Hemolymph of healthy Doclea rissoni Leach, 1815: A pool for Vibrionaceae?

As diseases have a great impact on the population dynamics, evolution and immune biology of affected organisms, it is important to understand the modes and mechanisms of interaction among the lower animals and their microbial symbionts in nature function together for survival. To achieve this, it is important to understand the community structure of the native flora of these animals. Spider crabs are well known for their tolerance to various pollutants. Nevertheless, the microbiology of their circulatory systems and their role in disease transmission are unknown. Therefore, the bacteria associated with the hemolymph of a spider crab, Doclea rissoni in its natural ecosystem was characterized. Nine healthy crabs were collected from the coastal areas of Kochi, and their hemolymphs were collected. Enumeration of viable bacteria using various media revealed a similar count in all the media (7-10×102 CFU/ml). Characterization of representative isolates by conventional microbiological methods and 16S rRNA gene sequencing was followed. Despite using three different media, all isolates belonged to a single family Vibrionaceae. There were two genera as Vibrio (86.67%) and Photobacterium (13.33%). Among Vibrio, five species belonging to three different clades were isolated, of which two could not be assigned to any known species. These were classified as novel species (belonging to Harveyi clade and, Brasiliensis clade) and their description is underway. The order of relative abundance was V. alginolyticus>Novel Vibrio-II>P. damselae>V. furnissii / V. parahaemolyticus / Novel Vibrio-I. Of these, V. alginolyticus, P. damselae and V. furnissii are implicated in occasional disease outbreaks in humans and animals, posing an increased risk to human economic activity, notably aquaculture practices. Therefore, further investigations are required to find the basis for the mutualistic relationship of vibrios in different crabs

Dioxygen binding is controlled by the protein environment in non-heme FeII and 2-oxoglutarate oxygenases: a study on histone demethylase PHF8 and an ethylene-forming enzyme

Invited for the cover of this issue are Christo Z. Christov and co-workers at Michigan Technological University, University of Oxford, and Michigan State University. The image depicts the oxygen diffusion channel in class 7 histone demethylase (PHF8) and ethylene-forming enzyme (EFE) and changes in the enzymes’ conformations upon binding. Read the full text of the article at 10.1002/chem.202300138

Does δ18O of O2 record meridional shifts in tropical rainfall?

Marine sediments, speleothems, paleo-lake elevations, and ice core methane and δ¹⁸O of O₂ (δ¹⁸Oatm) records provide ample evidence for repeated abrupt meridional shifts in tropical rainfall belts throughout the last glacial cycle. To improve understanding of the impact of abrupt events on the global terrestrial biosphere, we present composite records of δ¹⁸Oatm and inferred changes in fractionation by the global terrestrial biosphere (ΔεLAND) from discrete gas measurements in the WAIS Divide (WD) and Siple Dome (SD) Antarctic ice cores. On the common WD timescale, it is evident that maxima in ΔεLAND are synchronous with or shortly follow small-amplitude WD CH₄ peaks that occur within Heinrich stadials 1, 2, 4, and 5 – periods of low atmospheric CH₄ concentrations. These local CH₄ maxima have been suggested as markers of abrupt climate responses to Heinrich events. Based on our analysis of the modern seasonal cycle of gross primary productivity (GPP)-weighted δ¹⁸O of terrestrial precipitation (the source water for atmospheric O₂ production), we propose a simple mechanism by which ΔεLAND tracks the centroid latitude of terrestrial oxygen production. As intense rainfall and oxygen production migrate northward, ΔεLAND should decrease due to the underlying meridional gradient in rainfall δ¹⁸O. A southward shift should increase ΔεLAND. Monsoon intensity also influences δ¹⁸O of precipitation, and although we cannot determine the relative contributions of the two mechanisms, both act in the same direction. Therefore, we suggest that abrupt increases in ΔεLAND unambiguously imply a southward shift of tropical rainfall. The exact magnitude of this shift, however, remains under-constrained by ΔεLAND

The nomenclature, definition and classification of discordant atrioventricular connections

Congenitally corrected transposition is a complex cardiac lesion that is often associated with ventricular septal defect, obstruction of the outflow tract of the morphologically left ventricle, and abnormalities of the morphologically tricuspid valve.1,2Nomenclature for this lesion has been variable and confusing.1In this review, we define, and hopefully clarify this terminology. The lesion is a combination of discordant union of the atrial chambers with the ventricles, and the ventricles with the arterial trunks.1,2In rare circumstances, discordant atrioventricular connections can be associated with concordant ventriculo-arterial connections. This malformation has been called "isolated ventricular inversion". The term is less than precise, and the descriptive approach using the phrase "discordant atrioventricular connections with concordant ventriculo-arterial connections" is preferred, as discussed below

The nomenclature, definition and classification of cardiac structures in the setting of heterotaxy

AbstractIn 2000, The International Nomenclature Committee for Pediatric and Congenital Heart Disease was established. This committee eventually evolved into the International Society for Nomenclature of Paediatric and Congenital Heart Disease. The working component of this international nomenclature society has been The International Working Group for Mapping and Coding of Nomenclatures for Paediatric and Congenital Heart Disease, also known as the Nomenclature Working Group. The Nomenclature Working Group created the International Paediatric and Congenital Cardiac Code, which is available for free download from the internet at [http://www.IPCCC.NET].In previous publications from the Nomenclature Working Group, unity has been produced by cross-mapping separate systems for coding, as for example in the treatment of the functionally univentricular heart, hypoplastic left heart syndrome, or congenitally corrected transposition. In this manuscript, we review the nomenclature, definition, and classification of heterotaxy, also known as the heterotaxy syndrome, placing special emphasis on the philosophical approach taken by both the Bostonian school of segmental notation developed from the teachings of Van Praagh, and the European school of sequential segmental analysis. The Nomenclature Working Group offers the following definition for the term "heterotaxy": "Heterotaxy is synonymous with 'visceral heterotaxy' and 'heterotaxy syndrome'. Heterotaxy is defined as an abnormality where the internal thoraco-abdominal organs demonstrate abnormal arrangement across the left-right axis of the body. By convention, heterotaxy does not include patients with either the expected usual or normal arrangement of the internal organs along the left-right axis, also known as 'situs solitus', nor patients with complete mirror-imaged arrangement of the internal organs along the left-right axis also known as 'situs inversus'." "Situs ambiguus is defined as an abnormality in which there are components of situs solitus and situs inversus in the same person. Situs ambiguus, therefore, can be considered to be present when the thoracic and abdominal organs are positioned in such a way with respect to each other as to be not clearly lateralised and thus have neither the usual, or normal, nor the mirror-imaged arrangements."The heterotaxy syndrome as thus defined is typically associated with complex cardiovascular malformations. Proper description of the heart in patients with this syndrome requires complete description of both the cardiac relations and the junctional connections of the cardiac segments, with documentation of the arrangement of the atrial appendages, the ventricular topology, the nature of the unions of the segments across the atrioventricular and the ventriculoarterial junctions, the infundibular morphologies, and the relationships of the arterial trunks in space. The position of the heart in the chest, and the orientation of the cardiac apex, must also be described separately. Particular attention is required for the venoatrial connections, since these are so often abnormal. The malformations within the heart are then analysed and described separately as for any patient with suspected congenital cardiac disease. The relationship and arrangement of the remaining thoraco-abdominal organs, including the spleen, the lungs, and the intestines, also must be described separately, because, although common patterns of association have been identified, there are frequent exceptions to these common patterns. One of the clinically important implications of heterotaxy syndrome is that splenic abnormalities are common. Investigation of any patient with the cardiac findings associated with heterotaxy, therefore, should include analysis of splenic morphology. The less than perfect association between the state of the spleen and the form of heart disease implies that splenic morphology should be investigated in all forms of heterotaxy, regardless of the type of cardiac disease. The splenic morphology should not be used to stratify the form of disease within the heart, and the form of cardiac disease should not be used to stratify the state of the spleen. Intestinal malrotation is another frequently associated lesion that must be considered. Some advocate that all patients with heterotaxy, especially those with isomerism of the right atrial appendages or asplenia syndrome, should have a barium study to evaluate for intestinal malrotation, given the associated potential morbidity. The cardiac anatomy and associated cardiac malformations, as well as the relationship and arrangement of the remaining thoraco-abdominal organs, must be described separately. It is only by utilizing this stepwise and logical progression of analysis that it becomes possible to describe correctly, and to classify properly, patients with heterotaxy

Conformational effects on the Circular Dichroism of Human Carbonic Anhydrase II: a multilevel computational study

Circular Dichroism (CD) spectroscopy is a powerful method for investigating conformational changes in proteins and therefore has numerous applications in structural and molecular biology. Here a computational investigation of the CD spectrum of the Human Carbonic Anhydrase II (HCAII), with main focus on the near-UV CD spectra of the wild-type enzyme and it seven tryptophan mutant forms, is presented and compared to experimental studies. Multilevel computational methods (Molecular Dynamics, Semiempirical Quantum Mechanics, Time-Dependent Density Functional Theory) were applied in order to gain insight into the mechanisms of interaction between the aromatic chromophores within the protein environment and understand how the conformational flexibility of the protein influences these mechanisms. The analysis suggests that combining CD semi empirical calculations, crystal structures and molecular dynamics (MD) could help in achieving a better agreement between the computed and experimental protein spectra and provide some unique insight into the dynamic nature of the mechanisms of chromophore interactions

An 83 000-year-old ice core from Roosevelt Island, Ross Sea, Antarctica

In 2013 an ice core was recovered from Roosevelt Island, an ice dome between two submarine troughs carved by paleo-ice-streams in the Ross Sea, Antarctica. The ice core is part of the Roosevelt Island Climate Evolution (RICE) project and provides new information about the past configuration of the West Antarctic Ice Sheet (WAIS) and its retreat during the last deglaciation. In this work we present the RICE17 chronology, which establishes the depth–age relationship for the top 754 m of the 763 m core. RICE17 is a composite chronology combining annual layer interpretations for 0–343 m (Winstrup et al., 2019) with new estimates for gas and ice ages based on synchronization of CH4 and δ18Oatm records to corresponding records from the WAIS Divide ice core and by modeling of the gas age–ice age difference. Novel aspects of this work include the following: (1) an automated algorithm for multiproxy stratigraphic synchronization of high-resolution gas records; (2) synchronization using centennial-scale variations in methane for pre-anthropogenic time periods (60–720 m, 1971 CE to 30 ka), a strategy applicable for future ice cores; and (3) the observation of a continuous climate record back to ∼65 ka providing evidence that the Roosevelt Island Ice Dome was a constant feature throughout the last glacial period

Glimpse towards cultivable hemolymph microbiota of marine crabs: Untapped resource for aquatic probiotics/antibacterial agents

Bacterial diseases have turned out to be the primary constraint in sustainable aquaculture production, where, probiotics can play an important role to prevent or control fish and shellfish diseases. As the autochthonous preparations would be more effective than commercial products, continued search for novel antibacterial strains native to aquatic environment are warranted against aquatic pathogens. Further, knowledge on abundance, composition and role of hemolymph microbes is also essential to predict the health status and disease diagnosis. Hence, in present study, 4 commercially significant marine crabs that are important for aquaculture were used to unravel the implication and significance of cultivable hemolymph microbes. Bacterial abundance was found to be individual- and species-dependent; and statistically significant interaction was present between growth media and abundance. Gram negative isolates represented 84% of hemolymph microbes. Vibrio was the principal genera in all species; each carrying a specific hemolymph microbiota (both in terms of abundance and diversity). The present study forms the first report of genera viz., Enterovibrio, Pantoea, Kluyvera and Enterobacter in crustacean hemolymph. Interestingly, new Vibrio species were also found. Further, the study forms the first observation on inhibitory activity of marine crab hemolymph microbes against aquatic pathogens. Overall, the results highlight marine crab hemolymph microbiota as a promising moreover, an untapped resource for probiotics/ antimicrobial agents to combat aquatic pathogens. Concurrently, the present study fetches a platform for the prediction of health and disease diagnosis of 4 potentially important aquaculture crab species

The triterpene, methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA3), attenuates high glucose-induced oxidative damage and apoptosis by improving energy metabolism

BACKGROUND: Hyperglycemia-induced cardiovascular dysfunction has been linked to oxidative stress and accelerated apoptosis in the diabetic myocardium. While there is currently no treatment for diabetic cardiomyopathy (DCM), studies suggest that the combinational use of anti-hyperglycemic agents and triterpenes could be effective in alleviating DCM. HYPOTHESIS: To investigate the therapeutic effect of methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA3), in the absence or presence of the anti-diabetic drug, metformin (MET), against hyperglycemia-induced cardiac injury using an in vitro H9c2 cell model. METHODS: To mimic a hyperglycemic state, H9c2 cells were exposed to high glucose (HG, 33 mM) for 24 h. Thereafter, the cells were treated with RA3 (1 μM), MET (1 μM) and the combination of MET (1 μM) plus RA3 (1 μM) for 24 h, to assess the treatments therapeutic effect. RESULTS: Biochemical analysis revealed that RA3, with or without MET, improves glucose uptake via insulindependent (IRS-1/PI3K/Akt signaling) and independent (AMPK) pathways whilst ameliorating the activity of antioxidant enzymes in the H9c2 cells. Mechanistically, RA3 was able to alleviate HG-stimulated oxidative stress through the inhibition of reactive oxygen species (ROS) and lipid peroxidation as well as the reduced expression of the PKC/NF-кB cascade through decreased intracellular lipid content. Subsequently, RA3 was able to mitigate HG-induced apoptosis by decreasing the activity of caspase 3/7 and DNA fragmentation in the cardiomyoblasts. CONCLUSION: RA3, in the absence or presence of MET, demonstrated potent therapeutic properties against hyperglycemia-mediated cardiac damage and could be a suitable candidate in the prevention of DCM.South African National Treasury and National Research Foundation.https://www.elsevier.com/locate/phymedpm2022BiochemistryGeneticsMicrobiology and Plant Patholog

Risk Measurement and Management in a Crisis-Prone World

The current subprime crisis has prompted us to look again into the nature of risk at the tail of the distribution. In particular, we investigate the risk contribution of an asset, which has infrequent but huge losses, to a portfolio using two risk measures, namely Value-at-Risk (VaR) and Expected Shortfall (ES). While ES is found to measure the tail risk contribution effectively, VaR is consistent with intuition only if the underlying return distribution is well behaved. To facilitate the use of ES, we present a power function formula that can calculate accurately the critical values of the ES test statistic. This in turn enables us to derive a size-based multiplication factor for risk capital requirement