Median Arcuate Ligament Syndrome: A Case Report on a Rare Disease and Variant Hepatic Arterial Anatomy.

Median arcuate ligament syndrome (MALS) is a rare gastroenterological illness that arises from the compression of the celiac trunk by the fibrous arch known as the median arcuate ligament, which connects the muscular tendon of the diaphragm to the vertebral column. It is hypothesized that this syndrome arises due to the inadequate caudal migration of the celiac trunk during embryogenesis, although the exact pathophysiology behind this disease process remains unclear. While MALS is classically associated with a triad of post-prandial pain, weight loss, and epigastric bruit, the triad is often incomplete due to variations in vascular structures with collateral circulation from adjacent vessels. When symptoms are present, they can be vague and often characterized as unexplained nausea, vomiting, diarrhea, or flatulence. Frequently, MALS is identified incidentally upon imaging of the abdomen in response to these nonspecific complaints. We present the case of a patient suffering from MALS in which a rare anatomic variant of the celiac trunk was identified.

I saw the "hook" sign of median arcuate ligament syndrome.

The hook sign is a radiologic finding best appreciated on a sagittal view of the celiac artery with computed tomography (CT) that indicates compression of the celiac artery. It refers to the hooked-shape of the proximal celiac artery caused by extrinsic compression by the median arcuate ligament. When seen in a patient with concurrent abdominal symptoms, it suggests median arcuate ligament syndrome (MALS). We saw the sign in a 15-year-old male via duplex ultrasonography and abdominal CT. He underwent laparoscopic release of the median arcuate ligament and had full resolution of his symptoms at follow-up.

Metachronous Rupture of Pancreatoduodenal Artery Aneurysm with Median Arcuate Ligament Syndrome: A Case Report and Review of 11 Cases.

Median arcuate ligament syndrome (MALS) involves narrowing of the celiac artery root from MAL compression, leading to pancreatoduodenal artery aneurysm (PDAA) due to increased retrograde blood flow from the superior mesenteric artery into the PDA. We encountered a case in which coil embolization was performed for PDAA rupture due to MALS. Four years later, a second PDAA occurred and ruptured, necessitating coil reembolization. There have been no reports of recurrence during long-term follow-up after PDAA treatment in patients with MALS. We herein report a rare case of metachronous PDAA rupture in the context of MALS. The relevant literature and 11 PDAA/MALS cases are discussed.

Celiac plexus block: A diagnostic tool for neurogenic median arcuate ligament syndrome.

OBJECTIVE: The objective of this study was to evaluate the effect of outpatient celiac plexus block on acute pain reduction in patients with suspected median arcuate ligament syndrome. METHODS: This is an Institutional Review Board approved, retrospective chart review. Data were collected and analyzed from patients who received celiac plexus blocks from November 1, 2021 through April 6, 2023. The primary outcome was pain reduction, determined by the change in numerical pain rating scale (NPRS) from pre-procedure to post-procedure. Additional data collected include patient demographics, comorbidities, preoperative symptoms and duration of symptoms. RESULTS: There were 33 patients identified in this study. Thirty-one patients were included in the data analysis. The median age of the cohort was 29 years, and the median BMI was 20.4. 94% of the cohort was female. These patients were referred as part of an evaluation for symptomatic vascular compression disorders. For many patients, positive response to celiac plexus block was used as an indication to proceed with surgical MALS resection. We provide a diagnostic algorithm for MALs. All patients endorsed preoperative symptoms. Patients experienced a median pain reduction of -4 from baseline to immediately post-procedure. CONCLUSIONS: Celiac plexus blocks continue to be a tool for ruling out neurogenic median arcuate ligament syndrome in patients who have undergone extensive previous imaging and assessments for vascular compression disorders. Our data suggest that patients with suspected MALS may experience substantial immediate pain relief from temporary blocks of the celiac ganglion as guided by fluoroscopy in an outpatient setting.

Laparoscopic Treatment of a Symptomatic Young Woman With Median Arcuate Ligament Syndrome.

Median arcuate ligament syndrome (MALS), also known as Dunbar syndrome, celiac axis syndrome, or celiac artery compression syndrome, is caused by a band of tissue called the median arcuate ligament that compresses the celiac artery and sometimes the celiac plexus too. MALS does not always cause symptoms, but when symptoms occur, surgery is the treatment of choice. This case report focuses on the case of a 27-year-old woman presenting with postprandial episodes of abdominal pain and vomiting accompanied by loss of weight, which was found to be MALS.

Recurrent aneurysmatic bleeding of pancreaticoduodenal aneurysm due to median arcuate ligament syndrome: a case report.

Median arcuate ligament syndrome (MALS) involves coeliac artery compression, causing a range of symptoms from chronic pain to life-threatening complications. This case features a 52-year-old patient with recurrent retroperitoneal bleeding from MALS-related inferior pancreaticoduodenal artery aneurysms (PDAAs). Emergency interventions, including surgical bleeding control, angioplasty, percutaneous drainage, and median arcuate ligament release, were conducted. The case highlights challenges in diagnosing and managing MALS-related PDAA, emphasizing the importance of early identification and tailored interventions based on clinical symptoms and imaging. Surgical intervention to release the ligament is the primary treatment, with considerations for prophylactic intervention in PDAA cases. Lack of established PDAA management protocols underscores the need for prompt intervention to prevent complications. In conclusion, this report stresses the association between MALS and PDAA, advocating for early identification and tailored management to mitigate complications.

Structural evolution of pea-derived albumins during pH and heat treatment studied with light and X-ray scattering.

Pea albumins are found in the side stream during the isolation of pea proteins. They are soluble at acidic pH and have functional properties which differ from their globulin counterparts. In this study, we have investigated the aggregation and structural changes occurring to pea albumins under different environmental conditions, using a combination of size-exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALS) and small-angle X-ray scattering (SAXS). Albumins were extracted from a dry fractionated pea protein concentrate by precipitating the globulin fraction at acidic pH. The albumins were then studied at different pH (3, 4, 4.5, 7, 7.5, and 8) values. The effect of heating at 90 °C for 1, 3, and 5 min on their structural changes was investigated using SAXS. In addition, size exclusion of the albumins showed 4 distinct populations, depending on pH and heating conditions, with two large aggregates peaks (∼250 kDa): a dimer peak (∼24 kDa) containing predominantly pea albumin 2 (PA2), and a monomer peak of a molar mass of about 12 kDa (PA1). X-ray scattering intensities as a function of q were modeled as polydisperse spheres, and their aggregation was followed as a function of heating time. Albumins was most stable at pH 3, showing no aggregation during heat treatment. While albumins at pH 7.5 and 8 showed aggregation after heating, solutions at pH 4, 4.5, and 7 already contained aggregates even before heating. This work provides new knowledge on the overall structural development of albumins under different environmental conditions, improving our ability to employ these as future ingredients in foods.

Using Capillary Electrophoresis to Investigate Protein Conformational and Compositional Heterogeneity.

Detailed insights into protein structure/function relationships require robust characterization methodologies. Free-solution capillary electrophoresis (CE) is a unique separation technique which is sensitive to the conformation and/or composition of proteins, and therefore provides information on the heterogeneity of these properties. Three unrelated, conformationally/compositionally-altered proteins were separated by CE. An electrophoretic mobility distribution was determined for each protein along with its conformational and/or compositional heterogeneity. The CE results were compared with molar mass distributions obtained from size-exclusion chromatography coupled to light scattering (SEC-MALS). Bovine serum albumin multimers and two monomeric species were separated, highlighting variations in conformational/compositional heterogeneity among the multimers. Analysis of yeast alcohol dehydrogenase resolved two monomeric conformers and various tetrameric species, illustrating the impact of zinc ion removal and disulfide bond reduction on the protein's heterogeneity. The apo (calcium-free) and holo forms of bovine α-lactalbumin were separated and differences in the species' heterogeneity were measured; by contrast, the SEC-MALS profiles were identical. Comparative analysis of these structurally unrelated proteins provided novel insights into the interplay between molar mass and conformational/compositional heterogeneity. Overall, this study expands the utility of CE by demonstrating its capacity to discern protein species and their heterogeneity, properties which are not readily accessible by other analytical techniques.

In-line coupling of capillary-channeled polymer fiber columns with optical absorbance and multi-angle light scattering detection for the isolation and characterization of exosomes.

Extracellular vesicles (EVs) have garnered much interest due to their fundamental role in intracellular communication and their potential utility in clinical diagnostics and as biotherapeutic vectors. Of particular relevance is the subset of EVs referred to as exosomes, ranging in size from 30 to 150 nm, which contain incredible amounts of information about their cell of origin, which can be used to track the progress of disease. As a complementary action, exosomes can be engineered with therapeutic cargo to selectively target diseases. At present, the lack of highly efficient methods of isolation/purification of exosomes from diverse biofluids, plants, and cell cultures is a major bottleneck in the fundamental biochemistry, clinical analysis, and therapeutic applications. Equally impactful, the lack of effective in-line means of detection/characterization of isolate populations, including concentration and sizing, is limiting in the applications. The method presented here couples hydrophobic interaction chromatography (HIC) performed on polyester capillary-channeled polymer (C-CP) fiber columns followed by in-line optical absorbance and multi-angle light scattering (MALS) detection for the isolation and characterization of EVs, in this case present in the supernatant of Chinese hamster ovary (CHO) cell cultures. Excellent correlation was observed between the determined particle concentrations for the two detection methods. C-CP fiber columns provide a low-cost platform (< $5 per column) for the isolation of exosomes in a 15-min workflow, with complementary absorbance and MALS detection providing very high-quality particle concentration and sizing information.

Median Arcuate Ligament Syndrome in Children: A Single-Center Experience.

BACKGROUND: Data on median arcuate ligament syndrome (MALS) in children are scant. It is postulated that MALS can cause chronic abdominal pain. It is unclear what percentage of children with this condition are symptomatic and what comorbidities are associated with this syndrome. METHODS: In this retrospective study, data on consecutive patients in a single center diagnosed coincidentally with MALS during routine echocardiogram were reviewed. Symptom burden, comorbidities, and the effect of anthropometric indices on MALS were investigated. Descriptive statistics and nonparametric tests were used to describe the findings and to compare variables with normal distribution. RESULTS: Between 2013 and 2020, there were 82 children, 55 females (67%), mean age 13.9 ± 3.2 years, with MALS and complete record. Mean velocity across the stenotic area was 2.6 ± 0.4 m/s. Forty-six patients (57%) had abdominal pain. Age, gender, weight, body mass index (BMI), and Doppler velocity had no statistically significant influence on symptom occurrence. Conversely, patients with joint hypermobility and symptoms of orthostatic intolerance were more likely to have abdominal pain from MALS. Of 24 patients with joint hypermobility, 18 patients had abdominal pain (p=0.027). Thirty-eight patients with orthostatic intolerance (OI) with MALS complained of abdominal pain vs 13 patients with OI and no abdominal pain (p=<0.0001). CONCLUSION: Nearly half of patients with MALS had abdominal pain. Age, gender, weight, and the degree of stenosis had no statistically significant influence on symptom occurrence. OI, specifically postural orthostatic tachycardia syndrome (POTS), and joint hypermobility on exam predicted a higher propensity for abdominal pain in patients with MALS.

Assessment of Protein Binding Using Asymmetric-Flow Field-Flow Fractionation Combined with Multi-angle Light Scattering and Dynamic Light Scattering.

Asymmetric-flow field-flow fractionation (AF4) is a valuable tool to separate and assess different size populations in nanotherapeutics. When coupled with both static light scattering and dynamic light scattering, it can be used to qualitatively assess protein binding to nanoparticles by comparing the shape factors for both non-plasma-incubated samples and plasma-incubated samples. The shape factor is defined as the ratio of the derived root mean square radius (by static light scattering) to the measured hydrodynamic radius (by dynamic light scattering). The shape factor gives an idea of where the center of mass lies in a nanoparticle, and any shift in the shape factor to larger values is indicative of a mass addition to the periphery of the nanoparticle and suggests the presence of protein binding. This protocol will discuss how to set up an experiment to assess protein binding in nanoparticles using AF4, multi-angle light scattering (MALS), and dynamic light scattering (DLS).

Nanoparticle Size Distribution and Stability Assessment Using Asymmetric-Flow Field-Flow Fractionation.

Nanomaterials are inherently polydisperse. Traditional techniques, such as the widely used batch-mode dynamic light-scattering (DLS) analysis, are not ideal nor thoroughly descriptive enough to define the full complexity of these materials. Asymmetric-flow field-flow fractionation (AF4) with various in-line detectors, such as ultraviolet-visible (UV-vis), multi-angle light scattering (MALS), refractive index (RI), and DLS, is an alternative technique that can provide flow-mode analysis of not only size distribution but also shape, drug release/stability, and protein binding.

Hyaluronic acid from bluefin tuna by-product: Structural analysis and pharmacological activities.

The fishing and aquaculture industries generate a huge amount of waste during processing and preservation operations, especially those of tuna. Recovering these by-products is a major economic and environmental challenge for manufacturers seeking to produce new active biomolecules of interest. A new hyaluronic acid was extracted from bluefin tuna's vitreous humour to assess its antioxidant and pharmacological activities. The characterization by infrared spectroscopy (FT-IR), nuclear magnetic resonance ((1D1H) and 2D (1H COSY, 1H/13C HSQC)) and size exclusion chromatography (SEC/MALS/DRI/VD) revealed that the extracted polysaccharide was a hyaluronic acid with high uronic acid content (55.8 %) and a weight average molecular weight of 888 kDa. This polymer possesses significant anti-radical activity and ferrous chelating capacity. In addition, pharmacological evaluation of its anti-inflammatory and analgesic potential, using preclinical models, in comparison with reference drugs (Dexamethasone, diclofenac, and acetylsalicylate of lysine), revealed promising anti-inflammatory activity as well as interesting peripheral and central antinociceptive activity. Therefore, our new hyaluronic acid compound may therefore serve as a potential drug candidate for the treatment of pain sensation and inflammation of various pathological origins.

Laparoscopic median arcuate ligament section for median arcuate ligament compression syndrome initially detected as splenic infarction: a case report.

BACKGROUND: Median arcuate ligament compression syndrome (MALS) causes upper abdominal pain and at times hemodynamic abnormalities in the pancreaticoduodenal region. Herein, we present a case of a 70 year-old man, initially diagnosed with splenic infarction and was successfully treated laparoscopically. CASE PRESENTATION: A 70-year-old man with abdominal pain admitted to our hospital. Abdominal-enhanced computed tomography revealed a poorly contrasted area in the spleen and stenosis at the root of the celiac artery. Arterial dilatation was observed around the pancreaticoduodenal arcade, however, no obvious aneurysm formation or arterial dissection was observed. Abdominal-enhanced magnetic resonance imaging indicated the disappearance of the flow void at the root of the celiac artery. The patient had no history of atrial fibrillation and was diagnosed with splenic infarction due to median arcuate ligament compression syndrome. We performed a laparoscopic median arcuate ligament section with five ports. Intraoperative ultrasonography showed a retrograde blood flow in the common hepatic artery and the celiac artery. After releasing the compression, the antegrade blood flow from the celiac artery to the splenic artery, and the common hepatic artery were visualized using intraoperative ultrasonography. The postoperative course of the patient was uneventful, and he was discharged on postoperative day 9. Postoperative computed tomography a month after surgery revealed no residual stenosis of the celiac artery or dilation of the pancreaticoduodenal arcade. Furthermore, the poorly contrasted area of the spleen improved. CONCLUSIONS: Reports indicate that hemodynamic changes in the abdominal visceral arteries due to median arcuate ligament compression are related to the formation of pancreaticoduodenal aneurysms. In this case, median arcuate ligament compression syndrome caused splenic infarction by reducing blood flow to the splenic artery.

Characterization of complexes of PF4 and heparins by size-exclusion chromatography coupled with multi-angle light scattering detector.

Heparin-induced thrombocytopenia (HIT) is an immune complication of heparin therapy. Antibodies binding to complexes of platelet factor 4 (PF4) and heparin is the trigger of HIT. A method using size exclusion chromatography with multi-angle laser light scattering detector (SEC-MALS) was developed in this work. The soluble ultra-large complex (ULC) was separated from the small complex (SC) and their molecular weights (MWs) were firstly measured. The complexes of PF4 and three heparins with different MW, including unfractionated heparin (UFH), dalteparin (Daltep) and enoxaparin (Eno) were characterized using this method. The contents and the sizes of ULC increased gradually when heparins were added to PF4 to certain amounts. While, they reduced after more heparins were added. It is the first time to measure the MWs of the biggest ULC of PF4-heparins as millions of Dalton. at the proper ratios of PF4 to heparin (PHR). Meanwhile, those mixtures at those certain PHRs induced the higher expression of CD83 and CD14 markers on dendritic cells (DCs) suggesting that they had stronger immunogenicity and is critical for HIT.

Structural framework for the understanding spectroscopic and functional signatures of the cyanobacterial Orange Carotenoid Protein families.

The Orange Carotenoid Protein (OCP) is a unique photoreceptor crucial for cyanobacterial photoprotection. Best studied Synechocystis sp. PCC 6803 OCP belongs to the large OCP1 family. Downregulated by the Fluorescence Recovery Protein (FRP) in low-light, high-light-activated OCP1 binds to the phycobilisomes and performs non-photochemical quenching. Recently discovered families OCP2 and OCP3 remain structurally and functionally underexplored, and no systematic comparative studies have ever been conducted. Here we present two first crystal structures of OCP2 from morphoecophysiologically different cyanobacteria and provide their comprehensive structural, spectroscopic and functional comparison with OCP1, the recently described OCP3 and all-OCP ancestor. Structures enable correlation of spectroscopic signatures with the effective number of hydrogen and discovered here chalcogen bonds anchoring the ketocarotenoid in OCP, as well as with the rotation of the echinenone's ß-ionone ring in the CTD. Structural data also helped rationalize the observed differences in OCP/FRP and OCP/phycobilisome functional interactions. These data are expected to foster OCP research and applications in optogenetics, targeted carotenoid delivery and cyanobacterial biomass engineering.

[Diagnosis and treatment of Dunbar syndrome]. / Diagnostik und Therapie des Dunbar-Syndroms.

The rare Dunbar syndrome or medial arcuate ligament syndrome (MALS) is defined as compression of the celiac trunk and/or ganglion by the medial arcuate ligament. It is often diagnosed after patients have suffered for a long time and is characterized by intermittent food-related pain, nausea, and unexplained weight loss. After exclusion of other causes of the above symptoms by gastroscopy, colonoscopy, CT, or MRI, the gold standard for diagnosis is dynamic color-coded duplex sonography, which may be supplemented by CT or MR angiography. The treatment of choice is a laparoscopic division of the arcuate ligament at the celiac trunk, although percutaneous transluminal angioplasty (PTA) with stent implantation may be performed in cases of postoperative persistence of symptoms or recurrent stenosis. Since symptoms persist postoperatively in up to 50% of cases, strict indication and complete diagnosis in designated centers are of great importance for successful treatment.

Median arcuate ligament syndrome (Dunbar syndrome): A diagnosis not to be underestimated.

Medial arcuate ligament syndrome (MALS) is an anatomoclinical entity underestimated in most situations due to the lack of specific signs. However, the consequences can be disastrous if the diagnosis is not seriously considered and investigations are not fully undertaken to confirm this hypothesis. We report a case of Median Arcuate Ligament Syndrome in a young woman who presented to the Emergency Department with moderate postprandial pain. All investigations were carried out promptly, with no abnormalities, and the diagnosis was retained on the evidence of a well-performed and appropriately interpreted abdominal CT. This case illustrates a rare cause of epigastralgia simulating a surgical emergency. This condition should be considered when biological and often radiological investigations are inconclusive. The relative youth of the patient is often suggestive, but confirmation is based on a CT scan with injection of a well-technical contrast product, or angiography. Treatment is debatable between a conservative approach and surgery. Surgical approach is discussed depending on the degree of vascular stenosis and the impact on the digestive tract. However, the recurrence of symptoms may be a contributory factor in the therapeutic decision. The impact could be lethal depending on the degree of stenosis and consequently on the repercussions on the digestive tract. A multidisciplinary approach is required for its management.

Supradiaphragmatic origin of the celiac trunk leading to median arcuate ligament syndrome with superior mesenteric artery involvement.

Median arcuate ligament (MAL) syndrome (MALS) is a rare condition caused by compression of the celiac artery by the MAL. Symptoms include abdominal pain, nausea, and weight loss. Rarely, the MAL can compress both the celiac artery and the superior mesenteric artery (SMA). We describe the case of a young man with MALS involving the celiac artery and SMA. Laparoscopic release of the MAL was performed, and the patient had resolution of his symptoms at 6 months of follow-up. A review of the literature identified only six cases of MALS involving the SMA and celiac artery, making this a rare occurrence.

Characterisation of locust bean gum with asymmetric flow field-flow fractionation (AF4) and light scattering.

We present a detailed characterisation of locust bean gum (LBG), an industrially significant galactomannan, utilising asymmetric flow field-flow fractionation (AF4) and light scattering. Molecular weight and size determination of galactomannans is complicated by their tendency to aggregate, even in dilute solutions; AF4 allows us to confirm the presence of aggregates, separate these from well-dispersed polymer, and characterise both fractions. For the dispersed polymer, we find Mw=9.2×105 g mol-1 and Rg,z=82.1 nm; the distribution follows Flory scaling (Rg∼Mν) with ν∼ 0.63, indicating good solvent conditions. The aggregate fraction exhibited radii of up to 1000 nm and masses of up to 3×1010 g mol-1. Furthermore, we demonstrate how both fractions are influenced by changes to filtration procedure and solvent conditions. Notably, a 200 nm nylon membrane effectively removes the aggregated fraction; we present a concentration-dependent investigation of solutions following this protocol, using static and dynamic light scattering, which reveals additional weak aggregation in these unfractionated samples. Overall, we demonstrate that AF4 is highly suited to LBG characterisation, providing structural information for both well-dispersed and aggregated fractions, and expect the methods employed to apply similarly to other galactomannans and associating polymer systems.