Hasil untuk "Physiology"

A. Boldyrev, G. Aldini, W. Derave

R. Scherz-Shouval, Z. Elazar

Heather Cathcart, Gina Profetto, Amber Howard et al.

Cornelia S. Hahn, M. Schwartz

M. Joyner, E. Coyle

C. Lobban, P. Harrison

B. Dietrich

H. Fong

in dogs lasting up to 40 days following moderate doses of 1600 rads in eight treatments of X-irradiation. There is a discussion of the difficulties encountered in attempting to irradiate gastric mucosa with radioactive sources placed directly within the stomach. The techniques of external beam treatment used at the University of Chicago are described in detail. Finally, the clinical results and complications are presented for this rather considerable experience, over 3000 patients treated during a 35-yr period. The treatment of benign ulcer disease with X-irradiation is certainly controversial and has not been widely accepted for general use in most medical centers. The results of this considerable clinical experience are difficult to assess because of the variability in the natural history of this condition. Most encouraging are the results of a randomized prospective study carried out by Erwin Levin with 68 patients, all of whom were treated with intensive medical management, half of whom were randomly selected to receive approximately 2000 rads to the fundus and body of the stomach in about ten total treatments. The control group had significantly more failures in therapy than the irradiated group. In a 5-yr period over 70% of the nonir-radiated patients had recurrent ulcers compared to only 11 % in the irradiated group. The irradiated patients showed decreased levels of basal and Histalog stimulated free acid excretion. Particular emphasis is placed on the examination of the possibility of radiation induced neoplasia. Careful followup of the patients treated at the University of Chicago gives no indication that this is a significant complication. A number of criticisms may be offered. The general format of the book, a number of small independently written chapters, leads to disorganization, fragmentation, and needless repetition. In many instances the details of the radiation technique and the suggested mechanisms of action are not up to the standards of modern radiation therapy and radiobiology. This will be more annoying to radiation therapists than other readers. When describing what is clearly a nonuniversally accepted treatment, it might have been useful to include a brief presentation by a gastroenterologist not enthusiastic about this technique. In a very brief chapter, five pages, Dr. Melvin Griem, one of the country's leading radiation therapists and Director of the Tumor Institute at the University of Chicago, describes the techniques and dosimetry used at that institution in great detail, but conspicuously fails to discuss the usefulness of the treatment and …

M. Livingstone, D. Hubel

Staining for the mitochondrial enzyme cytochrome oxidase reveals an array of dense regions (blobs) in the primate primary visual cortex. They are most obvious in the upper layers, 2 and 3, but can also be seen in layers 4B, 5, and 6, in register with the blobs in layers 2 and 3. We compared cells inside and outside blobs in macaque and squirrel monkeys, looking at their physiological responses and anatomical connections. Cells within blobs did not show orientation selectivity, whereas cells between blobs were highly orientation selective. Receptive fields of blob cells had circular symmetry and were of three main types, Broad-Band Center-Surround, Red-Green Double-Opponent, and Yellow-Blue Double-Opponent. Double-Opponent cells responded poorly or not at all to white light in any form, or to diffuse light at any wavelength. In contrast to blob cells, none of the cells recorded in layer 4C beta were Double-Opponent: like the majority of cells in the parvocellular geniculate layers, they were either Broad-Band or Color- Opponent Center-Surround, e.g., red-on-center green-off-surround. To our surprise cells in layer 4C alpha were orientation selective. In tangential penetrations throughout layers 2 and 3, optium orientation, when plotted against electrode position, formed long, regular, usually linear sequences, which were interrupted but not perturbed by the blobs. Staining area 18 for cytochrome oxidase reveals a series of alternating wide and narrow dense stripes, separated by paler interstripes. After small injections of horseradish peroxidase into area 18, we saw a precise set of connections from the blobs in area 17 to thin stripes in area 18, and from the interblob regions in area 17 to interstripes in area 18. Specific reciprocal connections also ran from thin stripes to blobs and from interstripes to interblobs. We have not yet determined the area 17 connections to thick stripes in area 18. In addition, within area 18 there are stripe-to-stripe and interstripe- to-interstripe intrinsic connections. These results suggest that a system involved in the processing of color information, especially color-spatial interactions, runs parallel to and separate from the orientation-specific system. Color, encoded in three coordinates by the major blob cell types, red-green, yellow-blue, and black-white, can be transformed into the three coordinates, red, green, and blue, of the Retinex algorithm of Land.

C. Prosser, F. Brown

R. Sairam, A. Tyagi

J. Bangsbo

L. Sherwood

Lincy Koodaly, Erika Friedmann, Nancy R. Gee et al.

<b>Background:</b> The growth of the older adult population calls for innovative and cost-effective ways of promoting their physical, psychological, and cognitive health. Human–animal interaction, including pet ownership, is related to positive and negative aspects of human health. Not all pet owners respond in the same way. The levels of pet attachment and pets’ influence on their owners’ lives could moderate the relationship between psychological status and health outcomes. <b>Purpose:</b> We examined the moderating role of pet attachment in the relationships of psychological status (mental wellbeing, happiness, anxiety, depression) to physical function (physical wellbeing, usual- and rapid-gait speeds, physical performance battery) in community-residing older adult pet owners. <b>Methods:</b> A cross-sectional, secondary analysis of pet-owning older adult participants in the Baltimore Longitudinal Study of Aging (n = 178). <b>Results:</b> In regression analyses, controlling for age, gender, and comorbidities, pet attachment and pet influence moderated the relationships of physical wellbeing to mental wellbeing and anxiety (<i>p</i> < 0.05). Pet influence also moderated the relationship between anxiety and usual gait speed (<i>p</i> < 0.05). <b>Conclusions:</b> Greater attachment and influence buffer the relationship of perceptions of poor mental function with perceptions of poor physical wellbeing suggesting one mechanism for health benefits of human-animal interaction.

Igbayilola Yusuff Dimeji, Adekola Saheed Ayodeji

Central obesity, atherogenic dyslipidemia, insulin resistance, and hypertension are among the metabolic dysregulations associated with metabolic syndrome (MetS). Insulin resistance and chronic low-grade inflammation are 2 of the many acquired and genetic components that make up the pathophysiology of MetS. MetS is strongly linked to a greater risk of diabetes and cardiovascular disease in the absence of effective treatment. To create effective intervention strategies and preventative techniques, the MetS process needs to be thoroughly examined. Recent research has emphasized the critical roles that metabolic endotoxemia and the gut microbiota play in the pathophysiology of MetS. The manipulation of gut microbiota‒host metabolism interactions has been linked to several factors, including bile acid metabolism, short-chain fatty acid metabolism, and inflammation caused by malfunction of the gut barrier. Pharmacological treatments for the gut microbiota are becoming increasingly popular as treatment alternatives. This brief message highlights some of the most recent developments in pharmaceutical strategies for preventing both gut dysbiosis and systemic low-grade inflammation caused by endotoxemia. Antibiotics, prebiotics, probiotics, synbiotics, postbiotics, and metabolite modulators produced from the microbiota are all used in these tactics. Particular focus is placed on next-generation treatments such as small chemical inhibitors of microbial‒host interactions, bacteriophage therapy, and tailored probiotics. Significance Statement: Pharmacologic alteration of the gut microbiota to target endotoxemia, a major cause of systemic inflammation, is a viable next-generation treatment for metabolic syndrome. These treatments help stop lipopolysaccharide translocation, restore metabolic balance, and improve insulin sensitivity by strengthening the gut barrier and changing the makeup of microbes. This method improves lipid metabolism, decreases chronic inflammation, and targets the underlying causes of disease. As a result, to improve results, treatment is moving from just managing symptoms to changing the disease itself.

María Cristina Franco-Arellanes, Perla Xóchitl Toledo-Valdes, Cynthia Díaz-Hernández et al.

INTRODUCTION: O-GlcNAcylation is a post-translational modification in which a single N-Acetyl-D-Glucosamine (GlcNAc) molecule is added to Ser or Thr residues of proteins. The O-N-acetylglucosaminyl transferase (OGT) enzyme is responsible for adding GlcNAc to the target proteins and N-acetyl-β-D-glucosaminidase (OGA) that removes the GlcNAc residue. O-GlcNAcylation has been described in the pathophysiology of several diseases; however, little has been studied in dental tissue. The aim of the present work is to characterise the product of O-GlcNAcylation and its enzymes at the tissue level in the dental pulp, as well as its expression in dental pulp stem cells (DPSCs) both in situ and in vitro. This enables the recognition of the behaviour of O-GlcNAcylation in pulp tissue without pathology. MATERIAL AND METHODS: Pulp tissue was obtained from 10 healthy donors, and the expression of O-GlcNAc, OGT, and OGA was analysed using immunofluorescence with specific antibodies in different regions of the dental pulp. DPSCs were isolated, cultured, and identified with anti-STRO1 (antibody specific for human CD34+ cells, useful for DPSC identification). The expression of O-GlcNAc in DPSCs was confirmed in vitro through Western blot. Results. Different regions of the dental pulp and DPSCs express O-GlcNAc and the enzymes OGT and OGA. O-GlcNAc and OGT expression was more prominent in the odontoblastic layer, cell-rich zone, and in the central core. OGA was distributed throughout the pulp tissue with lower immunoreactivity compared to OGT. CONCLUSIONS: Our results suggest that O-GlcNAcylation may play a relevant role in human dental pulp homeostasis and in physiology of DPSCs.

S. Morton, D. Brodsky

Wonseok Chang, Yura Kim, Hye Jin Park

Purpose Although interest in various forms of learning media is increasing due to the coronavirus disease 2019 (COVID-19) pandemic there is relatively little research on influencing student motivation by intervening in cognitive processing. The purpose of this study was to present the optimal form of learning materials provided to medical students. Methods This study provided learning materials in class at a level according to social cues (script, video [artificial intelligence (AI) voice], video [professor voice]) based on the principle of voices among the principles of personalization, voices, image, and embodiment of social cues in multimedia learning, and surveyed students’ opinions. Results There was no statistically significant difference according to social clues in satisfaction and learning help, but both appeared in the order of silent videos containing the professor’s voice, followed by videos containing the AI voice. Conclusion This study is significant in that there is no research on the impact of student motivation on the provision of learning materials for medical school education in Korea, and we hope that it will help provide learning materials for self-directed learning of medical students in the post-COVID-19.

Thi Thanh Thuy Dao, Ravi Fotedar

We investigated the effect of feed deprivation for 45 days on the growth, immunity, and health of 0⁺marron (<i>Cherax cainii</i>) initially fed for 110 days on various protein sources including fishmeal (FM), poultry by-product meal (PBM), black soldier fly meal (BSFM), soybean meal (SBM), lupin meal (LM), and tuna hydrolysate. The marron were weighed and sacrificed immediately after feeding stopped (day 0) and at days 15, 30, and 45 after the feed deprivation trial commenced. Total haemolymph count, differential haemocyte count, lysozyme activity, protease activity, total bacterial count in the digestive tract, and organosomatic indices were analysed. Initially feeding marron any protein sources did not influence the percentage of weight gain and specific growth rates of marron. All marron showed more than 83% survival; however, marron fed soybean meal showed significantly lower survival than others. Dietary sources of protein altered organosomatic indices of starved marron during various starvation periods and resulted in a significant decrease in total haemocyte counts, lysozyme activity, protease activity, and bacterial count in the digestive tract of marron. Starved marron initially fed PBM and BSFM showed higher tolerance to starvation, followed by marron initially fed FM and SBM, while marron initially fed TH and LM showed the highest susceptibility to starvation.