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1.
J Pharmacol Exp Ther ; 385(2): 95-105, 2023 05.
Article in English | MEDLINE | ID: mdl-36849411

ABSTRACT

Leucine-rich repeat-containing G-protein-coupled receptor (LGR5) and LGR6 mark epithelial stem cells in normal tissues and tumors. They are expressed by stem cells in the ovarian surface and fallopian tube epithelia from which ovarian cancer arises. High-grade serous ovarian cancer is unique in expressing unusually high levels of LGR5 and LGR6 mRNA. R-spondins are the natural ligands for LGR5 and LGR6 to which they bind with nanomolar affinity. To target stem cells in ovarian cancer, we used the sortase reaction to site-specifically conjugate the potent cytotoxin monomethyl auristatin E (MMAE) via a protease sensitive linker to the two furin-like domains of RSPO1 (Fu1-Fu2) that mediate its binding to LGR5 and LGR6 and their co-receptors Zinc And Ring Finger 3 and Ring Finger Protein 43 via a protease-cleavable linker. An immunoglobulin Fc domain added to the N-terminal end served to dimerize the receptor-binding domains so that each molecule carries two MMAE. The resulting molecule, FcF2-MMAE, demonstrated: 1) selective LGR5-dependent low nanomolar cytotoxicity against ovarian cancer cells in vitro; 2) selectivity that was dependent on binding to both the LGR receptors and ubiquitin ligase co-receptors; 3) favorable stability and plasma pharmacokinetic properties when administered intravenously with an elimination half-life of 29.7 hours; 4) selective inhibition of LGR5-rich as opposed to isogenic LGR5-poor tumors in vivo; and, 5) therapeutic efficacy in three aggressive wild-type human ovarian cancer xenograft models. These results demonstrate the successful use of the Fu1-Fu2 domain of RSPO1 as a drug carrier and the ability of FcF2-MMAE to target cells in tumors that express stem cell markers. SIGNIFICANCE STATEMENT: FcF2-MMAE is a novel cancer therapeutic that exploits the high-affinity binding domains of RSPO1 to target monomethyl auristatin E to tumor stem cells that express LGR5. FcF2-MMAE has low nanomolar LGR5-dependent cytotoxicity in vitro, favorable pharmacokinetics, and differential efficacy in an isogenic LGR5-poor versus LGR5-rich ovarian cancer xenograft model when given on a weekly schedule.


Subject(s)
Ovarian Neoplasms , Receptors, G-Protein-Coupled , Female , Humans , Leucine , Ovarian Neoplasms/drug therapy , Peptide Hydrolases , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Stem Cells/metabolism , Thrombospondins/metabolism
2.
Molecules ; 27(12)2022 Jun 16.
Article in English | MEDLINE | ID: mdl-35744987

ABSTRACT

Paramyosins, muscle proteins occurring exclusively in invertebrates, are abundant in seafoods. The potential of seafood paramyosins (SP) as sources of anti-angiotensin-converting-enzyme (ACE) and anti-dipeptidyl-peptidase (DPP-IV) peptides is underexplored. This in silico study investigated the release of anti-ACE and anti-DPP-IV peptides from SP after gastrointestinal (GI) digestion. We focused on SP of the common octopus, Humboldt squid, Japanese abalone, Japanese scallop, Mediterranean mussel, Pacific oyster, sea cucumber, and Whiteleg shrimp. SP protein sequences were digested on BIOPEP-UWM, followed by identification of known anti-ACE and anti-DPP-IV peptides liberated. Upon screening for high-GI-absorption, non-allergenicity, and non-toxicity, shortlisted peptides were analyzed via molecular docking and dynamic to elucidate mechanisms of interactions with ACE and DPP-IV. Potential novel anti-ACE and anti-DPP-IV peptides were predicted by SwissTargetPrediction. Physicochemical and pharmacokinetics of peptides were predicted with SwissADME. GI digestion liberated 2853 fragments from SP. This comprised 26 known anti-ACE and 53 anti-DPP-IV peptides exhibiting high-GI-absorption, non-allergenicity, and non-toxicity. SwissTargetPrediction predicted three putative anti-ACE (GIL, DL, AK) and one putative anti-DPP-IV (IAL) peptides. Molecular docking found most of the anti-ACE peptides may be non-competitive inhibitors, whereas all anti-DPP-IV peptides likely competitive inhibitors. Twenty-five nanoseconds molecular dynamics simulation suggests the stability of these screened peptides, including the three predicted anti-ACE and one predicted anti-DPP-IV peptides. Seven dipeptides resembling approved oral-bioavailable peptide drugs in physicochemical and pharmacokinetic properties were revealed: AY, CF, EF, TF, TY, VF, and VY. In conclusion, our study presented in silico evidence for SP being a promising source of bioavailable and safe anti-ACE and anti-DPP-IV peptides following GI digestions.


Subject(s)
Dipeptidyl-Peptidase IV Inhibitors , Tropomyosin , Angiotensin-Converting Enzyme Inhibitors/chemistry , Cheminformatics , Digestion , Dipeptidyl Peptidase 4/chemistry , Dipeptidyl-Peptidase IV Inhibitors/chemistry , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases , Molecular Docking Simulation , Peptides/chemistry , Seafood
3.
Bioconjug Chem ; 32(2): 376-384, 2021 02 17.
Article in English | MEDLINE | ID: mdl-33492953

ABSTRACT

LGR5 and LGR6 mark epithelial stem cells in many niches including the ovarian surface and fallopian tube epithelia from which ovarian cancer arises. Human ovarian cancers express these receptors at high levels and express one of their ligands, RSPO1, at levels uniquely higher than all other tumor types except mesothelioma. Reasoning that these receptors are also important to tumor stem cells, arming the LGR binding domain of RSPO1 with a cytotoxin may permit depletion of the tumor stem cells. The Fu1-Fu2 receptor binding domain of RSPO1 (R1FF), containing a sortase recognition sequence at the C-terminal end, was produced in bacteria and a single molecule of MMAE was attached to each R1FF through a val-cit-PAB linker using the sortase reaction, thus producing a homogeneous population of armed molecules. R1FF-MMAE demonstrated (1) selective LGR-dependent binding, uptake, and cytotoxicity; (2) low nM cytotoxicity to multiple types of human tumor cell lines in vitro; (3) favorable plasma pharmacokinetic properties when administered iv with an elimination half-life of 27.8 h; (4) favorable absorption from the peritoneal cavity; and (5) therapeutic activity in aggressive xenograft models of ovarian cancer in the absence of any weight loss or other adverse events. These results demonstrate that the Fu1-Fu2 domain of RSPO1 can be exploited to deliver a potent cytotoxin to tumor cells that express the LGR4-6 family of stem cell receptors.


Subject(s)
Receptors, Cell Surface/metabolism , Stem Cells/metabolism , Animals , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Chromatography, High Pressure Liquid , Electrophoresis, Polyacrylamide Gel , HEK293 Cells , Half-Life , Humans , Xenograft Model Antitumor Assays
4.
Molecules ; 26(23)2021 Dec 06.
Article in English | MEDLINE | ID: mdl-34885982

ABSTRACT

Some seed-derived antioxidant peptides are known to regulate cellular modulators of ROS production, including those proposed to be promising targets of anticancer therapy. Nevertheless, research in this direction is relatively slow owing to the inevitable time-consuming nature of wet-lab experimentations. To help expedite such explorations, we performed structure-based virtual screening on seed-derived antioxidant peptides in the literature for anticancer potential. The ability of the peptides to interact with myeloperoxidase, xanthine oxidase, Keap1, and p47phox was examined. We generated a virtual library of 677 peptides based on a database and literature search. Screening for anticancer potential, non-toxicity, non-allergenicity, non-hemolyticity narrowed down the collection to five candidates. Molecular docking found LYSPH as the most promising in targeting myeloperoxidase, xanthine oxidase, and Keap1, whereas PSYLNTPLL was the best candidate to bind stably to key residues in p47phox. Stability of the four peptide-target complexes was supported by molecular dynamics simulation. LYSPH and PSYLNTPLL were predicted to have cell- and blood-brain barrier penetrating potential, although intolerant to gastrointestinal digestion. Computational alanine scanning found tyrosine residues in both peptides as crucial to stable binding to the targets. Overall, LYSPH and PSYLNTPLL are two potential anticancer peptides that deserve deeper exploration in future.


Subject(s)
Antineoplastic Agents/metabolism , Antioxidants/metabolism , Cheminformatics/methods , Drug Discovery/methods , Peptides/metabolism , Plant Extracts/metabolism , Seeds/chemistry , Antineoplastic Agents/chemistry , Antioxidants/chemistry , Catalytic Domain , Drug Stability , Humans , Kelch-Like ECH-Associated Protein 1/chemistry , Kelch-Like ECH-Associated Protein 1/metabolism , Molecular Docking Simulation , Molecular Dynamics Simulation , Peptides/chemistry , Peroxidase/chemistry , Peroxidase/metabolism , Plant Extracts/chemistry , Protein Binding , Xanthine Oxidase/chemistry , Xanthine Oxidase/metabolism
5.
Skeletal Radiol ; 49(3): 397-405, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31396669

ABSTRACT

OBJECTIVE: To study MRI criteria for diagnosing and predicting severity of carpal tunnel syndrome (CTS). METHODS: Sixty-nine wrists in 41 symptomatic CTS patients and 32 wrists in 28 asymptomatic subjects were evaluated by MRI. Circumferential surface area (CSA), flattening ratio, relative median nerve signal intensity, and retinacular bowing were measured. CTS severity was classified as mild, moderate, or severe. Parameters for patients with and without CTS and for the three severity groups were compared. ROC curves were plotted to assess accuracy for CTS diagnosis and severity prediction. RESULTS: Significant differences were found between CTS and control wrists for median nerve CSA, flattening ratio at inlet, relative median nerve signal intensity, and retinacular bowing. ROC curve analysis revealed a sensitivity, specificity, and accuracy of median nerve CSA > 15 mm2 proximal to the tunnel (CSAp) of 85.5, 100, and 90.1%. Using either CSAp or CSAd > 15 mm2 as a diagnostic criterion, MRI could achieve a sensitivity of 100% and specificity of 94% for diagnosis of CTS while overall accuracy was 98%. Significant differences were found among the three severity groups. Sensitivity, specificity, and accuracy of prediction of severe CTS using for CSAp > 19 mm2 were 75.0, 65.9, and 69.6%, respectively. CONCLUSIONS: MRI is highly accurate at diagnosing CTS and moderately accurate at determining CTS severity. We recommend using CSA > 15 mm2 either proximal to or distal to the tunnel as a diagnostic criterion for CTS and CSA > 19 mm2 proximal to the tunnel as a marker for severe CTS.


Subject(s)
Carpal Tunnel Syndrome/diagnostic imaging , Magnetic Resonance Imaging/methods , Adult , Aged , Carpal Tunnel Syndrome/classification , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Sensitivity and Specificity , Severity of Illness Index
6.
Semin Musculoskelet Radiol ; 23(4): 436-443, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31170740

ABSTRACT

The triangular fibrocartilage complex (TFCC) is a crucial structure for both maintaining the stability of the distal radioulnar joint (DRUJ) and acting as a cushion for axial loading of the ulnocarpal joint. Injury to the TFCC can lead to early degeneration of the DRUJ and ulnocarpal joint, with resultant chronic wrist pain and weakness. The TFCC is a moderately complex structure with several attachments to the adjacent bony and cartilaginous structures. Familiarity with the anatomy of the TFCC is a prerequisite for identification of TFCC tears. Several pitfalls can occur while assessing the TFCC on magnetic resonance imaging (MRI) if one is not familiar with the MRI appearances. This article illustrates key tips for diagnosing TFCC tears on MRI.


Subject(s)
Magnetic Resonance Imaging/methods , Triangular Fibrocartilage/diagnostic imaging , Triangular Fibrocartilage/injuries , Humans
7.
J Clin Ultrasound ; 47(3): 122-127, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30597562

ABSTRACT

BACKGROUND: This study compares median nerve cross-sectional area (CSA) measurements at the wrist obtained with ultrasound (US) and magnetic resonance imaging (MRI) using cadaveric measurements as the gold standard. METHODS: Median nerve CSA was measured using US and MRI in 9 cadaveric wrists obtained from 5 subjects at 5 locations: distal forearm, proximal to tunnel inlet, at tunnel inlet, at tunnel outlet, and distal to tunnel outlet and then on identical cadaveric transverse sections obtained with a bandsaw. All US, MRI, and cadaveric measurements were repeated to determine reliability. Median nerves of 10 patients with clinical carpal tunnel syndrome (CTS) were measured with US and MRI using an identical method US. RESULTS: Median nerve CSA MRI measurements correlated better (Pearson correlation: 0.80-0.95, P < .05) with cadaveric measurements than with US measurements (Pearson correlation: 0.61-0.79, P < .05). Median nerve CSA US measurements (8.6-12.5 mm2 , P < .05) were smaller at all levels than MRI (11.3-14.7 mm2 ) or cadaveric (11.0-14.9 mm2 ) measurements while MRI and cadaver measurements were similar at all levels. Median nerve CSA MRI measurements in CTS patients were larger than US measurements at all levels. CONCLUSION: Median nerve CSA measurements by MRI are larger than US measurements and correlated better with cadaveric measurements. Median nerve CSA criteria used for diagnosing CTS on US are not likely to be applicable to MRI.


Subject(s)
Magnetic Resonance Imaging/methods , Median Nerve/diagnostic imaging , Ultrasonography/methods , Wrist/diagnostic imaging , Aged , Aged, 80 and over , Cadaver , Cross-Sectional Studies , Humans , Male , Middle Aged , Neural Conduction , Reproducibility of Results , Wrist Joint
8.
Eur Radiol ; 27(3): 1277-1285, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27287482

ABSTRACT

PURPOSE: To compare axial and oblique axial planes on MR arthrography (MRA) and multidetector CT arthrography (CTA) to evaluate dorsal and volar parts of scapholunate (SLIL) and lunotriquetral interosseous (LTIL) ligaments. METHODS: Nine cadaveric wrists of five male subjects were studied. The visibility of dorsal and volar parts of the SLIL and LTIL was graded semi-quantitatively (good, intermediate, poor) on MRA and CTA. The presence of a ligament tear was determined on arthrosocopy and sensitivity, specificity and accuracy of tear detection were calculated. RESULTS: Oblique axial imaging was particularly useful for delineating dorsal and volar parts of the LTIL on MRA with overall 'good' visibility increased from 11 % to 78 %. The accuracy of MRA and CTA in revealing SLIL and LTIL tear was higher using the oblique axial plane. The overall accuracy for detecting SLIL tear on CTA improved from 94 % to 100 % and from 89 % to 94 % on MRA; the overall accuracy of detecting LTIL tear on CTA improved from 89 % to 100 % and from 72 % to 89 % on MRA CONCLUSION: Oblique axial imaging during CT and MR arthrography improves detection of tears in the dorsal and volar parts of both SLIL and LTIL. KEY POINTS: • Oblique axial imaging improves SLIL and LTIL visibility and tear detection. • This improvement is greater for the LTIL than for the SLIL ligament. • Overall, CT arthrography performed better than MR arthrography.


Subject(s)
Arthrography/methods , Joint Diseases/diagnostic imaging , Ligaments, Articular/diagnostic imaging , Magnetic Resonance Imaging/methods , Multidetector Computed Tomography/methods , Wrist Joint/diagnostic imaging , Aged , Aged, 80 and over , Cadaver , Humans , Ligaments, Articular/anatomy & histology , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Wrist Injuries/diagnostic imaging
9.
Hong Kong Med J ; 21(3): 217-23, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25810024

ABSTRACT

OBJECTIVE: To evaluate the treatment outcomes of enchondroma of the hand with artificial bone substitute versus autologous (iliac) bone graft. DESIGN: Historical cohort study. SETTING: Tertiary referral centre, Hong Kong. PATIENTS: A total of 24 patients with hand enchondroma from January 2001 to December 2013 who underwent operation at the Prince of Wales Hospital and Alice Ho Miu Ling Nethersole Hospital in Hong Kong were reviewed. Thorough curettage of the tumour was performed in all patients, followed by either autologous bone graft impaction under general anaesthesia in 13 patients, or artificial bone substitute in 11 patients (10 procedures were performed under local or regional anaesthesia and 1 was done under general anaesthesia). The functional outcomes and bone incorporation were measured by QuickDASH (shortened version of the Disabilities of the Arm, Shoulder and Hand questionnaire) scores and radiological appearance, respectively. The mean follow-up period was 59 months. RESULTS: There were eight men and 16 women, with a mean age of 40 years. Overall, 17 cases involved phalangeal bones and seven involved metacarpal bones. Among both groups of patients, most of the affected digits had good range of motion and function after surgery. One patient in each study group had complications of local soft tissue inflammation. One patient in the artificial bone substitute group was suspected to have recurrence 8 years after operation. Among the autologous bone graft group, four patients had persistent donor site morbidity at the last follow-up. In all patients, radiographs showed satisfactory bone incorporation. CONCLUSIONS: Artificial bone substitute is a safe and effective treatment option for hand enchondroma, with satisfactory functional and radiographic outcomes. Artificial bone substitute offers the additional benefits of enabling the procedure to be done under local anaesthesia on a day-case basis with minimal complications.


Subject(s)
Bone Neoplasms/surgery , Bone Substitutes/therapeutic use , Bone Transplantation , Chondroma/surgery , Hand/surgery , Neoplasm Recurrence, Local/surgery , Adult , Bone Neoplasms/diagnostic imaging , Bone Transplantation/adverse effects , Chondroma/diagnostic imaging , Female , Hand/diagnostic imaging , Humans , Ilium/transplantation , Male , Middle Aged , Radiography , Retrospective Studies , Tertiary Care Centers , Transplant Donor Site , Treatment Outcome , Young Adult
10.
Hong Kong Med J ; 21(3): 237-42, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25953929

ABSTRACT

OBJECTIVES: To determine the mechanism and epidemiology of paediatric finger injuries in Hong Kong during 2003-2005 and 2010-2012. DESIGN: Comparison of two case series. SETTING: University-affiliated teaching hospital, Hong Kong. PATIENTS: This was a retrospective study of two cohorts of children (age, 0 to 16 years) admitted to Prince of Wales Hospital with finger injuries during two 3-year periods. Comparisons were made between the two groups for age, involved finger(s), mechanism of injury, treatment, and outcome. Telephone interviews were conducted for parents of children who sustained a crushing injury of finger(s) by door. RESULTS: A total of 137 children (group A) were admitted from 1 January 2003 to 31 December 2005, and 109 children (group B) were admitted from 1 January 2010 to 31 December 2012. Overall, the mechanisms and epidemiology of paediatric finger injuries were similar between groups A and B. Most finger injuries occurred in children younger than 5 years (group A, 56%; group B, 76%) and in their home (group A, 67%; group B, 69%). The most common mechanism was crushing injury of finger by door (group A, 33%; group B, 41%) on the hinge side (group A, 63%; group B, 64%). The right hand was most commonly involved. The door was often closed by another child (group A, 37%; group B, 23%) and the injury often occurred in the presence of adults (group A, 60%; group B, 56%). Nailbed injury was the commonest type of injury (group A, 31%; group B, 39%). Fractures occurred in 24% and 23% in groups A and B, respectively. Traumatic finger amputation requiring replantation or revascularisation occurred in 12% and 10% in groups A and B, respectively. CONCLUSIONS: Crushing injury of finger by door is the most common mechanism of injury among younger children and accounts for a large number of hospital admissions. Serious injuries, such as amputations leading to considerable morbidity, can result. Crushing injury of finger by door occurs even in the presence of adults. There has been no significant decrease in the number of crushing injuries of finger by door in the 5 years between the two studies despite easily available and affordable preventive measures. It is the authors' view that measures aimed at promoting public awareness and education, and safety precautions are needed.


Subject(s)
Accidents, Home/trends , Finger Injuries/epidemiology , Finger Injuries/etiology , Finger Phalanges/injuries , Fractures, Bone/epidemiology , Adolescent , Amputation, Traumatic/epidemiology , Amputation, Traumatic/surgery , Child , Child, Preschool , Fractures, Bone/etiology , Hong Kong/epidemiology , Humans , Infant , Infant, Newborn , Lacerations/epidemiology , Lacerations/etiology , Nails/injuries , Replantation , Retrospective Studies
11.
Dev Biol ; 373(2): 431-41, 2013 Jan 15.
Article in English | MEDLINE | ID: mdl-22960038

ABSTRACT

Growth Factor Independence (Gfi) transcription factors play essential roles in hematopoiesis, differentially activating and repressing transcriptional programs required for hematopoietic stem/progenitor cell (HSPC) development and lineage specification. In mammals, Gfi1a regulates hematopoietic stem cells (HSC), myeloid and lymphoid populations, while its paralog, Gfi1b, regulates HSC, megakaryocyte and erythroid development. In zebrafish, gfi1aa is essential for primitive hematopoiesis; however, little is known about the role of gfi1aa in definitive hematopoiesis or about additional gfi factors in zebrafish. Here, we report the isolation and characterization of an additional hematopoietic gfi factor, gfi1b. We show that gfi1aa and gfi1b are expressed in the primitive and definitive sites of hematopoiesis in zebrafish. Our functional analyses demonstrate that gfi1aa and gfi1b have distinct roles in regulating primitive and definitive hematopoietic progenitors, respectively. Loss of gfi1aa silences markers of early primitive progenitors, scl and gata1. Conversely, loss of gfi1b silences runx-1, c-myb, ikaros and cd41, indicating that gfi1b is required for definitive hematopoiesis. We determine the epistatic relationships between the gfi factors and key hematopoietic transcription factors, demonstrating that gfi1aa and gfi1b join lmo2, scl, runx-1 and c-myb as critical regulators of teleost HSPC. Our studies establish a comparative paradigm for the regulation of hematopoietic lineages by gfi transcription factors.


Subject(s)
DNA-Binding Proteins/genetics , Gene Expression Regulation, Developmental , Hematopoiesis/genetics , Zebrafish Proteins/genetics , Zebrafish/genetics , Amino Acid Sequence , Animals , Cloning, Molecular , Conserved Sequence/genetics , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Embryo, Nonmammalian/metabolism , Epistasis, Genetic , Erythropoiesis/genetics , Evolution, Molecular , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/metabolism , Hematopoietic System/embryology , Hematopoietic System/metabolism , Models, Biological , Molecular Sequence Data , Zebrafish/embryology , Zebrafish Proteins/chemistry , Zebrafish Proteins/metabolism
12.
Blood ; 120(17): 3586-93, 2012 Oct 25.
Article in English | MEDLINE | ID: mdl-22968456

ABSTRACT

The human ankyrin-1 gene (ANK1) contains 3 tissue-specific alternative promoters. We have shown previously that the erythroid-specific ankyrin 1 (ANK1E) core promoter contains a 5' DNase I hypersensitive site (HS) with barrier insulator function that prevents gene silencing in vitro and in vivo. Mutations in the ANK1E barrier region lead to decreased ANK1 mRNA levels and hereditary spherocytosis. In this report, we demonstrate a second ANK1E regulatory element located in an adjacent pair of DNase I HS located 5.6 kb 3' of the ANK1E promoter at the 3' boundary of an erythroid-specific DNase I-sensitive chromatin domain. The 3' regulatory element exhibits enhancer activity in vitro and in transgenic mice, and it has the histone modifications associated with an enhancer element. One of the ANK1E 3'HS contains an NF-E2 binding site that is required for enhancer function. We show that a chromatin loop brings the 3' enhancer and NF-E2 into proximity with the 5' barrier region including the ANK1E core promoter. These observations demonstrate a model for the tissue-specific activation of alternative promoters that may be applicable to the ∼ 30% of mammalian genes with alternative promoters that exhibit distinct expression patterns.


Subject(s)
Ankyrins/genetics , Chromatin/genetics , Enhancer Elements, Genetic , Insulator Elements , NF-E2 Transcription Factor, p45 Subunit/genetics , Promoter Regions, Genetic , Spherocytosis, Hereditary/genetics , 3' Untranslated Regions , 5' Untranslated Regions , Animals , Ankyrins/metabolism , Binding Sites , Cell Line, Tumor , Chromatin/chemistry , Chromatin/metabolism , Deoxyribonuclease I/genetics , Deoxyribonuclease I/metabolism , Histones/genetics , Histones/metabolism , Humans , K562 Cells , Mice , Mice, Transgenic , NF-E2 Transcription Factor, p45 Subunit/metabolism , Organ Specificity , Protein Binding , Protein Isoforms/genetics , Protein Isoforms/metabolism , Spherocytosis, Hereditary/metabolism
13.
Skeletal Radiol ; 43(6): 725-43, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24522772

ABSTRACT

Pain on the radial side of the wrist is a common clinical presentation. Such wrist pain may provide a diagnostic challenge for radiologists, in view of the small size of the anatomic structures, the occasional subtlety of the imaging findings, the diversity of potential etiologies, as well as the non-infrequent occurrence of incidental asymptomatic findings in this area. This review discusses the imaging findings in both the more common and less common causes of radial-sided wrist pain, concentrating particularly on the detection of early disease and less readily apparent abnormalities.


Subject(s)
Arthralgia/etiology , Bone Diseases/complications , Bone Diseases/diagnosis , Carpal Bones/injuries , Diagnostic Imaging/methods , Fractures, Bone/complications , Fractures, Bone/diagnosis , Arthralgia/diagnosis , Carpal Bones/diagnostic imaging , Carpal Bones/pathology , Diagnosis, Differential , Humans , Radiography
14.
Skeletal Radiol ; 43(6): 713-24, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24595440

ABSTRACT

Radial wrist pain is a common clinical complaint. The relatively complex anatomy in this region, combined with the small size of the anatomical structures and occasionally subtle imaging findings, can pose problems when trying to localize the exact cause of pain. To fully comprehend the underlying pathology, one needs a good understanding of both radial-sided wrist anatomy and the relative merits of the different imaging techniques used to assess these structures. In part I of this review, these aspects will be discussed.


Subject(s)
Fractures, Bone/diagnosis , Magnetic Resonance Imaging/methods , Soft Tissue Injuries/diagnosis , Tomography, X-Ray Computed/methods , Ultrasonography/methods , Wrist Injuries/diagnosis , Wrist Joint/diagnostic imaging , Arthrography/methods , Humans , Models, Anatomic , Patient Positioning/methods , Positron-Emission Tomography/methods , Wrist Joint/pathology
15.
Hong Kong Med J ; 20(5): 460-3, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25307077

ABSTRACT

We report a case of digital ischaemia in a 31-year-old man who presented with sudden hand numbness, swelling, and cyanosis 4 days after a jellyfish sting. This is a rare complication of jellyfish sting, characterised by a delayed but rapid downhill course. Despite serial monitoring with prompt fasciotomy and repeated debridement, he developed progressive ischaemia in multiple digits with gangrenous change. He subsequently underwent major reconstructive surgery and aggressive rehabilitation. Although jellyfish stings are not uncommon, no severe jellyfish envenomation has been reported in the past in Hong Kong and there has not been any consensus on the management of such injuries. This is the first local case report of jellyfish sting leading to serious hand complications. This case revealed that patients who sustain a jellyfish sting deserve particular attention to facilitate early detection of complications and implementation of therapy.


Subject(s)
Bites and Stings/complications , Cnidaria , Hand/blood supply , Ischemia/diagnosis , Adult , Animals , Diagnosis, Differential , Gangrene/complications , Gangrene/diagnosis , Gangrene/surgery , Hand/pathology , Hand/surgery , Humans , Ischemia/complications , Male
16.
Hand Surg Rehabil ; 43(1): 101613, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37939917

ABSTRACT

OBJECTIVES: Dorsal central wrist pain, often a consequence of peri-scapholunate ligament injury, can result in a decline in functional performance. There is a scarcity of clinical data evaluating the effectiveness of conservative management on peri-scapholunate ligament injury. Conservative management includes education, immobilization with orthotic devices, scapholunate-stabilizing muscle strengthening, and proprioception training. The identification of the ligamento-muscular reflex and scapholunate-stabilizing muscles formed the rationale for a rehabilitation training program. We have devised an innovative standardized 16-week treatment program for patients with dorsal central wrist pain associated with acute peri-SL ligament injury. We hypothesized that the program can effectively reduce dorsal wrist pain and improve functional performance. MATERIALS AND METHODS: Recruited subjects underwent the 16-week home-based program, which included immobilization and rehabilitation exercises, to improve their wrist stability. Follow-up was arranged every 4 weeks for progress monitoring. The Short-Form 12 item questionnaire version 2, power grip, pinch grip, wrist range of motion, total performance score and total pain score when performing activities of daily living were used to evaluate the effectiveness of the program. An exercise adherence questionnaire was used to evaluate adherence to the home rehabilitation program. RESULTS: Twenty-three subjects (26 wrists) completed the program. Pain on visual analog scale improved by 5.1 cm and total pain score improved from 14.4/20 to 19.5/20. Total performance score reached 39/40, which indicated near-normal wrist function. Power grip and pinch grip increased by 22.3% and 17.8%, respectively. The physical component scale of the Short-Form 12 item questionnaire showed significant improvement, while the mental component scale did not. Overall adherence was fair. DISCUSSION: Conservative management, including immobilization and rehabilitation training, can provide significant clinical improvement in patients with dorsal central wrist pain associated with acute peri-scapholunate ligament injury. CONCLUSION: Standardized wrist rehabilitation can be taken as a reference treatment modality. It is an evidence-based non-invasive treatment option for clinicians and therapists.


Subject(s)
Joint Instability , Neuralgia , Wrist Injuries , Humans , Wrist , Activities of Daily Living , Treatment Outcome , Arthralgia
17.
Nat Metab ; 6(4): 741-763, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38664583

ABSTRACT

Due to the rise in overnutrition, the incidence of obesity-induced hepatocellular carcinoma (HCC) will continue to escalate; however, our understanding of the obesity to HCC developmental axis is limited. We constructed a single-cell atlas to interrogate the dynamic transcriptomic changes during hepatocarcinogenesis in mice. Here we identify fatty acid binding protein 5 (FABP5) as a driver of obesity-induced HCC. Analysis of transformed cells reveals that FABP5 inhibition and silencing predispose cancer cells to lipid peroxidation and ferroptosis-induced cell death. Pharmacological inhibition and genetic ablation of FABP5 ameliorates the HCC burden in male mice, corresponding to enhanced ferroptosis in the tumour. Moreover, FABP5 inhibition induces a pro-inflammatory tumour microenvironment characterized by tumour-associated macrophages with increased expression of the co-stimulatory molecules CD80 and CD86 and increased CD8+ T cell activation. Our work unravels the dual functional role of FABP5 in diet-induced HCC, inducing the transformation of hepatocytes and an immunosuppressive phenotype of tumour-associated macrophages and illustrates FABP5 inhibition as a potential therapeutic approach.


Subject(s)
Carcinoma, Hepatocellular , Fatty Acid-Binding Proteins , Ferroptosis , Liver Neoplasms , Neoplasm Proteins , Obesity , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/etiology , Animals , Fatty Acid-Binding Proteins/metabolism , Fatty Acid-Binding Proteins/genetics , Mice , Liver Neoplasms/metabolism , Liver Neoplasms/etiology , Obesity/complications , Obesity/metabolism , Male , Tumor Microenvironment/immunology , Humans , Mice, Inbred C57BL , Tumor-Associated Macrophages/metabolism , Tumor-Associated Macrophages/immunology
18.
Nucleic Acids Res ; 39(6): 2175-87, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21071415

ABSTRACT

Eukaryotic core promoters are often characterized by the presence of consensus motifs such as the TATA box or initiator elements, which attract and direct the transcriptional machinery to the transcription start site. However, many human promoters have none of the known core promoter motifs, suggesting that undiscovered promoter motifs exist in the genome. We previously identified a mutation in the human Ankyrin-1 (ANK-1) promoter that causes the disease ankyrin-deficient Hereditary Spherocytosis (HS). Although the ANK-1 promoter is CpG rich, no discernable basal promoter elements had been identified. We showed that the HS mutation disrupted the binding of the transcription factor TFIID, the major component of the pre-initiation complex. We hypothesized that the mutation identified a candidate promoter element with a more widespread role in gene regulation. We examined 17,181 human promoters for the experimentally validated binding site, called the TFIID localization sequence (DLS) and found three times as many promoters containing DLS than TATA motifs. Mutational analyses of DLS sequences confirmed their functional significance, as did the addition of a DLS site to a minimal Sp1 promoter. Our results demonstrate that novel promoter elements can be identified on a genome-wide scale through observations of regulatory disruptions that cause human disease.


Subject(s)
Ankyrins/genetics , Mutation , Promoter Regions, Genetic , Spherocytosis, Hereditary/genetics , Transcription Factor TFIID/metabolism , Base Sequence , Binding Sites , Consensus Sequence , Genome, Human , Humans , K562 Cells , Transcription Initiation Site
19.
PM R ; 15(4): 482-492, 2023 04.
Article in English | MEDLINE | ID: mdl-35233956

ABSTRACT

BACKGROUND: Prosthetic socket coupling with the residual limb should be comfortable without causing skin breakdown or excessive pressure. However, users report socket discomfort, and there is a scarcity of objective measurements available to assess this feeling of discomfort. Quantifying the specific pressure may enable clinicians and users to determine and improve comfort levels objectively. OBJECTIVES: (1) To evaluate if a peak pressure reduction assists in resolving wounds, redness, and pain inside prosthetic sockets in people with transtibial amputation. (2) To determine if peak pressures measured inside the prosthetic socket due to external forces could be used to quantify the level of improvement in socket discomfort. DESIGN: In this cohort study, we used a pressure sensor to quantify and facilitate adjustments to the prosthetic socket, correlating this information to the user's socket comfort. SETTING: Outpatient clinic in a tertiary hospital in Singapore. PARTICIPANTS: People (N = 16) with unilateral transtibial lower limb amputation using a prosthesis. INTERVENTIONS: NA. MAIN OUTCOME MEASURES: Peak pressure and socket comfort score (SCS). RESULTS: The peak pressure value showed a statistically significant reduction across all participants following adjustments at a 50% delta change in pressure (p = .001). This was achieved with a mean number of 2.6 ± 1.4 adjustments per participant. Following the adjustments, the paired t-test results showed a mean increase between the first SCS and final SCS was 2.6 (p = .001). CONCLUSION: The wound, redness, and pain resolved in 15 of 16 participants regardless of diabetic status following socket adjustments. Although the peak pressures values did not correlate to the SCS score, the reduction in peak pressure saw significant improvement to the SCS. The use of a portable sensor is a fast and efficient means to quantify adjustments inside the prosthetic socket and could potentially be considered as part of future care delivery.


Subject(s)
Amputation Stumps , Artificial Limbs , Humans , Adult , Cohort Studies , Prosthesis Design , Amputation, Surgical , Pain , Tibia/surgery
20.
Hand Surg Rehabil ; 42(6): 492-498, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37490953

ABSTRACT

OBJECTIVES: Triangular fibrocartilage complex (TFCC) injury is a common cause of ulnar-sided wrist pain. However, treatment protocols vary across clinical settings and a standardized treatment protocol is needed to improve quality of care. We devised a rehabilitation regime which comprised both orthoses and exercises. We hypothesized that the program can effectively reduce pain and improve functional performance. MATERIALS AND METHODS: Thirty-two subjects participated in the 5-phase rehabilitation program. Progress was monitored every 3 weeks. Outcome measures comprised numeric pain rating scale (NPRS), activities of daily living (ADL) pain score, wrist range of motion (ROM), ADL performance score, patient-rated wrist evaluation (PRWE), power grip and distal radioulnar joint (DRUJ) instability grade. RESULTS: NPRS decreased from 5.3/10 to 0.5/10 while the ADL pain score improved from 10/20 to 19.1/20. ROM in flexion/extension and supination/pronation improved by 35%. Functional performance on ADL performance score and PRWE improved from 21/40 to 38/40 and 49.5/100 to 14.6/100, respectively. Power grip increased by 59.5%, and DRUJ stability improved. DISCUSSION: The combination of orthoses and progressive strengthening and proprioception training was effective in re-establishing DRUJ stability, and improving wrist strength and functional performance. CONCLUSIONS: This study provided insight for the development of a rehabilitation protocol for patients with TFCC injury.


Subject(s)
Joint Instability , Triangular Fibrocartilage , Wrist Injuries , Humans , Triangular Fibrocartilage/injuries , Activities of Daily Living , Wrist Joint/surgery , Wrist Injuries/surgery , Pain , Joint Instability/surgery
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