Antibodies targeting the shared cytokine receptor IL-1 receptor accessory protein invoke distinct mechanisms to block all cytokine signaling.

Interleukin-1 (IL-1)-family cytokines are potent modulators of inflammation, coordinating a vast array of immunological responses across innate and adaptive immune systems. Dysregulated IL-1-family cytokine signaling, however, is involved in a multitude of adverse health effects, such as chronic inflammatory conditions, autoimmune diseases, and cancer. Within the IL-1 family of cytokines, six-IL-1α, IL-1ß, IL-33, IL-36α, IL-36ß, and IL-36γ-require the IL-1 receptor accessory protein (IL-1RAcP) as their shared co-receptor. Common features of cytokine signaling include redundancy of signaling pathways, sharing of cytokines and receptors, pleiotropy of the cytokines themselves, and multifaceted immune responses. Accordingly, targeting multiple cytokines simultaneously is an emerging therapeutic strategy and can provide advantages over targeting a single cytokine pathway. Here, we show that two monoclonal antibodies, CAN10 and 3G5, which target IL-1RAcP for broad blockade of all associated cytokines, do so through distinct mechanisms and provide therapeutic opportunities for the treatment of inflammatory diseases.

Coupling of zinc and GTP binding drives G-domain folding in Acinetobacter baumannii ZigA.

COG0523 proteins, also known as nucleotide-dependent metallochaperones, are a poorly understood class of small P-loop G3E GTPases. Multiple family members play critical roles in bacterial pathogen survival during an infection as part of the adaptive response to host-mediated "nutritional immunity." Our understanding of the structure, dynamics, and molecular-level function of COG0523 proteins, apart from the eukaryotic homolog, Zng1, remains in its infancy. Here, we use X-ray absorption spectroscopy to establish that Acinetobacter baumannii (Ab) ZigA coordinates ZnII using all three cysteines derived from the invariant CXCC motif to form an S3(N/O) coordination complex, a feature inconsistent with the ZnII-bound crystal structure of a distantly related COG0523 protein of unknown function from Escherichia coli, EcYjiA. The binding of ZnII and guanine nucleotides is thermodynamically linked in AbZigA, and this linkage is more favorable for the substrate GTP relative to the product GDP. Part of this coupling originates with nucleotide-induced stabilization of the G-domain tertiary structure as revealed by global thermodynamics measurements and hydrogen-deuterium exchange mass spectrometry (HDX-MS). HDX-MS also reveals that the HDX behavior of the G2 (switch 1) loop is highly sensitive to nucleotide status and becomes more exchange labile in the GDP (product)-bound state. Significant long-range perturbation of local stability in both the G-domain and the C-terminal domain define a candidate binding pocket for a client protein that appears sensitive to nucleotide status (GDP versus GTP). We place these new insights into the structure, dynamics, and energetics of intermolecular metal transfer into the context of a model for AbZigA metallochaperone function.

Computational Investigation of a Series of Small Molecules as Potential Compounds for Lysyl Hydroxylase-2 (LH2) Inhibition.

The catalytic function of lysyl hydroxylase-2 (LH2), a member of the Fe(II)/αKG-dependent oxygenase superfamily, is to catalyze the hydroxylation of lysine to hydroxylysine in collagen, resulting in stable hydroxylysine aldehyde-derived collagen cross-links (HLCCs). Reports show that high amounts of LH2 lead to the accumulation of HLCCs, causing fibrosis and specific types of cancer metastasis. Some members of the Fe(II)/αKG-dependent family have also been reported to have intramolecular O2 tunnels, which aid in transporting one of the required cosubstrates into the active site. While LH2 can be a promising target to combat these diseases, efficacious inhibitors are still lacking. We have used computational simulations to investigate a series of 44 small molecules as lead compounds for LH2 inhibition. Tunneling analyses indicate the existence of several intramolecular tunnels. The lengths of the calculated O2-transporting tunnels in holoenzymes are relatively longer than those in the apoenzyme, suggesting that the ligands may affect the enzyme's structure and possibly block (at least partially) the tunnels. The sequence alignment analysis between LH enzymes from different organisms shows that all of the amino acid residues with the highest occurrence rate in the oxygen tunnels are conserved. Our results suggest that the enolate form of diketone compounds establishes stronger interactions with the Fe(II) in the active site. Branching the enolate compounds with functional groups such as phenyl and pyridinyl enhances the interaction with various residues around the active site. Our results provide information about possible leads for further LH2 inhibition design and development.

Factors affecting compliance with infection prevention and control standard precautions among healthcare workers in Songwe region, Tanzania.

Background: Compliance with infection prevention and control standard precautions (IPCSPs) remains a major challenge in many countries including Tanzania. Lack of compliance exposes healthcare workers (HCWs) and patients to a high risk of developing healthcare-associated infections (HAIs) including antimicrobial-resistant microorganisms which can contribute to the spread of antimicrobial resistance (AMR). This study investigated compliance with IPCSPs and associated factors among HCWs in public healthcare facilities (HFs) in Songwe Region, Tanzania between January and March 2021. Methods: A cross-sectional study was conducted in all 5 districts in Songwe Region, involved 400 HCWs from difference healthcare facilities (HFs) including dispensaries, health centres and hospitals. The Compliance with Standard Precautions scale (CSPS) tool developed by WHO was used. Descriptive and modified Poisson regression analysis was done. A P-value of less than 0.05 indicated statistical significance. Results: Only 22.5% (90/400) of HCWs had high compliance (above 80%) to IPCSPs. The majority of HCWs reported highest compliance on discarding used needles/sharps into sharps containers (94%), the lowest IPCSPs compliance was for the correct handling of spills, taking a shower after extensive splashing and not re-using disposable masks, 8%, 28.5% and 34% respectively. Attending IPC training or an IPC seminar in the previous year (ARR=2.97 [1.87-4.72] P<0.001), the number of years of work experience (ARR=2.08 [1.22-3.54] P=0.007), and having experienced a needlestick injury (ARR=0.62 [0.40-0.95] P=0.028), were identified as predictors of HCWs compliance with IPCSPs. Conclusion: The majority of HCWs in Songwe region had low compliance with IPCSPs according to national standards. IPC training and the number of years of work experience predicted high compliance with IPCSPs. Capacity building initiatives, mentorship and supportive supervision should be emphasised for all HCWs in all HFs.

Characterization of interaction between blood coagulation factor VIII and LRP1 suggests dynamic binding by alternating complex contacts.

BACKGROUND: Deficiency in blood coagulation factor VIII (FVIII) results in life-threating bleeding (hemophilia A) treated by infusions of FVIII concentrates. To improve disease treatment, FVIII has been modified to increase its plasma half-life, which requires understanding mechanisms of FVIII catabolism. An important catabolic actor is hepatic low density lipoprotein receptor-related protein 1 (LRP1), which also regulates many other clinically significant processes. Previous studies showed complexity of FVIII site for binding LRP1. OBJECTIVES: To characterize binding sites between FVIII and LRP1 and suggest a model of the interaction. METHODS: A series of recombinant ligand-binding complement-type repeat (CR) fragments of LRP1 including mutated variants was generated in a baculovirus system and tested for FVIII interaction using surface plasmon resonance, tissue culture model, hydrogen-deuterium exchange mass spectrometry, and in silico. RESULTS: Multiple CR doublets within LRP1 clusters II and IV were identified as alternative FVIII-binding sites. These interactions follow the canonical binding mode providing major binding energy, and additional weak interactions are contributed by adjacent CR domains. A representative CR doublet was shown to have multiple contact sites on FVIII. CONCLUSIONS: FVIII and LRP1 interact via formation of multiple complex contacts involving both canonical and non-canonical binding combinations. We propose that FVIII-LRP1 interaction occurs via switching such alternative binding combinations in a dynamic mode, and that this mechanism is relevant to other ligand interactions of the low-density lipoprotein receptor family members including LRP1.

Modeling the native ensemble of PhuS using enhanced sampling MD and HDX-ensemble reweighting.

The cytoplasmic heme binding protein from Pseudomonas aeruginosa, PhuS, plays two essential roles in regulating heme uptake and iron homeostasis. First, PhuS shuttles exogenous heme to heme oxygenase (HemO) for degradation and iron release. Second, PhuS binds DNA and modulates the transcription of the prrF/H small RNAs (sRNAs) involved in the iron-sparing response. Heme binding to PhuS regulates this dual function, as the unliganded form binds DNA, whereas the heme-bound form binds HemO. Crystallographic studies revealed nearly identical structures for apo- and holo-PhuS, and yet numerous solution-based measurements indicate that heme binding is accompanied by large conformational rearrangements. In particular, hydrogen-deuterium exchange mass spectrometry (HDX-MS) of apo- versus holo-PhuS revealed large differences in deuterium uptake, notably in α-helices 6, 7, and 8 (α6,7,8), which contribute to the heme binding pocket. These helices were mostly labile in apo-PhuS but largely protected in holo-PhuS. In contrast, in silico-predicted deuterium uptake levels of α6,7,8 from molecular dynamics (MD) simulations of the apo- and holo-PhuS structures are highly similar, consistent only with the holo-PhuS HDX-MS data. To rationalize this discrepancy between crystal structures, simulations, and observed HDX-MS, we exploit a recently developed computational approach (HDXer) that fits the relative weights of conformational populations within an ensemble of structures to conform to a target set of HDX-MS data. Here, a combination of enhanced sampling MD, HDXer, and dimensionality reduction analysis reveals an apo-PhuS conformational landscape in which α6, 7, and 8 are significantly rearranged compared to the crystal structure, including a loss of secondary structure in α6 and the displacement of α7 toward the HemO binding interface. Circular dichroism analysis confirms the loss of secondary structure, and the extracted ensembles of apo-PhuS and of heme-transfer-impaired H212R mutant, are consistent with known heme binding and transfer properties. The proposed conformational landscape provides structural insights into the modulation by heme of the dual function of PhuS.

Infanticide by Females Is a Leading Source of Juvenile Mortality in a Large Social Carnivore.

AbstractSocial animals benefit from their groupmates, so why do they sometimes kill each other's offspring? Using 30 years of data from multiple groups of wild spotted hyenas, we address three critical aims for understanding infanticide in any species: (1) quantify the contribution of infanticide to overall mortality, (2) describe the circumstances under which infanticide occurs, and (3) evaluate hypotheses about the evolution of infanticide. We find that infanticide, although observed only rarely, is in fact a leading source of juvenile mortality. Infanticide accounted for 24% of juvenile mortality, and one in 10 hyenas born in our population perished as a result of infanticide. In all observed cases of infanticide, killers were adult females, but victims could be of both sexes. Of four hypotheses regarding the evolution of infanticide, we found the most support for the hypothesis that infanticide in spotted hyenas reflects competition over social status among matrilines.

Metagenomic analysis exploring taxonomic diversity of rumen microbial communities in Vechur and crossbred cattle of Kerala state, India.

Rumen, one of the most productive diverse microbial habitats plays a vital role in the breakdown of feed to produce energy for maintenance and milk production in cattle. Culture-based procedures could identify only 10% of microbial species present in the rumen. Kerala, one of the southern states of India, owns only one native cattle breed, the Vechur cattle, which is noted for its short stature, disease resistance and adaptability to hot humid climate. Lower population density and decreased milk production potential of Vechur cattle led to the development of crossbred cattle of Kerala, with higher milk yield. A study was conducted to assess the rumen microbial profile of low productive Vechur cattle and high productive crossbred cattle for a better understanding of the relationship between the host and microbial community. DNA isolated from rumen liquor of five cattle each from both genetic groups maintained on standard ration (forage, concentrate ratio of 50:50) was subjected to whole metagenome sequencing. Bioinformatics and statistical analysis revealed that bacteria followed by archaea and eukaryota dominated in the Vechur cattle as well as the crossbred cattle rumen. Bacterial community was dominated by Bacteroidetes and Firmicutes phyla in both genetic groups with a higher Firmicutes to Bacteroidetes ratio of 0.45 in Vechur cattle. Among archaea, Euryarchaeota was more abundant, which constitute methanogens, contributing 98% of total archaeal reads. Prevalent protozoal genus found in the Vechur cattle rumen was Entodinium and in crossbred cattle rumen was Entamoeba. In Vechur and crossbred cattle rumen, 1086 and 1262 microbial species were observed exclusively and 4731 species were shared between habitats. There was a significant difference in total microbial species abundance between the two genetic groups and Vechur cattle displayed significantly higher microbial diversity compared to crossbred. As per literature, this is presumably the first report of rumen metagenome profile of Vechur cattle, a unique short breed of India.

Effect of paddy straw plus nonforage fiber sources based complete rations with different levels of neutral detergent fiber on hemato-biochemical and mineral profile of lactating dairy cows.

AIM: This study was conducted to assess the effect of feeding paddy straw plus nonforage fiber sources based complete rations with different levels of neutral detergent fiber (NDF) on hemato-biochemical and mineral parameters of lactating dairy cows. MATERIALS AND METHODS: The study was conducted for 6 months in 18 lactating dairy cows, divided into three groups of six each, by feeding them on paddy straw plus nonforage fiber sources based complete rations containing different levels of NDF, in two phases of 3 months (90 days) each, being the early and mid lactation phases, respectively. Three isonitrogenous and isocaloric complete rations, T1, T2 and T3 with 25%, 30% and 35% NDF, respectively, were fed to the experimental animals. Blood samples were collected at the beginning and the end of each of the two phases to estimate the different hematological, plasma protein, and mineral parameters to know the overall health status of the animals and standard methods were followed to analyze the samples. RESULTS: There was no significant difference (p>0.05) in various hematological parameters such as hemoglobin, glucose, and blood urea nitrogen (BUN) in blood; plasma protein parameters such as total protein, albumin, globulin and albumin: globulin ratio and mineral parameters such as plasma calcium and phosphorus levels at the beginning and end of Phase I (1st day and 90th day) and Phase II (91st day and 180th day) as well as between the three dietary treatments, with all the values being in the normal range for lactating dairy cows. Even though nonsignificant (p>0.05), the BUN values of animals fed on ration T1, both at the beginning and end of Phase I, were higher than that of animals fed on rations T2 and T3 because the diet T1 with lowest NDF and the highest soluble carbohydrate content underwent rapid fermentation in the rumen, produced more energy, which was utilized by the rumen microbes to degrade the protein in the feed to ammonia, the excess ammonia being transported to the liver and excreted through the blood resulting in a higher BUN content. CONCLUSION: Feeding of paddy straw plus nonforage fiber sources based complete rations with different levels of NDF had no effect on hemato-biochemical and mineral profile as well as overall health status of lactating dairy cows. However, the higher, BUN values found in cows fed on diet T1 with 25% NDF as compared to those fed on T2 and T3 with 30% and 35% NDF, respectively, indicate more wastage of protein in T1 as compared to T2 and T3, in early lactation.

Effect of supplementation of lecithin and carnitine on growth performance and nutrient digestibility in pigs fed high-fat diet.

AIM: To study the effect of dietary supplementation of lecithin and carnitine on growth performance and nutrient digestibility in pigs fed high-fat diet. MATERIALS AND METHODS: A total of 30 weaned female large white Yorkshire piglets of 2 months of age were selected and randomly divided into three groups allotted to three dietary treatments, T1 - Control ration as per the National Research Council nutrient requirement, T2 - Control ration plus 5% fat, and T3 - T2 plus 0.5% lecithin plus 150 mg/kg carnitine. The total dry matter (DM) intake, fortnightly body weight of each individual animal was recorded. Digestibility trial was conducted toward the end of the experiment to determine the digestibility coefficient of various nutrients. RESULTS: There was a significant improvement (p<0.01) observed for pigs under supplementary groups T2 and T3 than that of control group (T1) with regards to growth parameters studied such as total DM intake, average final body weight and total weight gain whereas among supplementary groups, pigs reared on T3 group had better intake (p<0.01) when compared to T2 group. Statistical analysis of data revealed that no differences were observed (p>0.05) among the three treatments on average daily gain, feed conversion efficiency, and nutrient digestibility during the overall period. CONCLUSION: It was concluded that the dietary inclusion of animal fat at 5% level or animal fat along with lecithin (0.5%) and carnitine (150 mg/kg) improved the growth performance in pigs than non-supplemented group and from the economic point of view, dietary incorporation of animal fat at 5% would be beneficial for improving growth in pigs without dietary modifiers.

Effect of L-carnitine supplementation on growth performance, nutrient utilization, and nitrogen balance of broilers fed with animal fat.

AIM: This experiment was conducted to evaluate the effect of L-carnitine supplementation on growth performance, nutrient utilization and nitrogen balance in broilers fed with animal fat. MATERIALS AND METHODS: 80 day-old Cobb commercial broiler chicks were randomly assigned into two dietary treatment groups with four replicates of ten chicks each. The diets were isonitrogenous and isocaloric. The birds in both the control (T1) and treatment group (T2) were fed with a diet having 5% animal fat, while the treatment group (T2) was supplemented with 900 mg of L-carnitine. The birds were fed with standard broiler starter ration up to 4 weeks of age and finisher ration up to 6 weeks of age. RESULTS: The average body weight (g), cumulative feed intake (g) and cumulative feed conversion ratio belonging to groups T1 and T2 at 6(th) week of age were 2091.25 and 2151.11, 3976.49 and 4171.68, 1.97 and 1.96 respectively. The percentage availability of the nutrients of two experimental rations T1 and T2 was 68.23 and 68.00 for dry matter, 58.72 and 55.98 for crude protein, 73.85 and 71.35 for ether extract, 34.19 and 33.86 for crude fiber, 79.18 and 79.59 for nitrogen free extract, 70.24 and 70.03 for energy efficiency and nitrogen balance (g/day) were 2.35 and 2.39, respectively. CONCLUSION: This study suggests that the supplementation of 900 mg L-carnitine in diet with added animal fat had no effect on growth performance, nutrient utilization, and nitrogen balance of broilers.

[Contribution of magnesium gluconate in intravenous tocolysis with ritodrine]. / Apport du gluconate de magnésium dans la tocolyse parentérale par la ritodrine.

The purpose of this randomized study was to compare the efficacy of ritodrine alone (51) versus ritodrine plus magnesium gluconate (56). We concluded that high oral doses of magnesium therapy (4 x 3 gr) potentiate the effects of intravenous beta-agonists, allowing a reduction of the dosage needed and a better "tolerance". Considering the low side effects, it seems reasonable to consider using magnesium in the treatment of premature labour.

Pulmonary oedema associated with acidosis in patients with cholera.

Five patients with severe acidosis and pulmonary oedema complicating cholera were seen at the Cholera Research Laboratory, Dacca, in a two-year period. All had had inadequate treatment. Their disease resulted in acidosis prior to admission; only the two who subsequently survived received volumes of sodium bicarbonate solutions sufficiently large to repair completely their acidosis. Saline alone worsened pulmonary congestion, while alkali appeared to relieve it despite the accompanying volume expansion. These observations are consistent with the known redistribution of blood to the central circulation in acidosis. Timely and proper treatment of cholera will avert this syndrome, when use of isotonic sodium bicarbonate sufficient to correct acidosis may be very helpful.