Polysaccharide conformations are central to biological function but exhibit a strikingly counterintuitive, non-monotonic behaviour. Addition of a poorer cosolvent, such as glycerol, to aqueous polysaccharide solutions induces flexible coil → swollen → collapsed conformational transitions as the solvent quality becomes progressively poorer. Using complementary simulations, theory, and experiments, we show that preferential solvation governs the conformational transitions, where the distribution of solvent molecules around the polysaccharide chain deviates significantly from that in the bulk solution. Contrary to expectations, initial chain swelling arises from preferential binding of glycerol at lower glycerol volume fraction, whereas preferential hydration leads to a more compact (collapsed) configuration at higher glycerol volume fraction. Chains appear to conserve their total water contact via such conformational reconfigurations, which map directly onto viscoelastic response; a phenomenon that may be greatly accentuated in polysaccharides. Results are explained from the perspective of Kirkwood-Buff solution theory and solvent entropic penalties, which extend beyond the Flory-type mean-field description. A tentatively unified behaviour can be observed across complex polysaccharides, including pectin, as well as other linear and branched polysaccharides such as agar, alginate, carboxymethylcellulose, and dextran, suggesting potential fundamental significance for biological and industrial aspects of glycoscience.

Monoclonal gammopathy of undetermined significance (MGUS) is the asymptomatic precursor of multiple myeloma and related diseases but has also been associated with thrombosis. Prior studies have not been based on screened cohorts leading to bias. We assessed the risk of thrombosis in a cohort of 75 422 individuals over 40 years old who were screened for MGUS in Iceland. We also evaluated the association of M protein concentration with thrombotic risk. A total of 3668 participants had MGUS. After a median follow-up of similar to 3.7 years, 124 venous and 252 arterial thrombotic events (10.3 and 21.0 per 1000 person years respectively) were observed in the MGUS group, compared to 1509 and 3471 in the non-MGUS group (6.0 and 13.8 per 1000 person years respectively). After adjusting for multiple confounders, MGUS was associated with an increased risk of venous thrombosis (hazard ratio [HR] = 1.43; 95% confidence interval [CI]: 1.19-1.73) but not arterial thrombosis (HR = 0.96; 95% CI: 0.87-1.13). M protein concentration was not associated with venous (p = 0.72) or arterial (p = 0.95) thrombosis. The findings show, in a screened cohort, that MGUS is associated with venous, but not arterial, thrombosis. Furthermore, they suggest that there is a subset of individuals with MGUS with subclinical monoclonal gammopathy of thrombotic significance.

Hypercalcemia in monoclonal gammopathy of undetermined significance (MGUS) presents a clinical challenge because it may indicate progression to multiple myeloma (MM) but could also be due to a multitude of unrelated disorders. To inform the approach to this clinical challenge, we conducted a nested cohort study within the Iceland Screens, Treats, or Prevents Multiple Myeloma screening study. Of the 75 422 Icelanders aged 40 years and above who underwent screening for MGUS, we included 2546 with MGUS who were in active follow-up, including regular serum calcium measurements. In total, 191 individuals (7.5%) had hypercalcemia detected at least once, of whom 93 had persistent hypercalcemia (48.7%). MM was found in 3 participants with persistent hypercalcemia (3.2%); all had concurrent bone disease and other end-organ damage. The most common causes of hypercalcemia were primary hyperparathyroidism (56.0%) and malignancies other than MM (16.0%). In this first comprehensive study on hypercalcemia in MGUS, we observed that hypercalcemia rarely indicated MGUS progression and never in the absence of other symptoms of MM. More than half of hypercalcemia cases were transient, and the underlying causes were similar to those in the general population. We conclude that hypercalcemia in MGUS should be approached in the same way as in those without MGUS.

Detection of light chain (LC) monoclonal gammopathies (MGs) traditionally relies on serum free LC (FLC) kappa, lambda, and their ratio (kappa/lambda) reference ranges based on a mostly White population. We investigated FLC values in a racially diverse population by screening 10 035 individuals for heavy chain MG, identifying 9028 negative cases whose FLC were measured. Participants included 4149 from the PROMISE study (United States, n = 2383; South Africa, n = 1766) and 4879 from the Mass General Brigham Biobank, with 44% self-identifying as Black. Using standard FLC reference ranges, 1074 of 10 035 individuals (10.7%) were diagnosed with LC monoclonal gammopathy of undetermined significance (MGUS), with 99% being kappa-restricted. In the United States, 14.8% of Black and 4% of White individuals were diagnosed (P < .01). Among US participants of African (AFR) and European (EUR) genetic ancestry, 14.4% AFR and 2.9% EUR were diagnosed (P < .01). Among South Africans (100% Black), 27.8% were diagnosed using standard ranges. To avoid overdiagnosis, we propose a new kappa/lambda ratio reference range (0.686 to 2.10) for populations of AFR descent with normal renal function, with standard values for kappa and lambda being 7.97 to 77.50 mg/L and 6.20 to 49.20 mg/L, respectively. This reduces LC-MGUS overdiagnosis by 91% (10.7% vs 0.97%). Using the new reference, LC-MGUS accounts for 8.8% of MGUS cases, with 74% being kappa-restricted, consistent with LC myeloma rates. These findings highlight the importance of basing disease definitions, such as MGUS, on diverse populations. Adopting our proposed FLC reference values would reduce MGUS overdiagnosis among Black individuals, avoiding unnecessary financial, psychological, and medical consequences. This study includes data from NCT03689595.

The transition of immunotherapy administration from intravenous infusion to subcutaneous (SC) administration of monoclonal antibody formulations for oncology patients has garnered significant interest. SC administration offers multiple benefits, including potential for at-home administration, enhanced patient compliance, reduced hospital congestion, lowered health care costs, and improved sustainability by reducing drug wastage and minimizing environmental impact. However, for many biologics, the shift to SC administration requires the development of high-concentration monoclonal antibody products (HCmAP) due to the need for large dose volumes. Here we explore the impact of the COVID-19 pandemic on immunotherapy administration and the imperative of adopting SC administration. We discuss challenges encountered throughout the manufacturing, shipping, storage, and delivery of HCmAP. A central hurdle identified involves the biophysical instability and the large increase in viscosity of these biologics due to increased antibody concentration. Further complications can arise from “non-ideality” effects through molecular crowding or co-exclusion effects (macromolecules blocking the free movement in solution of other macromolecules) and elevated macromolecular interactions. For reducing the viscosity for a given concentration of antibody, the main excipients reported are salts and amino acids, with Arg-HCl demonstrating particularly improved formulation viscosity in an HCmAP. However, excipients with viscosity-lowering effects can also impact protein stability. The journey to discover suitable excipient strategies remains ongoing, combined with emerging approaches such as molecular engineering and computational techniques, with the ultimate aim of facilitating the successful integration of SC administration for economic savings, environmental sustainability, and social equity.

Enzymes from salt-in halophiles are stable in conditions of low water activity with applications in chiral synthesis requiring organic solvents, yet the origins of such stability remains poorly understood. Here we describe the molecular basis of the reaction mechanism and dual NADH/NADPH-specificity of D2HDH, a 2-hydroxyacid dehydrogenase from the extreme halophile Haloferax mediterranei, an organism whose proteins have to remain active in high intracellular concentrations of KCl. Halophilic adaptations of D2HDH include the expected acidic surface and a reduction in hydrophobic surface resulting from a lower lysine content. Structure determination of crystals of D2HDH grown with KCl showed that bound K+ ions were coordinated predominantly by clusters of main chain protein carbonyl ligands, with no involvement of the numerous exposed surface carboxyls. Structural comparisons identified similar sites in other halophilic proteins suggesting that the generic use of carbonyl clusters to coordinate K+ ions may also contribute in a carboxylate-independent way to the stabilisation of the folded state of the protein in its high salt environment.

This work investigated a sustainable and efficient approach of pectin extraction for banana peel waste valorisation and studied the influence of banana ripening stages (RS at 2,5 and 7). Although pectin content in banana peel raw material decreased during ripening, pectin extraction was favoured. The highest alcohol-insoluble solids (AIS) yield (12.5%) was achieved at 70 °C, 15 mins from RS 7 peel. All extracts were homogalacturan-rich with some rhamnogalacturonan-I content (showing HGA/RG-I ratio > 2) with varied degree of methylation (DM). The highest HGA content (837.2 mg/g AIS) and HGA/RG-I ratio (9.9) were achieved at 110 °C, 0 mins from RS 7, suggesting its promising application as gelling agent. The highest RG-I content (111.1 mg/g AIS) were obtained at 110 °C, 5 mins from RS 7, which was comparable with the pectin with reported prebiotic ability isolated from the literature, suggesting its potential application in novel products.

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition of multiple myeloma with few known risk factors. The emergence of mass spectrometry (MS) for the detection of MGUS has provided new opportunities to evaluate its risk factors. In total, 2628 individuals at elevated risk for multiple myeloma were enrolled in a screening study and completed an exposure survey (PROMISE trial). Participant samples were screened by MS, and monoclonal proteins (M-proteins) with concentrations of ≥0.2 g/L were categorized as MS-MGUS. Multivariable logistic models evaluated associations between exposures and MS outcomes. Compared with normal weight (body mass index [BMI] of 18.5 to <25 kg/m2), obesity (BMI of ≥30 kg/m2) was associated with MS-MGUS, adjusting for age, sex, Black race, education, and income (odds ratio [OR], 1.73; 95% confidence interval [CI], 1.21-2.47; P = .003). High physical activity (≥73.5 metabolic equivalent of task (MET)-hours per week vs <10.5 MET-hours per week) had a decreased likelihood of MS-MGUS (OR, 0.45, 95% CI, 0.24-0.80; P = .009), whereas heavy smoking and short sleep had increased likelihood of MS-MGUS (>30 pack-years vs never smoker: OR, 2.19; 95% CI, 1.24-3.74; P = .005, and sleep <6 vs ≥6 hours per day: OR, 2.11; 95% CI, 1.26-3.42; P = .003). In the analysis of all MS-detected monoclonal gammopathies, which are inclusive of M-proteins with concentrations of <0.2 g/L, elevated BMI and smoking were associated with all MS-positive cases. Findings suggest MS-detected monoclonal gammopathies are associated with a broader range of modifiable risk factors than what has been previously identified. This trial was registered at www.clinicaltrials.gov as #NCT03689595.

Light-chain (LC) monoclonal gammopathy of undetermined significance (MGUS) is a precursor of multiple myeloma (MM) and related conditions. LC-MGUS is characterized by free light-chain (FLC) levels outside defined reference intervals, indirectly indicating underlying plasma cell (PC) monoclonality. Next-generation flow cytometry (NGF) was used to evaluate clonal PC presence in bone marrow (BM) samples from individuals with LC-MGUS in the iStopMM study, aiming to assess the predictive value of the FLC ratio for clonal PC presence and its prognostic implications. BM samples from 61 individuals with LC monoclonal gammopathy were analyzed. Clonal plasma cells were detected in 53.6% of LC-MGUS samples (n = 28) and in all samples from individuals with more advanced conditions (n = 33). The FLC ratio was predictive of clonal PC presence for kappa-involved FLC ratios (p < 0.05; n = 42), with an optimal cutoff of 3.15 (96.7% sensitivity, 91.7% specificity). Of 195 individuals with kappa-involved LC-MGUS in follow-up within the iStopMM study, none with FLC ratios >1.65 to 3.15 progressed to MM (n = 124), whereas 4/71 (5.6%) with FLC ratios >3.15 progressed over median follow-up of 55 months. These findings support using a kappa-involved FLC ratio cutoff of >3.15 to more accurately identify individuals at increased risk of developing symptomatic PC disorders.

BACKGROUND:Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic precursor conditions to multiple myeloma and related disorders. Smoldering multiple myeloma is distinguished from MGUS by 10% or greater bone marrow plasma cells (BMPC) on sampling, has a higher risk for progression, and requires specialist management. OBJECTIVE:To develop a multivariable prediction model that predicts the probability that a person with presumed MGUS has 10% or greater BMPC (SMM or worse by bone marrow criteria) to inform the decision to obtain a bone marrow sample and compare its performance to the Mayo Clinic risk stratification model. DESIGN:iStopMM (Iceland Screens, Treats or Prevents Multiple Myeloma), a prospective population-based screening study of MGUS. (ClinicalTrials.gov: NCT03327597). SETTING:Icelandic population of adults aged 40 years or older. PATIENTS:1043 persons with IgG, IgA, light-chain, and biclonal MGUS detected by screening and an interpretable bone marrow sample. MEASUREMENTS:Monoclonal gammopathy of undetermined significance isotype; monoclonal protein concentration; free light-chain ratio; and total IgG, IgM, and IgA concentrations were used as predictors. Bone marrow plasma cells were categorized as 0% to 4%, 5% to 9%, 10% to 14%, or 15% or greater. RESULTS:The c-statistic for SMM or worse was 0.85 (95% CI, 0.82 to 0.88), and calibration was excellent (intercept, -0.07; slope, 0.95). At a threshold of 10% predicted risk for SMM or worse, sensitivity was 86%, specificity was 67%, positive predictive value was 32%, and negative predictive value was 96%. Compared with the Mayo Clinic model, the net benefit for the decision to refer for sampling was between 0.13 and 0.30 higher over a range of plausible low-risk thresholds. LIMITATION:The prediction model will require external validation. CONCLUSION:This accurate prediction model for SMM or worse was developed in a population-based cohort of persons with presumed MGUS and may be used to defer bone marrow sampling and referral to hematology. PRIMARY FUNDING SOURCE:International Myeloma Foundation and the European Research Council.

A BSTRACT : Sympatric species within a community often compete for limited resources, such as food items and habitat. The reliance by semi-aquatic snakes on resources in both terrestrial and aquatic habitats might influence either the frequency or intensity of interspecific interactions and also cause sympatric species to be disproportionately vulnerable to habitat alterations. To reduce competition, species might partition specific resources. Three watersnake species-Nerodia Nerodia erythrogaster, , N. harteri, , and N. rhombifer-occur -occur in the upper-middle reaches of the Brazos River, in central Texas. We examined the nature of coexistence among these watersnakes by (1) identifying habitat features that predicted site-level occupancy, (2) assessing microhabitat selection in relation to features such as riffle presence and canopy closure, and (3) quantifying environmental variables that influenced detection probabilities of the watersnakes. In-stream riffles were important for all three watersnake species at either the site or microhabitat level, or both. These three species of Nerodia appear to partition their habitat, however, because the snakes were distributed differently with respect to microhabitat features such as canopy closure and invasive saltcedar ( Tamarix spp.). Regular assessment of the community composition is needed because N. harteri continues to experience local population declines and extirpations. Habitat management, such as the removal of saltcedar and preservation of in-stream riffles, might promote long-term stability in the populations of all three species.

There is some evidence that a prior cancer is a risk factor for the development of multiple myeloma (MM). If this is true, prior cancer should be associated with a higher prevalence or increased progression rate of monoclonal gammopathy of undetermined significance (MGUS), the precursor of MM and related disorders. Those with a history of cancer might therefore constitute a target population for MGUS screening. This two-part study is the first study to evaluate a relationship between MGUS and prior cancers. First, we evaluated whether prior cancers were associated with having MGUS at the time of screening in the Iceland Screens Treats or Prevents Multiple Myeloma (iStopMM) study that includes 75,422 individuals screened for MGUS. Next, we evaluated the association of prior cancer and the progression of MGUS to MM and related disorders in a population-based cohort of 13,790 Swedish individuals with MGUS. A history of prior cancer was associated with a modest increase in the risk of MGUS (odds ratio=1.10; 95% confidence interval: 1.00-1.20). This excess risk was limited to prior cancers in the year preceding MGUS screening. A history of prior cancer was associated with progression of MGUS, except for myeloid malignancies which were associated with a lower risk of progression (hazard ratio=0.37; 95% confidence interval: 0.16-0.89; P=0.028). Our findings indicate that a prior cancer is not a significant etiological factor in plasma cell disorders. The findings do not warrant MGUS screening or different management of MGUS in those with a prior cancer.

This is a call for papers for a special issue of Biophysical Reviews devoted to British and Eire Biophysics, and follows a successful special issue dedicated to Japanese Biophysics published in 2020. Our objective is to have under one volume a selection of articles that can give the wider scientific community a firm insight into current developments in biophysical science in Britain and Eire.

Amyloidogenic serum free light chains (sFLCs) drive disease progression in AL amyloidosis. Matrix -assisted laser desorption/ionization time of fl ight mass spectrometry-based FLC assay (FLC-MS) has greater sensitivity than conventional sFLC assays allowing for the detection of serological residual disease. We report the utility of FLC-MS in a large series of patients with AL amyloidosis assessing the impact of FLC-MS negativity after treatment on overall survival (OS) and organ response rates. Serum samples were analyzed using FLC-MS at diagnosis and at 6 and 12 months after treatment. The impact of FLC-MS negativity over standard hematologic responses on survival and organ response was assessed. A total of 487 patients were included; 290 (59%) and 349 (71.5%) had cardiac and renal involvement, respectively. There was 100% concordance between the light chain (LC) fi bril type and LC isotype identi fi ed by FLC-MS. At 6 and 12 months, 81 (16.6%) and 101 (20.7%) were FLCMS negative. Of those achieving a conventional hematologic complete response (CR) at 6 and 12 months, 45 (27.7%) and 64 (39%) were FLC-MS negative. At 12 months, median OS for CR + FLC-MS negative was not reached vs 108 months in CR + FLC-MS positive ( P = .024). At 12 months, 70% of patients with FLC-MS negativity (vs 50% FLC-MS positive) achieved a cardiac response ( P = .015). In a multivariate analysis, FLC-MS negativity at 12 months was an independent predictor of better outcomes. FLCMS can detect persistent monoclonal light chains in a signi fi cant proportion of patients in a conventional hematologic CR. FLC-MS assessment promises to be a new standard for response assessment in AL amyloidosis.

Dr. Helmut Cölfen, an exceptional interdisciplinary scientist, mentor, colleague, and dear friend, passed away in November 2023 at the age of 58. His untimely departure is a profound loss for the fields of analytical ultracentrifugation, colloid, crystallization, and polymer research. This obituary pays tribute to Helmut, honoring his remarkable academic career and contributions to the study of nanochemistry, biophysics, and life sciences. Helmut was renowned for his pioneering research contributions in several key research areas: (1) Development of advanced analytical techniques: Helmut made major contributions to techniques such as analytical ultracentrifugation and field flow fractionation, which are widely utilized to characterize the structure of biomolecules and the growth of nanostructured crystalline materials; (2) Study of nucleation and crystallization processes: Helmut explored the early stages of crystallization which led to the discovery of pre-nucleation clusters and mesocrystal intermediates, in the presence of additives and templates; and (3) Investigation of structure and morphogenesis of mesocrystals, examining their molecular properties.

Introduction: Multiple myeloma (MM), Waldenström's macroglobulinemia (WM), and related disorders have been associated with excess risk of thrombosis. Furthermore, medications used to treat these disorders, in particular immunomodulatory agents, have been associated with excess thrombotic risk. Monoclonal gammopathy of undetermined significance (MGUS), the asymptomatic precursor of MM, WM, and related disorders, has also been associated with arterial and venous thrombosis. However, prior studies have been based on cohorts where MGUS was diagnosed as part of the work-up for other unrelated medical disorders. We have shown that these cohort have biased selection of individuals with chronic disease, including autoimmune disease, heart failure, endocrine disorders and more. This selection bias may have led to false associations or overestimation of the relationship of MGUS and thrombotic events. Aim: To evaluate the relationship of MGUS and thrombosis in a screened cohort of individuals with MGUS. Methods: Data were obtained from the Iceland screens, treats, or prevents multiple myeloma study (iStopMM), a population-based screening study for MGUS and a randomized trial of follow-up strategies with the aim of evaluating the benefits and harms of MGUS screening. As part of the study 75,422 Icelandic residents 40 years and older (54% of the underlying population) have provided their informed consent for the study and were screened by serum protein electrophoresis (SPEP) and free light chain (FLC) assay. The cohort was crosslinked to population-based Icelandic government registries that includes all diagnoses made in the universal healthcare system, recorded as international classification of diseases (ICD) 10 codes. The study exposure was MGUS at screening and the outcome was venous and arterial thrombosis, defined as recorded ICD-10 codes. Events recorded within 90 days of each other were considered the same event. We further analyzed subgroups of M protein isotype and light chain (LC) MGUS. We followed participants prospectively after the date of screening to arterial and venous thrombosis as the endpoint and censoring at death, progression to MM, WM, and related disorders, or end of follow-up. Hazard ratios (HR) for time to first thrombotic event were estimated using Cox regression models, while hazard ratios for recurrent thrombotic events were estimated using mixed-effects Cox regression models with a random intercept. Both prospective analyses were adjusted for age as a non-linear variable and sex. In a secondary analysis, M-protein concentration was included as a non-linear variable into similar models that were restricted to those with MGUS with an M-protein. Results: Of the 75,422 screened, 3,353 had MGUS with an M-protein, here termed heavy chain (HC) MGUS, and 315 had LC MGUS. Over a median follow-up of 3.67 to 3.90 years, depending on the outcome of interest, 263 and 3,557 arterial events (20.4 and 13.5 per 1,000 person years) and 260 and 3,092 venous events (20.2 and 11.7 per 1,000 person years) were observed in those with and without MGUS respectively. MGUS was found to be associated with venous thrombotic events (HR: 1.31; 95% CI: 1.08-1.57), in particular deep vein thrombosis (HR:1.46; 95% CI: 1.12-1.90). Of the different MGUS subtypes, this association was only observed in non-IgM MGUS. The results were similar in the recurrent events analysis. IgM MGUS was found to be associated with a higher of peripheral arterial embolic events (HR: 2.86; 95% 1.04-7.85) but this association was not observed in the recurrent event analysis. M-protein concentration was not correlated with the risk of thrombotic events. Discussion: In this large population-based study including more than 75,000 individuals screened for MGUS, we found that MGUS, and particularly non-IgM MGUS, was associated with venous thrombotic events. Interestingly, the size of the M-protein spike was not associated with a higher risk for thromboembolic events. Further studies are needed to identify the underlying mechanisms with the goal of identifying subgroups of the MGUS population that may require interventions to prevent thrombotic events, potentially improving the survival and quality of life of those with MGUS.

Introduction:The EXENT® Solution, a fully automated system, is a recent advancement for identifying and quantifying monoclonal immunoglobulins in serum. It combines immunoprecipitation with MALDI-TOF mass spectrometry. Compared to gel-based methods, like SPEP and IFE, it has demonstrated the ability to detect monoclonal immunoglobulins in serum at lower levels. In this study, samples that tested negative using EXENT® were reflexed to LC-MS to determine if the more sensitive LC-MS method could identify monoclonal immunoglobulins missed by EXENT®.Objectives:To assess whether monoclonal immunoglobulins that are not detected by EXENT® can be detected by LC-MS using a low flow LC system coupled to a Q-TOF mass spectrometer.Methods:Samples obtained from patients confirmed to have multiple myeloma (MM) were diluted with pooled polyclonal human serum and analyzed using EXENT®. If a specific monoclonal immunoglobulin was not detected by EXENT®, the sample was then subjected to analysis by LC-MS. For the LC-MS analysis, the sample eluate, obtained after the MALDI-TOF MS spotting step, was collected and transferred to an autosampler tray for subsequent analysis using LC-MS.Conclusion:LC-MS has the capability to detect monoclonal immunoglobulins that are no longer detected by EXENT®. Reflexing samples to LC-MS for analysis does not involve additional sample handling, allowing for a faster time-to-result compared to current approaches, such as Next-Generation Sequencing, Next-Generation Flow, and clonotypic peptide methods. Notably, LC-MS offers equivalent sensitivity in detecting these specific monoclonal immunoglobulins.