Biology subjects

Yuen, M.

Publications and source records attributed to Yuen, M..

3 recordsLinked to original sources

bioRxiv2024

Molecular Specification of Claustro-Amygdalar and Paleocortical Neurons and Connectivity

The ventropallial excitatory neurons (ExNs) in the claustro-amygdalar complex and piriform cortex (PIR; part of paleocortex) form crucial reciprocal connections with the prefrontal cortex (PFC), integrating cognitive and sensory information that result in adaptive behaviors. Early-life disruptions in these circuits are linked to neuropsychiatric disorders, highlighting the importance of understanding their development. Our study uncovers that transcription factors SOX4, SOX11, and TFAP2D play a pivotal role in the development, identity, and PFC connectivity of these neurons. Using mouse models, we demonstrate that the absence of transcription factors SOX4 and SOX11 in post-mitotic ExNs dramatically reduces the size of the basolateral amygdala complex (BLC), claustrum, and PIR. SOX4 and SOX11 control BLC formation through direct regulation of Tfap2d expression. Cross-species analyses, including humans, identified conserved Tfap2d expression in developing ExNs of BLC, claustrum, paleocortex including PIR, and the associated transitional areas of the frontal, insular and temporal cortex. While the loss and haploinsufficiency of Tfap2d yield similar alterations in learned threat behaviors, differences emerge in the manifestation of Tfap2d dosage, particularly in terms of changes observed in BLC size and the connectivity pattern between the BLC and PFC. This underscores the significance of Tfap2d dosage in orchestrating developmental shifts in BLC-PFC connectivity and behavioral modifications reminiscent of symptoms of neuropsychiatric disorders. Together, these findings reveal key elements of a conserved gene regulatory network that shapes the development and function of crucial ventropallial ExNs and their PFC connectivity and offer insights into their evolution and alterations in neuropsychiatric disorders.

neuroscience↗

bioRxiv2019

Human Chrysomya bezziana myiasis: A systematic review

BackgroundMyiasis due to Old World screw-worm fly, Chrysomya bezziana, is an important obligate zoonotic disease in the OIE-list of diseases and is found throughout much of Africa, the Indian subcontinent, southeast and east Asia. C. bezziana myiases cause not only morbidity and death to animals and humans, but also economic losses in the livestock industries. Because of the aggressive and destructive nature of this disease in hosts, we initiated this study to provide a comprehensive understanding of human myiasis caused by C. bezziana.\n\nMethodsWe conducted a systematic search of the databases in English (PubMed, Embase and African Index Medicus) and Chinese (CNKI, Wanfang, and Duxiu), and international government online reports to 6th February, 2019, to identify studies concerning Chrysomya bezziana. Another ten human cases in China and Papua New Guinea that our team had recorded were also included.\n\nResultsWe retrieved 1,048 reports from which 202 studies were ultimately eligible for inclusion in the present descriptive analyses. Since the first human case due to C. bezziana was reported in 1909, we have summarized 291 cases and found that these cases often occurred in poor hygiene, low socio-economic conditions, old age, and underlying diseases including infections, age-related diseases, and noninfectious chronic diseases. But C. bezziana myiasis appears largely neglected as a serious medical or veterinary condition, with human and animal cases only reported in 16 and 24 countries respectively, despite this fly species recorded as present in 44 countries worldwide.\n\nConclusionOur findings indicate that cryptic myiasis cases due to the obligate parasite, C. bezziana, are under-recognized. Through this in-depth study to clarify the knowledge of human C. bezziana myiasis including its etiology, clinical features, diagnosis, treatment, epidemiology, prevention and control, we call for more vigilance and awareness of the disease from governments, health authorities, clinicians, veterinary workers, nursing homes, and also the general public.\n\nAuthor summaryChrysomya bezziana larvae are characterized by feeding aggressively on the living tissues and body fluids of the host. The nightmare-like feelings of patients suffering from this myiasis, severe tissues and bones destruction, even death, and enormous economic loss in the livestock industries have been described in the previous reports. But our findings indicate that C. bezziana myiases still appear to be under-recognized as a serious medical or veterinary condition throughout the world. Both in China and the world at large, it is probable that C. bezziana distribution could be greater than currently reported. For the first time, we have therefore systematically investigated human myiasis caused by C. bezziana. Our study provides an opportunity for clinicians and health authorities to gain a better understanding of this disease from its etiology, pathology, clinical features, diagnosis, treatment, epidemiology, prevention and control. In addition, our findings will hopefully engage governments, health staff, veterinary workers, the elderly homes, and also the general public in efforts to recognize, prevent and control such infestations.

epidemiology↗

bioRxiv2017

Genome-Wide Comparison Of Toxigenic And Non-Toxigenic Corynebacterium diphtheriae Isolates Identifies Differences In The Pan Genomes Between Respiratory And Cutaneous Strains

ObjectivesCorynebacterium diphtheriae is the main etiological agent of diphtheria, a global disease causing life-threatening infections, particularly in infants and children. Vaccination with diphtheria toxoid protects against infection with potent toxin producing strains. However a growing number of apparently non-toxigenic but potentially invasive C. diphtheriae strains are identified in countries with low prevalence of diphtheria, raising key questions about genomic structures and population dynamics of the species.\n\nMethodsThis study examined genomic diversity among 47 C. diphtheriae isolates collected in Australia over a 10-year period using whole genome sequencing. Phylogeny was determined using SNP-based mapping and genome wide analysis.\n\nResultsC. diphtheriae sequence type (ST) 32, a non-toxigenic ST with evidence of enhanced virulence that is also circulating in Europe, appears to be endemic in Australia. Isolates from temporospatially related patients displayed the same ST and similarity in their core genomes. The genome-wide analysis highlighted a role of pilins, adhesion factors and iron utilization in infections caused by toxigenic as well as non-toxigenic strains.\n\nConclusionsThe genomic diversity of toxigenic and non-toxigenic strains of C. diphtheriae in Australia suggests multiple local and overseas sources of infection and colonisation. Our findings suggest that regular genomic surveillance of co-circulating toxigenic and non-toxigenic C. diphtheriae can deliver highly nuanced data in order to inform targeted public health actions and policy for predicting the future impact of this highly successful pathogen.

microbiology↗