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2.
Diabetes Metab Syndr ; 18(3): 102977, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38503114

ABSTRACT

AIMS: To investigate differences in maternal and foetal outcomes in pregnancy, where patients developed hypoglycaemia following the 2-hour 75g oral glucose tolerance test (OGTT). METHOD: A retrospective cohort study of 200 pregnancies attending the Antenatal Clinic at Tameside General Hospital between 2018 and 2022. Outcomes were compared between 4 groups: normal OGTT [G1; (n = 39, 20%), diagnosis of gestational diabetes mellitus (GDM) based on OGTT [G2; BG ≥ 5.6 mmol/L or 2-h OGTT ≥7.8 (n = 41, 21%)], hypoglycaemia [G3; 2 h OGTT 3.0-3.9 mmol/L (n = 93, 47%)], or clinically significant hypoglycaemia [G4; 2 h OGTT <3.0 mmol/L (n = 27, 14%)]. Maternal BMI, foetal birth weight (FBW), neonatal complications, neo-natal intensive care unit (NICU) stay and conversion to GDM were assessed. RESULTS: Maternal BMI was lower in G3 and G4 (27.3 kg/m2 and 28.1 kg/m2 respectively) compared to G1 (30.4 kg/m2) (p = 0.02). NICU stay was more frequent in G3 (12%, n = 11) and G4 (8%, n = 2) compared to G1 (5%, n = 2). Foetal complications occurred in 27% of G3 (n = 25) and 33% of G4 (n = 9) compared to 23% in G1 (n = 9) and 17% in G2 (n = 7). FBW was similar in G1 when compared to G3 and G4 (p = 0.34). Of the 120 patients in G3 and G4, 25 patients self-monitored blood glucose for two weeks; 28% (n = 7) subsequently developed GDM. CONCLUSION: Higher rates of NICU stay and foetal complications were seen in both hypoglycaemic groups. In patients with hypoglycaemia following OGTT there is evidence to support self-monitoring blood glucose as 28% were later diagnosed with GDM.


Subject(s)
Diabetes, Gestational , Glucose Tolerance Test , Hypoglycemia , Pregnancy Outcome , Humans , Pregnancy , Female , Hypoglycemia/epidemiology , Hypoglycemia/blood , Hypoglycemia/diagnosis , Retrospective Studies , Adult , Diabetes, Gestational/blood , Infant, Newborn , Blood Glucose/analysis , Prognosis , Follow-Up Studies , Biomarkers/blood , Biomarkers/analysis , Pregnancy Complications/blood
3.
Sci Rep ; 14(1): 4699, 2024 02 26.
Article in English | MEDLINE | ID: mdl-38409583

ABSTRACT

Deregulation of lipid composition in adipose tissue adjacent to breast tumour is observed in ex vivo and animal models. Novel non-invasive magnetic resonance imaging (MRI) allows rapid lipid mapping of the human whole breast. We set out to elucidate the spatial heterogeneity of peri-tumoural lipid composition in postmenopausal patients with oestrogen receptor positive (ER +) breast cancer. Thirteen participants (mean age, 62 ± [SD] 6 years) with ER + breast cancer and 13 age-matched postmenopausal healthy controls were scanned on MRI. The number of double bonds in triglycerides was computed from MRI images to derive lipid composition maps of monounsaturated, polyunsaturated, and saturated fatty acids (MUFA, PUFA, SFA). The spatial heterogeneity measures (mean, median, skewness, entropy and kurtosis) of lipid composition in the peri-tumoural region and the whole breast of participants and in the whole breast of controls were computed. The Ki-67 proliferative activity marker and CD163 antibody on tumour-associated macrophages were assessed histologically. Mann Whitney U or Wilcoxon tests and Spearman's coefficients were used to assess group differences and correlations, respectively. For comparison against the whole breast in participants, peri-tumoural MUFA had a lower mean (median (IQR), 0.40 (0.02), p < .001), lower median (0.42 (0.02), p < .001), a negative skewness with lower magnitude (- 1.65 (0.77), p = .001), higher entropy (4.35 (0.64), p = .007) and lower kurtosis (5.13 (3.99), p = .001). Peri-tumoural PUFA had a lower mean (p < .001), lower median (p < .001), a positive skewness with higher magnitude (p = .005) and lower entropy (p = .002). Peri-tumoural SFA had a higher mean (p < .001), higher median (p < .001), a positive skewness with lower magnitude (p < .001) and lower entropy (p = .012). For comparison against the whole breast in controls, peri-tumoural MUFA had a negative skewness with lower magnitude (p = .01) and lower kurtosis (p = .009), however there was no difference in PUFA or SFA. CD163 moderately correlated with peri-tumoural MUFA skewness (rs = - .64), PUFA entropy (rs = .63) and SFA skewness (rs = .59). There was a lower MUFA and PUFA while a higher SFA, and a higher heterogeneity of MUFA while a lower heterogeneity of PUFA and SFA, in the peri-tumoural region in comparison with the whole breast tissue. The degree of lipid deregulation was associated with inflammation as indicated by CD163 antibody on macrophages, serving as potential marker for early diagnosis and response to therapy.


Subject(s)
Breast Neoplasms , Animals , Humans , Middle Aged , Female , Breast Neoplasms/diagnostic imaging , Fatty Acids, Monounsaturated , Postmenopause , Fatty Acids , Receptors, Estrogen
4.
Front Oncol ; 13: 1277556, 2023.
Article in English | MEDLINE | ID: mdl-38125950

ABSTRACT

Introduction: The early identification of good responders to neoadjuvant chemotherapy (NACT) holds a significant potential in the optimal treatment of breast cancer. A recent Bayesian approach has been postulated to improve the accuracy of the intravoxel incoherent motion (IVIM) model for clinical translation. This study examined the prediction and early sensitivity of Bayesian IVIM to NACT response. Materials and methods: Seventeen female patients with breast cancer were scanned at baseline and 16 patients were scanned after Cycle 1. Tissue diffusion and perfusion from Bayesian IVIM were calculated at baseline with percentage change at Cycle 1 computed with reference to baseline. Cellular proliferative activity marker Ki-67 was obtained semi-quantitatively with percentage change at excision computed with reference to core biopsy. Results: The perfusion fraction showed a significant difference (p = 0.042) in percentage change between responder groups at Cycle 1, with a decrease in good responders [-7.98% (-19.47-1.73), n = 7] and an increase in poor responders [10.04% (5.09-28.93), n = 9]. There was a significant correlation between percentage change in perfusion fraction and percentage change in Ki-67 (p = 0.042). Tissue diffusion and pseudodiffusion showed no significant difference in percentage change between groups at Cycle 1, nor was there a significant correlation against percentage change in Ki-67. Perfusion fraction, tissue diffusion, and pseudodiffusion showed no significant difference between groups at baseline, nor was there a significant correlation against Ki-67 from core biopsy. Conclusion: The alteration in tumour perfusion fraction from the Bayesian IVIM model, in association with cellular proliferation, showed early sensitivity to good responders in NACT. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT03501394, identifier NCT03501394.

5.
Int J Mol Sci ; 24(16)2023 Aug 12.
Article in English | MEDLINE | ID: mdl-37628902

ABSTRACT

Clostridium botulinum neurotoxins (BoNTs) are the most potent toxins known, causing the deadly disease botulism. They function through Zn2+-dependent endopeptidase cleavage of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, preventing vesicular fusion and subsequent neurotransmitter release from motor neurons. Several serotypes of BoNTs produced by Clostridium botulinum (BoNT/A-/G and/X) have been well-characterised over the years. However, a BoNT-like gene (homologue of BoNT) was recently identified in the non-clostridial species, Enterococcus faecium, which is the leading cause of hospital-acquired multi-drug resistant infections. Here, we report the crystal structure of the catalytic domain of a BoNT homologue from Enterococcus faecium (LC/En) at 2.0 Å resolution. Detailed structural analysis in comparison with the full-length BoNT/En AlphaFold2-predicted structure, LC/A (from BoNT/A), and LC/F (from BoNT/F) revealed putative subsites and exosites (including loops 1-5) involved in recognition of LC/En substrates. LC/En also appears to possess a conserved autoproteolytic cleavage site whose function is yet to be established.


Subject(s)
Botulism , Clostridium botulinum , Cross Infection , Enterococcus faecium , Humans , Catalytic Domain , Biological Transport
6.
Cureus ; 15(3): e35951, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37038568

ABSTRACT

COVID-19 vaccines have been shown to be highly efficacious in preventing symptomatic COVID-19 infections throughout the pandemic. There have been emerging cases of inflammatory arthritis occurring in close relation to COVID-19 vaccination. We illustrate a case of new-onset inflammatory arthritis 10 days after receiving their second Vaxzevria COVID-19 vaccine. The patient responded dramatically to prednisolone treatment but subsequently required hydroxychloroquine due to persistent inflammatory joint symptoms. Inflammatory arthritis is an increasingly recognized rare adverse effect of COVID-19 vaccination and clinicians should actively consider this in patients with new or flares of inflammatory joint disease.

7.
Int J Mol Sci ; 23(17)2022 Aug 25.
Article in English | MEDLINE | ID: mdl-36077016

ABSTRACT

Clostridium botulinum neurotoxin A (BoNT/A) targets the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, by cleaving synaptosomal-associated protein of 25 kDa size (SNAP-25). Cleavage of SNAP-25 results in flaccid paralysis due to repression of synaptic transmission at the neuromuscular junction. This activity has been exploited to treat a range of diseases associated with hypersecretion of neurotransmitters, with formulations of BoNT/A commercially available as therapeutics. Generally, BoNT activity is facilitated by three essential domains within the molecule, the cell binding domain (HC), the translocation domain (HN), and the catalytic domain (LC). The HC, which consists of an N-terminal (HCN) and a C-terminal (HCC) subdomain, is responsible for BoNT's high target specificity where it forms a dual-receptor complex with synaptic vesicle protein 2 (SV2) and a ganglioside receptor on the surface of motor neurons. In this study, we have determined the crystal structure of botulinum neurotoxin A6 cell binding domain (HC/A6) in complex with GD1a and describe the interactions involved in ganglioside binding. We also present a new crystal form of wild type HC/A6 (crystal form II) where a large 'hinge motion' between the HCN and HCC subdomains is observed. These structures, along with a comparison to the previously determined wild type crystal structure of HC/A6 (crystal form I), reveals the degree of conformational flexibility exhibited by HC/A6.


Subject(s)
Botulinum Toxins, Type A , Botulinum Toxins, Type A/chemistry , Cell Membrane/metabolism , Clostridium/metabolism , Neurons/metabolism , Protein Binding , Synaptic Vesicles/metabolism
8.
Toxins (Basel) ; 14(5)2022 05 19.
Article in English | MEDLINE | ID: mdl-35622602

ABSTRACT

Botulinum neurotoxins (BoNT) are a group of clostridial toxins that cause the potentially fatal neuroparalytic disease botulism. Although highly toxic, BoNTs are utilized as therapeutics to treat a range of neuromuscular conditions. Several serotypes (BoNT/A-/G, /X) have been identified with vastly differing toxicological profiles. Each serotype can be further sub-categorised into subtypes due to subtle variations in their protein sequence. These minor changes have been attributed to differences in both the duration of action and potency for BoNT/A subtypes. BoNTs are composed of three domains-a cell-binding domain, a translocation domain, and a catalytic domain. In this paper, we present the crystal structures of the botulinum neurotoxin A2 cell binding domain, both alone and in complex with its receptor ganglioside GD1a at 1.63 and 2.10 Å, respectively. The analysis of these structures reveals a potential redox-dependent Lys-O-Cys bridge close to the ganglioside binding site and a hinge motion between the HCN and HCC subdomains. Furthermore, we make a detailed comparison with the previously reported HC/A2:SV2C structure for a comprehensive structural analysis of HC/A2 receptor binding.


Subject(s)
Botulinum Toxins, Type A , Botulism , Botulinum Toxins, Type A/metabolism , Clostridium/metabolism , Gangliosides , Humans , Protein Binding
9.
BMC Cancer ; 22(1): 285, 2022 Mar 17.
Article in English | MEDLINE | ID: mdl-35300617

ABSTRACT

BACKGROUND: Response guided treatment in breast cancer is highly desirable, but the effectiveness is only established based on residual cellularity from histopathological analysis after surgery. Tubule formation, a key component of grading score, is directly associated with cellularity, with significant implications on prognosis. Peri-tumoural lipid composition, a potential marker, can be rapidly mapped across the entire breast using novel method of chemical shift-encoded imaging, enabling the quantification of spatial distribution. We hypothesise that peri-tumoural spatial distribution of lipid composition is sensitive to tumour cellular differentiation and proliferative activity. METHODS: Twenty whole tumour specimens freshly excised from patients with invasive ductal carcinoma (9 Score 2 and 11 Score 3 in tubule formation) were scanned on a 3 T clinical scanner (Achieva TX, Philips Healthcare). Quantitative lipid composition maps were acquired for polyunsaturated, monounsaturated, and saturated fatty acids (PUFA, MUFA, SFA). The peri-tumoural spatial distribution (mean, skewness, entropy and kurtosis) of each lipid constituent were then computed. The proliferative activity marker Ki-67 and tumour-infiltrating lymphocytes (TILs) were assessed histologically. RESULTS: For MUFA, there were significant differences between groups in mean (p = 0.0119), skewness (p = 0.0116), entropy (p = 0.0223), kurtosis (p = 0.0381), and correlations against Ki-67 in mean (ρ = -0.5414), skewness (ρ = 0.6045) and entropy (ρ = 0.6677), and TILs in mean (ρ = -0.4621). For SFA, there were significant differences between groups in mean (p = 0.0329) and skewness (p = 0.0111), and correlation against Ki-67 in mean (ρ = 0.5910). For PUFA, there was no significant difference in mean, skewness, entropy or kurtosis between the groups. CONCLUSIONS: There was an association between peri-tumoural spatial distribution of lipid composition with tumour cellular differentiation and proliferation. Peri-tumoural lipid composition imaging might have potential in non-invasive quantitative assessment of patients with breast cancer for treatment planning and monitoring.


Subject(s)
Breast Neoplasms/metabolism , Breast/pathology , Fatty Acids/metabolism , Magnetic Resonance Imaging/methods , Adult , Aged , Breast/diagnostic imaging , Breast Neoplasms/diagnostic imaging , Cross-Sectional Studies , Entropy , Female , Humans , Ki-67 Antigen/metabolism , Lymphocytes, Tumor-Infiltrating/metabolism , Middle Aged
10.
Toxins (Basel) ; 14(2)2022 02 08.
Article in English | MEDLINE | ID: mdl-35202156

ABSTRACT

Botulinum neurotoxins (BoNT) cause the potentially fatal neuroparalytic disease botulism that arises due to proteolysis of a SNARE protein. Each BoNT is comprised of three domains: a cell binding domain (HC), a translocation domain (HN), and a catalytic (Zn2+ endopeptidase) domain (LC). The HC is responsible for neuronal specificity by targeting both a protein and ganglioside receptor at the neuromuscular junction. Although highly toxic, some BoNTs are commercially available as therapeutics for the treatment of a range of neuromuscular conditions. Here we present the crystal structures of two BoNT cell binding domains, HC/A4 and HC/A5, in a complex with the oligosaccharide of ganglioside, GD1a and GM1b, respectively. These structures, along with a detailed comparison with the previously reported apo-structures, reveal the conformational changes that occur upon ganglioside binding and the interactions involved.


Subject(s)
Botulinum Toxins, Type A/chemistry , Botulism/physiopathology , Carrier Proteins/metabolism , Gangliosides/metabolism , Molecular Structure , Neuromuscular Junction/metabolism , Neurons/metabolism , Botulinum Toxins, Type A/metabolism , Crystallography, X-Ray , Humans
11.
Nat Neurosci ; 25(2): 168-179, 2022 02.
Article in English | MEDLINE | ID: mdl-34931070

ABSTRACT

Bacterial products can act on neurons to alter signaling and function. In the present study, we found that dorsal root ganglion (DRG) sensory neurons are enriched for ANTXR2, the high-affinity receptor for anthrax toxins. Anthrax toxins are composed of protective antigen (PA), which binds to ANTXR2, and the protein cargoes edema factor (EF) and lethal factor (LF). Intrathecal administration of edema toxin (ET (PA + EF)) targeted DRG neurons and induced analgesia in mice. ET inhibited mechanical and thermal sensation, and pain caused by formalin, carrageenan or nerve injury. Analgesia depended on ANTXR2 expressed by Nav1.8+ or Advillin+ neurons. ET modulated protein kinase A signaling in mouse sensory and human induced pluripotent stem cell-derived sensory neurons, and attenuated spinal cord neurotransmission. We further engineered anthrax toxins to introduce exogenous protein cargoes, including botulinum toxin, into DRG neurons to silence pain. Our study highlights interactions between a bacterial toxin and nociceptors, which may lead to the development of new pain therapeutics.


Subject(s)
Anthrax , Bacillus anthracis , Bacterial Toxins , Induced Pluripotent Stem Cells , Animals , Anthrax/microbiology , Anthrax/therapy , Bacillus anthracis/metabolism , Bacterial Toxins/metabolism , Ganglia, Spinal/metabolism , Humans , Induced Pluripotent Stem Cells/metabolism , Mice , Nociceptors/metabolism , Pain , Receptors, Peptide/metabolism
12.
Toxins (Basel) ; 13(12)2021 11 24.
Article in English | MEDLINE | ID: mdl-34941672

ABSTRACT

Botulinum neurotoxins (BoNTs) are notorious toxins and powerful agents and can be lethal, causing botulism, but they are also widely used as therapeutics, particularly to treat neuromuscular disorders. As of today, the commercial BoNT treatments available are from native A or B serotypes. Serotype F has shown efficacy in a clinical trial but has scarcely been used, most likely due to its medium duration of effect. Previously, the uniqueness of the light chain of the F7 subtype was identified and reported, showing an extended interaction with its substrates, VAMPs 1, 2 and 3, and a superior catalytic activity compared to other BoNT/F subtypes. In order to more extensively study the properties of this neurotoxin, we engineered a modified F7 chimera, mrBoNT/F7-1, in which all the regions of the neurotoxin were identical to BoNT/F7 except the activation loop, which was the activation loop from BoNT/F1. Use of the activation loop from BoNT/F1 allowed easier post-translational proteolytic activation of the recombinant protein without otherwise affecting its properties. mrBoNT/F7-1 was expressed, purified and then tested in a suite of in vitro and in vivo assays. mrBoNT/F7-1 was active and showed enhanced potency in comparison to both native and recombinant BoNT/F1. Additionally, the safety profile remained comparable to BoNT/F1 despite the increased potency. This new modified recombinant toxin F7 could be further exploited to develop unique therapeutics to address unmet medical needs.


Subject(s)
Botulinum Toxins/chemistry , Botulinum Toxins/pharmacology , Muscle, Smooth/drug effects , Animals , Cell-Free System , Cloning, Molecular , Embryo, Mammalian , Escherichia coli , Female , Gene Expression Regulation, Bacterial , Glycine , Mice , Muscle, Skeletal/drug effects , Neurons/drug effects , Neurons/metabolism , Phrenic Nerve/drug effects , Rats , Recombinant Proteins/chemistry , Recombinant Proteins/pharmacology , Spinal Cord/cytology
13.
Clin Med (Lond) ; 21(5): e499-e504, 2021 09.
Article in English | MEDLINE | ID: mdl-34507934

ABSTRACT

There are more than 170 million confirmed cases of COVID-19 worldwide, yet its effects on the endocrine system remain under-reported due to lack of awareness by the public, primary care givers and specialists. This is a narrative review using up-to-date literature discussing the consequences that infection with SARS-CoV-2 can have on diabetes and the endocrine glands including the adrenals, thyroid and pituitary, as well as hyponatremia and hypogonadism. Endocrinologists, internists and primary care physicians need to be aware of the involvement of the endocrine organs when dealing with people recovering from COVID-19 and actively manage any complications to reduce mortality and improve the quality of life of those affected.


Subject(s)
COVID-19 , Diabetes Mellitus , Endocrinology , Humans , Quality of Life , SARS-CoV-2
14.
BMJ Case Rep ; 14(7)2021 Jul 27.
Article in English | MEDLINE | ID: mdl-34315736

ABSTRACT

The COVID-19 pandemic is revealing growing reports of atypical presentation of the disease beyond the respiratory system. SARS-CoV-2 infection has been linked to multisystem vasculopathy including cardiopulmonary, cerebral and renal vasculature, potentially brought on by a dysregulated host immune response in a probable setting of a cytokine storm. Here, we describe a case of a previously healthy and active 74-year-old man presenting with acute cognitive decline with preceding non-specific influenza-like symptoms. He was then diagnosed with cerebral amyloid angiopathy (CAA)-associated intracerebral haemorrhage and was found to be COVID-19 positive. COVID-19-induced immune response may have further compromised the cerebral vessels already weakened by CAA, triggering multiple microhaemorrhages leading to clinical presentation. The limited evidence about the heterogeneity of COVID-19 manifestations suggests that clinicians should be aware and screen for concurrent COVID-19 in patients presenting with neurological features during the peak of this pandemic, as this offers the best chance for better clinical outcome.


Subject(s)
COVID-19 , Pandemics , Aged , Brain/diagnostic imaging , Cerebral Hemorrhage , Humans , Male , SARS-CoV-2
15.
Eur Radiol ; 31(6): 3703-3711, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33270144

ABSTRACT

OBJECTIVES: Despite improved survival due to new treatments, the 10-year survival rate in patients with breast cancer is approximately 75%. Lymphovascular invasion (LVI), a prognostic marker independent from histological grade and stage, can only be fully determined at final histological examination. Lipid composition is deregulated in tumour via de novo lipogenesis, with alteration in lipogenic genes in LVI. We hypothesise alteration in lipid composition derived from novel non-invasive spectroscopy method is associated with LVI positivity. METHODS: Thirty female patients (age 39-78) with invasive ductal carcinoma were enrolled, with 13 LVI negative and 17 LVI positive. Saturated, monounsaturated, polyunsaturated fatty acids and triglycerides (SFA, MUFA, PUFA and TRG) were quantified from ex vivo breast tumours freshly excised from patients on a 3 T clinical MRI scanner, and proliferative activity marker Ki-67 and serotonin derived histologically. RESULTS: There were significantly lower MUFA (p = 0.0189) in LVI positive (median: 0.37, interquartile range (IQR): 0.25-0.64) than negative (0.63, 0.49-0.96). There were significantly lower TRG (p = 0.0226) in LVI positive (1.32, 0.95-2.43) than negative (2.5, 1.92-4.15). There was no significant difference in SFA (p = 0.6009) or PUFA (p = 0.1641). There was no significant correlation between lipid composition against Ki-67 or serotonin, apart from a borderline negative correlation between PUFA and serotonin (r = - 0.3616, p = 0.0496). CONCLUSION: Lipid composition might provide a biomarker to study lymphovascular invasion in breast cancer. KEY POINTS: • Monounsaturated fatty acids in lymphovascular invasion (LVI) positive invasive breast carcinoma were significantly lower than that in LVI negative. • Triglycerides in LVI positive invasive breast carcinoma were significantly lower than that in LVI negative. • Lipid composition from MR spectroscopy reflects the rate of de novo lipogenesis and provides a potential biomarker independent from histological grade and stage.


Subject(s)
Breast Neoplasms , Adult , Aged , Breast Neoplasms/diagnostic imaging , Female , Humans , Lipids , Lymphatic Metastasis , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Middle Aged , Neoplasm Invasiveness , Prognosis
16.
Sci Rep ; 10(1): 20041, 2020 11 18.
Article in English | MEDLINE | ID: mdl-33208767

ABSTRACT

Lipid composition in breast cancer, a central marker of disease progression, can be non-invasively quantified using 2D MRS method of double quantum filtered correlation spectroscopy (DQF-COSY). The low signal to noise ratio (SNR), arising from signal retention of only 25% and depleted lipids within tumour, demands improvement approaches beyond signal averaging for clinically viable applications. We therefore adapted and examined combination algorithms, designed for 1D MRS, for 2D MRS with both internal and external references. Lipid composition spectra were acquired from 17 breast tumour specimens, 15 healthy female volunteers and 25 patients with breast cancer on a clinical 3 T MRI scanner. Whitened singular value decomposition (WSVD) with internal reference yielded maximal SNR with an improvement of 53.3% (40.3-106.9%) in specimens, 84.4 ± 40.6% in volunteers, 96.9 ± 54.2% in peritumoural adipose tissue and 52.4% (25.1-108.0%) in tumours in vivo. Non-uniformity, as variance of improvement across peaks, was low at 21.1% (13.7-28.1%) in specimens, 5.5% (4.2-7.2%) in volunteers, 6.1% (5.0-9.0%) in peritumoural tissue, and 20.7% (17.4-31.7%) in tumours in vivo. The bias (slope) in improvement ranged from - 1.08 to 0.21%/ppm along the diagonal directions. WSVD is therefore the optimal algorithm for lipid composition spectra with highest SNR uniformly across peaks, reducing acquisition time by up to 70% in patients, enabling clinical applications.


Subject(s)
Algorithms , Breast Neoplasms/pathology , Computer Simulation , Lipids/analysis , Magnetic Resonance Spectroscopy/methods , Signal-To-Noise Ratio , Adult , Aged , Breast Neoplasms/metabolism , Case-Control Studies , Female , Humans , Middle Aged
17.
FEBS Open Bio ; 10(8): 1474-1481, 2020 08.
Article in English | MEDLINE | ID: mdl-32654405

ABSTRACT

Clostridium botulinum neurotoxins (BoNTs) cause flaccid paralysis through inhibition of acetylcholine release from motor neurons; however, at tiny doses, this property is exploited for use as a therapeutic. Each member of the BoNT family of proteins consists of three distinct domains: a binding domain that targets neuronal cell membranes (HC ), a translocation domain (HN ) and a catalytic domain (LC). Here, we present high-resolution crystal structures of the binding domains of BoNT subtypes/A5 (HC /A5) and/A6 (HC /A6). These structures show that the core fold identified in other subtypes is maintained, but with subtle differences at the expected receptor-binding sites.


Subject(s)
Botulinum Toxins, Type A/chemistry , Botulinum Toxins, Type A/isolation & purification , Crystallography, X-Ray , Models, Molecular , Protein Conformation
18.
Br J Cancer ; 123(2): 261-267, 2020 07.
Article in English | MEDLINE | ID: mdl-32424149

ABSTRACT

BACKGROUND: Precision medicine in breast cancer demands markers sensitive to early treatment response. Aerobic glycolysis (AG) upregulates lactate dehydrogenase A (LDH-A) with elevated lactate production; however, existing approaches for lactate quantification are either invasive or impractical clinically. METHODS: Thirty female patients (age 39-78 years, 15 grade II and 15 grade III) with invasive ductal carcinoma were enrolled. Lactate concentration was quantified from freshly excised whole tumours with double quantum filtered (DQF) magnetic resonance spectroscopy (MRS), and Nottingham Prognostic Index (NPI), LDH-A and proliferative marker Ki-67 were assessed histologically. RESULTS: There was a significantly higher lactate concentration (t = 2.2224, p = 0.0349) in grade III (7.7 ± 2.9 mM) than in grade II (5.5 ± 2.4 mM). Lactate concentration was correlated with NPI (ρ = 0.3618, p = 0.0495), but not with Ki-67 (ρ = 0.3041, p = 0.1023) or tumour size (r = 0.1716, p = 0.3645). Lactate concentration was negatively correlated with LDH-A (ρ = -0.3734, p = 0.0421). CONCLUSION: Our results showed that lactate concentration in whole breast tumour from DQF MRS is sensitive to tumour grades and patient prognosis.


Subject(s)
Breast Neoplasms/diagnosis , Lactic Acid/metabolism , Prognosis , Receptors, Estrogen/metabolism , Adult , Aged , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Female , Glycolysis/genetics , Humans , Lactate Dehydrogenase 5/genetics , Lactate Dehydrogenase 5/metabolism , Lactic Acid/isolation & purification , Magnetic Resonance Spectroscopy , Middle Aged , Receptors, Estrogen/genetics
19.
FEBS Open Bio ; 10(3): 298-305, 2020 03.
Article in English | MEDLINE | ID: mdl-31945264

ABSTRACT

Botulinum neurotoxins (BoNTs) are one of the most toxic proteins known to humans. Their molecular structure is comprised of three essential domains-a cell binding domain (HC ), translocation domain and catalytic domain (light chain) . The HC domain facilitates the highly specific binding of BoNTs to the neuronal membrane via a dual-receptor complex involving a protein receptor and a ganglioside. Variation in activity/toxicity across subtypes of serotype A has been attributed to changes in protein and ganglioside interactions, and their implications are important in the design of novel BoNT-based therapeutics. Here, we present the structure of BoNT/A3 cell binding domain (HC /A3) in complex with the ganglioside GD1a at 1.75 Å resolution. The structure revealed that six residues interact with the three outermost monosaccharides of GD1a through several key hydrogen bonding interactions. A detailed comparison of structures of HC /A3 with HC /A1 revealed subtle conformational differences at the ganglioside binding site upon carbohydrate binding.


Subject(s)
Botulinum Toxins, Type A/ultrastructure , Gangliosides/metabolism , Binding Sites/genetics , Botulinum Toxins/chemistry , Botulinum Toxins/metabolism , Botulinum Toxins/ultrastructure , Botulinum Toxins, Type A/metabolism , Carrier Proteins/metabolism , Cell Membrane/metabolism , Crystallography, X-Ray/methods , Humans , Neurons/metabolism , Protein Binding , Protein Domains/genetics
20.
Sci Rep ; 9(1): 9259, 2019 06 25.
Article in English | MEDLINE | ID: mdl-31239527

ABSTRACT

Polyunsaturated fatty acid (PUFA), a key marker in breast cancer, is non-invasively quantifiable using multiple quantum coherence (MQC) magnetic resonance spectroscopy (MRS) at the expense of losing half of the signal. Signal combination for phased array coils provides potential pathways to enhance the signal to noise ratio (SNR), with current algorithms developed for conventional brain MRS. Since PUFA spectra and the biochemical environment in the breast deviate significantly from those in the brain, we set out to identify the optimal algorithm for PUFA in breast cancer. Combination algorithms were compared using PUFA spectra from 17 human breast tumour specimens, 15 healthy female volunteers, and 5 patients with breast cancer on a clinical 3 T MRI scanner. Adaptively Optimised Combination (AOC) yielded the maximum SNR improvement in specimens (median, 39.5%; interquartile range: 35.5-53.2%, p < 0.05), volunteers (82.4 ± 37.4%, p < 0.001), and patients (median, 61%; range: 34-105%, p < 0.05), while independent from voxel volume (rho = 0.125, p = 0.632), PUFA content (rho = 0.256, p = 0.320) or water/fat ratio (rho = 0.353, p = 0.165). Using AOC, acquisition in patients is 1.5 times faster compared to non-noise decorrelated algorithms. Therefore, AOC is the most suitable current algorithm to improve SNR or accelerate the acquisition of PUFA MRS from breast in a clinical setting.


Subject(s)
Algorithms , Breast Neoplasms/metabolism , Carcinoma, Ductal, Breast/metabolism , Fatty Acids, Unsaturated/analysis , Fatty Acids, Unsaturated/metabolism , Image Processing, Computer-Assisted/methods , Magnetic Resonance Spectroscopy/methods , Adult , Aged , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Case-Control Studies , Female , Humans , Middle Aged , Signal-To-Noise Ratio
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