Temporal dynamics of apoptosis-induced proliferation in pupal wing development: implications for regenerative ability.

BACKGROUND: The ability of animals to regenerate damaged tissue is a complex process that involves various cellular mechanisms. As animals age, they lose their regenerative abilities, making it essential to understand the underlying mechanisms that limit regenerative ability during aging. Drosophila melanogaster wing imaginal discs are epithelial structures that can regenerate after tissue injury. While significant research has focused on investigating regenerative responses during larval stages our comprehension of the regenerative potential of pupal wings and the underlying mechanisms contributing to the decline of regenerative responses remains limited. RESULTS: Here, we explore the temporal dynamics during pupal development of the proliferative response triggered by the induction of cell death, a typical regenerative response. Our results indicate that the apoptosis-induced proliferative response can continue until 34 h after puparium formation (APF), beyond this point cell death alone is not sufficient to induce a regenerative response. Under normal circumstances, cell proliferation ceases around 24 h APF. Interestingly, the failure of reinitiating the cell cycle beyond this time point is not attributed to an incapacity to activate the JNK pathway. Instead, our results suggest that the function of the ecdysone-responsive transcription factor E93 is involved in limiting the apoptosis-induced proliferative response during pupal development. CONCLUSIONS: Our study shows that apoptosis can prolong the proliferative period of cells in the wing during pupal development as late as 34 h APF, at least 10 h longer than during normal development. After this time point, the regenerative response is diminished, a process mediated in part by the ecdysone-responsive transcription factor E93.

Congenital ichthyosis: a multidisciplinary approach in a neonatal care unit.

Congenital ichthyoses are a rare group of genetic disorders caused by defects in the two outermost skin layers, resulting in an abnormal barrier function. We report the case of a male preterm neonate presenting at delivery with thickened and scaling skin, ectropium and eclabium. Supportive care aiming at improving skin condition and handling possible complications was provided. Following gradual clinical improvement, he was discharged after 27 days. Molecular testing identified mutations in a gene encoding lipoxygenase (ALOX12B), associated with autosomal recessive congenital ichthyosis. This case highlights an uncommon disease that can determine significant morbidity and mortality in the first few weeks of life. Management of this complex disease benefits from a multidisciplinary approach. Molecular studies allow a more accurate diagnosis and enable genetic counselling.

Can behaviour and physiology mitigate effects of warming on ectotherms? A test in urban ants.

Global climate change is expected to have pervasive effects on the diversity and distribution of species, particularly ectotherms whose body temperatures depend on environmental temperatures. However, these impacts remain difficult to predict, in part because ectotherms may adapt or acclimate to novel conditions or may use behavioural thermoregulation to reduce their exposure to stressful microclimates. Here we examine the potential for physiological and behavioural changes to mitigate effects of environmental warming on five species of ants in a temperate forest habitat subject to urban warming. We worked in eight urban and eight non-urban forest sites in North Carolina, USA; sites experienced a 1.1°C range of mean summer air temperatures. At each site, we documented species-specific microclimates (ant operative temperatures, Te ) and ant activity on a transect of 14 bait stations at three times of day. In the laboratory, we measured upper thermal tolerance (CTmax ) and thermal preference (Tpref ) for each focal species. We then asked whether thermal traits shifted at hotter sites, and whether ants avoided non-preferred microclimates in the field. CTmax and Tpref did not increase at warmer sites, indicating that these populations did not adapt or acclimate to urban warming. Consistent with behavioural thermoregulation, four of the five species were less likely to occupy baits where Te departed from Tpref . Apparent thermoregulation resulted from fixed diel activity patterns that helped ants avoid the most inappropriate temperatures but did not compensate for daily or spatial temperature variation: Hotter sites had hotter ants. This study uses a novel approach to detect behavioural thermoregulation and sublethal warming in foraging insects. The results suggest that adaptation and behaviour may not protect common temperate forest ants from a warming climate, and highlight the need to evaluate effects of chronic, sublethal warming on small ectotherms.

Impact of Systemic Corticosteroids on Mortality in Older Adults With Critical COVID-19 Pneumonia.

BACKGROUND: The most susceptible population group to critical and fatal coronavirus disease 2019 (COVID-19) is older adults. In severe acute respiratory syndrome coronavirus 2 infection, the host immune response is thought to play a key role in the pathophysiological effects of lung damage. Therefore, corticosteroid therapy could modulate inflammation-mediated pulmonary injury and thereby reduce progression to severe respiratory failure and death. The aim of this study was to analyze the safety and clinical efficacy of corticosteroid therapy in older adults with severe COVID-19 pneumonia. METHOD: We reviewed the clinical records of confirmed COVID-19 patients aged 75 years or older admitted to our hospital over a 3-month period (March 1-May 31, 2020). A total of 143 patients were included in the study cohort. From 2 April, 2020, in accordance with World Health Organization guidance on COVID-19, our hospital protocol added corticosteroid for COVID-19 treatment. We compared in-hospital mortality among patients with critical COVID-19 who received corticosteroids therapy and those who did not. RESULTS: In total, 88 patients (61.5%) were treated with corticosteroids, and 55 patients (38.4%) were not. Both groups were similar in baseline characteristics. The median age was 85 years (interquartile range: 82-89), and 61.5% (88/143) were male. In-hospital mortality was lower in the corticosteroid group (68.2%) compared with patients in the noncorticosteroid group (81.8%). Treatment with corticosteroids was an independent survival factor (hazard ratio: 0.61; 95% CI: 0.41-0.93; p = .006). CONCLUSIONS: In critically ill older adults with COVID-19 pneumonia, the use of corticosteroid treatment resulted in lower mortality without severe adverse events.

Ocular lesions in hereditary hemorrhagic telangiectasia: genetics and clinical characteristics.

BACKGROUND: The aim of our study is to study the association between eye lesions in Hereditary Hemorrhagic Telangiectasia (HHT) and other signs of the disease, as well as to characterize its genetics. METHODS: A cross-sectional study was conducted of a cohort of 206 patients studied in the HHT Unit of Hospital de Sierrallana, a reference centre for Spanish patients with HHT. Odds ratios for several symptoms or characteristics of HHT and ocular lesions were estimated using logistic regression adjusting for age and sex. RESULTS: The ocular involvement was associated with being a carrier of a mutation for the ENG gene, that is, suffering from a type 1 HHT involvement (OR = 2.09; 95% CI [1.17-3.72]). p = 0.012). In contrast, patients with ocular lesions have less frequently mutated ACVRL1/ALK1 gene (OR = 0.52; 95% CI [0.30-3.88], p = 0.022). CONCLUSIONS: In conclusion, half of the patients with HHT in our study have ocular involvement. These eye lesions are associated with mutations in the ENG gene and ACVRL1/ALK1 gene. Thus, the ENG gene increases the risk of ocular lesions, while being a carrier of the mutated ACVRL1/ALK1 gene decreases said risk.

A comparison of coffee floral traits under two different agricultural practices.

Floral traits and rewards are important in mediating interactions between plants and pollinators. Agricultural management practices can affect abiotic factors known to influence floral traits; however, our understanding of the links between agricultural practices and floral trait expression is still poorly understood. Variation in floral morphological, nectar, and pollen traits of two important agricultural species, Coffea arabica and C. canephora, was assessed under different agricultural practices (sun and shade). Corolla diameter and corolla tube length were larger and pollen total nitrogen content greater in shade plantations of C. canephora than sun plantations. Corolla tube length and anther filament length were larger in shade plantations of C. arabica. No effect of agricultural practice was found on nectar volume, sugar or caffeine concentrations, or pollen production. Pollen total nitrogen content was lower in sun than shade plantations of C. canephora, but no difference was found between sun and shade for C. arabica. This study provides baseline data on the influence of agronomic practices on C. arabica and C. canephora floral traits and also helps fill a gap in knowledge about the effects of shade trees on floral traits, which can be pertinent to other agroforestry systems.

Construction of a Compact Low-Cost Radiation Shield for Air-Temperature Sensors in Ecological Field Studies.

Low cost temperature sensors are increasingly used by ecologists to assess climatic variation and change on ecologically relevant scales. Although cost-effective, if not deployed with proper solar radiation shielding, the observations recorded from these sensors will be biased and inaccurate. Manufactured radiation shields are effective at minimizing this bias, but are expensive compared to the cost of these sensors. Here, we provide a detailed methodology for constructing a compact version of a previously described custom fabricated radiation shield, which is more accurate than other published shielding methods that attempt to minimize shield size or construction costs. The method requires very little material: corrugated plastic sheets, aluminum foil duct tape, and cable ties. One 15 cm and two 10 cm squares of corrugated plastic are used for each shield. After cutting, scoring, taping and stapling of the sheets, the 10 cm squares form the bottom two layers of the solar radiation shield, while the 15 cm square forms the top layer. The three sheets are held together with cable ties. This compact solar radiation shield can be suspended, or placed against any flat surface. Care must be taken to ensure that the shield is completely parallel to the ground to prevent direct solar radiation from reaching the sensor, possibly causing increased warm biases in sun-exposed sites in the morning and afternoon relative to the original, larger design. Even so, differences in recorded temperatures between the smaller, compact shield design and the original design were small (mean daytime bias = 0.06 °C). Construction costs are less than half of the original shield design, and the new design results in a less conspicuous instrument that may be advantageous in many field ecology settings.

Accurate near surface air temperature measurements are necessary to gauge large-scale ecological responses to global climate change.

Linked Article: https://doi.org/10.1002/ece3.3965.

JNK and JAK/STAT signalling are required for inducing loss of cell fate specification during imaginal wing discs regeneration in Drosophila melanogaster.

The regenerative process after tissue damage relies on a variety of cellular responses that includes compensatory cell proliferation and cell fate re-specification. The identification of the signalling networks regulating these cellular events is a central question in regenerative biology. Tissue regeneration models in Drosophila have shown that two of the signals that play a fundamental role during the early stages of regeneration are the c-Jun N-terminal kinase (JNK) and JAK/STAT signalling pathways. These pathways have been shown to be required for controlling regenerative proliferation, however their contribution to the processes of cellular reprogramming and cell fate re-specification that take place during regeneration are largely unknown. Here, we present evidence for a previously unrecognised function of the cooperative activities of JNK and JAK/STAT signalling pathways in inducing loss of cell fate specification in imaginal discs. We show that co-activation of these signalling pathways induces both the cell fate changes in injured areas, as well as in adjacent cells. We have also found that this function relies on the activity of the Caspase initiator encoded by the gene dronc.

Drosophila as a Model System to Study Cell Signaling in Organ Regeneration.

Regeneration is a fascinating phenomenon that allows organisms to replace or repair damaged organs or tissues. This ability occurs to varying extents among metazoans. The rebuilding of the damaged structure depends on regenerative proliferation that must be accompanied by proper cell fate respecification and patterning. These cellular processes are regulated by the action of different signaling pathways that are activated in response to the damage. The imaginal discs of Drosophila melanogaster have the ability to regenerate and have been extensively used as a model system to study regeneration. Drosophila provides an opportunity to use powerful genetic tools to address fundamental problems about the genetic mechanisms involved in organ regeneration. Different studies in Drosophila have helped to elucidate the genes and signaling pathways that initiate regeneration, promote regenerative growth, and induce cell fate respecification. Here we review the signaling networks involved in regulating the variety of cellular responses that are required for discs regeneration.

Ad hoc instrumentation methods in ecological studies produce highly biased temperature measurements.

In light of global climate change, ecological studies increasingly address effects of temperature on organisms and ecosystems. To measure air temperature at biologically relevant scales in the field, ecologists often use small, portable temperature sensors. Sensors must be shielded from solar radiation to provide accurate temperature measurements, but our review of 18 years of ecological literature indicates that shielding practices vary across studies (when reported at all), and that ecologists often invent and construct ad hoc radiation shields without testing their efficacy. We performed two field experiments to examine the accuracy of temperature observations from three commonly used portable data loggers (HOBO Pro, HOBO Pendant, and iButton hygrochron) housed in manufactured Gill shields or ad hoc, custom-fabricated shields constructed from everyday materials such as plastic cups. We installed this sensor array (five replicates of 11 sensor-shield combinations) at weather stations located in open and forested sites. HOBO Pro sensors with Gill shields were the most accurate devices, with a mean absolute error of 0.2°C relative to weather stations at each site. Error in ad hoc shield treatments ranged from 0.8 to 3.0°C, with the largest errors at the open site. We then deployed one replicate of each sensor-shield combination at five sites that varied in the amount of urban impervious surface cover, which presents a further shielding challenge. Bias in sensors paired with ad hoc shields increased by up to 0.7°C for every 10% increase in impervious surface. Our results indicate that, due to variable shielding practices, the ecological literature likely includes highly biased temperature data that cannot be compared directly across studies. If left unaddressed, these errors will hinder efforts to predict biological responses to climate change. We call for greater standardization in how temperature data are recorded in the field, handled in analyses, and reported in publications.

Ecological Interactions Affecting the Efficacy of Aphidius colemani in Greenhouse Crops.

Aphidius colemani Viereck (Hymenoptera: Braconidae) is a solitary endoparasitoid used for biological control of many economically important pest aphids. Given its widespread use, a vast array of literature on this natural enemy exists. Though often highly effective for aphid suppression, the literature reveals that A. colemani efficacy within greenhouse production systems can be reduced by many stressors, both biotic (plants, aphid hosts, other natural enemies) and abiotic (climate and lighting). For example, effects from 3rd and 4th trophic levels (fungal-based control products, hyperparasitoids) can suddenly decimate A. colemani populations. But, the most chronic negative effects (reduced parasitoid foraging efficiency, fitness) seem to be from stressors at the first trophic level. Negative effects from the 1st trophic level are difficult to mediate since growers are usually constrained to particular plant varieties due to market demands. Major research gaps identified by our review include determining how plants, aphid hosts, and A. colemani interact to affect the net aphid population, and how production conditions such as temperature, humidity and lighting affect both the population growth rate of A. colemani and its target pest. Decades of research have made A. colemani an essential part of biological control programs in greenhouse crops. Future gains in A. colemani efficacy and aphid biological control will require an interdisciplinary, systems approach that considers plant production and climate effects at all trophic levels.

Neonatal thyrotoxicosis caused by maternal autoimmune hyperthyroidism.

Neonatal immune hyperthyroidism is a rare but potentially fatal condition. It occurs in 1-5% of infants born to women with Graves' disease (GD). In most of the cases it is due to maternal antibodies transferred from the mother into the fetal compartment, stimulating the fetal thyroid by binding thyrotropin (thyroid-stimulating hormone, TSH) receptor. We present a case of neonatal thyrotoxicosis due to maternal GD detected at 25 days of age and discuss the potential pitfalls in the diagnosis.

Severe congenital thrombocytopaenia--first clinical manifestation of Noonan syndrome.

This report focuses on a male infant, the first born of non-consanguineous parents diagnosed with polyhydramnios at 26 weeks of gestation. The newborn was admitted during the neonatal period with bleeding diathesis associated with a low platelet count at birth (5×10(9)/l).The authors registered a persistent low platelet count (9000-129 000/l) during the infants 1st year of life. Physical examination revealed a petechial rash, a dysmorphic face and bilateral cryptorchidism, in the absence of organomegaly. Additionally, cardiologic evaluation revealed an aortic valve dysplasia and an atrial septal defect, while bone marrow biopsy and aspiration were found normal. Throughout the investigation, the authors excluded congenital infection, alloimmune and familiar thrombocytopaenia, Fanconi anaemia and thrombocytopaenia absent radius syndrome. The cytogenetic analysis revealed a mutation in the PTPN11 gene associated with Noonan syndrome. Here the author highlights that severe neonatal thrombocytopaenia is a manifestation that should be considered in the diagnosis and clinical management of Noonan's syndrome.

Neonatal hyperglycaemia: a challenging diagnosis.

Neonatal diabetes mellitus (NDM) is a very rare disorder occurring between 1:400 000 and 1:500 000 live births and, until recently, little was known about this disease. The authors report a case of transient NDM in a 2-day-old female infant admitted in an intensive care unit with a blood glucose level greater than 400 mg/dl, glycosuria, ketonuria and with no evidence of autoimmunity. Treatment with insulin was necessary until the 51st day of life and many difficulties were found in the management of metabolic control because of the need for tiny quantities of insulin. Hyperglycaemia is sometimes routinely treated with insulin by neonatologists but after excluding the common causes of hyperglycaemia, NDM should be considered as a diagnostic possibility with clinical, genetic and therapeutic implications.

Adolescent with neurological manifestations of cardiac cause treated surgically.

Cardiac myxomas are a rare but important cause of embolic events and cerebrovascular disease in children and adolescents. The authors report the case of a 12-year-old girl with sudden dizziness and right-sided paresthesia of the lips and fingers of the right hand. She was observed by a pediatric neurologist and brain magnetic resonance imaging suggested demyelinating lesions or vasculitis. Echocardiography showed a left atrial mass compatible with an atrial myxoma. The myxoma was surgically removed without complications. This case highlights the need for cardiac evaluation to rule out a cardiac tumor with embolic potential in the presence of any child with neurological manifestations of cerebrovascular disease with inconclusive brain imaging, even with no previous evidence of cardiac disease. Prompt clinical recognition and surgical removal are essential to prevent serious complications.