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1.
Obes Surg ; 34(4): 1247-1256, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38411879

RESUMEN

INTRODUCTION: A liver biopsy is the gold standard for the diagnosis of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). Here, we combine preoperative transient elastography (TE) and intraoperative standardized visual liver score (VLS) which is compared with intraoperative liver biopsy for prediction of NAFLD and NASH in patients undergoing bariatric surgery. AIM: Evaluate the combined diagnostic accuracy of TE and VLS in assessing NAFLD or NASH and compare it with liver biopsy in patients undergoing bariatric surgery. METHODS: In a prospective cohort of 70 morbidly obese undergoing bariatric surgery, preoperative TE and intraoperative VLS were calculated. Findings of TE and VLS were compared with histology from intraoperative liver biopsy. RESULTS: Histologically, 44 (62.85%) had NAFLD (≥ S1). Significant steatosis was seen in 20 (28.57%) while significant fibrosis was visible in 18 (25.71%). Area Under the Receiver Operating Characteristics (AUROC) TE for diagnosis of NAFLD was excellent (0.844, p = 0.001). At the optimal cutoff of 8.1, the positive predictive value (PPV) was 92.9%, and diagnostic accuracy was 90.6%. VLS had a sensitivity of 90.9% for NAFLD. The combined sensitivity of TE + VLS was 95.5% for ruling out NAFLD. Fourteen (20%) had NASH. VLS had a diagnostic accuracy of 97% in identifying NASH in comparison to TE. AUROC-VLS was 0.987, p ≤ 0.001, and a sensitivity of 100%. The overall sensitivity of combined TE and VLS was 100% with a negative predictive value (NPV) of 100%. CONCLUSION: TE when combined with intraoperative VLS is comparable to liver biopsy and can be used for the diagnosis of NAFLD and NASH in patients undergoing bariatric surgery.


Asunto(s)
Cirugía Bariátrica , Diagnóstico por Imagen de Elasticidad , Enfermedad del Hígado Graso no Alcohólico , Obesidad Mórbida , Humanos , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Obesidad Mórbida/cirugía , Estudios Prospectivos , Hígado/patología , Cirrosis Hepática/patología , Biopsia
2.
Sensors (Basel) ; 24(4)2024 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-38400474

RESUMEN

In the rapidly evolving landscape of continuous electrocardiogram (ECG) monitoring systems, there is a heightened demand for non-invasive sensors capable of measuring ECGs and detecting heart rate variability (HRV) in diverse populations, ranging from cardiovascular patients to sports enthusiasts. Challenges like device accuracy, patient privacy, signal noise, and long-term safety impede the use of wearable devices in clinical practice. This scoping review aims to assess the performance and safety of novel multi-channel, sensor-based biopotential wearable devices in adults. A comprehensive search strategy was employed on four databases, resulting in 143 records and the inclusion of 12 relevant studies. Most studies focused on healthy adult subjects (n = 6), with some examining controlled groups with atrial fibrillation (AF) (n = 3), long QT syndrome (n = 1), and sleep apnea (n = 1). The investigated bio-sensor devices included chest-worn belts (n = 2), wrist bands (n = 2), adhesive chest strips (n = 2), and wearable textile smart clothes (n = 4). The primary objective of the included studies was to evaluate device performance in terms of accuracy, signal quality, comparability, and visual assessment of ECGs. Safety findings, reported in five articles, indicated no major side effects for long-term/continuous monitoring, with only minor instances of skin irritation. Looking forward, there are ample opportunities to enhance and test these technologies across various physical activity intensities and clinical conditions.


Asunto(s)
Fibrilación Atrial , Dispositivos Electrónicos Vestibles , Adulto , Humanos , Electrocardiografía , Frecuencia Cardíaca/fisiología , Monitoreo Fisiológico/métodos
3.
Biol Trace Elem Res ; 202(5): 1948-1964, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37632687

RESUMEN

The present study was carried out in the village Kaliprasad of Bhagalpur district of Bihar to know the arsenic exposure effect in the exposed population. A total of n = 102 households were studied, and their water and biological samples such as urine and hair were collected and analyzed in a graphite furnace atomic absorption spectrophotometer (GF-AAS). The assessment of arsenic-exposed village population reveals that the villagers were suffering from serious health-related problems such as skin manifestations (hyperkeratosis and melanosis in their palm and soles), breathlessness, general body weakness, mental disorders, diabetes, hypertension (raised blood pressure), hormonal imbalance, neurological disorders, and few cancer cases. About 77% of household hand pump water had arsenic level more than the WHO recommended level of 10 µg/L, with highest level of 523 µg/L. Moreover, in 60% individual's urine samples, arsenic concentration was very high with maximum 374 µg/L while in hair 64% individuals had arsenic concentration above the permissible limit with maximum arsenic concentration of 11,398 µg/kg. The hazard quotient (HQ) was also calculated to know the arsenic risk percentage in children as 87.11%, in females as 83.15%, and in males as 82.27% by groundwater. This has surpassed the threshold value of 1 × 10 - 6 for carcinogenic risk (CR) in children, female, and male population group in the village. Hence, the exposed population of Kaliprasad village are at very high risk of the disease burden.


Asunto(s)
Intoxicación por Arsénico , Arsénico , Agua Subterránea , Contaminantes Químicos del Agua , Niño , Humanos , Masculino , Femenino , Arsénico/análisis , Grupos de Población , Contaminantes Químicos del Agua/análisis , Intoxicación por Arsénico/epidemiología , India/epidemiología , Agua
4.
Plant Cell Environ ; 47(2): 629-650, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37904283

RESUMEN

Plants constantly perceive and process environmental signals and balance between the energetic demands of growth and defense. Growth arrest upon pathogen attack was previously suggested to result from a redirection of the plants' metabolic resources towards the activation of plant defense. The energy sensor Target of Rapamycin (TOR) kinase is a conserved master coordinator of growth and development in all eukaryotes. Although TOR is positioned at the interface between development and defense, little is known about the mechanisms by which TOR may potentially regulate the relationship between these two modalities. The plant hormones cytokinin (CK) and gibberellin (GA) execute various aspects of plant development and defense. The ratio between CK and GA was reported to determine the outcome of developmental programmes. Here, investigating the interplay between TOR-mediated development and TOR-mediated defense in tomato, we found that TOR silencing resulted in rescue of several different aberrant developmental phenotypes, demonstrating that TOR is required for the execution of developmental cues. In parallel, TOR inhibition enhanced immunity in genotypes with a low CK/GA ratio but not in genotypes with a high CK/GA ratio. TOR-inhibition mediated disease resistance was found to depend on developmental status, and was abolished in strongly morphogenetic leaves, while being strongest in mature, differentiated leaves. CK repressed TOR activity, suggesting that CK-mediated immunity may rely on TOR downregulation. At the same time, TOR activity was promoted by GA, and TOR silencing reduced GA sensitivity, indicating that GA signalling requires normal TOR activity. Our results demonstrate that TOR likely acts in concert with CK and GA signalling, executing signalling cues in both defense and development. Thus, differential regulation of TOR or TOR-mediated processes could regulate the required outcome of development-defense prioritisation.


Asunto(s)
Citocininas , Giberelinas , Giberelinas/metabolismo , Citocininas/metabolismo , Sirolimus , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas
5.
Econ Educ Rev ; 97: None, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38094182

RESUMEN

Improving school quality in low and middle income countries (LMICs) is a global priority. One way to improve quality may be to improve the management skills of school leaders. In this systematic review, we analyze the impact of interventions targeting school leaders' management practices on student learning. We begin by describing the characteristics and responsibilities of school leaders using data from large, multi-country surveys. Second, we review the literature and conduct a meta-analysis of the causal effect of school management interventions on student learning, using 39 estimates from 20 evaluations. We estimate a statistically significant improvement in student learning of 0.033 standard deviations. We show that effect sizes are not related to program scale or intensity. We complement the meta-analysis by identifying common limitations to program effectiveness through a qualitative assessment of the studies included in our review. We find three main factors which mitigate program effectiveness: (1) low take-up; (2) lack of incentives or structure for implementation of recommendations; and (3) the lengthy causal chain linking management practices to student learning. Finally, to assess external validity of our review, we survey practitioners to compare characteristics between evaluated and commonly implemented programs. Our findings suggest that future work should focus on generating evidence on the marginal effect of common design elements in these interventions, including factors that promote school leader engagement and accountability.

6.
Artículo en Inglés | MEDLINE | ID: mdl-38082597

RESUMEN

Bioimpedance Analysis (BIA) along the radial artery has been widely investigated for hemodynamic monitoring. However, its applicability to different body type populations still lacks sufficient research. The Finite Element Method (FEM) was performed on three different wrist models using ANSYS HFSS, aiming to reveal the influences of different fat and muscle proportions on the sensitivity of blood volume change-induced bioimpedance change. The simulation results confirmed that the current density in each tissue mainly depended on the conductivity of tissues. The higher conductivity of the tissue, the higher current density inside said tissue. The amounts of flowing current were decided by both volume and conductivity of tissues. Moreover, increasing the fat layer thickness from 4 mm to 6 mm raised simulated impedance from 86.82 Ω to 100.39 Ω and impedance change from 0.63 Ω to 1.55 Ω. However, a higher muscle proportion occupied more injected current from the blood and resulted in lower impedance change. Therefore, for the overweight population, the placement of BIA is recommended to avoid the muscular body parts for the acquirement of better-quality pulse waves.Clinical Relevance-This establishes the bio-impedance analysis should avoid the muscular body parts for a better blood pulse wave quality for overweight populations.


Asunto(s)
Volumen Sanguíneo , Sobrepeso , Humanos , Impedancia Eléctrica , Conductividad Eléctrica , Músculos
7.
Biosensors (Basel) ; 13(11)2023 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-37998136

RESUMEN

This work aims to describe the dielectric behaviors of four main tissues in the human forearm using mathematical modelling, including fat, muscle, blood and bone. Multi-frequency bioimpedance analysis (MF-BIA) was initially performed using the finite element method (FEM) with a 3D forearm model to estimate impedance spectra from 10 kHz to 1 MHz, followed by a pilot study involving two healthy subjects to characterize the response of actual forearm tissues from 1 kHz to 349 kHz. Both the simulation and experimental results were fitted to a single-dispersion Cole model (SDCM) and a multi-dispersion Cole model (MDCM) to determine the Cole parameters for each tissue. Cole-type responses of both simulated and actual human forearms were observed. A paired t-test based on the root mean squared error (RMSE) values indicated that both Cole models performed comparably in fitting both simulated and measured bioimpedance data. However, MDCM exhibited higher accuracy, with a correlation coefficient (R2) of 0.99 and 0.89, RMSE of 0.22 Ω and 0.56 Ω, mean difference (mean ± standard deviation) of 0.00 ± 0.23 Ω and -0.28 ± 0.23 Ω, and mean absolute error (MAE) of 0.0007 Ω and 0.2789 Ω for the real part and imaginary part of impedance, respectively. Determining the electrical response of multi-tissues can be helpful in developing physiological monitoring of an organ or a section of the human body through MF-BIA and hemodynamic monitoring by filtering out the impedance contributions from the surrounding tissues to blood-flow-induced impedance variations.


Asunto(s)
Antebrazo , Modelos Teóricos , Humanos , Proyectos Piloto , Simulación por Computador , Impedancia Eléctrica
8.
Cardiovasc Eng Technol ; 14(6): 810-826, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37848736

RESUMEN

PURPOSE: Bio-impedance analysis (BIA) has been widely investigated for hemodynamic monitoring. However, previous works rarely modelled two synchronously pulsatile arteries (representing the radial and ulnar arteries) in the wrist/forearm model. This work aims to clarify and quantify the influences of two pulsatile arteries on BIA. METHODS: First, two blood-filled arteries were structured in a 3D wrist segment using the finite element method (FEM). Afterwards, an easy-to-produce two-arteries artificial wrist was fabricated with two components: gelatine-based surrounding tissue phantom and saline blood phantom. A syringe driver was utilised to constrict the arteries, and the impedance signals were measured using a Multi-frequency Impedance Analyser (MFIA). RESULTS: Both simulation and experimental results demonstrated the non-negligible influences of the ulnar artery on the overall BIA, inducing unwanted resistance changes to the acquired signals from the radial artery. The phantom experiments revealed the summation of the individual resistance changes caused by a single pulsatile artery was approximately equal to the measured resistance change caused by two synchronously pulsatile arteries, confirming the measured impedance signal at the wrist contains the pulsatile information from both arteries. CONCLUSION: This work is the first simulation and phantom investigation into two synchronously pulsatile arteries under BIA in the distal forearm, providing a better insight and understanding in the morphology of measured impedance signals. Future research can accordingly select either a small spacing 4-spot electrode configuration for a single artery sensing or a band electrode configuration for overall pulsatile arteries sensing. A more accurate estimation of blood volume change and pulse wave analysis (PWA) could help to develop cuffless blood pressure measurement (BPM).


Asunto(s)
Arteria Radial , Muñeca , Muñeca/fisiología , Impedancia Eléctrica , Determinación de la Presión Sanguínea
9.
Cureus ; 15(7): e42489, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37637565

RESUMEN

An esophageal stricture is an abnormal tightening of the esophageal lumen. Benign strictures are often caused by gastroesophageal reflux disease (GERD) and are more common in patients over 40 years. When caused by GERD, these strictures develop when acid from the stomach regurgitates into the esophagus, leading to inflammation, fibrosis, and eventual narrowing of the lumen. This case report aims to highlight the importance of obtaining a detailed history in discovering the underlying cause of these strictures. We present a unique case of a young female presenting with dysphagia several months after experiencing Hyperemesis gravidarum. She was found to have a long esophageal stricture that would eventually recur within a few weeks of therapeutic intervention. The pathological report confirmed benign disease, but she ultimately would require surgical intervention for her condition.

10.
Surg Endosc ; 37(9): 7136-7143, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37328592

RESUMEN

INTRODUCTION: Laparoscopic Bariatric surgery despite being minimally invasive can cause moderate to severe pain in the immediate postoperative period. Adequate pain management remains a major challenge. Transversus Abdominis Plane (TAP) block is a regional anesthesia technique which blocks the sensory nerve supply of anterior-lateral abdominal wall. AIMS AND OBJECTIVES: Primary: evaluate Laparoscopic versus ultrasound (USG)-guided TAP block on immediate post-operative analgesia after undergoing laparoscopic bariatric surgery. Secondary: compare cost effectiveness of Laparoscopic versus ultrasound-guided TAP block after undergoing bariatric surgery. MATERIALS AND METHODS: Randomized Single blind study undertaken after sample size was calculated by (N) = 2(Zα + Z1-ß)2σ2/δ2 which proposed 60 patients in each group. Block randomization was done after excluding redo/revision surgeries and patients were alloted Group I: Laparoscopic-guided TAP block & Group II: USG-guided TAP block. In both groups, Bilaterally, 20 ml (0.25%) bupivacaine was injected immediately after completion of bariatric surgery. SPSS v23 (IBM Corp.) was used for analysis. RESULTS: Group I (N = 61 53F/8 M) & Group II (N = 60 42F/18 M) were demographically comparable. Group I (3.58 ± 0.67) had significantly lower procedure time compared to Group II (12.47 ± 1.61) (p-Value < 0.001). First rescue analgesia was administered at 7.07 ± 2.61 h in Group I vs 7.21 ± 2.39 h in Group II (p-Value 0.659). In first 24 h rescue analgesic dose requirement in Group I was 1.29 ± 0.53 vs 1.39 ± 0.50 in Group II (p-Value 0.487). VAS scores during rest and movement till 24 h post-operative were statistically similar. Procedural cost was more in group II. CONCLUSION: Laparoscopic-guided TAP block is a safe and cost-effective approach for postoperative pain management after bariatric surgery and provides similar comparable analgesic effect as the USG-TAP block. Laparoscopic TAP is a surgeon delivered, easy to administer and significantly less time-consuming procedure which is feasible even when an ultrasound machine is not available.


Asunto(s)
Cirugía Bariátrica , Laparoscopía , Humanos , Músculos Abdominales/inervación , Analgésicos , Analgésicos Opioides , Cirugía Bariátrica/métodos , Costos y Análisis de Costo , Laparoscopía/efectos adversos , Dolor Postoperatorio/etiología , Dolor Postoperatorio/prevención & control , Periodo Posoperatorio , Método Simple Ciego , Ultrasonografía Intervencional/métodos
11.
Cureus ; 15(2): e34945, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36938221

RESUMEN

Accessory parotid lobe tumors are very rare. For any mass occupying the mid-cheek, tumors of the accessory parotid gland should be strongly suspected. These tumors are properly evaluated using ultrasonography, computed tomography, and fine needle aspiration cytology. Different surgical approaches are mentioned in the literature for the resection of these parotid lesions. These surgical approaches are often accompanied by the extracapsular dissection of the tumor. The extracapsular dissection of the tumor is an adequate technique to resect tumors of the accessory lobe of the parotid.

12.
Sensors (Basel) ; 23(3)2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36772611

RESUMEN

Recent advancement in wearable and robot-assisted healthcare technology gives rise to the demand for smart interfaces that allow more efficient human-machine interaction. In this paper, a hydrogel-based soft sensor for subtle touch detection is proposed. Adopting the working principle of a biomedical imaging technology known as electrical impedance tomography (EIT), the sensor produces images that display the electrical conductivity distribution of its sensitive region to enable touch detection. The sensor was made from a natural gelatin hydrogel whose electrical conductivity is considerably less than that of human skin. The low conductivity of the sensor enabled a touch-detection mechanism based on a novel short-circuiting approach, which resulted in the reconstructed images being predominantly affected by the electrical contact between the sensor and fingertips, rather than the conventionally used piezoresistive response of the sensing material. The experimental results indicated that the proposed sensor was promising for detecting subtle contacts without the necessity of exerting a noticeable force on the sensor.


Asunto(s)
Tacto , Dispositivos Electrónicos Vestibles , Humanos , Tacto/fisiología , Impedancia Eléctrica , Hidrogeles , Tomografía Computarizada por Rayos X
13.
Front Mol Biosci ; 10: 1232573, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38322710

RESUMEN

The ability of gut microbial metabolites to influence the host is increasingly recognized. The microbiota extensively metabolizes the three aromatic amino acids, tryptophan, tyrosine, and phenylalanine. Previously we have found that a metabolite of tyrosine, 4-OH-phenylpropionic acid, can enhance type I interferon (IFN) signaling and protect from influenza pathogenesis in a murine model. Herein we screened 17 related aromatic amino acid metabolites for effects on IFN signaling in human lung epithelial cells and monocytes alone and in the presence of IFN-ß, influenza, and LPS. While the tryptophan family metabolites reduced IFN signaling in both cell types, the tyrosine and phenylalanine metabolites had varied effects, which were cell-type dependent. Pooled treatment of all these metabolites reduced IFN signaling in both cell types and suggested a tryptophan metabolite effect dominance. Strikingly, when all the metabolites were pooled together, we found reduced influenza recovery in both cell types. RNA sequencing further validated reduced viral loads and decreased IFN signaling. Single gene silencing of significantly upregulated genes identified by RNA sequencing (EGR2, ATP6VD02, SPOCK1, and IL31RA) did not completely abrogate the metabolite induced decrease in IFN signaling. However, these upregulated targets suggested a mechanistic link to TGF-beta signaling. Treatment with a TGF-beta inhibitor and combined targeted gene silencing led to a significant reversal of metabolite induced IFN signaling suppression. Finally, we demonstrated that intranasal administration of these metabolites prior to influenza infection led to reduced animal morbidity, viral titers, and inflammation. Our work implies that microbial metabolites can alter IFN signaling mechanistically through TGF-beta and promote beneficial outcomes during influenza infection.

14.
Cureus ; 15(12): e50647, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38229814

RESUMEN

A rare consequence of hysterectomy is vaginal vault dehiscence, which commonly occurs five to seven weeks after the procedure. Its frequency ranges from 0% to 7.5%. The incidence of delayed dehiscence is rare. The small bowel is the organ that prolapses most frequently, but other organs and multi-organ prolapses have also been documented. Due to potential catastrophes such as intestinal ischemia, blockage, and perforation, transvaginal protrusion of abdominal viscera is an emergency. A laparoscopic approach facilitates a thorough evaluation of the abdominal contents and provides assistance in challenging circumstances where the contents are not reducible.

15.
Sensors (Basel) ; 22(23)2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36502203

RESUMEN

Knowledge of foot growth can provide information on the occurrence of children's growth spurts and an indication of the time to buy new shoes. Podiatrists still do not have enough evidence as to whether footwear influences the structural development of the feet and associated locomotor behaviours. Parents are only willing to buy an inexpensive brand, because children's shoes are deemed expendable due to their rapid foot growth. Consumers are not fully aware of footwear literacy; thus, views of consumers on children's shoes are left unchallenged. This study aims to embed knitted smart textile sensors in children's shoes to sense the growth and development of a child's feet-specifically foot length. Two prototype configurations were evaluated on 30 children, who each inserted their feet for ten seconds inside the instrumented shoes. Capacitance readings were related to the proximity of their toes to the sensor and validated against foot length and shoe size. A linear regression model of capacitance readings and foot length was developed. This regression model was found to be statistically significant (p-value = 0.01, standard error = 0.08). Results of this study indicate that knitted textile sensors can be implemented inside shoes to get a comprehensive understanding of foot development in children.


Asunto(s)
Pie , Zapatos , Niño , Humanos , Dedos del Pie , Textiles
16.
Sensors (Basel) ; 22(21)2022 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-36366025

RESUMEN

There is a rapid increase in plantar pressure from the infant to toddler stage, yet little is known about the reasons for this change. More information about plantar pressure distribution can help clinicians identify early-stage foot-related diseases that may occur during transitions from childhood to adulthood. This information also helps designers create shoes that adapt to different needs. This research describes the development of a low-cost, built-in shoe plantar pressure measurement system that determines foot pressure distribution in toddlers. The study aimed to improve and provide data on pressure distribution during foot growth. This was accomplished by implementing a plantar pressure capacitive measurement system within shoes. The capacitive sensors were laminated using a copper tape sheet on plastic backing with adhesive, elastomer layers, and a combination of conductive and non-conductive fabrics. Constructed sensors were characterized using compression tests with repeated loads. Results demonstrated that the sensors exhibited rate-independent hysteresis in the estimation of pressure. This enabled a calibration model to be developed. The system can mimic more expensive plantar pressure measurement systems at lower fidelity. This emerging technology could be utilized to aid clinicians, researchers, and footwear designers interested in how pressure distribution changes from infants to toddlers.


Asunto(s)
Pie Diabético , Enfermedades del Pie , Humanos , Niño , Adolescente , Adulto Joven , Zapatos , Presión , Pie , Extremidad Inferior
17.
Sensors (Basel) ; 22(13)2022 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-35808233

RESUMEN

This paper improves the accuracy of quantification in the arterial diameter-dependent impedance variance by altering the electrode configuration. The finite element analysis was implemented with a 3D human wrist fragment using ANSYS Electronics Desktop, containing fat, muscle, and a blood-filled radial artery. Then, the skin layer and bones were stepwise added, helping to understand the dielectric response of multi-tissues and blood flow from 1 kHz to 1 MHz, the current distribution throughout the wrist, and the optimisation of electrode configurations for arterial pulse sensing. Moreover, a low-cost wrist phantom was fabricated, containing two components: the surrounding tissue simulant (20 wt % gelatine power and 0.017 M sodium chloride (NaCl) solution) and the blood simulant (0.08 M NaCl solution). The blood-filled artery was constricted using a desktop injection pump, and the impedance change was measured by the Multi-frequency Impedance Analyser (MFIA). The simulation revealed the promising capabilities of band electrodes to generate a more uniform current distribution than the traditional spot electrodes. Both simulation and phantom experimental results indicated that a longer spacing between current-carrying (CC) electrodes with shorter spacing between pick-up (PU) electrodes in the middle could sense a more uniform electric field, engendering a more accurate arterial diameter estimation. This work provided an improved electrode configuration for more accurate arterial diameter estimation from the numerical simulation and tissue phantom perspectives.


Asunto(s)
Cloruro de Sodio , Simulación por Computador , Impedancia Eléctrica , Electrodos , Humanos , Fantasmas de Imagen , Análisis Espectral
18.
Microbiol Res ; 262: 127103, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35797945

RESUMEN

Plant hormones act as chemical messengers, transducing cellular and organ-level cues, executing plant growth, development, reproduction, metabolism, and response to environmental stress. In addition to the production of hormones by plants, fungi can also produce compounds that are similar to phytohormones, and may modulate growth, physiology, and immunity in both plants and fungi. The "classical" plant growth hormone, cytokinin (CK) is known to have roles in plant-fungi interactions. In plants, CKs are involved in various processes including plant growth and development, seed germination, apical dominance, balance between shoot and root tissue, leaf senescence, and plant-pathogen-interactions. We recently reported that CK can also affect fungal development. CK is not produced solely by plants, as can be synthesized by plant-associated microorganisms such as bacteria and fungi. Fungal phytopathogens may also activate plant CK signalling/sensing via secretion of effector molecules. Fungal CKs secreted by (hemi)biotrophic pathogens can serve as virulence factors, however, most necrotrophic fungal plant pathogens have not been reported to secrete CKs during plant infection. Though a lifestyle-dependent role for CK signalling/perception was suggested for fungal plant pathogens, little is known about CK perception, sensing, and signalling in fungal organisms. In this review, we focus on the production of fungal CKs and their role in development and virulence, as well as the possibilities for CK perception and signalling in the fungal kingdom, where CHASE-domain containing proteins are largely absent.


Asunto(s)
Citocininas , Reguladores del Crecimiento de las Plantas , Citocininas/metabolismo , Hongos/metabolismo , Desarrollo de la Planta , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas/microbiología
19.
Microbiol Spectr ; 10(4): e0028022, 2022 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-35894612

RESUMEN

The plant hormone cytokinin (CK) is an important developmental regulator. Previous work has demonstrated that CKs mediate plant immunity and disease resistance. Some phytopathogens have been reported to secrete CKs and may manipulate CK signaling to improve pathogenesis. In recent work, we demonstrated that CK directly inhibits the development and virulence of fungal phytopathogens by attenuating the cell cycle and reducing cytoskeleton organization. Here, focusing on Botrytis cinerea, we report that CK possesses a dual role in fungal biology, with role prioritization being based on sugar availability. In a sugar-rich environment, CK strongly inhibited B. cinerea growth and deregulated cytoskeleton organization. This effect diminished as sugar availability decreased. In its second role, we show using biochemical assays and transgenic redox-sensitive fungal lines that CK can promote glycolysis and energy consumption in B. cinerea, both in vitro and in planta. Glycolysis and increased oxidation mediated by CK were stronger in low sugar availability, indicating that sugar availability could indeed be one possible element determining the role of CK in the fungus. Transcriptomic data further support our findings, demonstrating significant upregulation to glycolysis, oxidative phosphorylation, and sucrose metabolism upon CK treatment. Thus, the effect of CK in fungal biology likely depends on energy status. In addition to the plant producing CK during its interaction with the pathogen for defense priming and pathogen inhibition, the pathogen may take advantage of this increased CK to boost its metabolism and energy production, in preparation for the necrotrophic phase of the infection. IMPORTANCE The hormone cytokinin (CK) is a plant developmental regulator. Previous research has highlighted the involvement of CK in plant defense. Here, we report that CK has a dual role in plant-fungus interactions, inhibiting fungal growth while positively regulating B. cinerea energy utilization, causing an increase in glucose utilization and energy consumption. The effect of CK on B. cinerea was dependent on sugar availability, with CK primarily causing increases in glycolysis when sugar availability was low, and growth inhibition in a high-sugar environment. We propose that CK acts as a signal to the fungus that plant tissue is present, causing it to activate energy metabolism pathways to take advantage of the available food source, while at the same time, CK is employed by the plant to inhibit the attacking pathogen.


Asunto(s)
Citocininas , Interacciones Huésped-Patógeno , Botrytis/fisiología , Enfermedades de las Plantas/microbiología , Plantas/microbiología , Azúcares
20.
Phytopathology ; 112(11): 2360-2371, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35771048

RESUMEN

Nutrient elements play essential roles in plant growth, development, and reproduction. Balanced nutrition is critical for plant health and the ability to withstand biotic stress. Treatment with essential elements has been shown to induce disease resistance in certain cases. Understanding the functional mechanisms underlying plant immune responses to nutritional elements has the potential to provide new insights into crop improvement. In the present study, we investigated the effect of various elements-potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na)-in promoting resistance against the necrotrophic fungus Botrytis cinerea and the hemibiotrophic bacterium Xanthomonas euvesicatoria in tomato. We demonstrate that spray treatment of essential elements was sufficient to activate immune responses, inducing defense gene expression, cellular leakage, reactive oxygen species, and ethylene production. We report that different defense signaling pathways are required for induction of immunity in response to different elements. Our results suggest that genetic mechanisms that are modulated by nutrient elements can be exploited in agricultural practices to promote disease resistance.


Asunto(s)
Resistencia a la Enfermedad , Solanum lycopersicum , Solanum lycopersicum/microbiología , Enfermedades de las Plantas/microbiología , Regulación de la Expresión Génica de las Plantas , Botrytis , Nutrientes
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