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2.
PeerJ ; 12: e17189, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38699189

RESUMO

Quantifying the diet of endangered species is crucial for conservation, especially for diet specialists, which can be more susceptible to environmental changes. The vulnerable fairy pitta (Pitta nympha) is considered a specialist that primarily feeds its nestlings with earthworms. However, there have been few studies of the nestling diet provisioned by parents, and no assessments of earthworm proportion in the diet of adults. Our study aimed to fill these gaps, shedding light on crucial factors for conservation. Combining new observations with existing literature, we confirmed a consistent dominance of earthworms in the nestling diet, regardless of rainfall, nestling age, and time of day. We extrapolated the total earthworm consumption during a breeding event, accounting for potential variation in the availability of earthworms and their prevalence in the adult diet. We used literature-based earthworm densities in pitta habitats and our estimates of family earthworm consumption to calculate the habitat area that could provide a pitta family with the number of earthworms consumed during a breeding event. The predictions matched observed pitta home range sizes when assumed that the adult diet is comprised of approximately 70% earthworms. The results highlight the importance of earthworm-rich habitats for conservation planning of the fairy pitta. To mitigate the effects of habitat destruction, we discuss conservation practices that may involve enhancing earthworm abundance in natural habitats and providing vegetation cover for foraging pittas in adjacent anthropogenic habitats rich in earthworms. To guide conservation efforts effectively, future studies should investigate whether previously reported breeding in developed plantation habitats is due to high earthworm abundance there. Future studies should also quantify correlations between local earthworm densities, home range size, and the breeding success of the fairy pitta.


Assuntos
Conservação dos Recursos Naturais , Dieta , Espécies em Perigo de Extinção , Oligoquetos , Animais , Oligoquetos/fisiologia , Dieta/veterinária , Ecossistema , Comportamento Alimentar/fisiologia
3.
Biosens Bioelectron ; 252: 116145, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38412685

RESUMO

Coronaviruses are single-stranded RNA viruses with high mutation rates. Although a diagnostic method for coronaviruses has been developed, variants appear rapidly. Low test accuracy owing to single-point mutations is one of the main factors in the failure to prevent the early spread of coronavirus infection. Although reverse transcription-quantitative polymerase chain reaction can detect coronavirus infection, it cannot exclude the possibility of false positives, and an additional multiplexing kit is needed to discriminate single nucleotide polymorphism (SNP) variants. Therefore, in this study, we introduced a new nucleic acid amplification method to determine whether an infected person has a SNP mutation using a lateral flow assay (LFA) as a point-of-care test. Unlike traditional DNA amplification methods, direct insertion into rolling circle amplification amplifies the target genes without false amplification. After SNP-selective nucleic acid amplification, nuclease enzymes are used to make double-stranded DNA fragments that the LFA can detect, where specific mismatched DNA is found and cleaved to show different signals when a SNP-type is present. Therefore, wild- and SNP-type variants can be selectively detected. In this study, the limit of detection was 400 aM for viral RNA, and we successfully identified a dominant SNP variant selectively. Clinical tests were also conducted.


Assuntos
Técnicas Biossensoriais , Infecções por Coronavirus , Humanos , RNA Viral/genética , DNA , Mutação , Técnicas de Amplificação de Ácido Nucleico/métodos
4.
Sci Rep ; 13(1): 20287, 2023 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-37985886

RESUMO

The interspecific responses to alarm signals may be based on unlearned mechanisms but research is often constrained by the difficulties in differentiating between unlearned and learned responses in natural situations. In a field study of two Paridae species, Parus minor and Sittiparus varius, who originated from a common ancestor 8 million years ago, we found a considerable degree of between-species overlap in acoustic properties of referential snake-alarm calls. Playback of these calls triggered unlearned adaptive fledging behavior in conspecific and heterospecific naive nestlings, suggesting a between-species overlap in the hypothetical unlearned neural templates involved in nestlings' reactions to alarm calls in both species. This suggests that similar calls and similar unlearned sensitivity might have been present in the common ancestor of the two species, and possibly in the ancestor of the whole family Paridae that originated 10-15 million years ago in Asian regions rich in snakes.


Assuntos
Passeriformes , Vocalização Animal , Animais , Vocalização Animal/fisiologia , Aprendizagem , Evolução Biológica , Acústica , Serpentes
5.
ACS Synth Biol ; 12(12): 3506-3513, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37948662

RESUMO

There is a growing need for applications capable of handling large synthesis biology experiments. At the core of synthetic biology is the process of cloning and manipulating DNA as plasmids. Here, we report the development of an application named DNAda capable of writing automation instructions for any given DNA construct design generated by the J5 DNA assembly program. We also describe the automation pipeline and several useful features. The pipeline is particularly useful for the construction of combinatorial DNA assemblies. Furthermore, we demonstrate the platform by constructing a library of polyketide synthase parts, which includes 120 plasmids ranging in size from 7 to 14 kb from 4 to 7 DNA fragments.


Assuntos
DNA , Biologia Sintética , Plasmídeos/genética , DNA/genética , Biblioteca Gênica , Automação , Clonagem Molecular
6.
Vaccines (Basel) ; 11(8)2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37631890

RESUMO

Bivalent COVID-19 vaccines that contain BA.1 or BA.4/BA.5 have been introduced worldwide in response to pandemic waves of Omicron subvariants. This prospective cohort study was aimed to compare neutralizing antibodies (Nabs) against Omicron subvariants (BA.1, BA.5, BQ.1.1, BN.1, and XBB.1) before and 3-4 weeks after bivalent booster by the types of SARS-CoV-2 variants in prior infections and bivalent vaccine formulations. A total of 21 participants were included. Prior BA.1/BA.2-infected, and BA.5-infected participants showed significantly higher geometric mean titers of Nab compared to SARS-CoV-2-non-infected participants after bivalent booster (BA.1, 8156 vs. 4861 vs. 1636; BA.5, 6515 vs. 4861 vs. 915; BQ.1.1, 697 vs. 628 vs. 115; BN.1, 1402 vs. 1289 vs. 490; XBB.1, 434 vs. 355 vs. 144). When compared by bivalent vaccine formulations, Nab titers against studied subvariants after bivalent booster did not differ between BA.1 and BA.4/BA.5 bivalent vaccine (BA.1, 4886 vs. 5285; BA.5, 3320 vs. 4118; BQ.1.1, 311 vs. 572; BN.1, 1028 vs. 1095; XBB.1, 262 vs. 362). Both BA.1 and BA.4/BA.5 bivalent vaccines are immunogenic and provide enhanced neutralizing activities against Omicron subvariants. However, even after the bivalent booster, neutralizing activities against the later Omicron strains (BQ.1.1, BN.1, and XBB.1) would be insufficient to provide protection.

7.
Proc Natl Acad Sci U S A ; 120(30): e2219972120, 2023 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-37463206

RESUMO

Current theory for surface tension-dominant jumps on water, created for small- and medium-sized water strider species and used in bioinspired engineering, predicts that jumping individuals are able to match their downward leg movement speed to their size and morphology such that they maximize the takeoff speed and minimize the takeoff delay without breaking the water surface. Here, we use empirical observations and theoretical modeling to show that large species (heavier than ~80 mg) could theoretically perform the surface-dominated jumps according to the existing model, but they do not conform to its predictions, and switch to using surface-breaking jumps in order to achieve jumping performance sufficient for evading attacks from underwater predators. This illustrates how natural selection for avoiding predators may break the theoretical scaling relationship between prey size and its jumping performance within one physical mechanism, leading to an evolutionary shift to another mechanism that provides protection from attacking predators. Hence, the results are consistent with a general idea: Natural selection for the maintenance of adaptive function of a specific behavior performed within environmental physical constraints leads to size-specific shift to behaviors that use a new physical mechanism that secure the adaptive function.


Assuntos
Movimento , Água , Humanos , Tamanho Corporal , Tensão Superficial , Fenômenos Biomecânicos , Locomoção
8.
J Periodontal Implant Sci ; 53(4): 306-317, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37524378

RESUMO

PURPOSE: Biphasic calcium phosphate (BCP), a widely used biomaterial for bone regeneration, contains synthetic hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP), the ratio of which can be adjusted to modulate the rate of degradation. The aim of this study was to evaluate the clinical and radiographic benefits of reconstructing peri-implant bone defects with a newly developed BCP consisting of 40% ß-TCP and 60% HA compared to demineralized bovine bone mineral (DBBM). METHODS: This prospective, multicenter, parallel, single-blind randomized controlled trial was conducted at the periodontology departments of 3 different dental hospitals. Changes in clinical (defect width and height) and radiographic (augmented horizontal bone thickness) parameters were measured between implant surgery with guided bone regeneration (GBR) and re-entry surgery. Postoperative discomfort (severity and duration of pain and swelling) and early soft-tissue wound healing (dehiscence and inflammation) were also assessed. Data were compared between the BCP (test) and DBBM (control) groups using the independent t-test and the χ² test. RESULTS: Of the 53 cases included, 27 were in the test group and 26 were in the control group. After a healing period of 18 weeks, the full and mean resolution of buccal dehiscence defects were 59.3% (n=16) and 71.3% in the test group and 42.3% (n=11) and 57.9% in the control group, respectively. There were no significant differences between the groups in terms of the change in mean horizontal bone augmentation (test group: -0.50±0.66 mm vs. control groups: -0.66±0.83 mm, P=0.133), postoperative discomfort, or early wound healing. No adverse or fatal complications occurred in either group. CONCLUSION: The GBR procedure with the newly developed BCP showed favorable clinical, radiographic, postoperative discomfort-related, and early wound healing outcomes for peri-implant dehiscence defects that were similar to those for DBBM. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0006428.

9.
Microb Ecol ; 85(2): 429-440, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35094098

RESUMO

Eggshell bacterial communities may affect hatching success and nestling's condition. Nest materials are in direct contact with the eggshells, but the relationships with the eggshell microbiome during incubation have not been fully elucidated. Here, we characterize eggshell and nest material bacterial communities and their changes during incubation in the Oriental Tit (Parus minor). Bacterial communities on the nest material were relatively stable and remained distinct from the eggshell communities and had higher diversity and greater phylogenetic clustering than the eggshell communities from the same nest, resulting in lower phylogenetic turnover rate of nest material microbiome during incubation than expected by chance. While the species diversity of both communities did not change during incubation, we found significantly greater changes in the structure of bacterial communities on the eggshell than on the nest material. However, eggshell microbiome remained distinct from nest material microbiome, suggesting independent dynamics of the two microbiomes during incubation. We detected an increase in the relative abundance of several bacterial taxa on the eggshell that likely come from the bird's skin, feathers, cloaca/intestine, or uropygial secretion which suggests some exchange of bacteria between the incubating bird and the eggshell. Furthermore, incubation appeared to promote the abundance of antibiotic producing taxa on the eggshell, which may hypothetically inhibit growth of many bacteria including pathogenic ones. Our results suggest that the future studies should focus on simultaneous monitoring of absolute abundance as well as relative abundance in communities on eggshells, nest materials, and the incubating bird's body.


Assuntos
Bactérias , Casca de Ovo , Animais , Casca de Ovo/microbiologia , Filogenia , Aves/microbiologia , Pele
10.
Acta Crystallogr D Struct Biol ; 78(Pt 9): 1171-1179, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36048156

RESUMO

Ketosynthases (KSs) catalyse essential carbon-carbon bond-forming reactions in fatty-acid biosynthesis using a two-step, ping-pong reaction mechanism. In Escherichia coli, there are two homodimeric elongating KSs, FabB and FabF, which possess overlapping substrate selectivity. However, FabB is essential for the biosynthesis of the unsaturated fatty acids (UFAs) required for cell survival in the absence of exogenous UFAs. Additionally, FabB has reduced activity towards substrates longer than 12 C atoms, whereas FabF efficiently catalyses the elongation of saturated C14 and unsaturated C16:1 acyl-acyl carrier protein (ACP) complexes. In this study, two cross-linked crystal structures of FabB in complex with ACPs functionalized with long-chain fatty-acid cross-linking probes that approximate catalytic steps were solved. Both homodimeric structures possess asymmetric substrate-binding pockets suggestive of cooperative relationships between the two FabB monomers when engaged with C14 and C16 acyl chains. In addition, these structures capture an unusual rotamer of the active-site gating residue, Phe392, which is potentially representative of the catalytic state prior to substrate release. These structures demonstrate the utility of mechanism-based cross-linking methods to capture and elucidate conformational transitions accompanying KS-mediated catalysis at near-atomic resolution.


Assuntos
3-Oxoacil-(Proteína de Transporte de Acila) Sintase , Proteínas de Escherichia coli , 3-Oxoacil-(Proteína de Transporte de Acila) Sintase/química , 3-Oxoacil-(Proteína de Transporte de Acila) Sintase/metabolismo , Carbono/metabolismo , Catálise , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Ácido Graxo Sintase Tipo II , Ácidos Graxos Insaturados/metabolismo
11.
Diagnostics (Basel) ; 12(8)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36010344

RESUMO

The complex and lengthy protocol of current viral nucleic acid extraction processes limits their use outside laboratory settings. Here, we describe a rapid and reliable method for extracting nucleic acids from viral samples using a rotating blade and magnetic beads. The viral membrane can be instantly lysed using a high-speed rotating blade, and nucleic acids can be immediately isolated using a silica magnetic surface. The process was completed within 60 s by this method. Routine washing and eluting processes were subsequently conducted within 5 min. The results achieved by this method were comparable to those of a commercially available method. When the blade-based lysis and magnetic bead adsorption processes were performed separately, the RNA recovery rate was very low, and the Ct value was delayed compared to simultaneous lysis and RNA adsorption. Overall, this method not only dramatically shortens the conventional extraction time but also allows for its convenient use outside the laboratory, such as at remote field sites and for point-of-care testing.

12.
Appl Ergon ; 104: 103819, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35687993

RESUMO

Despite the lack of haptic feedback, two-finger typing remains as a common freehand mid-air text entry method in VR. To compensate for this limitation, we investigated the effect of pseudo-haptics and thumb-to-finger pinch self-haptics. Three types of virtual keyboards were developed for comparison: a normal virtual keyboard without any haptic features, a pseudo-haptic keyboard providing a haptic illusion by adding pseudo-haptic features to the normal virtual keyboard, and a pinch keyboard providing passive self-haptic feedback when the index finger touches the thumb to type bubble-shaped keys. A follow-up user study was conducted on the three keyboards to measure typing performance, perceived workload, and user experience. The results showed that the pseudo-haptic and pinch keyboards were comparable to the normal one in typing performance and workload, but beneficial in user experience and preference. The findings suggest that pseudo-haptics and self-haptics could achieve experiential benefits in VR text entry without obtrusive extra devices.


Assuntos
Tecnologia Háptica , Percepção do Tato , Retroalimentação , Dedos , Humanos , Tato , Interface Usuário-Computador
13.
RSC Chem Biol ; 3(3): 312-319, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35359491

RESUMO

Nonribosomal peptide synthetases (NRPSs) are complex multi-modular enzymes containing catalytic domains responsible for the loading and incorporation of amino acids into natural products. These unique molecular factories can produce peptides with nonproteinogenic d-amino acids in which the epimerization (E) domain catalyzes the conversion of l-amino acids to d-amino acids, but its mechanism remains not fully understood. Here, we describe the development of pantetheine crosslinking probes that mimic the natural substrate l-Phe of the initiation module of tyrocidine synthetase, TycA, to elucidate and study the catalytic residues of the E domain. Mechanism-based crosslinking assays and MALDI-TOF MS were used to identify both H743 and E882 as the crosslinking site residues, demonstrating their roles as catalytic bases. Mutagenesis studies further validated these results and allowed the comparison of reactivity between the catalytic residues, concluding that glutamate acts as the dominant nucleophile in the crosslinking reaction, resembling the deprotonation of the Cα-H of amino acids in the epimerization reaction. The crosslinking probes employed in these studies provide new tools for studying the molecular details of E domains, as well as the potential to study C domains. In particular, they would elucidate key information for how these domains function and interact with their substrates in nature, further enhancing the knowledge needed to assist combinatorial biosynthetic efforts of NRPS systems to produce novel compounds.

14.
J Clin Med ; 10(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34362150

RESUMO

Social distancing is an effective measure to mitigate the spread of novel viral infections in the absence of antiviral agents and insufficient vaccine supplies. Subway utilization density may reflect social activity and the degree of social distancing in the general population.; This study aimed to evaluate the correlations between subway use density and the activity of the influenza epidemic or coronavirus disease 2019 (COVID-19) pandemic using a time-series regression method. The subway use-based social distancing score (S-SDS) was calculated using the weekly ridership of 11 major subway stations. The temporal association of S-SDS with influenza-like illness (ILI) rates or the COVID-19 pandemic activity was analyzed using structural vector autoregressive modeling and the Granger causality (GC) test. During three influenza seasons (2017-2020), the time-series regression presented a significant causality from S-SDS to ILI (p = 0.0484). During the COVID-19 pandemic in January 2020, S-SDS had been suppressed at a level similar to or below the average of the previous four years. In contrast to the ILI rate, there was a negative correlation between COVID-19 activity and S-SDS. GC analysis revealed a negative causal relationship between COVID-19 and S-SDS (p = 0.0098).; S-SDS showed a significant time-series association with the ILI rate but not with COVID-19 activity. When public transportation use is sufficiently suppressed, additional social mobility restrictions are unlikely to significantly affect COVID-19 pandemic activity. It would be more important to strengthen universal mask-wearing and detailed public health measures focused on risk activities, particularly in enclosed spaces.

15.
J Clin Med ; 10(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34441840

RESUMO

Although some intravenous drugs have been used to treat coronavirus disease 2019 (COVID-19), no effective antiviral agents are currently available in the outpatient setting. We aimed to evaluate the efficacy and adverse events of 14-day ciclesonide treatment vs. standard care for patients with mild-to-moderate COVID-19. A randomized, open-label, multicenter clinical trial of ciclesonide inhalers was conducted in patients with mild-to-moderate COVID-19. Patients were enrolled within 3 days of diagnosis or within 7 days from symptom onset and randomly assigned to receive either ciclesonide (320 µg inhalation twice per day for 14 days) or standard care. The primary endpoint was the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) eradication rate on day 14 from study enrollment. Clinical status was assessed once daily, and serial nasopharyngeal viral load was evaluated by quantitative reverse transcription polymerase chain reaction. There were 35 and 26 patients in the ciclesonide and standard care groups, respectively. The SARS-CoV-2 eradication rate at day 14 was significantly higher in the ciclesonide group (p = 0.021). In multivariate analysis, SARS-CoV-2 negative conversion within 14 days was 12 times more likely in the ciclesonide group (95% confidence interval, 1.187-125.240). Additionally, the clinical failure rate (high-flow nasal oxygen therapy or mechanical ventilation) was significantly lower in the ciclesonide group (p = 0.034). In conclusion, ciclesonide inhalation shortened SARS-CoV-2 viral shedding duration, and it may inhibit the progression to acute respiratory failure in patients with mild-to-moderate COVID-19. Clinical Trial Registration NCT04330586.

16.
Vaccines (Basel) ; 9(6)2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34064299

RESUMO

Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of neonatal sepsis and meningitis in infants. Limitations of prenatal GBS screening and intrapartum antibiotic prophylaxis render developing GBS vaccines a high priority. In this study, we developed an enzyme-linked immunosorbent assay (ELISA) for the practical and large-scale evaluation of GBS capsular polysaccharide (PS) vaccine immunogenicity against three main serotypes, Ia, III, and V. GBS-ELISA was developed and subsequently validated using a standardized curve-fitting four-parameter logistic method. Specificity was measured using adsorption of serum with homologous and heterologous PS. Homologous adsorption showed a ≥75% inhibition of all three serotypes, whereas with heterologous PS, IgG GBS-ELISA inhibited only ≤25% of serotypes III and V. However, with serotype Ia, IgG antibody levels decreased by >50%, even after adsorption with heterologous PS (III or V). In comparison, the inhibition opsonophagocytic killing assay (OPA) of serotypes Ia GBS exhibited a reduction in opsonophagocytic activity of only 20% and 1.1% for serotypes III and V GBS, respectively. The precision of the GBS-ELISA was assessed in five independent experiments using four serum samples. The coefficient of variation was <5% for all three serotypes. This standardized GBS-ELISA would be useful for GBS vaccine development and its evaluation.

17.
ACS Chem Biol ; 16(5): 813-819, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-33955744

RESUMO

While thousands of environmental metagenomes have been mined for the presence of novel biosynthetic gene clusters, such computational predictions do not provide evidence of their in vivo biosynthetic functionality. Using fluorescent in situ enzyme assay targeting carrier proteins common to polyketide (PKS) and nonribosomal peptide synthetases (NRPS), we applied fluorescence-activated cell sorting to tunicate microbiome to enrich for microbes with active secondary metabolic capabilities. Single-cell genomics uncovered the genetic basis for a wide biosynthetic diversity in the enzyme-active cells and revealed a member of marine Oceanospirillales harboring a novel NRPS gene cluster with high similarity to phylogenetically distant marine and terrestrial bacteria. Interestingly, this synthase belongs to a larger class of siderophore biosynthetic gene clusters commonly associated with pestilence and disease. This demonstrates activity-guided single-cell genomics as a tool to guide novel biosynthetic discovery.


Assuntos
Genômica/métodos , Microbiota/genética , Família Multigênica/genética , Peptídeo Sintases/metabolismo , Sideróforos/genética , Animais , Bacillus subtilis/genética , Proteínas de Transporte/química , Proteínas de Transporte/genética , Ciona intestinalis/metabolismo , Biologia Computacional , Escherichia coli/genética , Citometria de Fluxo , Filogenia , Policetídeos/química , Metabolismo Secundário , Sideróforos/química , Análise de Célula Única
18.
Epidemiol Health ; 43: e2021002, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33445826

RESUMO

OBJECTIVES: As HIV/AIDS is becoming a chronic disease, the risk of developing cardiovascular disease (CVD) among people living with HIV/AIDS is rising. Anxiety and depression, which are common among people living with HIV/AIDS, have been linked with CVD. This study investigated the risk of CVD in people living with HIV/AIDS and explored the effects of depression and anxiety on CVD risk. METHODS: Data were collected for 457 people enrolled in the Korea Cohort HIV/AIDS study after 2010. Framingham risk scores were calculated to quantify the 10-year risk of developing CVD. Depression and anxiety variables were re-coded as a single combined variable. Multivariable logistic regression analysis was performed, adjusting for age, body mass index, low-density lipoprotein (LDL) cholesterol, triglycerides (TG), duration of human immunodeficiency virus (HIV) positivity after entry into the cohort, and depression/anxiety. RESULTS: Participants with both depression and anxiety were 2.28 times more likely than those with neither depression nor anxiety to have moderate/high-risk CVD risk. The 10-year risk of developing CVD was affected by LDL cholesterol, TG, age, and duration of HIV infection. LDL cholesterol and TG levels change according to the duration of HIV infection, and metabolic disorders affect the risk of CVD. Thus, a longer duration of HIV infection is associated with a higher risk of developing CVD. CONCLUSIONS: Screenings for depression and anxiety need to be provided regularly to assess the severity of those symptoms. To help decrease their risk of developing CVD, people living with HIV/AIDS should be offered behavioral modification interventions aimed at developing healthy lifestyle habits.


Assuntos
Ansiedade/epidemiologia , Doenças Cardiovasculares/psicologia , Depressão/epidemiologia , Infecções por HIV/psicologia , Adulto , Doenças Cardiovasculares/epidemiologia , Estudos de Coortes , Feminino , Infecções por HIV/epidemiologia , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , República da Coreia/epidemiologia , Medição de Risco
19.
ACS Catal ; 11(12): 6787-6799, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-36187225

RESUMO

Ketosynthases (KSs) catalyze carbon-carbon bond forming reactions in fatty acid synthases (FASs) and polyketide synthases (PKSs). KSs utilize a two-step ping pong kinetic mechanism to carry out an overall decarboxylative thio-Claisen condensation that can be separated into the transacylation and condensation reactions. In both steps, an acyl carrier protein (ACP) delivers thioester tethered substrates to the active sites of KSs. Therefore, protein-protein interactions (PPIs) and KS-mediated substrate recognition events are required for catalysis. Recently, crystal structures of Escherichia coli elongating type II FAS KSs, FabF and FabB, in complex with E. coli ACP, AcpP, revealed distinct conformational states of two active site KS loops. These loops were proposed to operate via a gating mechanism to coordinate substrate recognition and delivery followed by catalysis. Here we interrogate this proposed gating mechanism by solving two additional high-resolution structures of substrate engaged AcpP-FabF complexes, one of which provides the missing AcpP-FabF gate-closed conformation. Clearly defined interactions of one of these active site loops with AcpP are present in both the open and closed conformations, suggesting AcpP binding triggers or stabilizes gating transitions, further implicating PPIs in carrier protein-dependent catalysis. We functionally demonstrate the importance of gating in the overall KS condensation reaction and provide experimental evidence for its role in the transacylation reaction. Furthermore, we evaluate the catalytic importance of these loops using alanine scanning mutagenesis and also investigate chimeric FabF constructs carrying elements found in type I PKS KS domains. These findings broaden our understanding of the KS mechanism which advances future engineering efforts in both FASs and evolutionarily related PKSs.

20.
Magn Reson Imaging ; 76: 26-38, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33010377

RESUMO

G Protein-Coupled Receptor Kinase-Interacting Protein-1 (GIT1) regulates neuronal functions, including cell and axon migration and synapse formation and maintenance, and GIT1 knockout (KO) mice exhibit learning and memory deficits. We noted that male and female GIT1-KO mice exhibit neuroimaging phenotypes including microcephaly, and altered cortical layering, with a decrease in neuron density in cortical layer V. Micro-CT and magnetic resonance microscopy (MRM) were used to identify morphometric phenotypes for the skulls and throughout the GIT1-KO brains. High field MRM of actively-stained mouse brains from GIT1-KO and wild type (WT) controls (n = 6 per group) allowed segmenting 37 regions, based on co-registration to the Waxholm Space atlas. Overall brain size in GIT1-KO mice was ~32% smaller compared to WT controls. After correcting for brain size, several regions were significantly different in GIT1-KO mice relative to WT, including the gray matter of the ventral thalamic nuclei and the rest of the thalamus, the inferior colliculus, and pontine nuclei. GIT1-KO mice had reduced volume of white matter tracts, most notably in the anterior commissure (~26% smaller), but also in the cerebral peduncle, fornix, and spinal trigeminal tract. On the other hand, the basal ganglia appeared enlarged in GIT1-KO mice, including the globus pallidus, caudate putamen, and particularly the accumbens - supporting a possible vulnerability to addiction. Volume based morphometry based on high-resolution MRM (21.5 µm isotropic voxels) was effective in detecting overall, and local differences in brain volumes in GIT1-KO mice, including in white matter tracts. The reduced relative volume of specific brain regions suggests a critical, but not uniform, role for GIT1 in brain development, conducive to brain microcephaly, and aberrant connectivity.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Proteínas de Ciclo Celular/deficiência , Proteínas Ativadoras de GTPase/deficiência , Microcefalia/diagnóstico por imagem , Microcefalia/patologia , Neuroimagem , Animais , Encéfalo/metabolismo , Proteínas de Ciclo Celular/genética , Feminino , Proteínas Ativadoras de GTPase/genética , Técnicas de Inativação de Genes , Masculino , Camundongos , Microcefalia/genética , Neurônios/metabolismo , Neurônios/patologia , Microtomografia por Raio-X
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