Near-Infrared Fluorescence Imaging Contrast Agents for Clinical Research: Limitations and Alternatives

Introduction: Near-infrared fluorescence imaging is a technique that will establish itself in the short term at the international level because it is recognized for its potential to improve the performance of surgical interventions, its moderate investment and operating costs and its portability. Although the technology is now mature, there is currently the problem of the availability of contrast agents to be injected IV. The aim of this methodology article is to propose an alternative solution to the need for contrast agents for clinical research, particularly in oncology. Methodology: They consist of coupling a fluorescent marker in the form of an NHS derivative, such as IR DYE manufactured in compliance with GMP, with therapeutic monoclonal antibodies having marketing authorization for molecular imaging. For a given antibody, the marking procedure must be the subject of a validation file on the final preparation filtered on a sterilizing membrane at 0.22 μm. Once the procedure has been validated, it would be unnecessary to repeat the tests before each clinical research examination. A check of the marking by thin-layer chromatography (TLC) and place it in a sample bank at +4˚C for 1 month of each injected formulation would be sufficient for additional tests if necessary. Conclusion: Molecular near-infrared fluorescence imaging is experiencing development, the process of which could be accelerated by greater availability of clinical contrast agents. Alternative solutions are therefore necessary to promote clinical research in this area. These methods must be shared to make it easier for researchers.

On the cell biology of pit cells,the liver-specific NK cells

INTRODUCTION Natural killer (NK) cells are functionally defined by their ability to kill certain tumor cells and virus-infected cells without prior

Participation of CD45,NKR-P1A and ANK61 antigen in rat hepatic NK cell(pit cell)-mediated target cell cytotoxicity

AIM Several triggering receptors have beendescribed to be involved in natural killer（NK）cell-mediated target cytotoxicity.In these studies,NKcells derived from blood or spleen were used.Pitcells are liver-specific NK cells that possess ahigher level of natural cytotoxicity and a differentmorphology when compared to blood NK cells.The aim of this study was to characterize the roleof the NK-triggering molecules NKR-P1A,ANK61antigen,and CD45 in pit cell-mediated killing oftarget cells.METHODS 51Cr-release and DNA fragmentationwere used to quantify target cell lysis andapoptosis,respectively.RESULTS Flow cytometric analysis showed thatpit cells expressed CD45,NKR-P1A,and ANK61antigen.Treatment of pit cells with monoclonalantibody（mAb）to CD45（ANK74）not onlyinhibited CC531s or YAC-1 target lysis but alsoapoptosis induced by pit cells.The mAbs to NKR-P1A（3.2.3）and ANK61 antigen（ANK61）had no effect on pit cell-mediated CC531s or YAC-1 targetcytolysis or apoptosis,while they did increase theFcγ receptor positive（FcγR+）P815 cytolysis andapoptosis.This enhanced cytotoxicity could beinhibited by 3,4-dichloroisocoumarin,an inhibitorof granzymes.CONCLUSION These results indicate that CD45participates in pit cell-mediated CC531s and YAC-1target cytolysis and apoptosis.NKR-P1A andANK61 antigen on pit cells function as activationstructures against FcγR+ P815 cells,which wasmediated by the perforin/granzyme pathway.

Small extrachromosomal circular DNA in amyotrophic lateral sclerosis matter

Comprehensive studies identify motor neuron spectrum disorders including amyotrophic lateral sclerosis(ALS)as globally rising fatal disorders with the highest prevalence in aging populations,influenced by ethnicity and ancestry(GBD 2016 Motor Neuron Disease Colla borators,2018).While~10% of diagnoses involve a family history(fALS),most cases are considered sporadic(sALS).However,population-based studies suggest that even cases without a common index mutation impart heritability(Ryan et al.,2019),indicating a crucial role of rare and as yet unknown genetic denominators.

Nociceptin effect on intestinal motility depends on opioidreceptor like-1 receptors and nitric oxide synthase colocalization

AIM: To study the effect of the opioid-receptor like-1(ORL1) agonist nociceptin on gastrointestinal(GI)myenteric neurotransmission and motility. METHODS: Reverse transcriptase- polymerase chain reaction and immunohistochemistry were used to localize nociceptin and ORL1 in mouse tissues. Intracellular electrophysiological recordings of excitatory and inhibitory junction potentials(EJP, IJP) were made in a chambered organ bath. Intestinal motility was measured in vivo. RESULTS: Nociceptin accelerated whole and upper GI transit, but slowed colonic expulsion in vivo in an ORL1-dependent manner, as shown using [Nphe1]NOC and AS ODN pretreatment. ORL1 and nociceptin immunoreactivity were found on enteric neurons. Nociceptin reduced the EJP and the nitric oxide-sensitive slow IJP in an ORL1-dependent manner, whereas the fast IJP was unchanged. Nociceptin further reduced the spatial spreading of the EJP up to 2 cm. CONCLUSION: Compounds acting at ORL1 are good candidates for the future treatment of disorders associated with increased colonic transit, such as diarrhea or diarrhea-predominant irritable bowel syndrome.

Identification and functional characterization of fish IL‑17 receptors suggest important roles in the response to nodavirus infection

Th17 is a lymphocyte T helper(Th)subpopulation relevant in the control and regulation of the immune response characterized by the production of interleukin(IL)-17.This crucial cytokine family acts through their binding to the IL-17 receptors(IL-17R),having up to six members.Although the biology of fish Th17 is well-recognized,the molecular and functional characterization of IL-17 and IL-17R has been limited.Thus,our aim was to identify and characterize the IL-17R repertory and regulation in the two main Mediterranean cultured fish species,the gilthead seabream(Sparus aurata)and the European sea bass(Dicentrarchus labrax).Our in silico results showed the clear identification of six members in each fish species,from IL-17RA to IL-17RE-like,with well-conserved gene structure and protein domains with their human orthologues.All of them showed wide and constitutive transcription in naïve tissues but with highest levels in mucosal tissues,namely skin,gill or intestine.In leucocytes,T mitogens showed the strongest up-regulation in most of the il17 receptors though il17ra resulted in inhibition by most stimulants.Interestingly,in vivo nodavirus infection resulted in alterations on the transcription of il17 receptors.While nodavirus infection led to some increments in the il17ra,il17rb,il17rc and il17rd transcripts in the susceptible European sea bass,many down-regulations were observed in the resistant gilthead seabream.Our data identify the presence and conservation of six coding IL-17R in gilthead seabream and European sea bass as well as their differential regulation in vitro and upon nodavirus infection.

Using the endocannabinoid system as a neuroprotective strategy in perinatal hypoxic-ischemic brain injury

One of the most important causes of brain injury in the neonatal period is a perinatal hypoxicischemic event.This devastating condition can lead to long-term neurological deficits or even death.After hypoxic-ischemic brain injury,a variety of specific cellular mechanisms are set in motion,triggering cell damage and finally producing cell death.Effective therapeutic treatments against this phenomenon are still unavailable because of complex molecular mechanisms underlying hypoxic-ischemic brain injury.After a thorough understanding of the mechanism underlying neural plasticity following hypoxic-ischemic brain injury,various neuroprotective therapies have been developed for alleviating brain injury and improving long-term outcomes.Among them,the endocannabinoid system emerges as a natural system of neuroprotection.The endocannabinoid system modulates a wide range of physiological processes in mammals and has demonstrated neuroprotective effects in different paradigms of acute brain injury,acting as a natural neuroprotectant.The aim of this review is to study the use of different therapies to induce long-term therapeutic effects after hypoxic-ischemic brain injury,and analyze the important role of the endocannabinoid system as a new neuroprotective strategy against perinatal hypoxic-ischemic brain injury.

A new device for deep cervical artificial insemination in gilts reduces the number of sperm per dose without impairing final reproductive performance

Background: The aim of this study was to evaluate the reproductive performance of a new artificial insemination(AI) device specifically designed for gilts(Deep cervical AI, Dp-CAI) by means of which the sperm is deposited deeply in the cervix(8 cm more cranial than in traditional cervical insemination-CAI). New AI techniques have arisen in recent decades in the porcine industry, such as post-cervical artificial insemination(PCAI), which involves depositing the sperm in the body of the uterus [through a catheter(outer tube)-cannula(inner tube)] rather than by CAI. Although the PCAI method has been successfully applied in farm conditions to reduce sperm doses without impairing the reproductive performance, this technique has limitations in gilts mainly because of the difficulty involved in introducing the inner cannula through the cranial part of the cervix. For this reason, the Dp-CAI method described herein may be considered as an alternative to CAI and PCAI methods in gilts.Results: Gilts were divided in two experimental groups: 1) Dp-CAI: gilts(n = 1166) inseminated using 1.5 × 109 sperm/45 m L;2) CAI(as a control group): gilts(n = 130) inseminated using 2.5 × 10~9 sperm/85 mL. The Dp-CAI method was successfully applied in 88.90% of the gilts, with no differences detected between gilts with 1 or 2 previous oestrus cycles, although the catheter could be introduced more deeply in 2 oestrus gilts(P < 0.05). As the length of the insemination device that could not be introduced increased(at the moment of insemination), so the success rate of the Dp-CAI device fell, as did the total number of piglets born. When the reproductive output in CAI and Dp-CAI was compared, none of the parameters analysed [pregnancy and farrowing rates(%), and number of piglets born(total and live)] showed significant differences.Conclusions: The use of the Dp-CAI technique provides a new AI method as an alternative to CAI and PCAI for pigs. The device, especially designed for gilts, was used with a high degree of success reducing conventional sperm doses without impairing reproductive parameters.

Dietary n-3/n-6 polyunsaturated fatty acid ratio modulates growth performance in spotted seabass(Lateolabrax maculatus)through regulating lipid metabolism,hepatic antioxidant capacity and intestinal health

An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid(PUFA)ratio on growth performance,lipid metabolism,hepatic antioxidant status,and gut flora of spotted seabass(Lateolabrax maculatus).Six experimental diets were formulated to contain different levels of two purified oil sources including docosahexaenoic and eicosapentaenoic acids enriched oil(n-3)and linoleic acid-enriched oil(n-6)leading to n-3/n-6 PUFA ratios of 0.04,0.35,0.66,1.35,2.45 and16.17.Each diet was fed to triplicate groups of juvenile L.maculatus(11.06±0.20 g,30 fish/tank).Final body weight(FBW),weight gain(WG),specific growth rates(SGR),protein efficiency ratio(PER)and feed utilization efficiency increased as n-3/n-6 PUFA ratio increased up to a certain level,and then decreased thereafter.Fish fed the diet with n-3/n-6 PUFA ratio of 0.66 exhibited the highest FBW,WG,SGR and PER and the lowest feed conversion ratio.Lower n-3/n-6 PUFA ratios induced up-regulated expression of lipid synthesis-related genes(fas,acc2 and srebp-1c)and down-regulated expression of lipolysis related genes(atgl,ppara,cpt-1 and aox).Higher expression of lipolysis-related genes(atgl,ppara and cpt-1)was recorded at moderate n-3/n-6 PUFA ratios(0.66 to 1.35).Moreover,inappropriate n-3/n-6 PUFA ratios triggered up-regulation of pro-inflammatory genes(il-6 and tnf-a)and down-regulation of antiinflammatory genes(il-4 and il-10)in the intestine.The diet with n-3/n-6 PUFA ratio of 0.66 inhibited intestine inflammation,improved intestinal flora richness,increased the abundance of beneficial bacteria such as Lactobacillus,Alloprevotella and Ruminococcus,and reduced the abundance of harmful bacteria including Escherichia-Shigella and Enterococcus.In summary,it could be suggested that a dietary n-3/n-6PUFA ratio of 0.66 can improve growth performance and feed utilization in L.maculatus,as is deemed to be mediated through regulation of lipid metabolism and intestinal flora.

Recentdevelopments in fluorescence- basedmicroscopy applied in biomedical sciences

The present short review aims to give an overview of the most recent developments in fluorescence microscopy and its applications in biomedical sciences. Apart from improvements in well established methods based on conventional fluorescence microscopy and confocal microscopy (fluorescence in situ hybridisation (FISH), tyramide signal amplification (TSA) in immunocytochemistry, new fluorophores), more recently introduced techniques like fluorescence resonance energy transfer (FRET), fluorescence recovery after photobleaching (FRAP), multiphoton microscopy and fluorescence correlation spectroscopy (FCS) will be discussed.

Modern Monitoring Intraocular Pressure Sensing Devices Based on Application Specific Integrated Circuits

Glaucoma is a neurodegenerative condition that is the leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is the main risk factor for the development and progression of the disease. Methods to lower IOP remain the first line treatments for the condition. Current methods of IOP measurement do not permit temporary noninvasive monitoring 24-hour IOP on a periodic basis. Ongoing research will in time provide a means of developing a device that will enable continuous or temporary monitoring of IOP. At present a device suitable for clinical use is not yet available.This review contains a description of different devices currently in development for measuring IOP: soft contact lens, LC resonant circuits and on-chip sensing devices. All of them use application-specific integrated circuits (ASICS) to process the measured signals and send them to recording devices. Soft contact lens devices are based on an embedded strain gauge, LC circuits vary their resonance frequency depending on the intraocular pressure (IOP) and, finally, on-chip sensing devices include an integrated microelectromechanical sensor (MEMS). MEMS are capacitors whose capacity varies with IOP. These devices allow for an accurate IOP measurement (up to +/– 0.2 mm Hg) with high sampling rates (up to 1 sample/min) and storing 1 week of raw data. All of them operate in an autonomous way and even some of them are energetically independent.

Long-term live-cell microscopy with labeled nanobodies delivered by laser-induced photoporation

Fluorescence microscopy is the method of choice for studying intracellular dynamics.However,its success depends on the.availability of specific and stable markers.A prominent example of markers that are rapidly gaining interest are nanobodies(Nbs.-15 kDa),which can be functionalized with bright and photostable organic fluorophores.Due to their relatively small size and high specificity,Nbs offer great potential for high-quality long-term subcellular imaging,but suffer from the fact that they cannot spontaneously cross the plasma membrane of live cells.We have recently discovered that laser-induced photoporation is well suited to deliver extrinsic labels to living cells without compromising their viability.Being a laser-based technology,it is readily compatible with light microscopy and the typical cell recipients used for that.Spurred by these promising initial results,we demonstrate here for the first time successful long-term imaging of specific subcellular structures with labeled nanobodies in living cells.We illustrate this using Nbs that target GFP/YFP-protein constructs accessible in the cytoplasm,actin-bundling protein Fascin,and the histone H2A/H2B heterodimers.With an efficiency of more than 80%labeled cells and minimal toxicity(-2%),photoporation proved to be an excellent intracellular delivery method for Nbs.Time-lapse microscopy revealed that cell division rate and migration remained unaffected,confirming excellent cell viability and functionality.We conclude that laser-induced photoporation labeled Nbs can be easily delivered into living cells,laying the foundation for further development of a broad range of Nbs with intracellular targets as a toolbox for long-term live-cell microscopy.

Influence of in vitro capacitation time on structural and functional human sperm parameters

A cascade of dramatic physiological events is linked to the sperm acrosome reaction and binding to the oocyte's zona pellucida during human sperm capacitation.However,structural and functional sperm changes during capacitation currently remain poorly defined.Here,we performed a multibiomarker approach based on the utilization of sperm concentration,motility,viability,morphology,acrosome reaction,tyrosine phosphorylation,DNA fragmentation,and lectin-binding sites to analyze the impact caused by swim-up selection times(uncapacitated,1 h capacitated,and 4 h capacitated)on sperm function and structure in normozoospermic samples.We found that a 4 h swim-up capacitation increased sperm quality,because a large number of cells with normal morphology and lower DNA fragmentation rates were recovered.Furthermore,the long-term capacitation induced a higher percentage of cells with tyrosine phosphorylation of the principal piece as well as a redistribution of lectin-binding sites.Overall,the multivariate biomarkers analyzed showed a less variable distribution on spermatozoa recovered after 4 h capacitation than that with the shorter capacitation time.These findings stress the importance of capacitation time as a relevant factor in sperm quality with potential biological reproductive implications both for basic research and in assisted reproduction techniques.