Chain Variant Research Articles

Fate of biosolids-bound PFAS through pyrolysis coupled with thermal oxidation for air emissions control.

Pyrolysis has been identified as a possible thermal treatment process for reducing perfluoroalkyl and polyfluoroalkyl substances (PFAS) from wastewater solids, though off-gas from the pyrolysis unit can still be a source of PFAS emissions. In this work, the fate of PFAS through a laboratory-scale pyrolysis unit coupled with a thermal oxidizer for treatment of off-gasses is documented. Between 91.5% and >99.9% reduction was observed through the entire system for specific compounds based on targeted analyses. Overall, the pyrolysis and thermal oxidizer system removed 99.4% of the PFAS moles introduced. Furthermore, shorter chain variants comprised the majority of reportable PFAS in the thermal oxidizer flue gas, indicating the longer chain compounds present in the dried biosolids fed to pyrolyzer decompose through the system. PRACTITIONER POINTS: Thermal oxidation is a promising treatment technology for exhaust systems associated with thermal biosolids treatments. Thermal oxidation demonstrated significant degradation capabilities, with gas phase emissions comprising only 0.200% of initial PFAS concentrations to the system. Short-chain PFAS made up a higher percent of thermal oxidizer emissions, ranging between 54.4% and 79.5% of PFAS in the exhaust on a molar basis. The possibility of recombinant PFAS formation and partial thermal decomposition of PFAS in thermal oxidation is a needed area of research.

Development of imaged capillary isoelectric focusing as a platform mispairing byproduct testing method for asymmetric WuXiBody-based bispecific antibodies

This study explores the application of imaged capillary isoelectric focusing (icIEF) to distinguish and quantify mispairing byproducts in asymmetric WuXiBody-based bispecific antibodies (AsWXbsAbs). Bispecific antibody (BsAb), developed using Knobs-into-Holes (KiH) technology, often result in byproducts such as knob-knob (KK) and hole-hole (HH) homodimers, which share similar sizes with the target BsAb, complicating their separation by traditional methods like size exclusion chromatography-high performance liquid chromatography (SEC-HPLC). Our approach leverages the unique pI differences introduced by substituting the CH1/CL domain with the T cell receptor (TCR) constant domain in AsWXbsAbs. This modification enables icIEF to effectively differentiate between the KK and HH homodimers and the target BsAb. Through the construction and expression of heavy and light chain variants, we validated that the experimental pI values aligned with theoretical predictions, confirming icIEF’s capability in distinguishing these entities. Enrichment of in-process K-related and H-related species was achieved, allowing for high-purity samples necessary for icIEF method development. The method was qualified and showed good specificity and linearity, with a quantitation limit of 4 % for K-related species (R2 = 0.9919) and 1 % for H-related species (R2 = 0.9805). This method was used effectively as an in-process test and release assay, proving its simple and quick utility in multiple AsWXbsAbs projects.

A methodology to map chains of general practices in the Netherlands

Abstract Background Commercial entities are increasingly interested in acquiring Dutch general practices (GPs). They see profitable opportunities in upscaling by forming chains. Chain organizations integrate business processes of GPs within one organizational unit. The governance structure of these chains can be complex, leading to opacity and difficulties to see conflicts of interest and market power. To investigate how this development may have an impact on quality and accessibility of care, it is first needed to establish the ways in which these chains are formed. By mapping the chain structure in a data-driven way, impact monitoring becomes possible. For the Netherlands we investigated how chain structures of GPs can be empirically identified. Methods Background data of approximately 4,800 Dutch GPs from the Nivel Healthcare Professional Registries was linked with data from the Chamber of Commerce’s Trade Register. This enabled the determination of the legal form, business location, ownership, and director identification for all GPs. By this data-driven manner, the variation in organizational structures of all Dutch GPs was mapped and analyzed. Results Four different chain variants of Dutch GP chains were identified based on three types of relations between the chain organization and their GPs: ownership, location and the composition of the board of directors. Based on ownership, two ‘top-down’ chain variants were identified. Two ‘bottom-up’ chain variants were found based on location and board composition: (1) a chain organization acquires a seat on the board of the GP, and (2) the GP and the chain organization share the same business address. Combining these variants provides a new typology of GP chains in the Netherlands. Conclusions Our methodology enables to empirically map chain formation in primary care. By developing a new typology in a systematic way, a foundation is created to monitor organizational developments and their impact on quality and accessibility of care. Key messages • A typology of Dutch GP chains was developed based on three relations: the ownership, composition of the board and the establishment location of the chain organization and its practices. • Our methodology was put into practice to map different chain structures of GPs in the Netherlands, but it is not limited to primary care and can also be applied in other sectors and countries.

A Case for Co-oximetry: Methemoglobinemia secondary to a Rare Hemoglobin Variant

Abstract Introduction/Objective The presence of dyshemoglobins and some inherited hemoglobin (Hb) variants can cause over or underestimation of oxygen saturation (O2sat) when using a pulse oximeter (ox). These noninvasive medical devices rely on two wavelengths, a pulsing arterial bed, and light absorption properties of Hb to measure the difference between deoxy- and oxy-Hb. In contrast, a co-oximeter (co-ox) requires arterial blood. By using at least four wavelengths, co-ox measures the functional and fractional O2sat to detect all forms of Hb, including those that do not bind oxygen (O2), such as methemoglobin (metHb). Methemoglobinemia may be congenital or acquired, resulting from exposure to certain toxins, metabolic disorders, enzymatic deficiencies such as cytochrome b5 reductase deficiency, or hemoglobinopathies. Methods/Case Report A healthy, adolescent male undergoing a sports physical at his pediatrician’s office was hypoxic by pulse ox and sent to the emergency department (ED) for evaluation. On exam, he had cold, blue tinged fingertips and lips but was otherwise asymptomatic. His O2sat was 88-90% on room air with minimal improvement with 6L of supplemental O2. Co-ox revealed a metHb level > 20%. The father also mentioned that the mother had frequent ED visits for hypoxia. Capillary Hb electrophoresis showed peaks in the HbA, HbF, and HbA2 zones of 78.3%, 17.9%, and 3.6%, respectively. All CBC parameters were within the reference intervals. The large peak in the HbF zone would suggest hereditary persistence of fetal hemoglobin (HPFH); however, the clinical picture was not consistent. Further reference laboratory investigation determined that the patient was heterozygous for Hb Tübingen (HbTüb), a beta globin chain variant resulting from a point mutation at position 106. By mass spectrometry, the variant quantified as 38% of the total hemoglobin, indicating underestimation by electrophoretic techniques. Results (if a Case Study enter NA) NA Conclusion This case presents an essentially asymptomatic patient with hypoxia and elevated methemoglobin levels. Electrophoretic hemoglobinopathy and CBC workup were clinically inconsistent with HPFH and the presence of an aberrant hemoglobin migrating in the HbF must be considered in the differential diagnosis. The manifestation of HbTüb as methemoglobinemia in this context adds complexity to the diagnostic puzzle. Further laboratory exploration into the underlying mechanisms driving this unique presentation is crucial for a comprehensive understanding and tailored management approach.

A Rare Case of Homozygous Hemoglobin G-Philadelphia & Alpha Thalassemia

Abstract Introduction/Objective Hemoglobin (Hb) G-Philadelphia (GPh) is an alpha chain gene variant caused by a missense mutation resulting in a change from Glu to Asp at position 68. This change leads to alterations in the Hb structure and oxygen affinity. The mutation is inherited in an autosomal codominant pattern allowing for an asymptomatic carrier state. While the most common alpha chain variant, GPh heterozygosity is still infrequent, estimated at 1:5000 in African Americans. In African Americans, GPh is frequently linked to an alpha thalassemia deletion. On its own it is considered a benign variant that does not result in significant health issues. Homozygous HbGPh frequency is estimated at 1 in 25 million. Methods/Case Report A postpartum woman in her 4th decade of life was found to have a Hb of 10.8 and a mean corpuscular volume of 74. Initial work up included Hb electrophoresis that quantified HbA at 0%, Hb F at 0%, HbA2 at 0%, and 2 Hb variants representing 96.1% and 3.8% of the total globin. The major Hb variant migrated in the D or G position by alkaline and acid gel Hb electrophoresis. The minor variant was consistent with HbG2. Due to this abnormal Hb electrophoresis, a sample was sent out for a Hb evaluation reflexive cascade (HERC). HERC analysis by high-performance liquid chromatography and capillary gel electrophoresis found 99.9% of Hb consistent with the alpha chain variant HbG. Analysis of the alpha globin gene region revealed 2 copies of an alpha globin gene deletion that was interpreted as alpha-thal trait (-a/-a). This result is consistent with homozygous alpha-thal-2 and homozygous HbGPh (alpha^G/thal + alpha^G/thal). Results (if a Case Study enter NA) NA Conclusion Alpha^G/thal + alpha^G/thal presents a unique and complex challenge for diagnosis due to its rarity and because HbG2 is not always visualized by alkaline gel electrophoresis. The presence of a Hb G or D variant, a HbG2 variant, and the lack of both HbA and HbA2 are key electrophoretic findings. Clinically, alpha^G/thal + alpha^G/thal behaves essentially like a homozygous alpha-thal-2 trait with persistent microcytosis and erythrocytosis. Thus, co- inheritance of the alpha-thal trait will be suggested by a thalassemic complete blood count pattern.

Effect of a fluorinated surfactant on Langmuir monolayer properties of minimal-linker gemini surfactants

A new class of carboxylic acid-terminated gemini surfactants which contain the smallest possible headgroup linker (a single bond) has recently been reported in the literature. In this current work, we have explored how Langmuir monolayers of two different alkyl tail chain length variants (n = 12, n = 16) of these surfactants, dubbed Cn-0-Cn, are impacted by mixing with a benchmark perfluorinated surfactant, perfluorotetradecanoic acid (PF). Pure PF and C16-0-C16 monolayers share similar general characteristics, yielding compact, incompressible, solid-like films at the air-water interface. In contrast, the shorter tail chain variant, C12-0-C12 forms expanded, compressible liquid-like films. While both tail chain variants formed mixed films with PF that were generally expanded in comparison with their pure components, and were also phase-separated, the extent of interactions between film components and the resulting micron-scale morphology of the mixed films were different for the two alkyl chain lengths. Overall, PF induces different packing behavior in both the systems and the observations are attributed to the difference in the dispersion forces originating from the tail chain length differences.

Hb H disease associated with compound heterozygosity for --SEA deletion and a novel alpha globin chain variant (HBA2:c.175C>A) on the distal histidine in a Chinese family

ABSTRACT Objectives: In clinical practice, the majority of α-thalassaemia cases arise from deletions of the α-globin genes. However, a subset of cases is attributed to rare haemoglobin variants, which can manifest with borderline or normal screening results, potentially leading to missed diagnoses in clinical practice. Methods: Blood samples were collected from family members and underwent haematological, DNA and RNA analysis. Results: The five-month-old proband presented a haematological phenotype consistent with Hb H disease. The mother’s haematology profile was consistent with an α-thalassaemia carrier, while the father exhibited a borderline reduction in MCV and MCH. MALDI-TOF identified an abnormal α-chain in the proband. DNA analysis revealed a novel α-globin variant (HBA2:c.175C>A, α58His>Asn, Hb DG-Nancheng) affecting the distal histidine in the family. The father and the mother had α-genotype of --SEA/αα and αDG-Nanchengα/αα, respectively; while the proband inherited both mutant alleles (--SEA/αDG-Nanchengα). Sequencing of cDNA from HBA2 gene identified an equal ratio of normal and mutant alleles. Conclusion: This rare case highlighted the importance of identifying rare haemoglobin variant during prenatal screening. The clinical and genetic data provides useful information on the pathogenicity of this variant and further insight into the role of distal histidine residue of α-globin.

Wide spectrum of novel and rare hemoglobin variants in the multi-ethnic Indian population: A review.

The hemoglobin (Hb) variants are qualitative abnormalities due to production of structurally abnormal globin proteins. They are categorized based on the type of mutation present in the α1, α2, β, Gγ, Aγ and δ globin genes. So far, more than 1550 Hb variants are reported in the database. They could lead to Hb polymerization, Hb instability, altered oxygen affinity and decreased oxygen-carrying capacity of Hb or have no clinical manifestations. In India, ethnic diversity, consanguinity, regional variations and migration result in the presence of different Hb variants. We have compiled all the variants of α, β and δ globin chains in heterozygous, homozygous and in compound heterozygous forms reported from India in the last 52 years. Of the 63 rare and novel hemoglobin variants reported from India, 22 were α-globin chain variants, 37 were β-globin chain variants and 4 were δ-globin chain variants. Twelve novel Hb variants (Hb J Rajappan, Hb Koya Dora, Hb Rampa, Hb Godavari, Hb Chandigarh, Hb D Agri, Hb Lucknow, Hb Vellore, Hb Midnapore, Hb Bijnor, Hb A2Tianhe and Hb A2Saurashtra) were identified among persons of Indian origin. Majority of them were picked up on HPLC. Some of the variants like Hb Titusville, Hb Shimonoseki, Hb Chandigarh, Hb D Agri, Hb Yaizu and Hb Vellore eluted in the HbS window whereas variants like HbD Iran, Hb St. Louis, Hb G Coushata, HbM Saskatoon, Hb Lucknow, Hb Grange-Blanche and Hb Tianshui showed falsely elevated HbA2. Hence, careful and systematic investigations are required to identify them.

Identification of Novel Hb Guiyang [HBA2: c.151C > A α2 50 (CE8) His- Asn] and Phenotype- Genotype Correlation of Abnormal Hemoglobins in Guizhou, Southwest China.

To analyze the composition of abnormal hemoglobin and the relationship between genotype and phenotype by screening abnormal hemoglobin in a subpopulation of Guizhou, China. Routine blood evaluation, capillary electrophoresis of hemoglobin, and mutation of α - and β - thalassemia genes were evaluated in 19,976 individuals for thalassemia screening in Guizhou. Sanger sequencing of HBA1, HBA2 and HBB genes was performed in samples with abnormal bands or unexplained increases of normal bands. The types of abnormal hemoglobin were obtained by sequence analysis. Abnormal hemoglobin was detected in 84 individuals (detection rate, 0.42%). Ten types each of α and β globin chain variants were detected, including most commonly Hb E, Hb New York and Hb Port Phillip. In this study, the abnormal Hb Mizuho was identified for the first time in a Chinese population, and a novel abnormal hemoglobin Hb Guiyang (HBA2: c.151C > A) was detected for the first time. Except for Hb Mizuho, other abnormal hemoglobin heterozygotes without thalassemia or iron deficiency had no significant hematological changes. This study enriched the molecular epidemiological data of abnormal hemoglobin in Guizhou, China and provided reference data for genetic counseling and prenatal diagnosis of abnormal hemoglobin.

Genomic Surveillance of SARS-CoV-2 Sequence Variants at Universities in Southwest Idaho.

Although the impact of the SARS-CoV-2 pandemic on major metropolitan areas is broadly reported and readily available, regions with lower populations and more remote areas in the United States are understudied. The objective of this study is to determine the progression of SARS-CoV-2 sequence variants in a frontier and remote intermountain west state among university-associated communities. This study was conducted at two intermountain west universities from 2020 to 2022. Positive SARS-CoV-2 samples were confirmed by quantitative real-time reverse transcription-polymerase chain reaction and variants were identified by the next-generation sequencing of viral genomes. Positive results were obtained for 5355 samples, representing a positivity rate of 3.5% overall. The median age was 22 years. Viral genomic sequence data were analyzed for 1717 samples and phylogeny was presented. Associations between viral variants, age, sex, and reported symptoms among 1522 samples indicated a significant association between age and the Delta variant (B 1.167.2), consistent with the findings for other regions. An outbreak event of AY122 was detected August-October 2021. A 2-month delay was observed with respect to the timing of the first documented viral infection within this region compared to major metropolitan regions of the US.

A rare case of compound Hemoglobin Lansing/Hemoglobin S coinherited with alpha thalassemia trait (-alpha3.7) presented with spurious hypoxemia and moderate hemolytic anemia

Abstract We present a case of a 27-year-old female at 27 weeks of gestation, who presented at the emergency department for vaginal spotting. She was also found to have low oxygenation on pulse oximetry of approximately 82% at room air. Her SpO2 did not improve with O2 supplement. She had a similar presentation a month before, with mild light-headedness and low oxygenation. However, two repeated air blood gas (ABG) findings were normal for oxygen saturation. Hemoglobinopathy was suspected due to the disparity. She was anemic during her presentation, with hemoglobin 8.3 g/dl, RBC count 3.36 million/ul, MCV 81 fl and MCH 24.7 pg. Additional workup showed increased reticulocyte count, decreased haptoglobin, negative direct Coombs test, negative G6PD test, and no evidence of a PNH clone. Capillary hemoglobin electrophoresis showed HbA 59.8%, HbS 34.5%, HbA2 3.6% and a small peak (2.1%) in the Z8 zone with a trailing edge at HbF window. HPLC revealed an “unknown peak” of 8.2% with a retention time of 1.93 minutes as well as the HbS peak. There was also a tiny additional A2 peak unresolved from the main A2 peak. Alpha globin gene sequencing revealed one copy of the -alpha3.7 alpha-globin deletion and one copy of Hb Lansing variant in the alpha2-globin gene. This is consistent with the compound Hemoglobin Lansing/Hemoglobin S coinherited with alpha thalassemia trait. Hemoglobin Lansing is a rare unstable alpha hemoglobin variant with mutation of c.264C>G resulting with a substitution of His by Gln at codon 87. The mutation was first discovered in the alpha 2 gene. Then the same mutation was found in alpha 1 gene later and named as Hemoglobin Lansing-Ramathibodi. To the best of our knowledge, this is the first reported case of Hemoglobin Lansing with alpha thalassemia trait (-alpha3.7) and HbS. Spuriously low pulse oximetry measurements have previously been reported in Hb Lansing variants. It was speculated to be due to different absorption spectra of Hb Lansing which is under study now. The patient also presented with hemolytic anemia. The exact cause was undetermined yet although it might be related to her hemoglobinopathy. Mild hemolytic anemia was reported in two cases of co-inheritance of Lansing-Ramathibodi and Hb Pakse (a non-deletional alpha thalassemia) but not in the members of the same family with Hb Lansing alone. It was also reported that some unstable alpha chain variants, when associated with another alpha thalassemia defect, present with a more severe phenotype including hemolytic anemia even though essentially asymptomatic in a heterozygous state.

THU253 The Hemoglobin Wayne Variant And Association With Falsely Elevated HbA1c

Abstract Disclosure: N. Mulpuri: None. A. Bryant: None. D. Shahin: None. K. Soe: None. Background: Hemoglobin Wayne (Hb Wayne) is a rare, silent alpha chain variant caused by a frameshift mutation in the HbA2 gene. Although clinically silent, this mutation falsely elevates HbA1c values. Clinical cases: We are presenting three cases of Hb Wayne patients referred to our diabetes clinic within the last 5 years. All three cases were Caucasian-American males diagnosed with uncontrolled diabetes based on high HbA1c values of ranging from 10.1-10.6 %. One of the patients was initially started on metformin while the other patients’ treatment plan included dietary and lifestyle modifications. Review of the labs showed that renal function, complete blood count and fasting plasma glucose were within the normal range. High HbA1c value was noted by routine screening lab without having any symptoms related to DM or features of insulin resistance. The discrepancy between high HbA1c values and other glycemic index parameters (serum glucose and FSBG values) was noted. Subsequently, further work up was done (repeat HbA1c with different assay and fructosamine) to verify the diagnosis of uncontrolled DM. Fructosamine levels and repeat HbA1c with a different assay (enzymatic assay at Quest lab) were normal. Hemoglobin electrophoresis confirmed presence of an abnormal alpha variant consistent with Hb Wayne. The patients were reassured and educated about this Hb variant, and no further treatment for DM was pursued. Conclusion: Rare hemolgobinopathies may be more common than previously expected as they can be clinically silent and easily overlooked. While HbA1c has been an important clinical tool for diagnosis and management of diabetes, clinicians should look for underlying reasons which can affect HbA1c assay if there is any discrepancy between HbA1c, FSBG and plasma glucose values. The laboratory at our institution uses cation- exchange High Performance Liquid Chromatography method (Bio-Rad D-100 instrument) resulting in falsely high HbA1c values. Some hemoglobinopathies can affect the widely used HbA1c testing method such as CE-HPLC. The impact on HbA1c values will differ depending on hemoglobin variant and specific method and assay used. Given the limitations of HbA1c testing, clinicians should avoid relying heavily on HbA1c values in management and diagnosis of diabetes. It is vital that clinicians use their clinical judgment to correlate HbA1c with other clinical parameters such as continuous glucose monitoring data, glycated albumin,1,5 anhydroglucitrol (1,5 –AG), fingerstick blood glucose, plasma glucose and fructosamine values. Presentation: Thursday, June 15, 2023

Active site serine-193 modulates activity of human aromatic amino acid decarboxylase

Aromatic amino acid decarboxylase is a pyridoxal 5′-phosphate-dependent enzyme responsible for the synthesis of the neurotransmitters, dopamine and serotonin. Here, by a combination of bioinformatic predictions and analyses, phosphorylation assays, spectroscopic investigations and activity measurements, we determined that Ser-193, a conserved residue located at the active site, can be phosphorylated, increasing catalytic efficiency. In order to determine the molecular basis for this functional improvement, we determined the structural and kinetic properties of the site-directed variants S193A, S193D and S193E. While S193A retains 27% of the catalytic efficiency of wild-type, the two acidic side chain variants are impaired in catalysis with efficiencies of about 0.15% with respect to the wild-type. Thus, even if located at the active site, Ser-193 is not essential for enzyme activity. We advance the idea that this residue is fundamental for the correct architecture of the active site in terms of network of interactions triggering catalysis. This role has been compared with the properties of the Ser-194 of the highly homologous enzyme histidine decarboxylase whose catalytic loop is visible in the spatial structure, allowing us to propose the validation for the effect of the phosphorylation. The effect could be interesting for AADC deficiency, a rare monogenic disease, whose broad clinical phenotype could be also related to post translational AADC modifications.

Precision medicine using whole genome sequencing in a cat identifies a novel COL5A1 variant for classical Ehlers-Danlos syndrome.

Ehlers-Danlos syndromes (EDS) are a heterogeneous group of heritable connective tissue disorders occurring in both human and veterinary patients. The genetics of these disorders are poorly described in small animal patients. Define the clinical manifestations and genetic cause of a suspected form of EDS in a cat. A 14-week-old male domestic medium hair cat was presented with skin hyperextensibility and fragility. The classic tragic facial expression was observed as well as chronic pruritus and mild hyperesthesia. Blood samples and a skin biopsy sample were collected from the affected cat. Clinical examinations, histology, electron microscopy and whole genome sequencing were conducted to characterize the clinical presentation and identify possible pathogenic DNA variants to support a diagnosis. Criteria defining variant pathogenicity were examined including human disease variant databases. Histology showed sparse, disorganized collagen and an increase in cutaneous mast cells. Electron microscopy identified ultrastructural defects commonly seen in collagen type V alpha 1 chain (COL5A1) variants including flower-like collagen fibrils in cross-section. Whole genome sequencing and comparison with 413 cats in the 99 Lives Cat Genome Sequencing Consortium database identified a novel splice acceptor site variant at exon 4 in COL5A1 (c.501-2A>C). Our report broadens the current understanding of EDS in veterinary patients and supports the use of precision medicine techniques in clinical veterinary practice. The classification of variants for pathogenicity should be considered in companion animals.

Hemoglobin β-Globin Variants In Hispanic Patients: An Institutional Experience From Dallas, Texas

Hemoglobinopathies are the most common single-gene disorders in humans. There are 1,424 variants of human hemoglobin described with 951 involving the β-globin gene. Ancestry and geography play a significant role in the incidence and nature of hemoglobinopathies, with African, Asian, and Mediterranean populations and their descendants being amongst the most affected. Investigation of variants in individuals of Hispanic descent is needed to reflect the changing demographics of the United States. Hemoglobin β-globin evaluation through gel electrophoresis, high-performance liquid chromatography, and HBB gene sequencing was performed on patients from Texas hospitals between 2010 and 2015 and demographic parameters (age, sex, ethnicity) was subsequently analyzed. A total of 846 patients underwent hemoglobinopathy evaluation. A β chain variant was detected in 628 of the 846 total patients. Hispanic patients represented 37% (314/846 patients), which were equally distributed between females (50%; 156/314) and males (50%; 156/314). A β-globin chain variant was found in 67% of Hispanic patients with a distribution across 10 variants seen in greater than 1% of patients. For hemoglobin variants, an understanding of the regional and ethnic prevalence will improve patient care through more effective screening and identification of the variant, early diagnosis, and appropriate treatment if necessary, and better genetic counseling.

Incidental finding of rare hemoglobin: hemoglobin Bari in northeast Spain

Abstract Objectives Cation exchange high-performance liquid chromatography (HPLC) is one of the techniques available for determining glycated hemoglobin (HbA1c) and also the method of choice for structural hemoglobinopathies screening. The objective of this case is to show how in a routine HbA1c test it is possible to incidentally find a hemoglobinopathy. Case presentation In a routine blood analysis, an abnormal value for the hemoglobin A2 (HbA2) was obtained during the study of HbA1c with HPLC on the ADAMS™ A1c HA-8180T. After suspecting it could be due to the presence of a hemoglobinopathy, the study of possible variants was expanded using electrophoresis and HPLC on the Hydrasys and Variant II analysers, respectively. Since it could not be identified by these conventional methods, a genetic study was also carried out using Sanger sequencing. The patient presented a low HbA2 (1.3 %) and a 24.9 % variant with a retention time of 1.95 min, compatible with alpha-globin chain variant. In the genetic study, the pathogenic variant c.138C>G was detected in the HbA 2 gene in heterozygosis, which resulted in the expression of the structural hemoglobinopathy known as hemoglobin Bari. Conclusions The initial screening for structural hemoglobinopathies allows its identification or suspicion especially when it was performed with HbA1c analysis, requiring subsequent confirmation and diagnosis by other techniques.

Childhood Hypertrophic Cardiomyopathy Caused by Beta-Myosin Heavy Chain Variants Is Associated With a More Obstructive but Less Arrhythmogenic Phenotype Than Myosin-Binding Protein C Disease.

Childhood Hypertrophic Cardiomyopathy Caused by Beta-Myosin Heavy Chain Variants Is Associated With a More Obstructive but Less Arrhythmogenic Phenotype Than Myosin-Binding Protein C Disease.

Investigation of Naphthyl-Polyamine Conjugates as Antimicrobials and Antibiotic Enhancers.

As part of our search for new antimicrobials and antibiotic enhancers, a series of naphthyl- and biphenyl-substituted polyamine conjugates have been synthesized. The structurally-diverse library of compounds incorporated variation in the capping end groups and in the length of the polyamine (PA) core. Longer chain (PA-3-12-3) variants containing both 1-naphthyl and 2-naphthyl capping groups exhibited more pronounced intrinsic antimicrobial properties against methicillin-resistant Staphylococcus aureus (MRSA) (MIC ≤ 0.29 µM) and the fungus Cryptococcus neoformans (MIC ≤ 0.29 µM). Closer mechanistic study of one of these analogues, 20f, identified it as a bactericide. In contrast to previously reported diarylacyl-substituted polyamines, several examples in the current set were able to enhance the antibiotic action of doxycycline and/or erythromycin towards the Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli. Two analogues (19a and 20c) were of note, exhibiting greater than 32-fold enhancement in activity. This latter result suggests that α,ω-disubstituted polyamines bearing 1-naphthyl- and 2-naphthyl-capping groups are worthy of further investigation and optimization as non-toxic antibiotic enhancers.

Development of an antibody-ligand fusion protein scFvCD16A-sc4-1BBL in Komagataella phaffii with stimulatory activity for Natural Killer cells

BackgroundNatural killer (NK) cell-based immunotherapies have demonstrated substantial potential for the treatment of hematologic malignancies. However, its application is limited due to the difficulty in the production of a large number of NK cells in vitro and the insufficient therapeutic efficacy against solid tumors in vivo. Engineered antibodies or fusion proteins targeting activating receptors and costimulatory molecules of NK cells have been developed to encounter these problems. They are mostly produced in mammalian cells with high cost and long processing times. Yeast systems, such as Komagataella phaffii, present a convenient manipulation of microbial systems with the key advantages of improved folding machinery and low cost.ResultsIn this study, we designed an antibody fusion protein scFvCD16A-sc4-1BBL, composed of the single chain variant fragment (scFv) of anti-CD16A antibody and the three extracellular domains (ECDs) of human 4-1BBL in a single-chain format (sc) with the GS linker, aiming to boost NK cell proliferation and activation. This protein complex was produced in the K. phaffii X33 system and purified by affinity chromatography and size exclusion chromatography. The scFvCD16A-sc4-1BBL complex showed comparable binding abilities to its two targets human CD16A and 4-1BB as its two parental moieties (scFvCD16A and monomer ECD (mn)4-1BBL). scFvCD16A-sc4-1BBL specifically stimulated the expansion of peripheral blood mononuclear cell (PBMC)-derived NK cells in vitro. Furthermore, in the ovarian cancer xenograft mouse model, adoptive NK cell infusion combined with intraperitoneal (i.p) injection of scFvCD16A-sc4-1BBL further reduced the tumor burden and prolonged the survival time of mice.ConclusionOur studies demonstrate the feasibility of the expression of the antibody fusion protein scFvCD16A-sc4-1BBL in K. phaffii with favourable properties. scFvCD16A-sc4-1BBL stimulates PBMC-derived NK cell expansion in vitro and improves the antitumor activity of adoptively transferred NK cells in a murine model of ovarian cancer and may serve as a synergistic drug for NK immunotherapy in future research and applications.

α,ω-Diacyl-Substituted Analogues of Natural and Unnatural Polyamines: Identification of Potent Bactericides That Selectively Target Bacterial Membranes.

In this study, α-ω-disubstituted polyamines exhibit a range of potentially useful biological activities, including antimicrobial and antibiotic potentiation properties. We have prepared an expanded set of diarylbis(thioureido)polyamines that vary in central polyamine core length, identifying analogues with potent methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Acinetobacter baumannii and Candida albicans growth inhibition properties, in addition to the ability to enhance action of doxycycline towards Gram-negative bacterium Pseudomonas aeruginosa. The observation of associated cytotoxicity/hemolytic properties prompted synthesis of an alternative series of diacylpolyamines that explored aromatic head groups of varying lipophilicity. Examples bearing terminal groups each containing two phenyl rings (15a-f, 16a-f) were found to have optimal intrinsic antimicrobial properties, with MRSA being the most susceptible organism. A lack of observed cytotoxicity or hemolytic properties for all but the longest polyamine chain variants identified these as non-toxic Gram-positive antimicrobials worthy of further study. Analogues bearing either one or three aromatic-ring-containing head groups were either generally devoid of antimicrobial properties (one ring) or cytotoxic/hemolytic (three rings), defining a rather narrow range of head group lipophilicity that affords selectivity for Gram-positive bacterial membranes versus mammalian. Analogue 15d is bactericidal and targets the Gram-positive bacterial membrane.