Frontiers in bioscience (Scholar edition)最新文献

Background: Energy storage, transmission and dissipation are important considerations of normal mechanical homeostasis. In this paper we present a new technique termed vibrational optical coherence tomography (VOCT) to study the anterior anatomic structures of the pig eye to better understand how energy applied to the cornea is dissipated without delamination occurring.

Methods: VOCT uses infrared light and an applied sinusoidal audible sound wave to image and measure the resonant frequency and modulus of individual macromolecular components of tissue non-invasively. We have measured the resonant frequencies and calculated the moduli of tissues in the anterior portion of the pig eye using VOCT.

Results: While both pig and human eyes have similar resonant frequencies, they do differ in the peak amplitudes near the frequencies of 80, 120, 150 and 250 Hz. It is known that the stroma of pig cornea is much thicker than that of human corneas and these differences may explain the normalized peak height differences. The similarity of the resonant frequency peaks near 80, 120, 150 and 250 Hz of cornea, sclera and limbus suggest that the anatomically described layers in these tissues are connected into a single biomechanical unit that can store external mechanical energy and then transmit it for dissipation. Since the energy stored and dissipated is proportional to the modulus and the ability of the tissue to deform under stress, energy storage in these tissues is related to the stiffness.

Conclusions: It is concluded that stored energy is transmitted to the posterior segment of the eye for dissipation through the attachment with the sclera. This mechanism of energy dissipation may protect the cornea from changes in shape, curvature, and refractive power. However, ultimately, energy dissipation through thinning of the sclera may cause globe elongation observed in subjects with myopia and glaucoma.

Fibromyalgia is a central sensitivity syndrome that presents with chronic pain, fatigue, cognitive dysfunction, and disordered sleep. The pathophysiology which due to multisensory hypersensitivity of the central nervous system involves neuronal excitability leading to central sensitization. Treatments of the challenges associated with the complexities of fibromyalgia involve combinations of pharmacological and non-pharmacological therapeutic approaches which often offer limited benefit. Potassium (K+) channels play a fundamental role in establishing and maintaining stability of neuronal activity. The large molecular diversity and distribution of K+ channels support involvement in a broad range of physiological functions. In nociceptive pathways, neuronal hyperexcitability leading to pain sensation has been associated with reduced function of K+ channels and loss of cellular control. This article reviews the evidence of involvement of K+ channels in fibromyalgia. A potential role both in the pathophysiological processes responsible for the symptoms of fibromyalgia and as therapeutic targets for the management of the condition is considered.

Background: Since the beginning of COVID-19 pandemic, an increase in new diagnoses and pediatric hospital admission for anorexia nervosa (AN) or atypical AN in adolescents have been reported, suggesting an adverse effect of COVID-19 on youth mental health. We hypothesized possible differences in prevalence of hospitalization and/or disease severity, related to socio-economic status and/or ethnicity.

Methods: Retrospectively, patients were divided into two subgroups and compared according to the date of first hospital admission: "pre SARS-COV2 era" group (n. 45, 8th March 2016-8th March 2020) and "SARS-COV2 era" group (n. 43, 9th March 2020-8th March 2022).

Results: During the two years of the SARS-COV2 era, we reported an increase in hospital admission incidence more than doubled respect to the "pre-SARS-COV2 era". The "SARS-COV2 era group" showed a more rapid weight loss (p = 0.005), a minor duration of weight loss from lifetime maximum to admission (p = 0.019) and needed most frequently treatments with intravenous fluids (p < 0.0001), oral dietetic supplements (p <0.001) and enteral nutrition by nasogastric tube (p = 0.002). The same group presented higher prevalence of psychiatric comorbidities (63% vs. 22%, p < 0.0001) and required most frequently treatments with psychotropic drugs (56% vs. 24%, p = 0.002). We found higher family socioeconomic status (SES) in our patients with AN in both the periods and we did not find a shift in social class distribution over time.

Conclusions: Our study confirms a significant increase in incidence of hospitalization and of psychiatric comorbidity in the pediatric population with AN during the second year of COVID-19 pandemic, regardless of SES or ethnic background. Further studies are needed to understand potential mechanisms that during COVID-19 pandemic trigger eating disorder symptoms.

Background: Pulsed ultraviolet (UV) irradiation can be used to generate a broad UV-C spectrum. The pulsing nature of such a spectrum helps increase the damage to cancer cells, leading to their injury and death. In contrast, non-tumor cells repair the damage and survive the same pulsed UV irradiation energy. Herein, we describe the development of a pulsed UV irradiation method for cancer cell dysfunction that irradiates cells with pulsed light by generating tremendous instantaneous UV energy-tens of thousands of times greater than that generated by UV lamps-to cause specific cell injury and dysfunction of cancer cells.

Methods: A newly developed pulsed ultraviolet irradiation device was used. Features of the device used in this study. This device employs a quartz discharge xenon lamp. Cultured tumor cells and non-tumor cells were irradiated with pulsed light at different irradiation doses, and their reactions were observed using optical, electron, and laser microscopes.

Results: Cancer cells have more FAS (CD95) receptor domains than non-cancer cells, and pulsed UV irradiation stimulates the production of reactive oxygen species (ROS) and OH, which exceeds the oxidative stress removal function, resulting in cell injury and death. That is, at low UV doses, only cancer cells underwent cell death, whereas non-cancer cells did not. The pulsed UV irradiation technique directly destroys cancer cells and minimizes the number of residual cancer cells while allowing minimum invasion into non-tumor cells, thereby improving their survival. This suggests the possibility of activating the host's local immune response to eliminate residual cancer cells.

Conclusions: A newly developed pulsed UV radiation system shows potential for use in the development of a drug-free cancer treatment system that selectively kills tumor cells by irradiating them with high-intensity pulsed UV rays over a broad UV-C range of 230-280 nm.

Nosocomial infections pose an imminent challenge to hospitalized Coronavirus disease-19 (COVID-19) patients due to complex interplay of dysregulated immune response combined with immunomodulator therapy. In the pre-pandemic era, immunomodulatory therapy has shown benefit in certain autoimmune conditions with untamed inflammatory response. Efforts to recapitulate these immunomodulatory effects in COVID-19 patients has gained impetus and were followed by NIH COVID-19 expert panel recommendations. The current NIH guideline recommends interleukin-6 inhibitors (tocilizumab and sarilumab) and Janus kinase inhibitors (baricitinib and tofacitinib). Several landmark research trials like COVAVTA, EMPACTA, REMDACTA, STOP-COVID and COV BARRIER have detailed the various effects associated with administration of immunomodulators. The historical evidence of increased infection among patients receiving immunomodulators for autoimmune conditions, raised concerns regarding administration of immunomodulators in COVID-19 patients. The aim of this review article is to provide a comprehensive update on the currently available literature surrounding this issue. We reviewed 40 studies out of which 37 investigated IL-6 inhibitors and 3 investigated JAK inhibitors. Among the studies reviewed, the reported rates of nosocomial infections among the COVID-19 patients treated with immunomodulators were similar to patients receiving standard of care for COVID-19. However, these studies were not powered to assess the side effect profile of these medications. Immunomodulators, by dampening the pyrogenic response and inflammatory markers may delay detection of infections among the patients. This underscores the importance of long-term surveillance which are necessary to discover the potential risks associated with these agents.

Background: Carbohydrate digestive enzymes play a major role in the management of the postprandial hyperglycemia. A chronic hyperglycemia can lead to serious health problems due to excessive production of several reactive oxygen species. Therefore, the inhibition of carbohydrate digestive enzyme and the use of antioxidant natural product can be an important strategy to control the glycaemia level and prevent against the complication of diabetes.

Aim: The study aims to perform a phytochemical analysis, antioxidant activity, inhibitory effect on α -amylase, α -glucosidase (in vitro and in vivo) and the intestinal glucose absorption in Wistar rats of Artemisia campestris aqueous extract (AcAE) and hydro-ethanolic extract (AcEE).

Results: The test of total phenolic content, show that the AcAE has the highest quantity of polyphenol (44.65 ± 0.54 μ g GAE/mg extract) compared to the AcEE (31.7 ± 0.53 μ g GAE/mg extract) significantly. The amount of flavonoid and condensed tannins content in AcAE is 24.41 ± 3.57 μ g QrE/mg extract, 14.31 ± 5.26 μ g CE/mg respectively. The AcAE has also exhibit a great antioxidant activity in DPPH-scavenging and Ferric reducing antioxidant power assay (FRAP) compared to AcEE with an IC 50 = 0.355 ± 0.057 mg/mL and IC 50 = 0.269 ± 0.025 mg/mL. However, in a β -carotene bleaching assay the AcEE has the highest effect with an IC 50 = 0.319 ± 0.097 mg/mL. The both extract of Artemisia campestris L. (250 mg/kg) decreased postprandial hyperglycemia in the normal and alloxane diabetic rats in a very significant manner after starch or sucrose administration as an α -amylase and α -glucosidase substrate respectively. This result is confirmed in vitro by a remarkable inhibitory effect on α -amylase digestive enzymes by an IC 50 = 1.259 ± 0.128 mg/mL and IC 50 = 0.602 ± 0.072 mg/mL receptively for AcAE and AcEE. For the α -glucosidase enzyme, the both extracts significantly inhibit α -glucosidase activity compared to the control and they are almost similar to each other. Using a jejunum perfusion technique (in situ), Artemisia campestris L. decrease the intestinal D-glucose absorption activity significantly compared to the control and comparable to the Phlorizin used as a positive control by an amount of glucose absorbed equal a 6.53 ± 0.57, 5.34 ± 0.64 and 4.71 ± 0.24 mg/10 cm/h, for AcAE, AcEE and Phlorizin respectively.

Conclusions: These results showed that the Artemisia campestris L. has highest phenolic content, antioxidant activity and demonstrated a postprandial anti-hyperglycemic effect via the inhibiting of the carbohydrate digestive enzyme ( α -amylase and α -glucosidase) and the intestinal glucose absorption.

The main entry point of SARS-CoV-2 is the respiratory tract and as such immune defence in this site determines if the virus will spill-over to the systemic circulation and circulate and infect other major organs. The first line of mucosal immune defence is composed of mucins, an epithelial barrier, and immune cells in the nasal cavity. The lung immune defence is carried out by numerous alveoli. The lung microbiota is a key factor in determining the efficacy of lung mucosal immunity protection. The intestinal microbiota has been demonstrated to affect the severity of COVID-19. Gut dysbiosis is involved in hyperinflammation and multiple organ failure through communications with multiple organs. The gut lung axis could be the earliest axis affected in COVID-19. Through the gut-lung axis, gut dysbiosis can affect the pathogenesis of the lung in COVID-19. In this review, we summarise the effects that gut dysbiosis can progress on the lung, and the lung microbiota. The possible mechanisms and approaches for modulation are discussed.

Alzheimer's disease (AD) is the most common neurodegenerative disorder, resulting in memory loss, cognitive decline, bodily function impairment, and finally death. The growing number of people suffering from AD increasingly urges the development of effective early diagnosis and monitoring techniques. Here, we review the most recent developments in the field of Raman-based techniques, which have shown a significant potential in identifying AD by detecting specific biomarkers in biological fluids, as well as in providing fundamental insights into key molecules involved in the disease progression or in the analysis of histological specimens of patients with AD. These techniques comprise spontaneous and resonant Raman spectroscopies, exploit plasmon- or fiber- enhanced effects, such as surface-, tip- or fiber- enhanced Raman spectroscopies, or involve non-linear techniques like coherent Raman scattering. The scientific efforts employed up to now as well as the rapid technological advancements in optical detection instruments (spectrometers, lasers, substrates for analysis, etc.) and the diffusion of advanced data processing methods suggest a leading role of Raman techniques in the perspective of a preclinical or clinical detection of AD.

The most frequent arrhythmia treated is atrial fibrillation (AF), which necessitates the use of oral anticoagulants (OACs) to reduce the risk of thromboembolism and stroke. Patients with chronic kidney disease are more likely to develop AF, with a 10% frequency among those on chronic dialysis. Warfarin is the most widely prescribed OAC for individuals with end-stage kidney disease (ESKD). On the other hand, direct OACs (DOACs) are generally safer than warfarin, with fewer fatal bleeding events and a fixed dose that does not require close international normalized ratio (INR) monitoring. For those patients, warfarin and apixaban appear to be FDA-approved, whereas dabigatran, rivaroxaban, and edoxaban are not recommended yet. Due to a lack of large randomized studies, data from major trials cannot be extended to dialysis patients. In this review, we summarize the available data and literature referring to patients on chronic hemodialysis with concomitant AF. Due to the scarcity of data, we try to assist clinicians in selecting the appropriate therapy according to the specific characteristics of each patient. Finally, future directions are provided in two key areas of focus: left atrial appendage closure therapies and genetic research.