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1.
Opt Express ; 30(16): 29189-29205, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-36299099

ABSTRACT

The ability of a microscope to rapidly acquire wide-field, high-resolution images is limited by both the optical performance of the microscope objective and the bandwidth of the detector. The use of multiple detectors can increase electronic-acquisition bandwidth, but the use of multiple parallel objectives is problematic since phase coherence is required across the multiple apertures. We report a new synthetic-aperture microscopy technique based on Fourier ptychography, where both the illumination and image-space numerical apertures are synthesized, using a spherical array of low-power microscope objectives that focus images onto mutually incoherent detectors. Phase coherence across apertures is achieved by capturing diffracted fields during angular illumination and using ptychographic reconstruction to synthesize wide-field, high-resolution, amplitude and phase images. Compared to conventional Fourier ptychography, the use of multiple objectives reduces image acquisition times by increasing the area for sampling the diffracted field. We demonstrate the proposed scaleable architecture with a nine-objective microscope that generates an 89-megapixel, 1.1 µm resolution image nine-times faster than can be achieved with a single-objective Fourier-ptychographic microscope. New calibration procedures and reconstruction algorithms enable the use of low-cost 3D-printed components for longitudinal biological sample imaging. Our technique offers a route to high-speed, gigapixel microscopy, for example, imaging the dynamics of large numbers of cells at scales ranging from sub-micron to centimetre, with an enhanced possibility to capture rare phenomena.

2.
Int J Biol Macromol ; 262(Pt 1): 129434, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38232877

ABSTRACT

The field of cancer therapy is advancing rapidly, placing a crucial emphasis on innovative drug delivery systems. The increasing global impact of cancer highlights the need for creative therapeutic strategies. Natural polymer-based nanotherapeutics have emerged as a captivating avenue in this pursuit, drawing substantial attention due to their inherent attributes. These attributes include biodegradability, biocompatibility, negligible toxicity, extended circulation time, and a wide range of therapeutic payloads. The unique size, shape, and morphological characteristics of these systems facilitate profound tissue penetration, complementing active and passive targeting strategies. Moreover, these nanotherapeutics exploit specific cellular and subcellular trafficking pathways, providing precise control over drug release kinetics. This comprehensive review emphasizes the utilization of naturally occurring polymers such as polysaccharides (e.g., chitosan, hyaluronic acid, alginates, dextran, and cyclodextrin) and protein-based polymers (e.g., ferritin, gelatin, albumin) as the foundation for nanoparticle development. The paper meticulously examines their in vitro characteristics alongside in vivo efficacy, particularly focusing on their pivotal role in ameliorating diverse types of solid tumors within cancer therapy. The amalgamation of material science ingenuity and biological insight has led to the formulation of these nanoparticles, showcasing their potential to reshape the landscape of cancer treatment.


Subject(s)
Chitosan , Nanoparticles , Neoplasms , Humans , Polymers/therapeutic use , Drug Delivery Systems , Neoplasms/drug therapy , Polysaccharides/therapeutic use , Chitosan/therapeutic use
3.
Int J Pharm ; 660: 124346, 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-38889853

ABSTRACT

Breast cancer, the second leading global cause of death, affects 2.1 million women annually, with an alarming 15 percent mortality rate. Among its diverse forms, Triple-negative breast cancer (TNBC) emerges as the deadliest, characterized by the absence of hormone receptors. This article underscores the urgent need for innovative treatment approaches in tackling TNBC, emphasizing the transformative potential of polymeric nanomaterials (PNMs). Evolved through nanotechnology, PNMs offer versatile biomedical applications, particularly in addressing the intricate challenges of TNBC. The synthesis methods of PNMs, explored within the tumor microenvironment using cellular models, showcase their dynamic nature in cancer treatment. The article anticipates the future of TNBC therapeutics through the optimization of PNMs-based strategies, integrating them into photothermal (PT), photodynamic (PT), and hyperthermia therapy (HTT), drug delivery, and active tumor targeting strategies. Advancements in synthetic methods, coupled with a nuanced understanding of the tumor microenvironment, hold promise for personalized interventions. Comparative investigations of therapeutic models and a thorough exploration of polymeric nanoplatforms toxicological perspectives become imperative for ensuring efficacy and safety. We have explored the interdisciplinary collaboration between nanotechnology, oncology, and molecular biology as pivotal in translating PNMs innovations into tangible benefits for TNBC patients.


Subject(s)
Nanostructures , Polymers , Triple Negative Breast Neoplasms , Triple Negative Breast Neoplasms/therapy , Humans , Nanostructures/chemistry , Nanostructures/administration & dosage , Polymers/chemistry , Female , Animals , Theranostic Nanomedicine/methods , Drug Delivery Systems/methods , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Tumor Microenvironment/drug effects , Hyperthermia, Induced/methods
4.
Sci Adv ; 10(28): eadn4824, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38985872

ABSTRACT

Molecular chaperones are central to the maintenance of proteostasis in living cells. A key member of this protein family is trigger factor (TF), which acts throughout the protein life cycle and has a ubiquitous role as the first chaperone encountered by proteins during synthesis. However, our understanding of how TF achieves favorable interactions with such a diverse substrate base remains limited. Here, we use microfluidics to reveal the thermodynamic determinants of this process. We find that TF binding to empty 70S ribosomes is enthalpy-driven, with micromolar affinity, while nanomolar affinity is achieved through a favorable entropic contribution for both intrinsically disordered and folding-competent nascent chains. These findings suggest a general mechanism for cotranslational TF function, which relies on occupation of the exposed TF-substrate binding groove rather than specific complementarity between chaperone and nascent chain. These insights add to our wider understanding of how proteins can achieve broad substrate specificity.


Subject(s)
Protein Binding , Thermodynamics , Substrate Specificity , Protein Biosynthesis , Escherichia coli Proteins/metabolism , Escherichia coli Proteins/chemistry , Escherichia coli Proteins/genetics , Ribosomes/metabolism , Protein Folding , Peptidylprolyl Isomerase
5.
bioRxiv ; 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-39005454

ABSTRACT

Understanding how circuits in the brain simultaneously coordinate their activity to mediate complex ethnologically relevant behaviors requires recording neural activities from distributed populations of neurons in freely behaving animals. Current miniaturized imaging microscopes are typically limited to imaging a relatively small field of view, precluding the measurement of neural activities across multiple brain regions. Here we present a miniaturized micro-camera array microscope (mini-MCAM) that consists of four fluorescence imaging micro-cameras, each capable of capturing neural activity across a 4.5 mm x 2.55 mm field of view (FOV). Cumulatively, the mini-MCAM images over 30 mm 2 area of sparsely expressed GCaMP6s neurons distributed throughout the dorsal cortex, in regions including the primary and secondary motor, somatosensory, visual, retrosplenial, and association cortices across both hemispheres. We demonstrate cortex-wide cellular resolution in vivo Calcium (Ca 2+ ) imaging using the mini-MCAM in both head-fixed and freely behaving mice.

6.
IEEE Trans Image Process ; 32: 5138-5152, 2023.
Article in English | MEDLINE | ID: mdl-37676804

ABSTRACT

Perceptual video quality assessment (VQA) is an integral component of many streaming and video sharing platforms. Here we consider the problem of learning perceptually relevant video quality representations in a self-supervised manner. Distortion type identification and degradation level determination is employed as an auxiliary task to train a deep learning model containing a deep Convolutional Neural Network (CNN) that extracts spatial features, as well as a recurrent unit that captures temporal information. The model is trained using a contrastive loss and we therefore refer to this training framework and resulting model as CONtrastive VIdeo Quality EstimaTor (CONVIQT). During testing, the weights of the trained model are frozen, and a linear regressor maps the learned features to quality scores in a no-reference (NR) setting. We conduct comprehensive evaluations of the proposed model against leading algorithms on multiple VQA databases containing wide ranges of spatial and temporal distortions. We analyze the correlations between model predictions and ground-truth quality ratings, and show that CONVIQT achieves competitive performance when compared to state-of-the-art NR-VQA models, even though it is not trained on those databases. Our ablation experiments demonstrate that the learned representations are highly robust and generalize well across synthetic and realistic distortions. Our results indicate that compelling representations with perceptual bearing can be obtained using self-supervised learning.

7.
Stem Cell Res ; 73: 103211, 2023 12.
Article in English | MEDLINE | ID: mdl-37890334

ABSTRACT

The most common cause of autosomal recessive familial Parkinson's disease (PD) are mutations in the PRKN/PARK2 gene encoding an E3 ubiquitin protein-ligase PARKIN. We report the generation of an iPSC cell line from the fibroblasts of a male PD patient carrying a common missense variant in exon 7 (p.Arg275Trp), and a 133 kb deletion encompassing exon 8, using transiently-present Sendai virus. The established line displays typical human primed iPSC morphology and expression of pluripotency-associated markers, normal karyotype without SNP array-detectable copy number variations and can give rise to derivatives of all three embryonic germ layers. We envisage the usefulness of this iPSC line, carrying a common and well-studied missense mutation in the RING1 domain of the PARKIN protein, for the elucidation of PARKIN-dependent mechanisms of PD using in vitro and in vivo models.


Subject(s)
Induced Pluripotent Stem Cells , Parkinson Disease , Humans , Male , Induced Pluripotent Stem Cells/metabolism , Parkinson Disease/genetics , Parkinson Disease/metabolism , DNA Copy Number Variations , Mutation/genetics , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism
8.
Nat Photonics ; 17(5): 442-450, 2023 May.
Article in English | MEDLINE | ID: mdl-37808252

ABSTRACT

Wide field of view microscopy that can resolve 3D information at high speed and spatial resolution is highly desirable for studying the behaviour of freely moving model organisms. However, it is challenging to design an optical instrument that optimises all these properties simultaneously. Existing techniques typically require the acquisition of sequential image snapshots to observe large areas or measure 3D information, thus compromising on speed and throughput. Here, we present 3D-RAPID, a computational microscope based on a synchronized array of 54 cameras that can capture high-speed 3D topographic videos over an area of 135 cm2, achieving up to 230 frames per second at spatiotemporal throughputs exceeding 5 gigapixels per second. 3D-RAPID employs a 3D reconstruction algorithm that, for each synchronized snapshot, fuses all 54 images into a composite that includes a co-registered 3D height map. The self-supervised 3D reconstruction algorithm trains a neural network to map raw photometric images to 3D topography using stereo overlap redundancy and ray-propagation physics as the only supervision mechanism. The resulting reconstruction process is thus robust to generalization errors and scales to arbitrarily long videos from arbitrarily sized camera arrays. We demonstrate the broad applicability of 3D-RAPID with collections of several freely behaving organisms, including ants, fruit flies, and zebrafish larvae.

9.
ArXiv ; 2023 Jan 19.
Article in English | MEDLINE | ID: mdl-36713250

ABSTRACT

To study the behavior of freely moving model organisms such as zebrafish (Danio rerio) and fruit flies (Drosophila) across multiple spatial scales, it would be ideal to use a light microscope that can resolve 3D information over a wide field of view (FOV) at high speed and high spatial resolution. However, it is challenging to design an optical instrument to achieve all of these properties simultaneously. Existing techniques for large-FOV microscopic imaging and for 3D image measurement typically require many sequential image snapshots, thus compromising speed and throughput. Here, we present 3D-RAPID, a computational microscope based on a synchronized array of 54 cameras that can capture high-speed 3D topographic videos over a 135-cm^2 area, achieving up to 230 frames per second at throughputs exceeding 5 gigapixels (GPs) per second. 3D-RAPID features a 3D reconstruction algorithm that, for each synchronized temporal snapshot, simultaneously fuses all 54 images seamlessly into a globally-consistent composite that includes a coregistered 3D height map. The self-supervised 3D reconstruction algorithm itself trains a spatiotemporally-compressed convolutional neural network (CNN) that maps raw photometric images to 3D topography, using stereo overlap redundancy and ray-propagation physics as the only supervision mechanism. As a result, our end-to-end 3D reconstruction algorithm is robust to generalization errors and scales to arbitrarily long videos from arbitrarily sized camera arrays. The scalable hardware and software design of 3D-RAPID addresses a longstanding problem in the field of behavioral imaging, enabling parallelized 3D observation of large collections of freely moving organisms at high spatiotemporal throughputs, which we demonstrate in ants (Pogonomyrmex barbatus), fruit flies, and zebrafish larvae.

10.
J Oral Rehabil ; 39(10): 737-43, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22631608

ABSTRACT

The aim of the present investigation was to assess the psychological profile of a sample of patients with temporomandibular disorders (TMD) and to compare the psychometric scores between patients with pain of different diffusion, location, intensity and duration. One hundred and ten (N = 110) patients with painful TMD fulfilled three psychometric instruments. Pain features were assessed as categorical variables as concerns its diffusion, viz., diffuse or localised, duration, viz., more or <6 months, and location, viz., joint and/or muscles. Pain intensity was scored on a 0-100 Visual Analog Scale (VAS) rating. Patients with diffuse pain showed higher psychometric scores than patients with localised pain. No significant differences were detected between patients with pain lasting from more or equal than 6 months and those with pain lasting from <6 months as well as between patients with pain localised in the jaw muscles, joints or both, even if a trend for lower scores for patients with joint pain alone was observed. Pain intensity was significantly related with anxiety (ANX), depression (DEP) and somatisation(SOM) scores. In conclusion, pain diffusion and intensity were strongly related with high levels of SOM, ANX and DEP, while no differences in psychometric scores were detected between patients with pain of different duration and location.


Subject(s)
Arthralgia/psychology , Facial Pain/psychology , Temporomandibular Joint Dysfunction Syndrome/psychology , Adult , Anxiety Disorders/complications , Anxiety Disorders/psychology , Arthralgia/complications , Depressive Disorder/complications , Depressive Disorder/psychology , Facial Pain/complications , Female , Humans , Male , Middle Aged , Pain Measurement/methods , Psychometrics , Somatoform Disorders/complications , Somatoform Disorders/psychology , Temporomandibular Joint Dysfunction Syndrome/complications
11.
IEEE Trans Image Process ; 31: 4149-4161, 2022.
Article in English | MEDLINE | ID: mdl-35700254

ABSTRACT

We consider the problem of obtaining image quality representations in a self-supervised manner. We use prediction of distortion type and degree as an auxiliary task to learn features from an unlabeled image dataset containing a mixture of synthetic and realistic distortions. We then train a deep Convolutional Neural Network (CNN) using a contrastive pairwise objective to solve the auxiliary problem. We refer to the proposed training framework and resulting deep IQA model as the CONTRastive Image QUality Evaluator (CONTRIQUE). During evaluation, the CNN weights are frozen and a linear regressor maps the learned representations to quality scores in a No-Reference (NR) setting. We show through extensive experiments that CONTRIQUE achieves competitive performance when compared to state-of-the-art NR image quality models, even without any additional fine-tuning of the CNN backbone. The learned representations are highly robust and generalize well across images afflicted by either synthetic or authentic distortions. Our results suggest that powerful quality representations with perceptual relevance can be obtained without requiring large labeled subjective image quality datasets. The implementations used in this paper are available at https://github.com/pavancm/CONTRIQUE.

12.
Exp Neurol ; 358: 114219, 2022 12.
Article in English | MEDLINE | ID: mdl-36055392

ABSTRACT

Donor cell age can have a significant impact on transplantation outcomes. Despite the rapid advancement of human pluripotent stem cell (hPSC)-derived dopaminergic (DA) progenitors to the clinic for transplantation into Parkinson's Disease (PD), surprisingly limited data exists regarding the influence of cellular age on neural graft survival, composition, and integration. Here we examined the impact of transplanting ventral midbrain (VM) progenitors at varying days of differentiation (from day 13-30) into a rodent PD model, comparing two hPSC lines (an embryonic and an induced pluripotent cell line, hESC and hiPSC, respectively). Both hPSC lines expressed GFP under the promoter PITX3 enabling specific tracking of graft-derived DA neurons. Post-mortem analysis at 6 months revealed larger grafts from Day19 (D19), D22 and D25 progenitors, yet contained a higher proportion of non-DA and poorly specified (FOXA2-) cells. While D13 and D30 progenitors yielded smaller grafts. D13-derived grafts had the highest DA neuron proportion and proportionally more GIRK2+ DA neurons, the subpopulation critical for motor function. These younger progenitor grafts maintained their capacity to innervate developmentally relevant DA targets, with increased innervation capacity per DA neuron, collectively resulting in restoration of motor deficits with equal or greater proficiency than older donor cells. While donor age effects were reproducible for a given hPSC line and trends were similar between the two hPSC lines, grafts of D13 hiPSC-derived progenitors showed a 6-fold greater density of DA neurons compared to D13 hESC-derived grafts, highlighting between-line variability. These findings show that hPSC-derived VM donor age has a direct impact on graft survival, composition and maturation, and that careful assessment, on a line-to-line basis is required prior to translation.


Subject(s)
Parkinson Disease , Pluripotent Stem Cells , Animals , Cell Differentiation/physiology , Dopamine/metabolism , Dopaminergic Neurons/metabolism , Humans , Mesencephalon/metabolism , Parkinson Disease/metabolism , Parkinson Disease/surgery , Rodentia/metabolism , Stem Cell Transplantation/methods
13.
Elife ; 112022 12 14.
Article in English | MEDLINE | ID: mdl-36515989

ABSTRACT

The dynamics of living organisms are organized across many spatial scales. However, current cost-effective imaging systems can measure only a subset of these scales at once. We have created a scalable multi-camera array microscope (MCAM) that enables comprehensive high-resolution recording from multiple spatial scales simultaneously, ranging from structures that approach the cellular scale to large-group behavioral dynamics. By collecting data from up to 96 cameras, we computationally generate gigapixel-scale images and movies with a field of view over hundreds of square centimeters at an optical resolution of 18 µm. This allows us to observe the behavior and fine anatomical features of numerous freely moving model organisms on multiple spatial scales, including larval zebrafish, fruit flies, nematodes, carpenter ants, and slime mold. Further, the MCAM architecture allows stereoscopic tracking of the z-position of organisms using the overlapping field of view from adjacent cameras. Overall, by removing the bottlenecks imposed by single-camera image acquisition systems, the MCAM provides a powerful platform for investigating detailed biological features and behavioral processes of small model organisms across a wide range of spatial scales.


Subject(s)
Microscopy , Zebrafish , Animals , Microscopy/methods
14.
IEEE Trans Image Process ; 30: 7446-7457, 2021.
Article in English | MEDLINE | ID: mdl-34449359

ABSTRACT

We consider the problem of conducting frame rate dependent video quality assessment (VQA) on videos of diverse frame rates, including high frame rate (HFR) videos. More generally, we study how perceptual quality is affected by frame rate, and how frame rate and compression combine to affect perceived quality. We devise an objective VQA model called Space-Time GeneRalized Entropic Difference (GREED) which analyzes the statistics of spatial and temporal band-pass video coefficients. A generalized Gaussian distribution (GGD) is used to model band-pass responses, while entropy variations between reference and distorted videos under the GGD model are used to capture video quality variations arising from frame rate changes. The entropic differences are calculated across multiple temporal and spatial subbands, and merged using a learned regressor. We show through extensive experiments that GREED achieves state-of-the-art performance on the LIVE-YT-HFR Database when compared with existing VQA models. The features used in GREED are highly generalizable and obtain competitive performance even on standard, non-HFR VQA databases. The implementation of GREED has been made available online: https://github.com/pavancm/GREED.

15.
Pharmacogenomics J ; 10(5): 408-17, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20029385

ABSTRACT

Atypical antipsychotics (APDs) are currently used in clinical practice for a variety of mental disorders such as schizophrenia, bipolar disorder and severe behavioral disturbances. A well-known disadvantage of using these compounds is a propensity for weight gain, resulting frequently in obesity. The mechanisms underlying pharmacologically induced weight gain are still controversial. The objective of this study was to evaluate in vitro the effects of different APDs on adipogenic events in cultured human pre-adipocytes and in rat muscle-derived stem cells (MDSCs), aiming to identify a common intracellular event contributable to these drugs. Culture behavior was evaluated in terms of cell proliferation, lipid accumulation, gene expression and morphological features. Results indicate that APDs influence adipogenic events through changes in the differentiation and proliferation of pre-adipocytes and MDSCs that are brought on by protein kinase C-ß (PKC-ß) activation. These data identify a signaling route that could be a potential target of pharmacological approaches for preventing the weight gain associated with APD treatment.


Subject(s)
Adipocytes/drug effects , Adipogenesis/drug effects , Antipsychotic Agents/adverse effects , Protein Kinase C/metabolism , Stem Cells/drug effects , Weight Gain/drug effects , Adipocytes/cytology , Adipocytes/enzymology , Adipogenesis/genetics , Animals , Animals, Newborn , Cell Culture Techniques , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Enzyme Activation , Gene Expression/drug effects , Gene Silencing/drug effects , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/genetics , Protein Kinase C beta , RNA, Small Interfering/genetics , RNA, Small Interfering/pharmacology , Rats , Stem Cells/cytology , Stem Cells/enzymology , Weight Gain/genetics
16.
Science ; 151(3717): 1556-8, 1966 Mar 25.
Article in English | MEDLINE | ID: mdl-17730085

ABSTRACT

The main effects of two infections, one by a protozoan and the other by a virus, in cells of Rhynchosciara angelae (Diptera, Sciaridae) are an increase in cell size and changes in the size, shape, and behavior of the chromosomes. The X chromosome of some cells reacts differently from the autosome to the protozoan infection. Some chromosomes show specific, easily traceable points after infection by the virus. Some of the effects of these infections may be similar to the effects of infective agents in other organisms.

17.
J Oral Rehabil ; 36(3): 193-8, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19207446

ABSTRACT

The aim of the present investigation is to test the null hypothesis that the presence of psychopathology in patients with temporomandibular disorders (TMD) is related to the presence of pain, independent of its location [(i.e. myofascial and/or temporomandibular joint (TMJ) pain]. Ninety-six (n = 96) patients affected by painful TMD underwent a clinical assessment in accordance with the research diagnostic criteria for TMD (RDC/TMD) guidelines and filled out the Symptoms Check List - Revised (SCL-90-R) instrument to investigate the presence of symptoms of psychopathology. Patients with myofascial pain, alone or combined with TMJ pain, endorsed the highest scores in all SCL-90-R scales and showed the highest percentage of abnormal values in the depression (DEP) and somatization (SOM) scales for the assessment of depressive and somatization symptoms. Nonetheless, anova revealed no significant differences between groups in any of the SCL-90-R scales, except than in the Positive Symptom Total Index (F = 3.463; P = 0.035), and the chi-squared test did not detect any significant differences between groups for the prevalence of abnormal scores in the DEP and SOM scales. The existence of a close association between pain and psychosocial disorders in TMD patients was supported by the present study. The null hypothesis is that no differences exist between patients with different painful TMD cannot be fully accepted for the presence of psychosocial disorders because of the trend evidencing higher SCL-90-R scores for myofascial pain patients, alone or combined with TMJ pain, with respect to TMJ pain alone.


Subject(s)
Facial Neuralgia/psychology , Mental Disorders/etiology , Temporomandibular Joint Dysfunction Syndrome/psychology , Adult , Arthralgia/psychology , Depressive Disorder/etiology , Female , Humans , Male , Middle Aged , Psychiatric Status Rating Scales , Somatoform Disorders/etiology , Young Adult
18.
Sci Rep ; 9(1): 7457, 2019 05 15.
Article in English | MEDLINE | ID: mdl-31092867

ABSTRACT

The revolution in low-cost consumer photography and computation provides fertile opportunity for a disruptive reduction in the cost of biomedical imaging. Conventional approaches to low-cost microscopy are fundamentally restricted, however, to modest field of view (FOV) and/or resolution. We report a low-cost microscopy technique, implemented with a Raspberry Pi single-board computer and color camera combined with Fourier ptychography (FP), to computationally construct 25-megapixel images with sub-micron resolution. New image-construction techniques were developed to enable the use of the low-cost Bayer color sensor, to compensate for the highly aberrated re-used camera lens and to compensate for misalignments associated with the 3D-printed microscope structure. This high ratio of performance to cost is of particular interest to high-throughput microscopy applications, ranging from drug discovery and digital pathology to health screening in low-income countries. 3D models and assembly instructions of our microscope are made available for open source use.

19.
Methods Find Exp Clin Pharmacol ; 9(11): 739-47, 1987 Nov.
Article in English | MEDLINE | ID: mdl-3129626

ABSTRACT

The muscular response to pharmacological agents is directly dependent on intracellular ionic calcium (Ca2+) and is modulated by membrane permeability and cation-binding to subcellular organelles. The isometric contraction of the ventral guinea-pig taenia coli was registered in a bath with a Rich KCl-Ringer in the absence of Ca2+ and sodium (Na+) with or without EDTA or Sammarium (Sm3+). Our experimental sequence was based on alternate succession between the concentration-response-curves or decay-curves procedure to acetylcholine and barium (Ba2+) in the same preparation. It was found that a contracture elicited by barium ion was not significantly affected by inclusion of EDTA (.01 mM) or Sm3+ (.06 mM). Also, prior exposure of the depolarized muscle to acetylcholine did not affect the barium response. However, prior exposure of the muscle to acetylcholine sensitized the barium-induced contracture to the inhibitory actions of EDTA and Sm3+. Prior exposure of the muscle to barium ions strongly reduced the mechanical response to acetylcholine. In addition, tension recorded during an acetylcholine decay curve was observed to be reduced by EDTA and Sm3+, although some degree of tension could be elicited by acetylcholine even after the depolarized muscle had been exposed to EDTA or Sm3+ up to 70 min. The suggestion is put forward that barium ions mobilize intracellular stores of calcium which may be restored from calcium pools that are mobilized by acetylcholine, EDTA and Sm3+. Acetylcholine would be able to mobilize calcium ions from a firmly bound membrane store and additional less firmly bound membrane stores.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Calcium/metabolism , Muscle, Smooth/metabolism , Acetylcholine/pharmacology , Animals , Barium/pharmacology , Colon/drug effects , Colon/metabolism , Edetic Acid/pharmacology , Guinea Pigs , In Vitro Techniques , Models, Biological , Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Samarium/pharmacology
20.
J Hum Lact ; 15(2): 125-30, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10578788

ABSTRACT

Sore and cracked nipples are common and may represent an obstacle to successful breastfeeding. In Italy, it is customary for health professionals to prescribe some type of ointment to prevent or treat sore and cracked nipples. The efficacy of these ointments is insufficiently documented. The incidence of sore and cracked nipples was compared between mothers given routine nipple care, including an ointment (control group), and mothers instructed to avoid the use of nipple creams and other products (intervention group). Breastfeeding duration was also compared between the two groups. Eligible mothers were randomly assigned, after informed consent, to one of the two groups. No difference was found between the control (n = 96) and the intervention group (n = 123) in the incidence of sore and cracked nipples and in breastfeeding duration. However, several factors were associated with sore nipples and with breastfeeding duration. The use of a pacifier and of a feeding bottle in the hospital were both associated with sore nipples at discharge (p = 0.02 and p = 0.03, respectively). Full breastfeeding up to 4 months postpartum was significantly associated with the following early practices: breastfeeding on demand, rooming-in at least 20 hours/day, non-use of formula and pacifier, no test-weighing at each breastfeed. The incidence of sore and cracked nipples and the duration of breastfeeding were not influenced by the use of a nipple ointment. Other interventions, such as providing the mother with guidance and support on positioning and latching, and modifications of hospital practices may be more effective in reducing nipple problems.


Subject(s)
Breast Feeding/adverse effects , Emollients/therapeutic use , Nipples/injuries , Pain/etiology , Pain/prevention & control , Skin Care/methods , Adult , Breast Feeding/statistics & numerical data , Female , Humans , Mothers/education , Ointments
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