RESUMEN

Fluorescent turn-on probes have been extensively used in disease diagnosis and research on pathological disease mechanisms because of their low background interference. Hydrogen peroxide (H2O2) plays a vital role in regulating various cellular functions. In the current study, a fluorescent probe, HCyB, based on hemicyanine and arylboronate structures, was designed to detect H2O2. HCyB reacted with H2O2 and exhibited a good linear relationship for H2O2 concentrations ranging from 15 to 50 µM and good selectivity over other species. The fluorescent detection limit was 76 nM. Moreover, HCyB exhibited less toxicity and mitochondrial-targeting abilities. HCyB was successfully used to monitor exogenous or endogenous H2O2 in mouse macrophage RAW 264.7, human skin fibroblast WS1, breast cancer cell MDA-MB-231, and human leukemia monocytic THP1 cells.

Asunto(s)

RESUMEN

Abstract: Hydraulic jumps are commonly employed as energy dissipators to guarantee long-term operation of hydraulic structures. A comprehensive and in-depth understanding of their main features is therefore fundamental. In this context, the current study focused on hydraulic jumps with low Froude numbers, i.e. Fr1 = 2.1 and 2.4, at relatively high Reynolds number: Re ~2 × 105. Experimental tests employed a combination of dual-tip phase-detection probes and ultra-high-speed video camera to provide a comprehensive characterisation of the main air-water flow properties of the hydraulic jump, including surface flow features, void fraction, bubble count rate and interfacial velocities. The current research also focused on the transverse distributions of air-water flow properties, i.e. across the channel width, with the results revealing lower values of void fraction and bubble count rate next to the sidewalls compared to the channel centreline data. Such a spatial variability in the transverse direction questions whether data near the side walls may be truly representative of the behaviour in the bulk of the flow, raising the issue of sidewall effects in image-based techniques. Overall, these findings provide new information to both researchers and practitioners for a better understanding of the physical processes inside the hydraulic jump with low Froude numbers, leading to an optimised design of hydraulic structures. Article Highlights: Experimental investigation of air-water flow properties in hydraulic jumps with low Froude numbersDetailed description of the main air-water surface features on the breaking rollerTransversal distribution of the air-water flow properties across the channel width and comparison between centreline and sidewall.

RESUMEN

Parasitic helminths are usually known as undesired pathogens, causing various diseases in both human and animal species. In this study, we explore supercapacitance/resistance behaviors as a novel probe for rapid identification and direct differentiation of Fasciola hepatica, Parascaris equorum (with and without larvae), Dicrocoelium dendriticum, Taenia multiceps, and Moniezia expansa eggs. This claim is attributed to some characteristics, such as grave supercapacitance/area, high-energy storage/area, large power/egg, huge permittivity, and great electrical break-down potential, respectively (Fasciola hepatica: 2,158, 0.485, 2.7 × 10-3, 267, 52.6, Parascaris equorum without larvae: 2,825, 0.574, 3.0 × 10-3, 351, 68.4, Parascaris equorum with larvae: 4,519, 0.716, 2.4 × 10-3, 1.96, 97.6, Dicrocoelium dendriticum: 1,581, 0.219, 2.8 × 10-3, 1.96, 48.8, Moniezia expansa: 714, 0.149, 2.2 × 10-3, 0.88, 35.2, Taenia multiceps: 3,738, 0.619, 4.7 × 10-3, 4.63, 84.4), and durable capacitance up to at least 15,000 sequential cycles at different scan rates (between 2.0 × 10-4 and 120.0 V s-1) as well as highly differentiated resistance between 400 and 600 Ω. These traits are measured by the "Blind Patch-Clamp" method, at the giga ohm sealed condition (6.18 ± 0.12 GΩ cm-1, n = 5). Significant detection ranges are detected for each capacitance and resistance with gradient limits as large as at least 880 to 1,000 mF and 400 to 600 Ω depending on the type of helminth egg. The effect of water in the structure of helminth eggs has also been investigated with acceptable reproducibility (RSD 7%-10%, n = 5). These intrinsic characteristics would provide novel facilitators for direct helminth egg identification in comparison with several methods, such as ELISA, PCR, and microscopic methods.

RESUMEN

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome, and plays a key role in the pigmentation of hair and skin. The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism, vitiligo, melanoma and Parkinson disease. Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body, and it is also closely related to browning of fruits and vegetables and insect molting. Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these diseases. Therefore, many selective optical detection probes and small molecular inhibitors have been developed, and have made significant contributions to the basic and clinical research on these diseases. In this paper, the detection and inhibition of tyrosinase and their application in whitening products are reviewed, with special emphasis on development of fluorescent probes and inhibitors. Hopefully, this review will help design more efficient and sensitive tyrosinase probes and inhibitors, as well as shed light on novel treatment of diseases such as melanoma.

RESUMEN

Fluorescent polyhydroquinoline (PHQ) derivative was fabricated utilizing one-pot engineered course. The PHQ derivative indicated aggregation induced emission enhancement (AIEE) with arrangement of nanoaggregates of size 11-13 nm in 95% watery DMF medium. The fluorescence emission of PHQ nanoaggregates was extinguished by including TNP and Cr (VI). They indicated prevalent fluorescence quenching towards both TNP and Cr (VI) over other meddling nitro-compounds and metal particles. In light of results got we presumed that both photo-induced fluorescence quenching of PHQ nanoaggregates by TNP, while Inner Filter Effect (IFE) was in charge of fluorescence quenching of PHQ nanoaggregates by Cr (VI). The PHQ nanoaggregates empowered identification of TNP and Cr (VI) down to 0.66 µM (TNP) and 0.28 µM (Cr (VI)). The use of PHQ nanoaggregates were reached out for location of TNP and Cr (VI) in genuine water tests.

RESUMEN

Radioguided surgery (RGS) is the use of radiation detection probes and handheld gamma cameras in surgery rooms to identify radioactively labeled lesions inside the body with an aim to improve surgical outcome. In today's surgery, application of these devices is a well-established practice, which provides surgeons with real-time information to guide them to the site of a lesion. In recent years, there have been several major improvements in the technology and design of gamma probes and handheld gamma cameras, enhancing their applications in surgical practices. Handheld gamma cameras, for example, are now moving from single-modality to dual-modality scanners that add anatomical data to the physiologic data, and with that provide more clinical information of the tissue under study. Also, in the last decade, a radioguided surgical technique based on the Cerenkov radiation was introduced, with more improved sensitivity in identifying radioactively labeled lesions. Additionally, recent advances in hybrid tracers have led to more efficient detection of lesions labeled with these tracers. Besides, it seems that combining medical robotics and augmented reality technology with current radioguided surgical practices potentially will change the delivery and performance of RGS in the near future. The current paper aims to give an overview of the physics of RGS and summarizes recent advances in this field that have a potential to improve the application of radioguided surgical procedures in the management of cancer.

Asunto(s)

RESUMEN

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome, and plays a key role in the pigmentation of hair and skin. The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism, vitiligo, melanoma and Parkinson disease. Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body, and it is also closely related to browning of fruits and vegetables and insect molting. Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these dis-eases. Therefore, many selective optical detection probes and small molecular inhibitors have been developed, and have made significant contributions to the basic and clinical research on these diseases. In this paper, the detection and inhibition of tyrosinase and their application in whitening products are reviewed, with special emphasis on development of fluorescent probes and inhibitors. Hopefully, this review will help design more efficient and sensitive tyrosinase probes and inhibitors, as well as shed light on novel treatment of diseases such as melanoma.

RESUMEN

Recombinant protein production can create artificial proteins with desired functions by introducing genetic modifications to the target proteins. Horseradish peroxidase (HRP) has been used extensively as a reporter enzyme in biotechnological applications; however, recombinant production of HRP has not been very successful, hampering the utilization of HRP with genetic modifications. A fusion protein comprising an antibody binding protein and HRP will be an ideal bio-probe for high-quality HRP-based diagnostic systems. A HRP-protein A/G fusion protein (HRP-pAG) is designed and its production in silkworm (Bombyx mori) is evaluated for the first time. HRP-pAG is expressed in a soluble apo form, and is activated successfully by incubating with hemin. The activated HRP-pAG is used directly for ELISA experiments and retains its activity over 20 days at 4 °C. Moreover, HRP-pAG is modified with biotin by the microbial transglutaminase (MTG) reaction. The biotinylated HRP-pAG is conjugated with streptavidin to form a HRP-pAG multimer and the multimeric HRP-pAG produced higher signals in the ELISA system than monomeric HRP-pAG. The successful production of recombinant HRP in silkworm will contribute to creating novel HRP-based bioconjugates as well as further functionalization of HRP by applying enzymatic post-translational modifications.

Asunto(s)

RESUMEN

Disease research and treatment development have turned to the impact and utility of microRNA. The dynamic and highly specific expression of these molecular regulators can be used to predict and monitor disease progression as well as therapeutic treatment efficacy and safety, thus aiding decisions in patient care. In situ hybridization (ISH) of biopsy material has become a routine clinical pathology procedure for monitoring gene structure, expression, and sample characterization. For ribonucleic acid (RNA), determining cell source and level of expression of these biomarkers gives insight into the cellular function and physiopathology. Identification and monitoring of microRNA biomarkers are made possible through locked nucleic acid (LNA)™-based detection probes. LNA™ enhances the sensitivity and specificity of target binding, most profoundly so for the short, highly similar, microRNA sequences. We present a robust 1-day ISH protocol for formalin-fixed, paraffin-embedded (FFPE) tissue sections based on microRNA-specific LNA™ detection probes which can be labeled with digoxigenin (DIG) or 6-carboxyfluorescein (FAM) and detected through enzyme-linked specific antibodies that catalyze substrates into deposited chromogen products at the target RNA site. The variety of haptens and detection reagents in combination with LNA™ chemistry offer flexibility and ease to multiple target assessment of therapeutic response.

Asunto(s)

RESUMEN

Freehand SPECT (fhSPECT) is a technology platform for providing 3-dimensional (3D) navigation for radioguided surgical procedures, such as sentinel lymph node (SLN) biopsy (SLNB). In addition to the information provided by conventional handheld gamma detection probes, fhSPECT allows for direct visualization of the distribution of radioactivity in any given region of interest, allowing for improved navigation to radioactive target lesions and providing accurate lesion depth measurements. Herein, we will review the currently available clinical data on the use of fhSPECT: (i) for SLNB of various malignancies, including difficult-to-detect SLNs, and (ii) for radioguided localization of solid tumors. Moreover, the combination of fhSPECT with other technologies (e.g., small field-of-view gamma cameras, and diagnostic ultrasound) is discussed. These technical advances have the potential to greatly expand the clinical application of radioguided surgery in the future.

Asunto(s)

RESUMEN

BACKGROUND: The main prognostic factor in early staged breast cancer is the axillary lymph node metastatic affection. Sentinel lymph node biopsy, as a staging modality, significantly decreases surgical morbidity. The status of internal mammary lymph nodes gains an increased predictive role in grading breast carcinomas and modulation of postoperative therapeutic protocols. If positive, almost always are associated with worse disease outcome. Nevertheless, the clinical significance of internal mammary lymph node micrometastases has not been up to date precisely defined. AIM: To present a case of female patient clinically diagnosed as T1, N0, M0 (clinical TNM) ductal breast carcinoma with scintigraphic detection of internal mammary and axillary sentinel lymph nodes. METHODS: Dual method of scintigraphic sentinel lymph node detection using 99mTc-SENTI-SCINT and blue dye injection, intraoperative gamma probe detection, radioguided surgery and intraoperative ex tempore biopsy were used. CASE REPORT: We present a case of clinically T1, N0, M0 ductal breast cancer with scintigraphic detection of internal mammary and axillary sentinel lymph nodes. Intraoperative ex tempore biopsy revealed micrometastases in the internal mammary node and no metastatic involvement of the axillary sentinel lymph node. CONCLUSION: Detection of internal mammary lymph node metastases improves N (nodal) grading of breast cancer by selecting a high risk subgroup of patients that require adjuvant hormone therapy, chemotherapy and/or radiotherapy.

RESUMEN

PURPOSE: Sentinel lymph node (SLN) biopsy has emerged as a substitute for a conventional axillary lymph node (ALN) dissection in early breast carcinomas. We evaluated SLN biopsy in breast carcinoma using a gamma-detection probe in order to identify its accuracy as a staging procedure for lymph node status. METHODS: Fifty-one patients with breast carcinomas who underwent a SLN biopsy followed by an ALN dissection between June 1999 and January 2001 were evaluated. Tc 99m antimony trisulfide colloid was used as a tracer and SLN biopsy using a gamma-detection probe was done following breast lymphoscintigraphy. Intraoperative imprint cytology (II C) was done for each SLN. If a SLN biopsy was free of metastasis by permanent hematoxylin and eosin (H&E) staining, immun ohistochemical (IHC) staining using pan-cytokeratin was do ne to detect micrometastasis. RESULTS: ALN metastases were identified in 21.6% of pa tients and the resection rate of SLN was 94.1%. The mean number of resected SLN was 1.8, all located at the axilla. IIC had a sensitivity of 72.7% and a spe cificity of 100%. The false-negative rate of SLN biopsy was 12.5% when SLNs were evaluated by H&E staining alone. However, the false-negative rate improved up to 0% when IHC staining was added. CONCLUSION: SLN biopsy using a gamma-detection probe proved to be a very sensitive method to detect SLN in breast carcinoma patients. Frozen biopsy should be added to im prove the outcomes of intraoperative examination of SLN. If permanent biopsy revealed that SLN was free of tumorthe by H&E staining, IHC staining should be done to improve false-negative rate of SLN biopsy.

Asunto(s)

RESUMEN

PURPOSE: Sentinel lymph node (SLN) biopsy has emerged as a substitute for a conventional axillary lymph node (ALN) dissection in early breast carcinomas. We evaluated SLN biopsy in breast carcinoma using a gamma-detection probe in order to identify its accuracy as a staging procedure for lymph node status. METHODS: Fifty-one patients with breast carcinomas who underwent a SLN biopsy followed by an ALN dissection between June 1999 and January 2001 were evaluated. Tc 99m antimony trisulfide colloid was used as a tracer and SLN biopsy using a gamma-detection probe was done following breast lymphoscintigraphy. Intraoperative imprint cytology (II C) was done for each SLN. If a SLN biopsy was free of metastasis by permanent hematoxylin and eosin (H&E) staining, immun ohistochemical (IHC) staining using pan-cytokeratin was do ne to detect micrometastasis. RESULTS: ALN metastases were identified in 21.6% of pa tients and the resection rate of SLN was 94.1%. The mean number of resected SLN was 1.8, all located at the axilla. IIC had a sensitivity of 72.7% and a spe cificity of 100%. The false-negative rate of SLN biopsy was 12.5% when SLNs were evaluated by H&E staining alone. However, the false-negative rate improved up to 0% when IHC staining was added. CONCLUSION: SLN biopsy using a gamma-detection probe proved to be a very sensitive method to detect SLN in breast carcinoma patients. Frozen biopsy should be added to im prove the outcomes of intraoperative examination of SLN. If permanent biopsy revealed that SLN was free of tumorthe by H&E staining, IHC staining should be done to improve false-negative rate of SLN biopsy.

Asunto(s)