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1.
JAMA Netw Open ; 7(4): e246548, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38639939

RESUMEN

Importance: Unintended tumor-positive resection margins occur frequently during minimally invasive surgery for colorectal liver metastases and potentially negatively influence oncologic outcomes. Objective: To assess whether indocyanine green (ICG)-fluorescence-guided surgery is associated with achieving a higher radical resection rate in minimally invasive colorectal liver metastasis surgery and to assess the accuracy of ICG fluorescence for predicting the resection margin status. Design, Setting, and Participants: The MIMIC (Minimally Invasive, Indocyanine-Guided Metastasectomy in Patients With Colorectal Liver Metastases) trial was designed as a prospective single-arm multicenter cohort study in 8 Dutch liver surgery centers. Patients were scheduled to undergo minimally invasive (laparoscopic or robot-assisted) resections of colorectal liver metastases between September 1, 2018, and June 30, 2021. Exposures: All patients received a single intravenous bolus of 10 mg of ICG 24 hours prior to surgery. During surgery, ICG-fluorescence imaging was used as an adjunct to ultrasonography and regular laparoscopy to guide and assess the resection margin in real time. The ICG-fluorescence imaging was performed during and after liver parenchymal transection to enable real-time assessment of the tumor margin. Absence of ICG fluorescence was favorable both during transection and in the tumor bed directly after resection. Main Outcomes and Measures: The primary outcome measure was the radical (R0) resection rate, defined by the percentage of colorectal liver metastases resected with at least a 1 mm distance between the tumor and resection plane. Secondary outcomes were the accuracy of ICG fluorescence in detecting margin-positive (R1; <1 mm margin) resections and the change in surgical management. Results: In total, 225 patients were enrolled, of whom 201 (116 [57.7%] male; median age, 65 [IQR, 57-72] years) with 316 histologically proven colorectal liver metastases were included in the final analysis. The overall R0 resection rate was 92.4%. Re-resection of ICG-fluorescent tissue in the resection cavity was associated with a 5.0% increase in the R0 percentage (from 87.4% to 92.4%; P < .001). The sensitivity and specificity for real-time resection margin assessment were 60% and 90%, respectively (area under the receiver operating characteristic curve, 0.751; 95% CI, 0.668-0.833), with a positive predictive value of 54% and a negative predictive value of 92%. After training and proctoring of the first procedures, participating centers that were new to the technique had a comparable false-positive rate for predicting R1 resections during the first 10 procedures (odds ratio, 1.36; 95% CI, 0.44-4.24). The ICG-fluorescence imaging was associated with changes in intraoperative surgical management in 56 (27.9%) of the patients. Conclusions and Relevance: In this multicenter prospective cohort study, ICG-fluorescence imaging was associated with an increased rate of tumor margin-negative resection and changes in surgical management in more than one-quarter of the patients. The absence of ICG fluorescence during liver parenchymal transection predicted an R0 resection with 92% accuracy. These results suggest that use of ICG fluorescence may provide real-time feedback of the tumor margin and a higher rate of complete oncologic resection.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Hepáticas , Anciano , Femenino , Humanos , Masculino , Estudios de Cohortes , Neoplasias Colorrectales/cirugía , Neoplasias Colorrectales/patología , Verde de Indocianina , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/cirugía , Neoplasias Hepáticas/patología , Márgenes de Escisión , Imagen Óptica/métodos , Estudios Prospectivos , Persona de Mediana Edad
2.
Burns ; 50(6): 1437-1455, 2024 08.
Artículo en Inglés | MEDLINE | ID: mdl-38580580

RESUMEN

OBJECTIVE: To evaluate the efficacy of therapeutic interventions on pediatric burn patients' height, weight, body composition, and muscle strength. METHODS: A systematic literature search was conducted in PubMed, Embase, and Web of Science up to March 2021. Eligible interventional studies reported metrics on the height, weight, body composition, or muscle strength of pediatric burn patients in a peer-reviewed journal. Meta-analyses were performed if ≥ 2 trials of clinical homogeneity reported on an outcome measure at the same time point post-burn. RESULTS: Twenty-six interventional studies were identified, including twenty-two randomised controlled trials and four non-randomised trials. Most studies were conducted by a single institution. On average, the burn covered 45.3% ( ± 9.9) of the total body surface area. Three categories of interventions could be distinguished: rehabilitative exercise programs, pharmacologic agents, and nutrition support. CONCLUSIONS: Each of the interventions had a positive effect on height, weight, body composition, or muscle strength. The decision to initiate an intervention should be made on a case-by-case basis following careful consideration of the benefits and risks. In future research, it is important to evaluate the heterogeneity of intervention effects and whether participation in an intervention allowed pediatric burn patients to reach the physical and functional status of healthy peers.


Asunto(s)
Composición Corporal , Estatura , Peso Corporal , Quemaduras , Fuerza Muscular , Humanos , Quemaduras/terapia , Quemaduras/rehabilitación , Quemaduras/fisiopatología , Niño , Fuerza Muscular/fisiología , Terapia por Ejercicio/métodos , Apoyo Nutricional/métodos , Resultado del Tratamiento
3.
Ann Surg Open ; 4(4): e354, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38144496

RESUMEN

Background: A potential downside of robotic pancreatoduodenectomy (RPD) is the lack of tactile feedback when tying sutures, which could be especially perilous during pancreatic anastomosis. Near-infrared fluorescence imaging with indocyanine green (NIRF-ICG) could detect transpancreatic-suture-induced hypoperfusion of the pancreatic stump during RPD, which may be related to postoperative pancreatic fistula (POPF) grade B/C, but studies are lacking. Methods: This prospective study included 37 patients undergoing RPD to assess the relation between pancreatic stump hypoperfusion as objectified with NIRF-ICG using Firefly and the rate of POPF grade B/C. In 27 patients, NIRF-ICG was performed after tying down the transpancreatic U-sutures. In 10 'negative control' patients, NIRF-ICG was performed before tying these sutures. Results: Pancreatic stump hypoperfusion was detected using NIRF-ICG in 9/27 patients (33%) during RPD. Hypoperfusion was associated with POPF grade B/C (67% [6/9 patients] versus 17% [3/18 patients], P = 0.026). No hypoperfusion was objectified in 10 'negative controls'. Conclusions: Transpancreatic-suture-induced pancreatic stump hypoperfusion can be detected using NIRF-ICG during RPD and was associated with POPF grade B/C. Surgeons could use NIRF-ICG to adapt their suturing approach during robotic pancreatico-jejunostomy. Further larger prospective studies are needed to validate the association between transpancreatic-suture-induced hypoperfusion and POPF.

4.
Burns Trauma ; 11: tkad011, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37663674

RESUMEN

Background: The epidemiological data on post-burn growth, body composition and motor development is ambiguous and scattered. The aim of this systematic review was therefore to summarize the current body of evidence on post-burn growth, body composition and motor development in children. Methods: A literature search was conducted in PubMed, EMBASE and Web of Science up to March 2021. We considered observational studies that reported (1) metrics on weight, height, body composition, bone mineral content, bone mineral density or motor development, in (2) paediatric burn patients and (3) published in a peer-reviewed journal. Results: A total of 16 studies were included. Each of the included studies used quantitative methods, but with differing methodology: prospective cohort studies (n = 8), retrospective chart reviews (n = 3), case-control studies (n = 2), cross sectional studies (n = 2) and a retrospective cohort study (n = 1). When combined, the included studies represented 2022 paediatric burn patients, with a mean age of 7.7 (±3.2) years. The average burn size was 52.8% (±12.7) of the total body surface area. Identified outcome measures included weight (n = 12), height (n = 7), muscular strength (n = 4), bone mineral content (n = 5), bone mineral density (n = 5), body mass index (n = 3), fat mass (n = 5), lean body mass (n = 7) and fine and gross motor development (n = 1). Conclusions: Following an initial decline, patients' growth and motor development started to recover during the first or second year post-burn. Nonetheless, burns may have a profound and prolonged effect on the paediatric burn patients' muscular strength, bone mineral content and lean body mass. It should be noted that the vast majority of studies included only patients with burns covering ≥30% total body surface area. The evidence presented in this review may thus not be representative of the whole paediatric burn population.

5.
J Burn Care Res ; 44(5): 1083-1091, 2023 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-36728628

RESUMEN

This study evaluates the short- and long-term effect of burns on children's height and weight, by comparing their pre and postburn growth trajectory. We invited children (≤17 years old), who sustained a burn requiring surgical treatment or admission at one of the Dutch burn centers in 2013 (n = 175). As well as children who sustained a severe burn, covering >10% of the total body surface area (TBSA), throughout 2009-2018 (n = 228). Data was collected from a survey on health-related topics, Youth Health Care records, and the Dutch Burn Repository R3. For all participants, height and weight were converted to Z-scores using Dutch reference values. Linear mixed modeling, nested on the individual level, was used to examine the associations between burns and children's height and weight Z-scores. Children's height and weight Z-scores remained within the normal range throughout the study period. During the first-year postburn, children's height and weight Z-scores decreased by -0.21 (95% CI -0.41, -0.01) and -0.23 (95% CI -0.46, -0.04), respectively. Beyond the first-year postburn, estimates were consistent with a positive linear association between burn size and the overall effect of burns on participants' height and weight Z-scores. This included a modest, but statistically significant, effect among participants with a burn covering ≤4.5% and >14.0% of the TBSA. Sensitivity analyses did not alter our findings. In conclusion, children were on track or even surpassed their growth potential. Our findings could therefore be considered reassuring to patients, parents, and clinicians.


Asunto(s)
Quemaduras , Adolescente , Humanos , Niño , Estudios de Cohortes , Quemaduras/terapia , Hospitalización , Superficie Corporal , Unidades de Quemados
6.
Mol Pharm ; 20(1): 616-629, 2023 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-36468979

RESUMEN

Chiral molecules are challenging for the pharmaceutical industry because although physical properties of the enantiomers are the same in achiral systems, they exhibit different effects in chiral systems, such as the human body. The separation of enantiomers is desired but complex, as enantiomers crystallize most often as racemic compounds. A technique to enable the chiral separation of racemic compounds is to create an asymmetry in the thermodynamic system by generating chiral cocrystal(s) using a chiral coformer and using the solubility differences to enable separation through crystallization from solution. However, such quaternary systems are complex and require analytical methods to quantify different chiral molecules in solution. Here, we develop a new chiral quantification method using ultraviolet-circular dichroism spectroscopy and multivariate partial least squares calibration models, to build multicomponent chiral phase diagrams. Working on the quaternary system of (R)- and (S)-2-(2-oxopyrrolidin-1-yl)butanamide enantiomers with (S)-mandelic acid in acetonitrile, we measure accurately the full quaternary phase diagram for the first time. By understanding the phase stabilities of the racemic compound and the enantiospecific cocrystal, the chiral resolution of levetiracetam could be designed due to a large asymmetry in overall solubility between both sides of the racemic composition. This new method offers improvements for chiral molecule quantification in complex multicomponent chiral systems and can be applied to other chiral spectroscopy techniques.


Asunto(s)
Levetiracetam , Humanos , Dicroismo Circular , Cristalización , Termodinámica , Estereoisomerismo
7.
Cryst Growth Des ; 22(9): 5511-5525, 2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-36097547

RESUMEN

Pharmaceutical cocrystals are highly interesting due to their effect on physicochemical properties and their role in separation technologies, particularly for chiral molecules. Detection of new cocrystals is a challenge, and robust screening methods are required. As numerous techniques exist that differ in their crystallization mechanisms, their efficiencies depend on the coformers investigated. The most important parameters characterizing the methods are the (a) screenable coformer fraction, (b) coformer success rate, (c) ability to give several cocrystals per successful coformer, (d) identification of new stable phases, and (e) experimental convenience. Based on these parameters, we compare and quantify the performance of three methods: liquid-assisted grinding, solvent evaporation, and saturation temperature measurements of mixtures. These methods were used to screen 30 molecules, predicted by a network-based link prediction algorithm (described in Cryst. Growth Des. 2021, 21(6), 3428-3437) as potential coformers for the target molecule praziquantel. The solvent evaporation method presented more drawbacks than advantages, liquid-assisted grinding emerged as the most successful and the quickest, while saturation temperature measurements provided equally good results in a slower route yielding additional solubility information relevant for future screenings, single-crystal growth, and cocrystal production processes. Seventeen cocrystals were found, with 14 showing stability and 12 structures resolved.

8.
Cryst Growth Des ; 21(6): 3428-3437, 2021 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-34276256

RESUMEN

Cocrystallization has been promoted as an attractive early development tool as it can change the physicochemical properties of a target compound and possibly enable the purification of single enantiomers from racemic compounds. In general, the identification of adequate cocrystallization candidates (or coformers) is troublesome and hampers the exploration of the solid-state landscape. For this reason, several computational tools have been introduced over the last two decades. In this study, cocrystals of Praziquantel (PZQ), an anthelmintic drug used to treat schistosomiasis, are predicted with network-based link prediction and experimentally explored. Single crystals of 12 experimental cocrystal indications were grown and subjected to a structural analysis with single-crystal X-ray diffraction. This case study illustrates the power of the link-prediction approach and its ability to suggest a diverse set of new coformer candidates for a target compound when starting from only a limited number of known cocrystals.

9.
Angew Chem Int Ed Engl ; 60(37): 20264-20268, 2021 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-34233036

RESUMEN

We tap into an unexplored area of preferential crystallization, being the first to develop simultaneous chiral resolution of two racemic compounds by preferential cocrystallization. We highlight how the two racemic compounds RS-mandelic acid (MAN) and RS-etiracetam (ETI) can be combined together as enantiospecific R-MAN⋅R-ETI and S-MAN⋅S-ETI cocrystals forming a stable conglomerate system and subsequently develop a cyclic preferential crystallization allowing to simultaneous resolve both compounds. The developed process leads to excellent enantiopurity both for etiracetam (ee>98 %) and mandelic acid (ee≈95 %) enantiomers.

11.
J Control Release ; 323: 269-281, 2020 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-32330574

RESUMEN

RATIONALE: A substantial number of breast cancer patients with an overexpression of the human epidermal growth factor receptor 2 (HER2) have residual disease after neoadjuvant therapy or become resistant to trastuzumab. Photodynamic therapy (PDT) using nanobodies targeted to HER2 is a promising treatment option for these patients. Here we investigate the in vitro and in vivo antitumor efficacy of HER2-targeted nanobody-photosensitizer (PS) conjugate PDT. METHODS: Nanobodies targeting HER2 were obtained from phage display selections. Monovalent nanobodies were engineered into a biparatopic construct. The specificity of selected nanobodies was tested in immunofluorescence assays and their affinity was evaluated in binding studies, both performed in a panel of breast cancer cells varying in HER2 expression levels. The selected HER2-targeted nanobodies 1D5 and 1D5-18A12 were conjugated to the photosensitizer IRDye700DX and tested in in vitro PDT assays. Mice bearing orthotopic HCC1954 trastuzumab-resistant tumors with high HER2 expression or MCF-7 tumors with low HER2 expression were intravenously injected with nanobody-PS conjugates. Quantitative fluorescence spectroscopy was performed for the determination of the local pharmacokinetics of the fluorescence conjugates. After nanobody-PS administration, tumors were illuminated to a fluence of 100 J∙cm-2, with a fluence rate of 50 mW∙cm-2, and thereafter tumor growth was measured with a follow-up until 30 days. RESULTS: The selected nanobodies remained functional after conjugation to the PS, binding specifically and with high affinity to HER2-positive cells. Both nanobody-PS conjugates potently and selectively induced cell death of HER2 overexpressing cells, either sensitive or resistant to trastuzumab, with low nanomolar LD50 values. In vivo, quantitative fluorescence spectroscopy showed specific accumulation of nanobody-PS conjugates in HCC1954 tumors and indicated 2 h post injection as the most suitable time point to apply light. Nanobody-targeted PDT with 1D5-PS and 1D5-18A12-PS induced significant tumor regression of trastuzumab-resistant high HER2 expressing tumors, whereas in low HER2 expressing tumors only a slight growth delay was observed. CONCLUSION: Nanobody-PS conjugates accumulated selectively in vivo and their fluorescence could be detected through optical imaging. Upon illumination, they selectively induced significant tumor regression of HER2 overexpressing tumors with a single treatment session. Nanobody-targeted PDT is therefore suggested as a new additional treatment for HER2-positive breast cancer, particularly of interest for trastuzumab-resistant HER2-positive breast cancer. Further studies are now needed to assess the value of this approach in clinical practice.


Asunto(s)
Neoplasias de la Mama , Fotoquimioterapia , Anticuerpos de Dominio Único , Animales , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Femenino , Humanos , Ratones , Fármacos Fotosensibilizantes/uso terapéutico , Receptor ErbB-2 , Trastuzumab , Ensayos Antitumor por Modelo de Xenoinjerto
12.
Eur J Med Chem ; 191: 112146, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32088496

RESUMEN

In continuation of our pharmacomodulation work on the nitroimidazooxazole series, we report the synthesis of new 5-substituted 6-nitroimidazooxazole derivatives. Our aim was to evaluate how functionalization of the 5-position of the 6-nitroimidazooxazole scaffold affects antileishmanial and antitrypanosomal in vitro activities. Twenty-one original compounds were synthesized and evaluated for their in vitro antileishmanial (L. donovani) and antitrypanosomal (T. cruzi) properties. Pallado-catalyzed cross-coupling reactions were used to introduce an aryl or ethynyl aryl substituent in 5-position from a 5-brominated-6-nitroimidazooxazole starting product. Unfortunately, the first series of compounds bearing an aryl group in 5-position presented limited in vitro activities against L. donovani and T. cruzi, with IC50 > 10 µM (vs 0.18 µM and 2.31 µM for the reference drugs amphotericin B and benznidazole respectively). Interestingly, the second series of compounds bearing an ethynyl aryl substituent in 5-position showed more promising, particularly against T. cruzi. Compounds 6a, 6b, 6c, 6g and 6h had better activity than the reference drug benznidazole (0.92 µM ≤ IC50 ≤ 2.18 µM vs IC50 = 2.31 µM), whereas the non-functionalized 2-methyl-6-nitro-2,3-dihydroimidazo [2,1-b]oxazole 2 was not active against T. cruzi (IC50 > 10 µM).


Asunto(s)
Antiprotozoarios/farmacología , Leishmania donovani/efectos de los fármacos , Nitroimidazoles/farmacología , Oxazoles/farmacología , Trypanosoma cruzi/efectos de los fármacos , Antiprotozoarios/síntesis química , Antiprotozoarios/química , Relación Dosis-Respuesta a Droga , Estructura Molecular , Nitroimidazoles/síntesis química , Nitroimidazoles/química , Oxazoles/síntesis química , Oxazoles/química , Pruebas de Sensibilidad Parasitaria , Relación Estructura-Actividad
13.
J Thorac Dis ; 11(Suppl 5): S755-S765, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31080655

RESUMEN

BACKGROUND: Fluorescent imaging using indocyanine green (ICG) is an emerging technique that aids the surgeon with intraoperative decision making during upper gastrointestinal cancer surgery. In this systematic review we aim to provide an overview of current practice of fluorescence imaging using ICG during esophagectomy, and to show how this technology can prevent surgical morbidity, such as anastomotic leakage, graft necrosis and chylothorax. METHODS: The PRISMA standard for systematic reviews was used. The PubMed and Embase database were searched to identify articles matching our systematic literature search. Two authors screened all included articles for eligibility. Risk of bias was assessed for all included articles. RESULTS: A total of 25 articles were included in this review: 22 articles on perfusion assessment, and three on the detection of chyle fistula. Five out of 22 articles concerning perfusion assessment evaluated fluorescence signals in quantitative values. In 20 articles the pooled incidence of anastomotic leakage and graft necrosis in the ICG group was 11.10% (95% CI: 8.06-15.09%) and in eight studies the pooled change in management rate was 24.55% (95% CI: 19.16-30.88%). After change in management, the pooled incidence of anastomotic leakage and graft necrosis was 14.08% (95% CI: 6.55-27.70%). A meta-analysis showed that less anastomotic leakages and graft necrosis occur in the ICG group (OR 0.30, 95% CI: 0.14-0.63). Three case-reports (N=3) were identified regarding chyle fistula detection, and ICG lymphography detected the thoracic duct in all cases and the chyle fistula in one case. CONCLUSIONS: Fluorescence imaging using ICG is a promising and safe technology to reduce surgical morbidity after esophagectomy with continuity restoration. ICG fluorescence angiography showed a reduction in anastomotic leakage and graft necrosis. Future studies are needed to demonstrate the feasibility of ICG lymphography for chyle fistula detection.

14.
ChemMedChem ; 14(5): 561-569, 2019 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-30644169

RESUMEN

Metronidazole is one of the first-line treatments for non-severe Clostridium difficile infections (CDI). However, resistance limits its use in cases of severe and complicated CDI. Structure-activity relationships previously described for the 5-nitroimidazole series have shown that functionalization at the 2- and 4-positions can impart better activity against parasites and anaerobic bacteria than metronidazole. Herein we report the synthesis of new 2,4-disubstituted 5-nitroimidazole compounds that show potent antibacterial activity against C. difficile. We used a vicarious nucleophilic substitution of hydrogen (VNS) reaction to introduce a phenylmethylsulfone at the 4-position and a unimolecular radical nucleophilic substitution (SRN 1) reaction to introduce an ethylenic function at the 2-position of the 5-nitroimidazole scaffold.


Asunto(s)
Antibacterianos/síntesis química , Infecciones por Clostridium/tratamiento farmacológico , Nitroimidazoles/síntesis química , Animales , Antibacterianos/farmacología , Células CHO , Supervivencia Celular/efectos de los fármacos , Clostridioides difficile/efectos de los fármacos , Cricetulus , Diseño de Fármacos , Farmacorresistencia Bacteriana/efectos de los fármacos , Humanos , Metronidazol/farmacología , Estructura Molecular , Nitroimidazoles/farmacología , Relación Estructura-Actividad , Sulfonas/química
15.
Microbiologyopen ; 8(5): e00735, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30280501

RESUMEN

With the aim of describing the human microbiota by the means of culture methods, culturomics was developed in order to target previously un-isolated bacterial species and describe it via the taxono-genomics approach. While performing a descriptive study of the human gut microbiota of the pygmy people, strain Marseille-P4678T has been isolated from a stool sample of a healthy 39-year-old pygmy male. Cells of this strain were Gram-positive cocci, spore-forming, non-motile, catalase-positive and oxidase-negative, and grow optimally at 37°C under anaerobic conditions. Its 16S rRNA gene sequence exhibited 89.69% of sequence similarity with Parvimonas micra strain 3119BT (NR 036934.1), its phylogenetically closest species with standing in nomenclature. The genome of strain Marseille-P4678T is 2,083,161 long with 28.26 mol% of G+C content. Based on its phenotypic, biochemical, genotypic and proteomic profile, this bacterium was classified as a new bacterial genus and species Miniphocibacter massiliensis gen. nov., sp. nov. with the type strain Marseille-P4678T .


Asunto(s)
Heces/microbiología , Firmicutes/aislamiento & purificación , Filogenia , Anaerobiosis , Técnicas Bacteriológicas , Composición de Base , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Firmicutes/clasificación , Firmicutes/genética , Genómica , Humanos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Temperatura
16.
Eur J Med Chem ; 157: 115-126, 2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-30092366

RESUMEN

Based on a previously identified antileishmanial 6,8-dibromo-3-nitroimidazo[1,2-a]pyridine derivative, a Suzuki-Miyaura coupling reaction at position 8 of the scaffold was studied and optimized from a 8-bromo-6-chloro-3-nitroimidazo[1,2-a]pyridine substrate. Twenty-one original derivatives were prepared, screened in vitro for activity against L. infantum axenic amastigotes and T. brucei brucei trypomastigotes and evaluated for their cytotoxicity on the HepG2 human cell line. Thus, 7 antileishmanial hit compounds were identified, displaying IC50 values in the 1.1-3 µM range. Compounds 13 and 23, the 2 most selective molecules (SI = >18 or >17) were additionally tested on both the promastigote and intramacrophage amastigote stages of L. donovani. The two molecules presented a good activity (IC50 = 1.2-1.3 µM) on the promastigote stage but only molecule 23, bearing a 4-pyridinyl substituent at position 8, was active on the intracellular amastigote stage, with a good IC50 value (2.3 µM), slightly lower than the one of miltefosine (IC50 = 4.3 µM). The antiparasitic screening also revealed 8 antitrypanosomal hit compounds, including 14 and 20, 2 very active (IC50 = 0.04-0.16 µM) and selective (SI = >313 to 550) molecules toward T. brucei brucei, in comparison with drug-candidate fexinidazole (IC50 = 0.6 & SI > 333) or reference drugs suramin and eflornithine (respective IC50 = 0.03 and 13.3 µM). Introducing an aryl moiety at position 8 of the scaffold quite significantly increased the antitrypanosomal activity of the pharmacophore. Antikinetoplastid molecules 13, 14, 20 and 23 were assessed for bioactivation by parasitic nitroreductases (either in L. donovani or in T. brucei brucei), using genetically modified parasite strains that over-express NTRs: all these molecules are substrates of type 1 nitroreductases (NTR1), such as those that are responsible for the bioactivation of fexinidazole. Reduction potentials measured for these 4 hit compounds were higher than that of fexinidazole (-0.83 V), ranging from -0.70 to -0.64 V.


Asunto(s)
Antineoplásicos/farmacología , Leishmania donovani/efectos de los fármacos , Nitrorreductasas/metabolismo , Tripanocidas/farmacología , Trypanosoma brucei brucei/efectos de los fármacos , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Células Hep G2 , Humanos , Leishmania donovani/metabolismo , Modelos Moleculares , Estructura Molecular , Pruebas de Sensibilidad Parasitaria , Relación Estructura-Actividad , Tripanocidas/química , Tripanocidas/metabolismo , Trypanosoma brucei brucei/metabolismo
17.
Oral Oncol ; 78: 1-7, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29496035

RESUMEN

OBJECTIVES: Tumour-positive resection margins are a major problem during oral cancer surgery. gGlu-HMRG is a tracer that becomes fluorescent upon activation by gamma-glutamyltranspeptidase (GGT). This study aims to investigate the combination of gGlu-HMRG and a clinical fluorescence imaging system for the detection of tumour-positive resection margins. MATERIALS AND METHODS: The preclinical Maestro and clinical Artemis imaging systems were compared in vitro and ex vivo with cultured human head and neck cancer cells (OSC19, GGT-positive; and FaDu, GGT negative) and tumour-bearing nude mice. Subsequently, frozen sections of normal and oral cancer tissues were ex vivo sprayed with gGlu-HMRG to determine the sensitivity and specificity. Finally, resection margins of patients with suspected oral cancer were ex vivo sprayed with gGlu-HMRG to detect tumour-positive resection margins. RESULTS: Both systems could be used to detect gGlu-HMRG activation in vitro and ex vivo in GGT positive cancer cells. Sensitivity and specificity of gGlu-HMRG and the Artemis on frozen tissue samples was 80% and 87%, respectively. Seven patients undergoing surgery for suspected oral cancer were included. In three patients fluorescence was observed at the resection margin. Those margins were either tumour-positive or within 1 mm of tumour. The margins of the other patients were clear (≥8 mm). CONCLUSION: This study demonstrates the feasibility to detect tumour-positive resection margins with gGlu-HMRG and a clinical fluorescence imaging system. Applying this technique would enable intraoperative screening of the entire resection margin and allow direct re-resection in case of tumour-positivity.


Asunto(s)
Carcinoma de Células Escamosas/cirugía , Colorantes Fluorescentes/administración & dosificación , Márgenes de Escisión , Neoplasias de la Boca/cirugía , gamma-Glutamiltransferasa/metabolismo , Animales , Femenino , Colorantes Fluorescentes/metabolismo , Xenoinjertos , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos
18.
Molecules ; 22(8)2017 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-28771219

RESUMEN

A one-pot regioselective bis-Suzuki-Miyaura or Suzuki-Miyaura/Sonogashira reaction on 2,4-dibromo-1-methyl-5-nitro-1H-imidazole under microwave heating was developed. This method is applicable to a wide range of (hetero)arylboronic acids and terminal alkynes. Additionally, this approach provides a simple and efficient way to synthesize 2,4-disubstituted 5-nitroimidazole derivatives with antibacterial and antiparasitic properties.


Asunto(s)
Antibacterianos , Antiparasitarios , Nitroimidazoles , Antibacterianos/síntesis química , Antibacterianos/química , Antiparasitarios/síntesis química , Antiparasitarios/química , Nitroimidazoles/síntesis química , Nitroimidazoles/química
19.
Sci Rep ; 7: 44739, 2017 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-28303942

RESUMEN

The self-assembly of the microtubule associated tau protein into fibrillar cell inclusions is linked to a number of devastating neurodegenerative disorders collectively known as tauopathies. The mechanism by which tau self-assembles into pathological entities is a matter of much debate, largely due to the lack of direct experimental insights into the earliest stages of aggregation. We present pulsed double electron-electron resonance measurements of two key fibril-forming regions of tau, PHF6 and PHF6*, in transient as aggregation happens. By monitoring the end-to-end distance distribution of these segments as a function of aggregation time, we show that the PHF6(*) regions dramatically extend to distances commensurate with extended ß-strand structures within the earliest stages of aggregation, well before fibril formation. Combined with simulations, our experiments show that the extended ß-strand conformational state of PHF6(*) is readily populated under aggregating conditions, constituting a defining signature of aggregation-prone tau, and as such, a possible target for therapeutic interventions.


Asunto(s)
Agregado de Proteínas , Proteínas tau/química , Secuencia de Aminoácidos , Electrones , Heparina/farmacología , Simulación de Dinámica Molecular , Proteínas Mutantes/química , Péptidos/química , Conformación Proteica , Soluciones , Factores de Tiempo , Proteínas tau/ultraestructura
20.
J Tissue Eng Regen Med ; 11(9): 2479-2489, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-27125623

RESUMEN

In the clinical and pharmacological fields, there is a need for the production of tissue-engineered small-diameter blood vessels. We have demonstrated previously that the extracellular matrix (ECM) produced by fibroblasts can be used as a scaffold to support three-dimensional (3D) growth of another cell type. Thus, a resistant tissue-engineered vascular media can be produced when such scaffolds are used to culture smooth muscle cells (SMCs). The present study was designed to develop an anisotropic fibroblastic ECM sheet that could replicate the physiological architecture of blood vessels after being assembled into a small diameter vascular conduit. Anisotropic ECM scaffolds were produced using human dermal fibroblasts, grown on a microfabricated substrate with a specific topography, which led to cell alignment and unidirectional ECM assembly. Following their devitalization, the scaffolds were seeded with SMCs. These cells elongated and migrated in a single direction, following a specific angle relative to the direction of the aligned fibroblastic ECM. Their resultant ECM stained for collagen I and III and elastin, and the cells expressed SMC differentiation markers. Seven days after SMCs seeding, the sheets were rolled around a mandrel to form a tissue-engineered vascular media. The resulting anisotropic ECM and cell alignment induced an increase in the mechanical strength and vascular reactivity in the circumferential direction as compared to unaligned constructs. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Prótesis Vascular , Proteínas de la Matriz Extracelular , Matriz Extracelular , Fibroblastos/metabolismo , Andamios del Tejido/química , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Proteínas de la Matriz Extracelular/biosíntesis , Proteínas de la Matriz Extracelular/química , Fibroblastos/citología , Humanos , Músculo Liso Vascular/citología , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/citología , Miocitos del Músculo Liso/metabolismo
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