stable isotope ratios of N preserved in carbonates are one way to create temporal N records. However, records that span periods of human occupation are scarce, limiting our ability to contextualize modern N dynamics. Here, we produce a fossil-bound N-record using coral subfossils, spanning 6700 years in China's Greater Bay Area (GBA). We found that during the mid-to-late Holocene, the GBA's coastal N was dominated by fluvial sources. The weakening of the Asia monsoon throughout the late-Holocene decreased river outflow, leading to a relative increase of marine nitrate. This source shift from riverine-to-ocean dominance was overprinted by anthropogenic N. During the late 1980s to early 1990s, human development and associated effluent inundated the coastal system, contributing to the decline of coral communities.


Assuntos
Antozoários , Nitrogênio , Animais , Humanos , Nitrogênio/análise , Monitoramento Ambiental , Isótopos , Carbonatos , Rios , China , Isótopos de Nitrogênio/análise
18.
Ann Clin Transl Neurol ; 10(4): 632-643, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36861178

RESUMO

OBJECTIVES: Mutations in VCP, HNRNPA2B1, HNRNPA1, and SQSTM1, encoding RNA-binding proteins or proteins in quality-control pathways, cause multisystem proteinopathies (MSP). They share pathological findings of protein aggregation and clinical combinations of inclusion body myopathy (IBM), neurodegeneration [motor neuron disorder (MND)/frontotemporal dementia (FTD)], and Paget disease of bone (PDB). Subsequently, additional genes were linked to similar but not full clinical-pathological spectrum (MSP-like disorders). We aimed to define the phenotypic-genotypic spectrum of MSP and MSP-like disorders at our institution, including long-term follow-up features. METHODS: We searched the Mayo Clinic database (January 2010-June 2022) to identify patients with mutations in MSP and MSP-like disorders causative genes. Medical records were reviewed. RESULTS: Thirty-one individuals (27 families) had pathogenic mutations in: VCP (n = 17), SQSTM1 + TIA1 (n = 5), TIA1 (n = 5), MATR3, HNRNPA1, HSPB8, and TFG (n = 1, each). Myopathy occurred in all but 2 VCP-MSP patients with disease onset at age 52 (median). Weakness pattern was limb-girdle in 12/15 VCP-MSP and HSPB8 patient, and distal-predominant in other MSP and MSP-like disorders. Twenty/24 muscle biopsies showed rimmed vacuolar myopathy. MND and FTD occurred in 5 (4 VCP, 1 TFG) and 4 (3 VCP, 1 SQSTM1 + TIA1) patients, respectively. PDB manifested in 4 VCP-MSP. Diastolic dysfunction occurred in 2 VCP-MSP. After 11.5 years (median) from symptom onset, 15 patients ambulated without gait-aids; loss of ambulation (n = 5) and death (n = 3) were recorded only in VCP-MSP. INTERPRETATION: VCP-MSP was the most common disorder; rimmed vacuolar myopathy was the most frequent manifestation; distal-predominant weakness occurred frequently in non-VCP-MSP; and cardiac involvement was observed only in VCP-MSP.


Assuntos
Demência Frontotemporal , Doenças Musculares , Humanos , Pessoa de Meia-Idade , Demência Frontotemporal/genética , Proteína com Valosina/genética , Proteína Sequestossoma-1/genética , Doenças Musculares/genética , Proteínas de Ligação a RNA , Proteínas Associadas à Matriz Nuclear
19.
Commun Biol ; 6(1): 373, 2023 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-37029186

RESUMO

Nitrogen isotopes are widely used to study the trophic position of animals in modern food webs; however, their application in the fossil record is severely limited by degradation of organic material during fossilization. In this study, we show that the nitrogen isotope composition of organic matter preserved in mammalian tooth enamel (δ15Nenamel) records diet and trophic position. The δ15Nenamel of modern African mammals shows a 3.7‰ increase between herbivores and carnivores as expected from trophic enrichment, and there is a strong positive correlation between δ15Nenamel and δ15Nbone-collagen values from the same individuals. Additionally, δ15Nenamel values of Late Pleistocene fossil teeth preserve diet and trophic level information, despite complete diagenetic loss of collagen in the same specimens. We demonstrate that δ15Nenamel represents a powerful geochemical proxy for diet that is applicable to fossils and can help delineate major dietary transitions in ancient vertebrate lineages.


Assuntos
Cadeia Alimentar , Mamíferos , Animais , Isótopos de Nitrogênio/análise , Isótopos de Carbono/análise , Colágeno/química , Esmalte Dentário/química , Esmalte Dentário/metabolismo
20.
Therap Adv Gastroenterol ; 16: 17562848231156285, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36910163

RESUMO

Background: Patients with inflammatory bowel disease (IBD) are at an increased risk of developing Clostridioides difficile infection (CDI). Treatment of CDI in patients with IBD is challenging due to higher failure rates and concomitant IBD activity. Objectives: We performed a multicentre cohort study in patients with IBD who received fecal microbiota transplantation (FMT) for recurrent CDI (rCDI), to further investigate factors that influence the clinical outcome and course of both rCDI and IBD. Design: This is a multicentre cohort study conducted in five European FMT centres. Methods: Adult IBD patients treated with FMT for rCDI were studied. Cure was defined as clinical resolution of diarrhoea or diarrhoea with a negative C. difficile test. The definition of an IBD flare was record based. Long-term follow-up data were collected including new episodes of CDI, IBD flares, infections, hospital admissions, and death. Results: In total, 113 IBD patients underwent FMT because of rCDI. Mean age of the patients was 48 years; 64% had ulcerative colitis. Concomitant rCDI was associated with an IBD flare in 54%, of whom 63% had received IBD remission-induction therapy prior to FMT. All FMT procedures were preceded by vancomycin treatment, 40% of patients received FMT via colonoscopy. CDI cure rate was 71%. Long-term follow-up data were available in 90 patients with a median follow-up of 784 days (402-1251). IBD activity decreased in 39% of patients who had active IBD at baseline, whereas an IBD flare occurred in only 5%. During follow-up of up to 2 years, 27% of the patients had infections, 39% were hospitalized, 5% underwent colectomy, and 10% died (median age of these latter patients: 72 years). Conclusion: FMT for rCDI in IBD patients is safe and effective, and IBD exacerbation after FMT is infrequent. Further studies should investigate the effects on IBD course following FMT.

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