Evolutionary cell biology: Functional insight from “Endless forms most beautiful”

In animal and fungal model organisms, the complexities of cell biology have been analyzed in exquisite detail and much is known about how these organisms function at the cellular level. However, the model organisms cell biologists generally use include only a tiny fraction of the true diversity of eukaryotic cellular forms. The divergent cellular processes observed in these more distant lineages are still largely unknown in the general scientific community. Despite the relative obscurity of these organisms, comparative studies of them across eukaryotic diversity have had profound implications for our understanding of fundamental cell biology in all species and have revealed the evolution and origins of previously observed cellular processes. In this Perspective, we will discuss the complexity of cell biology found across the eukaryotic tree, and three specific examples of where studies of divergent cell biology have altered our understanding of key functional aspects of mitochondria, plastids, and membrane trafficking

Surgical Treatment of Persistent Fetal Vasculature and Visual Rehabilitation: One-Year Followup

We present the management and postoperative course of a persistent fetal vasculature (PFV) case. A four-year-old girl visited the Eye Department of Hippokration, General Hospital of Thessaloniki due to reduced visual acuity of her left eye. She was diagnosed with PFV and underwent surgery (lensectomy, capsulorhexis of the posterior capsule, insertion of an intraocular lens in the posterior chamber, and posterior vitrectomy) in order to dissect the PFV. Along with the postoperative medical care, she underwent intensive treatment for amblyopia. The postoperative course was uncomplicated, and the visual acuity of her left eye improved from hand movement to 20/25 with proper correction. Patients with unilateral PFV and gradually deteriorating visual acuity could be good candidates for a combined surgical procedure, as the one described above, with a good prognosis

Development and Psychometric Evaluation of the Questionnaire of Ethical Leadership (QueL)

In this five-study paper, we developed and validated the Questionnaire of ethical Leadership (QueL). We examined the factor structure of QueL using Exploratory and Confirmatory Factor Analysis, along with measurement invariance techniques, using data from more than 1,200 leaders and subordinates working in Greece. Exploratory analysis indicated two latent highly-correlated factors that were labeled “Telos” and “Ethos.” Confirmatory analysis verified a bifactor solution. The bifactor QueL showed configural, metric, and scalar invariance across independent samples of leaders and subordinates. QueL was found to be a reliable measure across time and occupational groups (leaders and subordinates). We found criterion correlations in the expected direction with other ethical leadership scales, related constructs (i.e., integrity, trust, ethical climate), as well as workplace attitudes and behaviors (i.e., burnout, organizational commitment, organizational citizenship behaviors, deviant behaviors), leadership characteristics (transformational and transactional leadership, abusive supervision, personality), and socio-demographics (i.e., educational level and gender). We conclude that the new measure is a valuable tool for measuring workplace ethical leadership

A nonmitochondrial hydrogen production in Naegleria gruberi

Naegleria gruberi is a free-living heterotrophic aerobic amoeba well known for its ability to transform from an amoeba to a flagellate form. The genome of N. gruberi has been recently published, and in silico predictions demonstrated that Naegleria has the capacity for both aerobic respiration and anaerobic biochemistry to produce molecular hydrogen in its mitochondria. This finding was considered to have fundamental implications on the evolution of mitochondrial metabolism and of the last eukaryotic common ancestor. However, no actual experimental data have been shown to support this hypothesis. For this reason, we have decided to investigate the anaerobic metabolism of the mitochondrion of N. gruberi. Using in vivo biochemical assays, we have demonstrated that N. gruberi has indeed a functional [FeFe]-hydrogenase, an enzyme that is attributed to anaerobic organisms. Surprisingly, in contrast to the published predictions, we have demonstrated that hydrogenase is localized exclusively in the cytosol, while no hydrogenase activity was associated with mitochondria of the organism. In addition, cytosolic localization displayed for HydE, a marker component of hydrogenase maturases. Naegleria gruberi, an obligate aerobic organism and one of the earliest eukaryotes, is producing hydrogen, a function that raises questions on the purpose of this pathway for the lifestyle of the organism and potentially on the evolution of eukaryotes

Transcatheter closure of muscular ventricular septal defects with the amplatzer ventricular septal defect occluder: initial clinical applications in children11The Amplatzer VSD occluders were provided by AGA, Medical Corporation, Golden Valley, Minnesota. There were no sources of financial support.

AbstractOBJECTIVESThe aim of this study was to close muscular ventricular septal defects (MVSDs) in children, with a new device, the Amplatzer ventricular septal defect occluder (AVSDO).BACKGROUNDThe design of previously used devices for transcatheter closure of MVSDs is not ideal for this purpose and their use has been limited by several drawbacks.METHODSSix patients, aged 3 to 10 years, with MVSDs underwent transcatheter closure using the AVSDO. The device is a modified self-centering and repositionable Amplatzer device that consists of two low profile disks made of Nitinol wire mesh with a 7-mm connecting waist. The prosthesis size (connecting waist diameter) was chosen according to the measured balloon stretched VSD diameters. A 6-F or 7-F sheath was used for the delivery of the AVSDO. Fluoroscopy and transesophageal echocardiography were utilized for optimal guidance.RESULTSThe location of the defect was midmuscular in five patients and beneath the pulmonary valve in one. The balloon stretched MVSD diameter ranged from 6 to 11 mm. Device placement was successful in all patients, and complete occlusion occurred in all six patients (95% confidence interval 54.06% to 100%). Two patients developed transient complete left bundle branch block. No other complications were observed.CONCLUSIONSThis encouraging initial clinical success indicates that the AVSDO is a promising device for transcatheter closure of MVSDs in children. Further clinical trials and longer follow-up are needed before the widespread use of this technique can be recommended

Description and prevalence of gregarines infecting the amphipod Gammarus pulex, in the Water of Leith, Scotland, UK

Gregarines are symbiotic protists that are found in a broad spectrum of invertebrates, including insects, crustaceans, and annelids. Among these the globally distributed amphipod Gammarus pulex is one of the earliest recognized hosts for aquatic gregarines and is prevalent among macroinvertebrates in freshwater environments. In this study, samples of G. pulex were collected in the Water of Leith river, Scotland, UK. Gregarines were identified using light and scanning electron microscopy (SEM) as well as standard molecular techniques. We identified three septate eugregarine symbionts—Heliospora longissima, Cephaloidophora gammari, and the here newly characterized Cephaloidophora conus n. sp. (formerly Cephaloidophora sp.) associated with Gammarus pulex in the Water of Leith. Prevalences for identified gregarine species were calculated and seasonal dynamics of gregarine infections/colonization were analyzed. Prevalences were highest in autumn and spring reaching almost 50%. While the two Cephaloidophora species showed similar colonization patterns, the prevalence of Heliospora showed an opposite trend. Identifying gregarine infection/colonization patterns is one step towards better understanding the gregarine-host relationship, as well as possible impacts of the gregarines on their hosts

Localization of Fe?S Biosynthesis Machinery in Cryptosporidium parvum Mitosome

Cryptosporidium is a protozoan, apicomplexan, parasite that poses significant risk to humans and animals, as a common cause of potentially fatal diarrhea in immunodeficient hosts. The parasites have evolved a number of unique biological features that allow them to thrive in a highly specialized parasitic lifestyle. For example, the genome of Cryptosporidium parvum is highly reduced, encoding only 3,805 proteins, which is also reflected in its reduced cellular and organellar content and functions. As such, its remnant mitochondrion, dubbed a mitosome, is one of the smallest mitochondria yet found. While numerous studies have attempted to discover the function(s) of the C. parvum mitosome, most of them have been focused on in silico predictions. Here, we have localized components of a biochemical pathway in the C. parvum mitosome, in our investigations into the functions of this peculiar mitochondrial organelle. We have shown that three proteins involved in the mitochondrial iron-sulfur cluster biosynthetic pathway are localized in the organelle, and one of them can functionally replace its yeast homolog. Thus, it seems that the C. parvum mitosome is involved in iron-sulfur cluster biosynthesis, supporting the organellar and cytosolic apoproteins. These results spearhead further research on elucidating the functions of the mitosome and broaden our understanding in the minimalistic adaptations of these organelles

The symbiotic spectrum: where do the gregarines fit?

Gregarine apicomplexans are closely related to parasites such as Plasmodium, Toxoplasma, and Cryptosporidium, which are causing severe health and economic burdens. Colonizing only invertebrates and having no obvious medical relevance, they are mostly ignored in ‘omics’ studies, although gregarines are the most basal apicomplexans and therefore key players in the understanding of the evolution of parasitism in the Apicomplexa from free-living ancestors. They belong to the largest exclusively parasitic phylum, but is this perception actually true? The effects ofgregarines on their hosts seem to cover the whole spectrum of symbiosis from mutualistic to parasitic. We suggest future research directions to understand the evolutionary role of gregarines, by elucidating their biology and interaction with their hosts and the hosts’ microbiota

Blastocystis One Health Approach in a Rural Community of Northern Thailand: Prevalence, Subtypes and Novel Transmission Routes

Blastocystis is the most commonly found eukaryote in the gut of humans and other animals. This protist is extremely heterogeneous genetically and is classified into 28 subtypes (STs) based on the small subunit ribosomal RNA (SSU rRNA) gene. Numerous studies exist on prevalence of the organism, which usually focus on either humans or animals or the environment, while only a handful investigates all three sources simultaneously. Consequently, understanding of Blastocystis transmission dynamics remains inadequate. Our aim was to explore Blastocystis under the One Health perspective using a rural community in northern Thailand as our study area. We surveyed human, other animal and environmental samples using both morphological and molecular approaches. Prevalence rates of Blastocystis were 73% in human hosts (n = 45), 100% in non-human hosts (n = 44) and 91% in environmental samples (n = 35). Overall, ten subtypes were identified (ST1, ST2, ST3, ST4 ST5, ST6, ST7, ST10, ST23, and ST26), eight of which were detected in humans (ST1, ST2, ST3, ST4, ST5, ST7, ST10, and ST23), three in other animals (ST6, ST7, and ST23), while seven (ST1, ST3, ST6, ST7, ST10, ST23, and ST26) were found in the environment. In our investigation of transmission dynamics, we assessed various groupings both at the household and community level. Given the overall high prevalence rate, transmission amongst humans and between animals and humans are not as frequent as expected with only two subtypes being shared. This raises questions on the role of the environment on transmission of Blastocystis. Water and soil comprise the main reservoirs of the various subtypes in this community. Five subtypes are shared between humans and the environment, while three overlap between the latter and animal hosts. We propose soil as a novel route of transmission, which should be considered in future investigations. This study provides a thorough One Health perspective on Blastocystis. Using this type of approach advances our understanding on occurrence, diversity, ecology and transmission dynamics of this poorly understood, yet frequent gut resident

Circulation and colonisation of Blastocystis subtypes in schoolchildren of various ethnicities in rural northern Thailand

is a protist of controversial pathogenicity inhabiting the gut of humans and other animals. Despite a century of intense study, understanding of the epidemiology of remains fragmentary. Here, we aimed to explore its prevalence, stability of colonisation and association with various factors in a rural elementary school in northern Thailand. One hundred and forty faecal samples were collected from 104 children at two time points (tp) 105 days apart. For tp2, samples were also obtained from 15 animals residing on campus and seven water locations. Prevalence in children was 67% at tp1 and 89% at tp2, 63% in chickens, 86% in pigs, and 57% in water. Ten STs were identified, two of which were shared between humans and animals, one between animals and water, and three between humans and water. Eighteen children (out of 36) carried the same ST over both time points, indicating stable colonisation. Presence of (or ST) was not associated with body mass index, ethnicity, birth delivery mode, or milk source as an infant. This study advances understanding of prevalence in an understudied age group, the role of the environment in transmission, and the ability of specific STs to stably colonise children