Optical control of light polarization in heliconical cholesteric liquid crystals.

We show here that light polarization of a beam propagating through a heliconical cholesteric cell can be controlled by tuning the Bragg resonance of the structure. We demonstrate that this control is achieved by varying either the low-frequency electric field or the intensity of a pump beam impinging on the sample. The study confirms the recently reported phenomenon of optical tuning of the heliconical cholesterics and opens the door for the development of simple and efficient polarization modulators controlled electrically or optically.

Impact of Cadmium Mediated by Tobacco Use in Musculoskeletal Diseases.

Tobacco use has a negative impact on health due to its relationship with the development of high-mortality diseases, such as pulmonary cancer. However, the effect of cadmium (Cd), present in tobacco smoke, on the development of joint diseases has been scarcely studied. The objective of this review is to discuss the evidence regarding the mechanisms by which Cd exposure, through tobacco smoke, may lead to the development of osteoarthritis (OA), osteoporosis (OP), and rheumatoid arthritis (RA). There's evidence suggesting a string association between moderate to severe OA development and tobacco use, and that a higher blood concentration of Cd can trigger oxidative stress (OS) and inflammation, favoring cartilage loss. At the bone level, the Cd that is inhaled through tobacco smoke affects bone mineral density, resulting in OP mediated by a decrease in the antioxidant enzymes, which favors the bone resorption process. In RA, tobacco use promotes the citrullination process through Cd exposure and increases OS and inflammation. Understanding how tobacco use can increase the damage at the articular level mediated by a toxic metal, i.e., Cd, is important. Finally, we propose prevention, control, and treatment strategies for frequently disabling diseases, such as OA, OP, and RA to reduce its prevalence in the population.

Effect of cadmium on the viability on monolayer cultures of synoviocytes, chondrocytes, and Hoffa: A preliminary study.

Osteoarthritis (OA) is the gradual loss of articular cartilage and involves several tissues, such as the synovial membrane, meniscus, ligaments, and adipose tissue known as Hoffa fat pad. There are largely unexplored factors that lead to OA development, such as the impact of exposure to heavy metals like cadmium (Cd) on the viability of cells in the knee joint tissue. The objective of this report was to identify the cell type with the highest susceptibility to Cd toxicity with respect to cell viability and death. Our findings showed that a concentration as low as 3 µM cadmium chloride for 12 h affects the viability of synovial cells, and a concentration of 10 µM affects Hoffa cells. Our results suggest that Cd can affect the viability of synovial and chondral cells primarily. In contrast, Hoffa cells were less susceptible, likely because Cd favors the production of pro-inflammatory cytokines before triggering their death as part of its damage mechanism at the articular level.

Effect of cadmium on the concentration of essential metals in a human chondrocyte micromass culture.

BACKGROUND: An essential element imbalance in the joint might favor gradual degeneration of the articular cartilage. It has been reported that cadmium (Cd) plays an antagonistic role with regards to the presence of essential elements, such as zinc (Zn), iron (Fe), and manganese (Mn), which may favor the development of disabling diseases, like osteoarthritis (OA) and osteoporosis. METHODS: 3D cultures of human chondrocytes were phenotyped with the Western blot technique and structurally evaluated with histological staining. The samples were exposed to 1, 5, and 10 µM of CdCl2 for 12 h, with a non-exposed culture as control. The concentration of Cd, Fe, Mn, Zn, chromium (Cr), and nickel (Ni) was quantified through plasma mass spectrometry (ICP-MS). The data were analyzed with a Kruskal Wallis test, a Kendall's Tau test and Spearman's correlation coefficient with the Stata program, version 14. RESULTS: Our results suggest that Cd exposure affects the structure of micromass cultures and plays an antagonistic role on the concentration of essential metals, such as Zn, Ni, Fe, Mn, and Cr. CONCLUSION: Cd exposure may be a risk factor for developing joint diseases like OA, as it can interfere with cartilage absorption of other essential elements that maintain cartilage homeostasis.

Toxicity of cadmium in musculoskeletal diseases.

Epidemiological studies have reported that exposure to toxic metals like cadmium (Cd) may promote the development of musculoskeletal diseases, such as osteoporosis, rheumatoid arthritis (RA), and osteoarthritis (OA), among others. The objective of this review is to summarize the molecular mechanisms of inflammation and oxidative stress activated by Cd at the bone level, particularly in osteoporosis, RA, and OA. Cadmium can increase bone resorption, affect the activity of osteoclasts and calcium (Ca) absorption, and impair kidney function, which favors the development of osteoporosis. In the case of RA, Cd interferes with the activity of antioxidant proteins, like superoxide dismutase (SOD) and catalase (CAT). It also promotes an inflammatory state, inducing the process of citrullination, which affects the proteins of immune response. On the other hand, accumulation of Cd in the tissues and blood of smokers has been related to the development of some musculoskeletal diseases. Therefore, knowing the negative impact of Cd toxicity at the articular level can help understand the damage mechanisms it produces, leading to the development of such diseases.

[Synchronous primary double: condrosarcoma and sarcoma high grade fusocelular associated with Maffucci syndrome]. / Doble primario sincrónico: condrosarcoma y sarcoma fusocelular de alto grado asociado a síndrome de Maffucci.

Maffucci syndrome is characterized by the presence of multiple enchondromes and hemangiomas that can affect soft tissues and other organs. The risk of malignant transformation of lesions is 100% during the life of the individual, with chondrosarcoma being the most frequently associated malignant tumor. We present the case of a 44-year-old man diagnosed with Maffucci syndrome who developed a synchronous double primary: chondrosarcoma and high-grade multicenter fusocellular sarcoma of scapular and tricipital region, was treated with disarticulation interscapule-thoracic, presented accelerated progression and lung disease. There are other neoplasms associated with Maffucci syndrome, such as pancreatic adenocarcinoma, mesenchymal ovarian tumors, gliomas, astrocytomas and pituitary tumors. It is therefore very interesting to report the uncommon association between fusocellular sarcoma and secondary chondrosarcoma in patients with Maffucci syndrome. Follow-up in this group of patients is complex and is based on the intentional search for accelerated growing lesions, paying attention to progressive growth injuries, clinical symptoms or radiological malignancy data.

El síndrome de Maffucci se caracteriza por la presencia de múltiples encondromas y hemangiomas que pueden afectar tejidos blandos y otros órganos. El riesgo de transformación maligna de las lesiones es de 100% durante la vida del individuo, siendo el condrosarcoma el tumor maligno más frecuentemente asociado. Se presenta el caso de un hombre de 44 años de edad con diagnóstico de síndrome de Maffucci, el cual desarrolló un doble primario sincrónico: condrosarcoma y sarcoma fusocelular de alto grado multicéntrico de región escapular y tricipital, fue tratado con desarticulación interescapulotorácica, mostró progresión acelerada y enfermedad pulmonar. Existen otras neoplasias asociadas al síndrome de Maffucci tales como adenocarcinoma de páncreas, tumores mesenquimales de ovario, gliomas, astrocitomas y tumores de la pituitaria. Por lo que resulta muy interesante reportar la asociación infrecuente entre un sarcoma fusocelular y un condrosarcoma secundario en pacientes con síndrome de Maffucci. El seguimiento en este grupo de pacientes es complejo y se basa en la búsqueda intencionada de lesiones con crecimiento acelerado, prestando atención en lesiones de crecimiento progresivo, síntomas clínicos o datos radiológicos de malignidad.

Amino acid profiles of young adults differ by sex, body mass index and insulin resistance.

BACKGROUND AND AIMS: An increase in plasma branched-chain amino acids is associated with a higher risk of developing type 2 diabetes and cardiovascular diseases. However, little is known about the basal plasma amino acid concentrations in young adults. Our aim was to determine the plasma amino acid profiles of young adults and to evaluate how these profiles were modified by sex, body mass index (BMI) and insulin resistance (IR). METHODS AND RESULTS: We performed a transversal study with 608 Mexican young adults aged 19.9 ± 2.4 years who were applicants to the Universidad Autónoma de San Luis Potosí. The subjects underwent a physical examination and provided a clinical history and a blood sample for biochemical, hormonal and amino acid analyses. The women had higher levels of arginine, aspartate and serine and lower levels of α-aminoadipic acid, cysteine, isoleucine, leucine, methionine, proline, tryptophan, tyrosine, urea and valine than the men. The obese subjects had higher levels of alanine, aspartate, cysteine, ornithine, phenylalanine, proline and tyrosine and lower levels of glycine, ornithine and serine than the normal weight subjects. Subjects with IR (defined as HOMA > 2.5) had higher levels of arginine, alanine, aspartate, isoleucine, leucine, phenylalanine, proline, tyrosine, taurine and valine than the subjects without IR. Furthermore, we identified two main groups in the subjects with obesity and/or IR; one group was composed of amino acids that positively correlated with the clinical, biochemical and hormonal parameters, whereas the second group exhibited negative correlations. CONCLUSION: This study demonstrates that young adults with obesity or IR have altered amino acid profiles characterized by an increase in alanine, aspartate, proline and tyrosine and a decrease in glycine.

[Primary sacral tumors: analysis of results and complications]. / Tumores primarios de sacro: análisis de resultados y complicaciones.

INTRODUCTION: Primary sacral tumors are rare, treatment in most cases is surgical with or without adjuvant radiotherapy; oncology and functional results are usually adverse with a high rate of complications. MATERIAL AND METHODS: We conducted a retrospective, analytical and observational studies that includes 22 cases treated between 2000 and 2017, analyzed their characteristics demographic, the type of treatment received, and the oncological, functional results and the rate of complications were analized. RESULTS: 22 patients were subjected to sacrectomy with posterior approah because of cordoma (13 patients), giant cell tumour (three patients) and other (six patients). Three total sacrectomies, 13 partial sacrectomies, two hemisacrectomies and four sacrectomies enlarged were performed. The mean surgical time was 229 minutes, with an average bleeding of 2,100 cm3, the average tumour size was 13.8 cm (6-30cm); 10 patients were presented with complications, eight by surgical site infection, one sacral hernia and one osteomyelitis. Overall survival was 44.4 months. CONCLUSIONS: Treatment of sacral tumors is complex, requires a multidisciplinary team; the oncological result is adequate when you get free margins of neoplasia, the functional results will be determined by the type of resection, and the rate of complications is high however is the best alternative healing in our hospital.

INTRODUCCIÓN: Los tumores primarios de sacro son poco frecuentes, el tratamiento en la mayoría de los casos es quirúrgico con o sin radioterapia adyuvante; los resultados oncológicos y funcionales suelen ser adversos con una tasa alta de complicaciones. MATERIAL Y MÉTODOS: Se realizó un estudio retrospectivo, analítico y observacional que incluye 22 casos tratados entre el 2000 y 2017, se analizaron sus características demográficas, el tipo de tratamiento en la recidiva y el resultado oncológico y funcional; asimismo, se analizó la tasa de complicaciones. RESULTADOS: 22 pacientes fueron sometidos a sacrectomía, con abordaje posterior por cordoma (13 pacientes), tumor de células gigantes (tres pacientes) y otros (seis pacientes). Se realizaron tres sacrectomías totales, 13 sacrectomías parciales, dos hemisacrectomías y cuatro sacrectomías ampliadas. La media de duración quirúrgica fue de 229 minutos, con un sangrado promedio de 2,100 cm3, el tamaño tumoral promedio fue de 13.8 cm (6-30 cm); presentaron complicaciones 10 pacientes, ocho por infección de sitio quirúrgico, uno por hernia sacra y uno por osteomielitis. La supervivencia global fue de 44.4 meses. DISCUSIÓN: El tratamiento de los tumores sacros es complejo y requiere un equipo multidisciplinario; el resultado oncológico es adecuado cuando se consiguen márgenes libres de neoplasia, los resultados funcionales estarán determinados por el tipo de resección y la tasa de complicaciones es alta; sin embargo, es la mejor alternativa de curación.

Two glutathione transferase isoforms isolated from juvenile cysts of Taenia crassiceps: identification, purification and characterization.

We identified and characterized the first two glutathione transferases (GSTs) isolated from juvenile cysts of Taenia crassiceps (EC 2.5.1.18). The two glutathione transferases (TcGST1 and TcGST2) were purified in a single-step protocol using glutathione (GSH)-sepharose chromatography in combination with a GSH gradient. The specific activities of TcGST1 and TcGST2 were 26 U mg-1 and 19 U mg-1, respectively, both at 25°C and pH 6.5 with 1-chloro-2,4-dinitrobenzene (CDNB) and GSH as substrates. The Km(CDNB) and Kcat(CDNB) values for TcGST1 and TcGST2 (0.86 µm and 62 s-1; 1.03 µm and 1.97 s-1, respectively) and Km(GSH) and Kcat(GSH) values for TcGST1 and TcGST2 (0.55 µm and 11.61 s-1; 0.3 µm and 32.3 s-1, respectively) were similar to those reported for mammalian and helminth GSTs. Mass spectrometry analysis showed that eight peptides from each of the two parasite transferases were a match for gi|29825896 glutathione transferase (Taenia solium), confirming that both enzymes are GSTs. The relative molecular masses were 54,000 ± 0.9 for the native enzymes and 27,500 ± 0.5 for the enzyme subunits. Thus, TcGST1 and TcGST2 are dimeric proteins. Optimal TcGST1 and TcGST2 activities were observed at pH 8.5 in the range of 20-55°C and pH 7.5 at 35-40°C, respectively. TcGST1 and TcGST2 were inhibited by cibacron blue (CB), bromosulphophthalein (BST), rose bengal (RB), indomethacin and haematin (Hm) with 50% inhibitory concentrations (IC50) in the µm range. TcGST1 was inhibited in a non-competitive manner by all tested inhibitors with the exception of indomethacin, which was uncompetitive. The discovery of these new GSTs facilitates the potential use of T. crassiceps as a model to investigate multifunctional GSTs.

Hypoxia-Inducible Factors (HIFs) in the articular cartilage: a systematic review.

Osteoarthritis (OA) is the most common joint disease, and in recent years has become a major public health problem. The hallmark of OA is cartilage destruction with local commitment of subchondral bone and the synovial membrane. Hypoxia-inducible factors (HIFs) are transcriptional factors and key regulators of the cellular response to hypoxia. To date, three members of the human HIF-α protein family have been described: HIF-1α, HIF-2α, and HIF-3α. HIF-1α plays an essential role in the articular cartilage (a hypoxic tissue), as it has a protective effect in the maintenance of the articular cartilage matrix, HIF-2α has a harmful effect on the articular cartilage matrix, and HIF-3α acts as a negative regulator of HIF-1α and HIF-2α. Due to the recent growing interest in the role of HIFs in rheumatic diseases, we focused this review on the potential role of these key regulators in articular cartilage maintenance as the central axis in OA development.

Label-free detection of DNA single-base mismatches using a simple reflectance-based optical technique.

Rapid and quantitative detection of the binding of nucleic acids to surface-immobilized probes remains a challenge in many biomedical applications. We investigated the hybridization of a set of fully complementary and defected 12-base long DNA oligomers by using the Reflective Phantom Interface (RPI), a recently developed multiplexed label-free detection technique. Based on the simple measurement of reflected light intensity, this technology enables to quantify the hybridization directly as it occurs on the surface with a sensitivity of 10 pg mm(-2). We found a strong effect of single-base mismatches and of their location on hybridization kinetics and equilibrium binding. In line with previous studies, we found that DNA-DNA binding is weaker on a surface than in the bulk. Our data indicate that this effect is a consequence of weak nonspecific binding of the probes to the surface.

Endoscopic sleeve gastroplasty with 1-year follow-up: factors predictive of success.

BACKGROUND AND STUDY AIMS: Bariatric endoscopy has emerged as an aid in the nonsurgical treatment of obesity. The objective of this study is to critically provide the results and follow-up of endoscopic sleeve gastroplasty 1 year after the procedure. PATIENTS AND METHODS: Prospective single-center follow-up study of 25 patients (5 men, 20 women) who underwent flexible endoscopic suturing for endoluminal gastric volume reduction. A multidisciplinary team provided post-procedure care. Patient outcomes were recorded at 1 year after the procedure. Linear regression analysis was done to evaluate the variables associated with best results at 1 year of follow-up. RESULTS: Mean body mass index (BMI) was 38.5 ±â€Š4.6 kg/m(2) (range 30 - 47) and mean age 44.5 ±â€Š8.2 years (range 29 - 60). At 1 year, 22 patients continued with the follow-up (2 dropped out at 6 months and 1 at 3 months). There were no major intra-procedural, early, or delayed adverse events. Mean BMI loss was 7.3 ±â€Š4.2 kg/m(2), and mean percentage of total body weight loss was 18.7 ±â€Š10.7 at 1 year. In the linear regression analysis, adjusted by initial BMI, variables associated with %TBWL involved the frequency of nutritional (ß = 0.563, P = 0.014) and psychological contacts (ß = 0.727, P = 0.025). The number of nutritional and psychological contacts were predictive of good weight loss results. CONCLUSIONS: Endoscopic sleeve gastroplasty is a feasible, reproducible, and effective procedure to treat obesity. Nutritional and psychological interaction are predictive of success.

Improving appearance and microbiologic quality of broiler carcasses with an allostatic modulator.

An important priority of poultry producers is to guarantee animal welfare during animal production; however, broilers are exposed to unavoidable chronic stress (also known as allostasis) when they are captured, caged, and transported to the processing plant. This antemortem management causes allostatic load, animal injuries, and poor carcass quality. The aim of the present study was to evaluate the effects of an allostatic modulator (AM) on antemortem stress by measuring the appearance and microbiological quality of broiler carcasses. The AM consisted of a liquid formula containing ascorbic acid, acetyl salicylic acid, and electrolytes, administered orally 48 h before shipment to the processing plant. A total of 600 chickens (49-days-old) were used under a factorial arrangement 2 × 2 × 2 [2 commercial hybrid lines, 2 feed withdrawal programs (10 and 16 h), and 2 water treatments (control and AM)]. Each treatment included 25 chickens per pen and was carried out in triplicate. The broilers were shipped, slaughtered, and processed in a commercial processing plant where carcass defects (bruises and broken bones caused by antemortem management), crop pH, and carcass bacterial counts were evaluated in all experimental groups. Broilers under AM treatment showed a reduction in carcass defects (P = 0.015), crop pH (P = 0.0001), coliforms counts (P = 0.014), and total aerobic mesophilic bacteria (P = 0.0001) when compared to the control treatment. The present study indicates that the AM can be used to improve carcass quality in broilers. Our study provides a novel and economic alternative to reduce the allostatic load in broilers.

Endoscopic Sleeve Gastroplasty: How I Do It?

BACKGROUND: Primary endoscopic weight loss therapies are of interest for access, simplicity, and economy. The objective of this manuscript is to describe the endoscopic sleeve gastroplasty used in 50 patients. METHODS: The goal of this procedure is to reduce the gastric lumen into a tubular configuration, with the greater curvature modified by a line of sutured plications. General anesthesia with endotracheal intubation is needed. An endoscopic suturing system requiring a specific double-channel endoscope delivers full-thickness sets of running sutures from the antrum to the fundus. Patients are admitted and observed, with discharge planned within 24 h. Post-procedure outpatient care includes diet instruction with intensive follow-up by a multidisciplinary team. Voluntary oral contrast and endoscopy studies are scheduled to assess the gastroplasty at 3, 6, and 12 months. RESULTS: The technique was applied in 50 patients (13 men) with an average body mass index (BMI) of 37.7 kg/m(2) (range 30-47) with 13 having reached 1 year. Procedure duration averaged 66 min during which six to eight sutures on average were placed. All patients were discharged in less than 24 h. There were no major intra-procedural, early, or delayed adverse events. Weight loss parameters were satisfactory, mean BMI changes from 37.7 ± 4.6 to 30.9 ± 5.1 kg/m(2) at 1 year, and mean %TBWL was 19.0 ± 10.8. Oral contrast studies and endoscopy revealed sleeve gastroplasty configuration at least until 1 year of follow-up. CONCLUSION: Endoscopic sleeve gastroplasty is a safe, effective, and reproducible primary weight loss technique.

Dual Intragastric Balloon: Single Ambulatory Center Spanish Experience with 60 Patients in Endoscopic Weight Loss Management.

BACKGROUND: Many obese patients fail conventional medical management and decline bariatric surgery. Less invasive weight loss options such as intragastric balloons may provide an opportunity to reach this large number of untreated patients. The aim of this study was to investigate the safety and effectiveness of the Dual Intragastric Balloon (DIGB) in the treatment of obese patients, as well as the impact of degree of obesity, age, and gender. METHODS: The study was conducted at the Bariatric Endoscopy Unit of the Madrid Sanchinarro University Hospital. Sixty patients (11 men, 49 women) underwent endoscopic placement of a DIGB filled with a total of 900 cc of saline (450 cc in each balloon) for at least 6 months, along with regular counseling from a multidisciplinary team. Study outcomes included: change in body weight (TBWL), % of loss of initial body weight (%TBWL), % of excess body weight loss (%EWL), and adverse events. RESULTS: Initial BMI 38.8 kg/m(2) decreased 6.1 units, with mean TBWL, %TBWL, and %EWL of 16.6 kg, 15.4 %, and 47.1 %, respectively. We found no difference in %TBWL between grade of obesity, age or sex, but morbidly obese patients demonstrated greater TBWL, and women and less obese subjects obtained higher %EWL. The DIGB was generally well tolerated, with one early removal for patient intolerance, one early deflation without migration, and one gastric perforation. Fourteen patients had small, clinically insignificant ulcers or erosions noted at the time of removal. CONCLUSIONS: The present study shows that the DIGB was easy to use, resulted in significant weight loss, safe, and well tolerated.

An optofluidic constriction chip for monitoring metastatic potential and drug response of cancer cells.

Cellular mechanical properties constitute good markers to characterize tumor cells, to study cell population heterogeneity and to highlight the effect of drug treatments. In this work, we describe the fabrication and validation of an integrated optofluidic chip capable of analyzing cellular deformability on the basis of the pressure gradient needed to push a cell through a narrow constriction. We demonstrate the ability of the chip to discriminate between tumorigenic and metastatic breast cancer cells (MCF7 and MDA-MB231) and between human melanoma cells with different metastatic potential (A375P and A375MC2). Moreover, we show that this chip allows highlighting the effect of drugs interfering with microtubule organization (paclitaxel, combretastatin A-4 and nocodazole) on cancer cells, which leads to changes in the pressure-gradient required to push cells through the constriction. Our single-cell microfluidic device for mechanical evaluation is compact and easy to use, allowing for an extensive use in different laboratory environments.

An integrated optofluidic device for single-cell sorting driven by mechanical properties.

We present a novel optofluidic device for real-time sorting on the basis of cell mechanical properties, measured by optical stretching. The whole mechanism, based on optical forces, does not hamper the viability of the tested cells, which can be used for further analysis. The device effectiveness is demonstrated by extracting a sample population enriched with highly metastatic cells from a heterogeneous cell mixture.

Cervical cancer-associated promoter polymorphism affects akna expression levels.

Cervical cancer (CC) is responsible for >260,000 deaths worldwide each year. Efforts are being focused on identifying genetic susceptibility factors, especially in genes related to the immune response. Akna has been proposed to be one of them, but data regarding its functional role in the disease is scarce. Supporting the notion of akna as a CC susceptibility gene, we found two polymorphisms associated with squamous intraepithelial lesion (SIL) and CC; moreover, we identified an association between high akna expression levels and CC and SIL, but its direction differs in each disease stage. To show the potential existence of a cis-acting polymorphism, we assessed akna allelic expression imbalance for the alleles of the -1372C>A polymorphism. We found that, regardless of the study group, the number of transcripts derived from the A allele was significantly higher than those from the C allele. Our results support the hypothesis that akna is a CC susceptibility genetic factor and suggest that akna transcriptional regulation has a role in the disease. We anticipate our study to be a starting point for in vitro evaluation of akna transcriptional regulation and for the identification of transcription factors and cis-elements regulating AKNA function that are involved in carcinogenesis.

Evaluation of the non-catalytic binding function of Ts26GST a glutathione transferase isoform of Taenia solium.

Taenia solium glutathione transferase isoform of 26.5 kDa (Ts26GST) was observed to bind non-catalytically to porphyrins, trans-trans-dienals, bile acids and fatty acids, as assessed by inhibition kinetics, fluorescence spectroscopy and competitive fluorescence assays with 8-anilino-1-naphthalene sulfonate (ANS). The quenching of Ts26GST intrinsic fluorescence allowed for the determination of the dissociation constants (KD) for all ligands. Obtained data indicate that Ts26GST binds to all ligands but with different affinity. Porphyrins and lipid peroxide products inhibited Ts26GST catalytic activity up to 100% in contrast with only 20-30% inhibition observed for bile acids and two saturated fatty acids. Non-competitive type inhibition was observed for all enzyme inhibitor ligands except for trans-trans-2,4-decadienal, which exhibited uncompetitive type inhibition. The dissociation constant value KD = 0.7 µM for the hematin ligand, determined by competitive fluorescence assays with ANS, was in good agreement with its inhibition kinetic value Ki = 0.3 µM and its intrinsic fluorescence quenching KD = 0.7 µM. The remaining ligands did not displace ANS from the enzyme suggesting the existence of different binding sites. In addition to the catalytic activity of Ts26GST the results obtained suggest that the enzyme exhibits a ligandin function with broad specificity towards nonsubstrate ligands.