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Differential involvement of NMDA and AMPA receptors within the nucleus accumbens in consolidation of information necessary for place navigation and guidance strategy of mice.

Recent evidence now points to a role of glutamate transmission within the nucleus accumbens (Nacc) in spatial learning and memory. Unfortunately, the role of the distinct classes of glutamate receptors within this structure in mediating the different steps of the memorization process is not clear. The aim of this study therefore was to further investigate this issue, trying to assess the involvement of the two classes of glutamate receptors within the Nacc in consolidation of spatial information using an associative spatial task, the water maze. For this purpose, focal injections of the NMDA antagonist, AP-5, and of the AMPA antagonist, DNQX, have been performed immediately after the training phase, and mice have been tested for retention 24 h later. Two different versions of the water-maze task have been used: In the place version, animals could learn the position of the platform using visual distal cues, and in the cue version, the location of the platform was indicated by a single proximal cue. The results demonstrated that posttraining NMDA receptor blockade affects mice response in the place but not in the cue water-maze task. On the contrary, AMPA receptor blockade induced no effect in either version of the task. These data confirm a functional dissociation between glutamate receptors located in the Nacc in modulating spatial memory consolidation and indicate that they are specifically involved in consolidation of information necessary to acquire a place but not to a guidance strategy.

Animals↗

Transmission of lung sounds through light clothing.

BACKGROUND: Doctors are exhorted to always place the stethoscope directly on the skin and never to auscultate through clothing. Nevertheless, casual observation reveals that doctors and even pulmonologists often violate this principle. OBJECTIVES: This study was designed to evaluate the sensitivity of two common stethoscopes when used through clothing. METHODS: Littmann Classic and Littmann Master Cardiology stethoscopes were studied under conditions of light (60-100 g), medium (240 g) and heavy (555 g) force when placed on a lung sound test platform with one or two layers of cloth (T-shirt material and flannel) interposed between the stethoscope and the test surface. The test platform was designed to mimic the acoustic and mechanical properties of the chest wall and was driven by amplified white noise. The recorded amplitude spectra were compared over a range of 150-1,000 Hz. RESULTS: Compared to the sensitivity on a bare test platform surface, either fabric in single or double layers attenuated the sounds by a mean of 5-18 dB under light pressure. This attenuation was nearly abolished by the addition of either medium or heavy force on the stethoscope head. CONCLUSIONS: The deleterious effect of one or two layers of indoor clothing on lung sounds acquired through a stethoscope can be negated by force on the stethoscope head making effective auscultation possible. Nevertheless, auscultation through clothing remains problematic due to the hindrance to inspection and percussion and the risk of acoustic artifacts caused by clothing.

Auscultation↗

A comparison of cardiac troponin T and cardiac troponin I in patients with acute coronary syndromes.

The majority of studies have shown that the performance of assays for cTnT and cTnI is almost identical in detecting AMI in patients with coronary artery disease. Currently cTnT may have an advantage over cTnI because available laboratory and POC platforms are standardized to a single reference material. Nevertheless, the decision to use cTnT or cTnI a given laboratory will probably be made on the basis of cost and the availability of automated instrumentation within that institution, and not necessarily on assay performance. A laboratory is unlikely to purchase an instrument to perform a single test. Because cTnI will soon be available on all commercial immunoassay analyzers, it seems likely that cTnI will become the analyte of choice.

Acute Disease↗

Spot check of the calibrated force platform location.

In a movement analysis laboratory, stereophotogrammetric motion capture systems and force platforms must share one absolute reference frame that allows the computation of joint moments and powers. The correct calibration of the platform location identifies the transformation between force plate and absolute reference systems, which determines the spatial coherence among the equipments' measurements. The aim of this study was to develop and test a spot check for the assessment of platform location calibration. Platform location calibration was assessed by comparing the measured outcome of an experiment performed with a pointed rigid rod bearing a set of markers with the corresponding expected results, computed with a model. A set of indices was then proposed to define a confidence volume in which the true ground reaction force is expected to be. The spot check was applied to a real laboratory setup and the effects of simulated platform mislocations were analysed. It was verified that the hip joint moment may be equally affected by a single marker misplacement of about 20mm during platform location calibration, an occurrence that was clearly identified by the spot check, and by a hip centre location inaccuracy of 30mm.

Biomechanical Phenomena↗

Multigenerational exposure to dietary nonylphenol has no severe effects on spatial learning in female rats.

Nonylphenol is a common intermediate in the production of many consumer compounds and reportedly acts as an estrogen mimic. Because estrogen affects the spatial learning and memory in rats, the effects of nonylphenol exposure on the performance of female rats in the Morris water maze were investigated. Here, Sprague-Dawley rats (F0) consumed soy-free diets containing 0, 25, 200 or 750 ppm nonylphenol (0, 2, 16 or 60 mg/kg per day) beginning on postnatal day (PND) 42 and continuing for two generations (F1 and F2) with breeding occurring within treatments. Females to be behaviorally tested (n = 7-8 per treatment per generation) were ovariectomized at adulthood and assessed for spatial learning and memory between PND 125-150 (young adult age). Each rat was tested for four consecutive days (three trials per day) in the Morris water maze with the platform in a fixed location. One week later, each subject was primed with estrogen and progesterone and assessed on a single day (three trials). The F1 rats continued on the same diets until PND 380-395 (middle aged) when they were re-tested as above (four consecutive days followed 1 week later with hormonal priming and a single test day). Latency to find the platform, path length and swim speed were averaged over the three trials per day and analyzed using repeated measures analyses of variance. There were no consistent effects of dietary nonylphenol exposure and no interactions of nonylphenol exposure on any measure of performance in either generation at the young age nor at the middle age in the F1 generation. When tested at the young adult age, however, hormone priming resulted in latencies and path lengths that were significantly shorter than in those exhibited during the unprimed test days, and there was no such effect when tested at middle age. Middle aged rats exhibited better performance than the same animals tested at a young age, likely as a result of familiarity and practice with the test paradigm. These data suggest that multigenerational dietary nonylphenol exposure does not cause gross alterations in Morris water maze performance in young adult or middle aged ovariectomized female rats.

Animals↗

Acute administration of estrogen and progesterone impairs the acquisition of the spatial morris water maze in ovariectomized rats.

Although several markers of synaptic efficacy are enhanced during proestrus, spatial water maze performance is impaired. Because levels of both estrogen and progesterone are elevated in proestrus, the nature of their individual and combined effects on spatial learning was examined. Long-Evans hooded rats were ovariectomized postpubertally and pretrained on a water maze with a visible platform (nonspatial). Following pretraining, rats were administered estrogen (5 microg sc) or oil 48 and 24 h prior to testing and progesterone (500 microg sc) or oil 4 h prior to testing. Rats were tested on a water maze in a different room with a submerged platform (spatial) for 16 trials with random start location in a single testing day. Latency and path length to the target platform were significantly greater in estrogen plus progesterone-treated animals than in controls. Neither estrogen nor progesterone alone significantly impaired performance relative to controls on either measure. Swim speed was not significantly affected by any of the hormone treatments. Performance on a nonspatial cue task was not significantly altered by ovarian steroids. Thus, the combination of estrogen and progesterone produces deficits in the acquisition of the Morris water maze that may be specific to spatial reference memory. These deficits could be due to hormonal influences on extrahippocampal structures or to detrimental effects on behavior resulting from the increased synaptic activity intrinsic to the hippocampus proper.

Animals↗

Desorption/ionization on silicon nanowires.

Dense arrays of single-crystal silicon nanowires (SiNWs) have been used as a platform for laser desorption/ionization mass spectrometry of small molecules, peptides, protein digests, and endogenous and xenobiotic metabolites in biofluids. Sensitivity down to the attomole level has been achieved on the nanowire surfaces by optimizing laser energy, surface chemistry, nanowire diameter, length, and growth orientation. An interesting feature of the nanowire surface is that it requires lower laser energy as compared to porous silicon and MALDI to desorb/ionize small molecules, therefore reducing background ion interference. Taking advantage of their high surface area and fluid wicking capabilities, SiNWs were used to perform chromatographic separation followed by mass analysis of the separated molecules providing a unique platform that can integrate separation and mass spectrometric detection on a single surface.

Chromatography↗

Molecular Diagnostics for WHO Priority Bacterial Pathogens: A Bibliometric Mapping of Diagnostic Platforms, Resistance Markers, and Antimicrobial Resistance Research Trends.

Antimicrobial resistance (AMR) constrains effective treatment and carries implications for infection control, surveillance, and public health. The World Health Organization (WHO) priority bacterial pathogen framework has intensified the need for diagnostic innovation by redefining research priorities around organisms combining high disease burden with complex resistance profiles. Molecular diagnostics have accordingly moved beyond culture-based workflows, integrating rapid pathogen identification, resistance-marker detection, genomic surveillance, and clinical decision support. The present study conducted a bibliometric mapping of the literature on WHO priority pathogens. Rather than addressing resistance at a general level or a single pathogen or technology, it integrates priority pathogens, molecular platforms, and resistance markers within a single framework, tracing their joint thematic and temporal evolution along an explicit pathogen-platform-marker axis. Scopus-indexed articles and reviews (2000-2025) were retrieved, yielding 1746 publications after screening adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Analyses used Bibliometrix/Biblioshiny, R, and VOSviewer. The literature expanded markedly after 2018, led by China and the United States. Methicillin-resistant Staphylococcus aureus (MRSA), Mycobacterium tuberculosis, Enterococcus faecium, and the Enterobacterales-carbapenemase axis constituted the principal thematic cores, whereas conventional polymerase chain reaction (PCR)/nucleic acid amplification testing (NAAT) and whole-genome sequencing were the dominant platforms. Overall, the field has evolved from pathogen detection into an AMR-centered translational domain encompassing resistance prediction, genomic epidemiology, surveillance, and clinical decision support. Diagnostic development, stewardship, and surveillance depend on hybrid workflows coupling rapid marker-targeted assays with genome-based characterization, delivering actionable resistance within clinically meaningful timeframes, and extending coverage to underrepresented pathogens and platforms.

Humans↗

Design of a novel MEMS platform for the biaxial stimulation of living cells.

Micromechanical systems are increasingly being used as tools in biological applications, since their characteristic dimensions permit to operate at the same length scale of the structures under investigation. Here, we present a methodology for the design, fabrication and operation of a tool for the assessment of mechanical properties of single cells. In particular, we describe a microsystems platform to study bio-mechanical response of single living cells to in-plane biaxial stretching. The proposed device employs a new linkage design in order to obtain the displacement of the quadrants of a sliced circular plate in mutually-orthogonal directions using just one linear actuator. With this linkage geometry, the whole device has only one degree of freedom. This results in a very predictable and reliable mechanical behaviour, thereby allowing use a simple and easily available control electronics. Results of this study have relevance for the design of a powerful yet simple BioMEMS platform for the characterization of living cells as in-plane bi-axial loading simulated the conditions experienced by cells in vivo more realistically than a uniaxial stretching.

Animals↗

Test-retest reliability of lower extremity functional instability measures.

OBJECTIVES: 1) To evaluate the test-retest reliability of lower extremity functional instability measures involving testing situations of varying complexity, and 2) To evaluate the interrelationships among performances observed during these tests and a maximal single-limb forward hop for distance. DESIGN: A repeated measures design, repeated on two occasions. SETTING: Postural control laboratory. PARTICIPANTS: Thirty young healthy subjects (23.5 +/- 2.0 years). MAIN OUTCOME MEASURES: Subjects performed single-limb standing balance and forward hop tests on two occasions completed within 1 week and at least 24 hours apart. Standing balance was assessed using a force platform and the following four progressively complex test situations: 1) standing on the stable platform with eyes open, 2) standing on a foam mat placed over the platform with eyes open, 3) standing on the stable platform with eyes closed, and 4) standing on the stable platform after landing from a maximal single-limb forward hop. RESULTS AND CONCLUSIONS: Intraclass correlation coefficients were moderate to excellent (0.41 to 0.91) suggesting that the standing balance tests are appropriate for distinguishing among group performances. Standard errors of measurement and associated 95% confidence intervals suggested that a change in an individual's standing balance performance of approximately 10-30% would be necessary in order to confidently state that a true change had occurred. Stronger relationships were observed between hop distance and standing balance tests performed with eyes closed (r = -0.63, p < 0.001) and after landing from a maximal hop (r = -0.53, p = 0.003), suggesting that tests that challenge postural control to a greater extent are more representative of functional performance.

Adult↗

Spatial isoform sequencing at single-cell resolution reveals cell-type-specific spatial isoform variability in multiple brain cell types.

Spatial long-read technologies are increasingly common but usually lack single-cell resolution. This leaves unanswered whether spatially variable isoforms reflect variability within one cell type or differences in region-specific cell-type composition. Here, we developed Spl-ISO-Seq2 (500-nm resolution) and accompanying software, Spl-IsoQuant-2 and Spl-IsoFind, enabling long-read sequencing of >450 million barcodes versus 80,000 previously. Applying this to the adult mouse brain, we compared differential isoform abundance between known regions and spatial isoform patterns independent of predefined regions. Both identified overlapping hits, for example, Rps24 in oligodendrocytes. For known Snap25 spatial isoform variation, we show that it occurs in excitatory neurons. The region-agnostic approach also uncovered patterns missed by region-based comparisons, for example, for Ighm. Notably, many spatial isoform signals are not driven by cell-type composition alone. Finally, our software is applicable to many spatial and single-cell protocols, demonstrating reproducibility between platforms (for example, Visium HD/Stereo-seq). Overall, our experimental/analytical methods enable a submicron-resolution-isoform view and open avenues for spatial isoform disease research.

Animals↗

Microarray analysis in cystic fibrosis.

DNA microarrays provide a versatile platform for applications including gene expression analysis and genotyping. In the case of cystic fibrosis (CF), DNA microarrays enable the measurement of gene expression levels of thousands of genes in parallel, and potentially therefore, to identify non-CFTR genes down- or up-regulated in CF, which could lead to insights into disease pathophysiology, as well as novel molecular markers and therapeutic strategies. Moreover, using optimised microarray protocols based on either primer extension analysis (i.e. minisequencing) or electronic hybridisation stringency control, the potential now exists to detect all relevant CFTR mutations on a single DNA microarray as a novel platform for CF screening.

Cystic Fibrosis↗

Improved performance of pyrosequencing using single-stranded DNA-binding protein.

In modern biology, there is a critical need to develop a high-throughput and inexpensive platform for DNA sequencing. Pyrosequencing is a nonelectrophoretic single-tube DNA sequencing method that takes advantage of cooperativity between four enzymes to monitor DNA synthesis. In these studies, single-stranded DNA-binding protein (SSB) was added to the primed DNA template prior to the Pyrosequencing reaction. The addition of SSB to a Pyrosequencing reaction system resulted in a read length of more than 30 nucleotides. Improvements were observed as: (i) increased efficiency of the enzymes, (ii) reduced mispriming, as measured by nonspecific signals, (iii) an increase in signal intensity during the reaction, (iv) higher accuracy in reading the number of identical adjacent nucleotides in difficult templates, and (v) longer reads. The usefulness of these results for future Pyrosequencing applications is discussed.

Apyrase↗

Applications of Luminex xMAP technology for rapid, high-throughput multiplexed nucleic acid detection.

BACKGROUND: As we enter the post-genome sequencing era and begin to sift through the enormous amount of genetic information now available, the need for technologies that allow rapid, cost-effective, high-throughput detection of specific nucleic acid sequences becomes apparent. Multiplexing technologies, which allow for simultaneous detection of multiple nucleic acid sequences in a single reaction, can greatly reduce the time, cost and labor associated with single reaction detection technologies. METHODS: The Luminex xMAP system is a multiplexed microsphere-based suspension array platform capable of analyzing and reporting up to 100 different reactions in a single reaction vessel. This technology provides a new platform for high-throughput nucleic acid detection and is being utilized with increasing frequency. Here we review specific applications of xMAP technology for nucleic acid detection in the areas of single nucleotide polymorphism (SNP) genotyping, genetic disease screening, gene expression profiling, HLA DNA typing and microbial detection. CONCLUSIONS: These studies demonstrate the speed, efficiency and utility of xMAP technology for simultaneous, rapid, sensitive and specific nucleic acid detection, and its capability to meet the current and future requirements of the molecular laboratory for high-throughput nucleic acid detection.

Animals↗

Microfabricated platform for studying stem cell fates.

Platforms that allow parallel, quantitative analysis of single cells will be integral to realizing the potential of postgenomic biology. In stem cell biology, the study of clonal stem cells in multiwell formats is currently both inefficient and time-consuming. Thus, to investigate low-frequency events of interest, large sample sizes must be interrogated. We report a simple, versatile, and efficient micropatterned arraying system conducive to the culture and dynamic monitoring of stem cell proliferation. This platform enables: 1) parallel, automated, long-term ( approximately days to weeks), live-cell microscopy of single cells in culture; 2) tracking of individual cell fates over time (proliferation, apoptosis); and 3) correlation of differentiated progeny with founder clones. To achieve these goals, we used microfabrication techniques to create an array of approximately 10,000 microwells on a glass coverslip. The dimensions of the wells are tunable, ranging from 20 to >500 microm in diameter and 10-500 microm in height. The microarray can be coated with adhesive proteins and is integrated into a culture chamber that permits rapid (approximately min), addressable monitoring of each well using a standard programmable microscope stage. All cells share the same media (including paracrine survival signals), as opposed to cells in multiwell formats. The incorporation of a coverslip as a substrate also renders the platform compatible with conventional, high-magnification light and fluorescent microscopy. We validated this approach by analyzing the proliferation dynamics of a heterogeneous adult rat neural stem cell population. Using this platform, one can further interrogate the response of distinct stem cell subpopulations to microenvironmental cues (mitogens, cell-cell interactions, and cell-extracellular matrix interactions) that govern their behavior. In the future, the platform may also be adapted for the study of other cell types by tailoring the surface coatings, microwell dimensions, and culture environment, thereby enabling parallel investigation of many distinct cellular responses.

Cell Count↗

RNaseCut: a MALDI mass spectrometry-based method for SNP discovery.

MALDI mass spectrometry is an established platform for high-throughput genotyping of single nucleotide polymorphisms (SNPs). For many species and also for specific ethnic groups, the number of described SNPs is far from sufficient. Here we present a method for SNP discovery that can use existing MALDI genotyping platforms and is automation-compatible. The method is based on in vitro RNA transcripts from PCR products, that can be used to obtain highly informative sequence fingerprints by digestion with the guanosine- specific ribonuclease T1. In these fingerprints, a mutation can be detected as either a mass shift, absence of an existing peak or appearance of an additional peak. Due to mass-degeneracy of fragments and multiple presence of shorter fragments in a given sequence, a certain fraction of possible mutations will remain undetected with this method. Screening of both strands from one PCR product is possible by using T3- and T7-tailed primers and the respective RNA polymerases, and markedly decreases the probability of missing an existing SNP. The use of mass-shifted nucleotides can significantly reduce fragment overlaps and hence increase detectability. We have used a simulation of RNase digests of a set of randomly generated sequences to provide estimates for the general detection probability in dependence on PCR product length. A software package is provided that helps to design PCR primers by plotting out regions with a high SNP discovery score, calculates expected mass fingerprints and peaklists from the target sequence selected for screening and helps in interpretation of digest spectra.

Animals↗

Single-cell and spatial transcriptomic technologies for lung cancer tumor microenvironment analysis.

Lung cancer remains one of the leading causes of cancer-related mortality worldwide; beyond its rising incidence, its marked molecular heterogeneity and complex tumor microenvironment (TME) hinder treatment response and drive resistance, contributing directly to its high mortality rate. Single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) provide complementary approaches for dissecting these features. scRNA-seq enables high-resolution analysis of cellular diversity and transcriptional states but requires tissue dissociation and therefore loses spatial context. In contrast, ST preserves tissue architecture and provides insights into how gene-expression programs within the TME are organized, although no currently available spatial platform combines whole-transcriptome coverage with true single-cell resolution over large tissue areas. Together, these technologies have enabled detailed mapping of tumor, immune and stromal populations and of their spatial interactions, revealing functionally distinct cellular niches that contribute to immune evasion, metastasis and response to therapy. In this narrative review we organize the primary literature around a single question, how spatially structured cellular ecosystems, rather than individual cell types, determine therapeutic response and resistance in lung cancer - and we explicitly separate observations that are reproducible across independent cohorts and platforms from those that remain confined to single studies. We further summarize the technical, analytical and logistic barriers that currently prevent spatially resolved signatures from entering routine diagnostic pathology. Understanding dysregulated pathways and spatially constrained intercellular communication within the TME helps identify candidate biomarkers and may support the identification of therapeutic approaches directed at tumor-intrinsic programs as well as at microenvironment-driven resistance mechanisms.

Cell-cell communication↗

Postural instability of extremely obese individuals improves after a body weight reduction program entailing specific balance training.

The purposes of this study were to compare postural stability between obese and lean subjects and to investigate the effect of a 3-week body weight reduction (BWR) program entailing specific balance training on postural stability of extremely obese patients. Time of balance maintenance and mean error on the medial-lateral direction at the trunk and lower limb level were assessed during a single limb stance on a movable platform in 19 non-obese and in 20 extremely obese individuals (age range: 20-40 yr). Time of balance maintenance was shorter (obese: 21.1+/-7.7 vs lean: 27.3+/-3.1 sec) and medial-lateral sway of the trunk was larger in obese (5.4+/-3.2 degrees) than in lean (3.2+/-1.1 degrees) subjects (p<0.05). Two subgroups of obese subjects were also tested after a BWR program (energy-restricted diet, moderate physical exercise, nutritional education and psychological counselling) combined with or without 6 sessions of specific balance training on a movable platform. BWR plus specific balance training enhanced time of balance maintenance (pre: 23.8+/-7.2 vs post: 30.0+/-0.0 sec) and reduced the trunk sway (5.2+/-2.8 degrees vs 2.6+/-0.9 degrees ) more than BWR alone (p<0.05). The present findings indicate that extremely obese individuals have inadequate postural stability (compared to their lean counterparts) that could however be improved by few sessions of specific balance training incorporated into a multidisciplinary BWR program. It was concluded that balance improvement is an important goal of rehabilitation, that would probably reduce the propensity of overweight individuals to fall while performing everyday activities.

Adult↗