scholarly journals Does the claustrum have a function? Lessons from human lesion and animal studies point to divergent multifunctionality

2021 ◽  
Author(s):  
Huriye Atilgan ◽  
Max Doody ◽  
David K Oliver ◽  
Thomas M McGrath ◽  
Andrew M Shelton ◽  
...  
Keyword(s):  
Animal Studies ◽  
Animal Experiments ◽  
Experimental Studies ◽  
Signs And Symptoms ◽  
Global Function ◽  
Motor Abilities ◽  
Neural Processes ◽  
Wide Range ◽  
Functional Implications ◽  
Lesion Studies

The claustrum is the most densely interconnected region in the human brain. Despite the accumulating data from clinical and experimental studies, the functional role(s) of the claustrum remain unknown. Here, we systematically review claustrum lesion studies and discuss their functional implications. Claustral lesions are associated with an array of signs and symptoms, including changes in cognitive, perceptual and motor abilities; electrical activity; mental state; and sleep. The wide range of symptoms observed following claustral lesions suggests that the claustrum may either have a number of distinct functions, or a global function that impacts many neural processes. We further discuss the implications of these lesions in the context of recent evidence linking the claustrum to sensory perception, sleep, and salience as well as highlighting an underexplored link between the claustrum and pain. We hypothesize that the claustrum is connected to multiple brain networks, both ancient and advanced, which underly fundamental functions as well as higher cognitive processes. Extensive evidence derived from human lesion studies and animal experiments provides unequivocal evidence for a key function of the claustrum as a multifunctional node in numerous networks.

scholarly journals Animal Experiments Using Rotator Cuff

2014 ◽  
Vol 17 (2) ◽  
pp. 84-90 ◽  
Author(s):  
Seok Won Chung ◽  
Sae Hoon Kim ◽  
Joo Han Oh
Keyword(s):  
Rotator Cuff ◽  
Animal Studies ◽  
Animal Experiments ◽  
Experimental Studies ◽  
Experimental Models ◽  
Complete Understanding ◽  
Experimental Animals

In conducting animal studies using rotator cuff, researchers should select the appropriate types of animals and experimental models. This should also be followed by complete understanding of the selected experimental animals as well as the methods for evaluating the results. Thus, researchers could minimize errors and failure in conducting animal experimental studies. Further, this will provide a basis of establishing new idea and theory about rotator cuff diseases.

scholarly journals To Cull or Not To Cull? Considerations for Studies of Endocrine-Disrupting Chemicals

Endocrinology ◽  
2016 ◽  
Vol 157 (7) ◽  
pp. 2586-2594 ◽  
Author(s):  
Alexander Suvorov ◽  
Laura N. Vandenberg
Keyword(s):  
Laboratory Animal ◽  
Animal Studies ◽  
Metabolic Diseases ◽  
Endocrine Disrupting Chemicals ◽  
Animal Experiments ◽  
Postnatal Growth ◽  
Increased Risk ◽  
Wide Range ◽  
Endocrine Disrupting ◽  
Health Related

The power of animal models is derived from the ability to control experimental variables so that observed effects may be unequivocally attributed to the factor that was changed. One variable that is difficult to control in animal experiments is the number and composition of offspring in a litter. To account for this variability, artificial equalization of the number of offspring in a litter (culling) is often used. The rationale for culling, however, has always been controversial. The Developmental Origins of Health and Disease concept provides a new context to evaluate the pros and cons of culling in laboratory animal studies, especially in the context of endocrine-disrupting chemicals. Emerging evidence indicates that culling, especially of large litters, can drastically change the feeding status of a pup, which can result in compensatory growth with long-term consequences for the animal, including increased risk of cardio-metabolic diseases. Similarly, culling of litters to intentionally bias sex ratios can alter the animal's behavior and physiology, with effects observed on a wide range of outcomes. Thus, in an attempt to control for variability in developmental rates, culling introduces an uncontrolled or confounding variable, which itself may affect a broad spectrum of health-related consequences. Variabilities in culling protocols could be responsible for differences in responses to endocrine-disrupting chemicals reported across studies. Because litter sex composition and size are vectors that can influence both prenatal and postnatal growth, they are essential considerations for the interpretation of results from laboratory animal studies.

Integrating epidemiology and toxicology in neurotoxicity risk assessment

2007 ◽  
Vol 26 (4) ◽  
pp. 283-293 ◽  
Author(s):  
William K Boyes ◽  
Virginia C Moser ◽  
Andrew M Geller ◽  
Vernon A Benignus ◽  
Philip J Bushnell ◽  
...  
Keyword(s):  
Animal Studies ◽  
Meta Analysis ◽  
Scientific Information ◽  
Animal Experiments ◽  
Experimental Studies ◽  
Objective Evaluation ◽  
Neurological Status ◽  
Weight Of Evidence ◽  
Statistical Control ◽  
Epidemiology Studies

Neurotoxicity risk assessments depend on the best available scientific information, including data from animal toxicity studies, human experimental studies and human epidemiology studies. There are several factors to consider when evaluating the comparability of data from studies. Regarding the epidemiology literature, issues include choice of study design, use of appropriate controls, methods of exposure assessment, subjective or objective evaluation of neurological status, and assessment and statistical control of potential confounding factors, including co-exposure to other agents. Animal experiments must be evaluated regarding factors such as dose level and duration, procedures used to assess neurological or behavioural status, and appropriateness of inference from the animal model to human neurotoxicity. Major factors that may explain apparent differences between animal and human studies include: animal neurological status may be evaluated with different procedures than those used in humans; animal studies may involve shorter exposure durations and higher dose levels; and most animal studies evaluate a single substance whereas humans typically are exposed to multiple agents. The comparability of measured outcomes in animals and humans may be improved by considering functional domains rather than individual test measures. The application of predictive models, weight of evidence considerations and meta-analysis can help evaluate the consistency of outcomes across studies. An appropriate blend of scientific information from toxicology and epidemiology studies is necessary to evaluate potential human risks of exposure to neurotoxic substances. Human & Experimental Toxicology (2007) 26, 283-293

scholarly journals Mesenchymal stromal cells: what have we learned so far about their therapeutic potential and mechanisms of action?

2021 ◽  
Author(s):  
Francesco Amadeo ◽  
Katherine Trivino Cepeda ◽  
James Littlewood ◽  
Bettina Wilm ◽  
Arthur Taylor ◽  
...  
Keyword(s):  
Animal Models ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Animal Studies ◽  
Therapeutic Potential ◽  
Animal Experiments ◽  
Mechanisms Of Action ◽  
Clinical Translation ◽  
Beneficial Effects ◽  
Wide Range

Mesenchymal stromal cells (MSCs) have been found to be safe and effective in a wide range of animal models of human disease. MSCs have been tested in thousands of clinical trials, but results show that while these cells appear to be safe, they tend to lack efficacy. This has raised questions about whether animal models are useful for predicting efficacy in patients. However, a problem with animal studies is that there is a lack of standardisation in the models and MSC therapy regimes used; there appears to be publication bias towards studies reporting positive outcomes; and the reproducibility of results from animal experiments tends not to be confirmed prior to clinical translation. A further problem is that while some progress has been made towards investigating the mechanisms of action (MoA) of MSCs, we still fail to understand how they work. To make progress, it is important to ensure that prior to clinical translation, the beneficial effects of MSCs in animal studies are real and can be repeated by independent research groups. We also need to understand the MoA of MSCs to assess whether their effects are likely to be beneficial across different species. In this review, we give an overview of the current clinical picture of MSC therapies and discuss what we have learned from animal studies. We also give a comprehensive update of what we know about the MoA of MSCs, particularly in relation to their role in immunomodulation.

CLINICAL AND FORENSIC ASPECTS OF PHARMACOBEZOARS

2020 ◽  
Vol 12 ◽  
Author(s):  
Francisco Basílio ◽  
Ricardo Jorge Dinis-Oliveira
Keyword(s):  
State Of The Art ◽  
Signs And Symptoms ◽  
Immediate Release ◽  
Diagnosis And Treatment ◽  
Blood Concentrations ◽  
Forensic Practice ◽  
Wide Range ◽  
Therapeutic Doses ◽  
Complete History ◽  
Lethal Blood

Background: Pharmacobezoars are specific types of bezoars formed when medicines, such as tablets, suspensions, and/or drug delivery systems, aggregate and may cause death by occluding airways with tenacious material or by eluting drugs resulting in toxic or lethal blood concentrations. Objective: This work aims to fully review the state-of-the-art regarding pathophysiology, diagnosis, treatment and other relevant clinical and forensic features of pharmacobezoars. Results: patients of a wide range of ages and in both sexes present with signs and symptoms of intoxications or more commonly gastrointestinal obstructions. The exact mechanisms of pharmacobezoar formation are unknown but is likely multifactorial. The diagnosis and treatment depend on the gastrointestinal segment affected and should be personalized to the medication and the underlying factor. A good and complete history, physical examination, image tests, upper endoscopy and surgery through laparotomy of the lower tract are useful for diagnosis and treatment. Conclusion: Pharmacobezoars are rarely seen in clinical and forensic practice. They are related to controlled or immediate-release formulations, liquid or non-digestible substances, in normal or altered digestive motility/anatomy tract, and in overdoses or therapeutic doses, and should be suspected in the presence of risk factors or patients taking drugs which may form pharmacobezoars.

scholarly journals Image Statistics Preserving Encrypt-then-Compress Scheme Dedicated for JPEG Compression Standard

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 421
Author(s):  
Dariusz Puchala ◽  
Kamil Stokfiszewski ◽  
Mykhaylo Yatsymirskyy
Keyword(s):  
Statistical Analysis ◽  
Image Encryption ◽  
Experimental Studies ◽  
Quality Measures ◽  
Input Image ◽  
Jpeg Compression ◽  
Image Statistics ◽  
Compression Stage ◽  
Wide Range ◽  
The Impact

In this paper, the authors analyze in more details an image encryption scheme, proposed by the authors in their earlier work, which preserves input image statistics and can be used in connection with the JPEG compression standard. The image encryption process takes advantage of fast linear transforms parametrized with private keys and is carried out prior to the compression stage in a way that does not alter those statistical characteristics of the input image that are crucial from the point of view of the subsequent compression. This feature makes the encryption process transparent to the compression stage and enables the JPEG algorithm to maintain its full compression capabilities even though it operates on the encrypted image data. The main advantage of the considered approach is the fact that the JPEG algorithm can be used without any modifications as a part of the encrypt-then-compress image processing framework. The paper includes a detailed mathematical model of the examined scheme allowing for theoretical analysis of the impact of the image encryption step on the effectiveness of the compression process. The combinatorial and statistical analysis of the encryption process is also included and it allows to evaluate its cryptographic strength. In addition, the paper considers several practical use-case scenarios with different characteristics of the compression and encryption stages. The final part of the paper contains the additional results of the experimental studies regarding general effectiveness of the presented scheme. The results show that for a wide range of compression ratios the considered scheme performs comparably to the JPEG algorithm alone, that is, without the encryption stage, in terms of the quality measures of reconstructed images. Moreover, the results of statistical analysis as well as those obtained with generally approved quality measures of image cryptographic systems, prove high strength and efficiency of the scheme’s encryption stage.

Animal Experiments and their Alternatives in Psychiatry

1988 ◽  
Vol 15 (4) ◽  
pp. 313-318
Author(s):  
Anthony Stevens
Keyword(s):  
Animal Models ◽  
Human Study ◽  
Animal Experiments ◽  
Experimental Production ◽  
Potential Utility ◽  
Pharmacological Agents ◽  
Wide Range ◽  
Influential Paper ◽  
Adequate Data ◽  
Human Primate

During the last twenty years, the most enthusiastic advocates of the use of animal models in the study of human psychiatric dysfunction have been Harlow and Suomi. In an influential paper, Induced Depression in Monkeys (1974), they argued that more extensive use of non-human primates “would have great potential utility since many manipulations and measurements presently prohibited in human study by ethical and practical considerations could be readily performed on non-human primate subjects in well-controlled experimental environments.” Harlow & Suomi concluded this paper with the following statement: “The results obtained to date on induced depression in monkeys show that proper and profound depressions can be produced relatively easily by a variety of techniques. These induced depressions either bear a close resemblance to human depression or have such similarity as to suggest that closely correlated human and animal depressive patterns may be achieved with refined techniques. The results to date also provide adequate data for the conduct of meaningful researches on the effects of pharmacological agents which either enhance, inhibit or preclude the experimental production of depression. Further, the existence of firm and fast monkey depression syndromes offers vast opportunities for testing a wide range of therapeutic techniques, either behavioural or biochemical.”

scholarly journals Effects of electrical stimulation on isolated rodent gastric smooth muscle cells evaluated via a joint computational simulation and experimental approach

2009 ◽  
Vol 297 (4) ◽  
pp. G672-G680 ◽  
Author(s):  
P. Du ◽  
S. Li ◽  
G. O'Grady ◽  
L. K. Cheng ◽  
A. J. Pullan ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Electrical Stimulation ◽  
Pulse Train ◽  
Pulse Width ◽  
Computational Simulation ◽  
Minimum Energy ◽  
Experimental Studies ◽  
Single Pulse ◽  
Plateau Phase ◽  
Wide Range

Gastric electrical stimulation (GES) involves the delivery of electrical impulses to the stomach for therapeutic purposes. New GES protocols are needed that are optimized for improved motility outcomes and energy efficiency. In this study, a biophysically based smooth muscle cell (SMC) model was modified on the basis of experimental data and employed in conjunction with experimental studies to define the effects of a large range of GES protocols on individual SMCs. For the validation studies, rat gastric SMCs were isolated and subjected to patch-clamp analysis during stimulation. Experimental results were in satisfactory agreement with simulation results. The results define the effects of a wide range of GES parameters (pulse width, amplitude, and pulse-train frequency) on isolated SMCs. The minimum pulse width required to invoke a supramechanical threshold response from SMCs (defined at −30 mV) was 65 ms (at 250-pA amplitude). The minimum amplitude required to invoke this threshold was 75 pA (at 1,000-ms pulse width). The amplitude of the invoked response beyond this threshold was proportional to the stimulation amplitude. A high-frequency train of stimuli (40 Hz; 10 ms, 150 pA) could invoke and maintain the SMC plateau phase while requiring 60% less power and accruing ∼30% less intracellular Ca2+ concentration during the plateau phase than a comparable single-pulse protocol could in a demonstrated example. Validated computational simulations are an effective strategy for efficiently identifying effective minimum-energy GES protocols, and pulse-train protocols may also help to reduce the power consumption of future GES devices.

Assessment of needs for care among patients with schizophrenic disorders 15 and 17 years after first onset of psychosis

1997 ◽  
Vol 6 (S1) ◽  
pp. 21-28 ◽  
Author(s):  
Durk Wiersma ◽  
Fokko J. Nienhuis ◽  
Cees J. Slooff ◽  
Robert Giel ◽  
Aant De Jong
Keyword(s):  
Mental Disorders ◽  
Empirical Studies ◽  
Signs And Symptoms ◽  
Expected Improvement ◽  
Chronic Patients ◽  
Cross Sectional ◽  
Wide Range ◽  
Social Disablement ◽  
First Onset

Severe and long term mental disorders, like schizophrenia, show in general a wide range of psychiatric signs and symptoms, psychological and physiological impairments and social disablement (Shepherd, 1994; Wing, 1982) reflecting a variety of mental health needs. Many studies provide only a cross-sectional view of the clinical and social problems of the patient population, for example at intake or admission to a mental hospital. Longitudinal studies following patients after discharge for some period of months or years show in general the expected improvement of functioning (e.g. Nienhuis et al., 1994), but as far as only chronic patients are concerned such a positive change is much less noted. The concept of chronicity of mental disorders would presume that after some time needs are fairly predictable and stable and do not change much over time. Our investigation on the long-term course of schizophrenia (Wiersma et al., 1996; 1997) enables us to study over a period of two years, from 15 to 17 years since first onset of psychosis, the stability or variability of needs in schizophrenic disorder. We are not aware of empirical studies on changes in needs among patients with long-term disorders.

Experimental Studies on Cooling Effectiveness of the Double-Decker Air Jet Impingement With Film Outflow

2007 ◽  
Author(s):  
Junkui Mao ◽  
Wen Guo ◽  
Zhenxiong Liu ◽  
Jun Zeng
Keyword(s):  
Infrared Radiation ◽  
Experimental Studies ◽  
Jet Impingement ◽  
Experimental Results ◽  
Thermal Camera ◽  
Local Cooling ◽  
Cooling Effectiveness ◽  
Air Jet ◽  
Double Decker ◽  
Wide Range

Experiments were carried out to investigate the cooling effectiveness of a lamellar double-decker impingement/effusion structure. Infrared radiation (I.R.) thermal camera was used to measure the temperature on the outside surface of the lamellar double-decker. Experimental results were obtained for a wide range of governing parameters (blowing rate M (0.0017∼0.0066), the ratio of the jet impingement distance to the diameter of film hole H/D (0.5∼1.25), the ratio of the distance between the jet hole and film hole to the diameter of the film hole P/D (0, 3, 4), and the material of double-decker (Steel and Copper)). It was observed that the local cooling effectiveness η varies with all these parameters in a complicated way. All the results show that higher cooling effectiveness η is achieved in larger blowing rate cases. A certain range of H/D and P/D can be designed to result in the maximum cooling effectiveness η. And η is less sensitive to the material type compared with those parameters such as H/D, M and P/D.

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