Methods for assessing and removing non-specific photoimmunotherapy damage in patient-derived tumor cell culture models.

Tumor-targeted, activatable photoimmunotherapy (taPIT) has been shown to selectively destroy tumor in a metastatic mouse model. However, the photoimmunoconjugate (PIC) used for taPIT includes a small fraction of non-covalently associated (free) benzoporphyrin derivative (BPD), which leads to non-specific killing in vitro. Here, we report a new treatment protocol for patient-derived primary tumor cell cultures ultrasensitive to BPD photodynamic therapy (BPD-PDT). Based on free BPD efflux dynamics, the updated in vitro taPIT protocol precludes non-specific BPD-PDT by silencing the effect of free BPD. Following incubation with PIC, incubating cells with PIC-free medium allows time for expulsion of free BPD whereas BPD covalently bound to PIC fragments is retained. Administration of the light dose after the intracellular free BPD drops below the threshold for inducing cell death helps to mitigate non-specific damage. In this study, we tested two primary ovarian tumor cell lines that are intrinsically chemoresistant, yet ultrasensitive to BPD-PDT such that small amounts of free BPD (a few percent of the total BPD dose) lead to potent induction of cell death upon irradiation. The modifications in the protocol suggested here improve in vitro taPIT experiments that lack in vivo mechanisms of free BPD clearance (i.e., lymph and blood flow).

Site-Specific Conjugation of Native Antibody: Transglutaminase-Mediated Modification of a Conserved Glutamine While Maintaining the Primary Sequence and Core Fc Glycan via Trimming with an Endoglycosidase.

A versatile chemo-enzymatic tool to site-specifically modify native (nonengineered) antibodies is using transglutaminase (TGase, E.C. 2.3.2.13). With various amines as cosubstrates, this enzyme converts the unsubstituted side chain amide of glutamine (Gln or Q) in peptides and proteins into substituted amides (i.e., conjugates). A pleasant surprise is that only a single conserved glutamine (Gln295) in the Fc region of IgG is modified by microbial TGase (mTGase, EC 2.3.2.13), thereby providing a highly specific and generally applicable conjugation method. However, prior to the transamidation (access to the glutamine residue by mTGase), the steric hindrance from the nearby conserved N-glycan (Asn297 in IgG1) must be reduced. In previous approaches, amidase (PNGase F, EC 3.5.1.52) was used to completely remove the N-glycan. However, PNGase F also converts a net neutral asparagine (Asn297) to a negatively charged aspartic acid (Asp297). This charge alteration may markedly change the structure, function, and immunogenicity of an IgG antibody. In contrast, in our new method presented herein, the N-glycan is trimmed by an endoglycosidase (EndoS2, EC 3.2.1.96), hence retaining both the core N-acetylglucosamine (GlcNAc) moiety and the neutral asparaginyl amide. The trimmed glycan also reduces or abolishes Fc receptor-mediated functions, which results in better imaging agents by decreasing nonspecific binding to other cells (e.g., immune cells). Moreover, the remaining core glycan allows further derivatization such as glycan remodeling and dual conjugation. Practical and robust, our method generates conjugates in near quantitative yields, and both enzymes are commercially available.

A Nominal Group Technique to finalise Safewards Secure model and interventions for forensic mental health services.

WHAT IS KNOWN ON THE SUBJECT?: Safewards was developed for acute mental health units, and while could be effective in forensic mental health services, there are some gaps in the model for such services, where factors including offending behaviour and longer term care can have an influence. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: The importance of acknowledging and addressing responses related to offending behaviour in forensic mental health settings, while also understanding the vulnerability of the consumer group and responsibilities to the maintenance of professional boundaries. Enhancing collaboration with consumers/families/carers/supporters is important in a forensic mental health setting, and an important element of Safewards Secure. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: This study completes the development of Safewards Secure, designed to foster collaboration, address issues pertinent to forensic mental health settings to enhance implementation and acceptance of the model and reduce conflict and containment. ABSTRACT: INTRODUCTION: Safewards is a model developed for acute mental health settings designed to reduce conflict and containment; however, it requires adaptation to forensic mental health settings. AIM: To develop the Safewards Secure model, a model to assist forensic mental health services to reduce conflict and containment. METHOD: A literature review was conducted to elicit possible modifiers and adjustments to the interventions. A Nominal Group Technique was then used to engage forensic mental health experts who had experience implementing Safewards (n = 12) to seek feedback about the suggestions and reach consensus on the Safewards Secure model and interventions. Data were thematically analysed. RESULTS: Experts reached consensus on all suggestions, however, did recommend minor additions and modifications. Two themes were also interpreted: Safewards Secure is just as much for staff as it is for consumers, and the proposed additions encourage more meaningful staff to consumer collaboration. DISCUSSION: This study identified key challenges experienced by nurses working in forensic mental health settings, however, these challenges were not seen as insurmountable. The Safewards Secure model offers prompts and suggestions to encourage reflection, collaboration and a humanistic approach to care in forensic mental health settings. IMPLICATIONS FOR PRACTICE: Addressing reactions to offending behaviour and encouraging more collaboration might assist in ensuring a more person-centred approach to forensic mental health nursing care.

RETINAL DEPOSITS OF TRIAMCINOLONE-MOXIFLOXACIN AFTER DROPLESS CATARACT SURGERY.

PURPOSE: To report a case of epiretinal crystalline deposits observed on fundus examination and optical coherence tomography 2 years after transzonular intravitreal injection of triamcinolone-moxifloxacin (TriMoxi) during "dropless" cataract surgery. METHODS: Observational case report with literature review of toxic effects of intravitreal triamcinolone and differential diagnosis of retinal crystalline deposits. RESULTS: A 37-year-old asymptomatic pseudophakic man presented with refractile crystalline retinal deposits that had prompted an extensive systemic embolic workup. The systemic evaluation for emboli was negative. OCT imaging revealed that the crystalline deposits were confined to the anterior surface of the internal limiting membrane. Further historical inquiry determined that transzonular intravitreal triamcinolone-moxifloxacin injection had been performed at the time of cataract surgery 2 years earlier. CONCLUSION: Transzonular triamcinolone acetonide delivered during cataract surgery can deposit on the retinal surface for long periods. These epiretinal crystalline deposits are benign and generally do not interfere with visual acuity. Nevertheless, clinicians should be aware of this differential diagnosis because clinical misdiagnosis can lead to unwarranted evaluation and treatment.

Pharmacologic Targeting of the C-Terminus of Heat Shock Protein 90 Improves Neuromuscular Function in Animal Models of Charcot Marie Tooth X1 Disease.

Charcot-Marie-Tooth X1 (CMTX1) disease is an inherited peripheral neuropathy that arises from loss-of-function mutations in the protein connexin 32 (Cx32). CMTX1 currently lacks a pharmacologic approach toward disease management, and we have previously shown that modulating the expression of molecular chaperones using novologue therapy may provide a viable disease-modifying approach to treat metabolic and demyelinating neuropathies. Cemdomespib is an orally bioavailable novologue that manifests neuroprotective activity by modulating the expression of heat shock protein 70 (Hsp70). We examined if 1 to 5 months of daily cemdomespib therapy may improve neuropathic symptoms in three mouse models of CMTX1 (Cx32 deficient (Cx32def), T55I-Cx32def, and R75W-Cx32 mice). Daily drug therapy significantly improved motor nerve conduction velocity (MNCV) and grip strength in all three models, but the compound muscle action potential was only improved in Cx32def mice. Drug efficacy required Hsp70 as improvements in MNCV, and the grip strength was abrogated in Cx32def × Hsp70 knockout mice. Five months of novologue therapy was associated with improved neuromuscular junction morphology, femoral motor nerve myelination, reduction in foamy macrophages, and a decrease in Schwann cell c-jun levels. To determine if c-jun may be downstream of Hsp70 and necessary for drug efficacy, c-jun expression was specifically deleted in Schwann cells of Cx32def mice. While the deletion of c-jun worsened the neuropathy, cemdomespib therapy remained effective in improving MNCV and grip strength. Our data show that cemdomespib therapy improves CMTX1-linked neuropathy in an Hsp70-dependent but a c-jun-independent manner and without regard to the nature of the underlying Cx32 mutation.

Denoising multiplexed microscopy images in n-dimensional spectral space.

Hyperspectral fluorescence microscopy images of biological specimens frequently contain multiple observations of a sparse set of spectral features spread in space with varying intensity. Here, we introduce a spectral vector denoising algorithm that filters out noise without sacrificing spatial information by leveraging redundant observations of spectral signatures. The algorithm applies an n-dimensional Chebyshev or Fourier transform to cluster pixels based on spectral similarity independent of pixel intensity or location, and a denoising convolution filter is then applied in this spectral space. The denoised image may then undergo spectral decomposition analysis with enhanced accuracy. Tests utilizing both simulated and empirical microscopy data indicate that denoising in 3 to 5-dimensional (3D to 5D) spectral spaces decreases unmixing error by up to 70% without degrading spatial resolution.

Two-photon peak molecular brightness spectra reveal long-wavelength enhancements of multiplexed imaging depth and photostability.

The broad use of two-photon microscopy has been enabled in part by Ti:Sapphire femtosecond lasers, which offer a wavelength-tunable source of pulsed excitation. Action spectra have thus been primarily reported for the tunable range of Ti:Sapphire lasers (∼700-1000 nm). However, longer wavelengths offer deeper imaging in tissue via reduced scattering and spectral dips in water absorption, and new generations of pulsed lasers offer wider tunable ranges. We present the peak molecular brightness spectra for eight Alexa Fluor dyes between 700-1300 nm as a first-order surrogate for action spectra measured with an unmodified commercial microscope, which reveal overlapping long-wavelength excitation peaks with potential for multiplexed excitation. We demonstrate simultaneous single-wavelength excitation of six spectrally overlapping fluorophores using either short (∼790 nm) or long (∼1090 nm) wavelengths, and that the newly characterized excitation peaks measured past 1000 nm offer improved photostability and enhanced fidelity of linear spectral unmixing at depth compared to shorter wavelengths.

High-power light-emitting diode array design and assembly for practical photodynamic therapy research.

SIGNIFICANCE: Commercial lasers, lamps, and light-emitting diode (LED) light sources have stimulated the clinical translation of photodynamic therapy (PDT). Yet, the continued exploration of new photosensitizers (PSs) for PDT often requires separate activation wavelengths for each agent being investigated. Customized light sources for such research frequently come at significant financial or technical cost, especially when compounded over many agents and wavelengths. AIM: LEDs offer potential as a cost-effective tool for new PS and multi-PS photodynamic research. A low-cost-per-wavelength tool leveraging high-power LEDs to facilitate efficient and versatile research is needed to further accelerate research in the field. APPROACH: We developed and validated a high-power LED array system for benchtop PDT with a modular design for efficient switching between wavelengths that overcome many challenges in light source design. We describe the assembly of a low-cost LED module plus the supporting infrastructure, software, and protocols to streamline typical in vitro PDT experimentation. RESULTS: The LED array system is stable at intensities in excess of 100 mW / cm2 with 2.3% variation across the illumination field, competitive with other custom and commercial devices. To demonstrate efficacy and versatility, a primary ovarian cancer cell line was treated with two widely used PSs, aminolevulinic acid and verteporfin, using the LED modules at a clinically relevant 50 J / cm2 light dose that induced over 90% cell death for each treatment. CONCLUSIONS: Our work provides the community with a tool for new PS and multi-PS benchtop photodynamic research that, unlike most commercial light sources, affords the user a low barrier to entry and low-cost-per-wavelength with the goal of illuminating new insights at the forefront of PDT.

Site-specific Bioconjugation and Convergent Click Chemistry Enhances Antibody-Chromophore Conjugate Binding Efficiency.

Photosensitizer (PS)-antibody conjugates (photoimmunoconjugates, PICs) enable cancer cell-targeted photodynamic therapy (PDT). Nonspecific chemical bioconjugation is widely used to synthesize PICs but gives rise to several shortcomings. The conjugates are heterogeneous, and the process is not easily reproducible. Moreover, modifications at or near the binding sites alter both binding affinity and specificity. To overcome these limitations, we introduce convergent assembly of PICs via a chemo-enzymatic site-specific approach. First, an antibody is conjugated to a clickable handle via site-specific modification of glutamine (Gln) residues catalyzed by transglutaminase (TGase, EC 2.3.2.13). Second, the modified antibody intermediate is conjugated to a compatible chromophore via click chemistry. Utilizing cetuximab, we compared this site-specific conjugation protocol to the nonspecific chemical acylation of amines using N-hydroxysuccinimide (NHS) chemistry. Both the heavy and light chains were modified via the chemical route, whereas, only a glutamine 295 in the heavy chain was modified via chemo-enzymatic conjugation. Furthermore, a 2.3-fold increase in the number of bound antibodies per cell was observed for the site-specific compared with nonspecific method, suggesting that multiple stochastic sites of modification perturb the antibody-antigen binding. Altogether, site-specific bioconjugation leads to homogenous, reproducible and well-defined PICs, conferring higher binding efficiency and probability of clinical success.

Multichannel correlation improves the noise tolerance of real-time hyperspectral microimage mosaicking.

Live-subject microscopies, including microendoscopy and other related technologies, offer promise for basic biology research as well as the optical biopsy of disease in the clinic. However, cellular resolution generally comes with the trade-off of a microscopic field-of-view. Microimage mosaicking enables stitching many small scenes together to aid visualization, quantitative interpretation, and mapping of microscale features, for example, to guide surgical intervention. The development of hyperspectral and multispectral systems for biomedical applications provides motivation for adapting mosaicking algorithms to process a number of simultaneous spectral channels. We present an algorithm that mosaics multichannel video by correlating channels of consecutive frames as a basis for efficiently calculating image alignments. We characterize the noise tolerance of the algorithm by using simulated video with known ground-truth alignments to quantify mosaicking accuracy and speed, showing that multiplexed molecular imaging enhances mosaic accuracy by leveraging observations of distinct molecular constituents to inform frame alignment. A simple mathematical model is introduced to characterize the noise suppression provided by a given group of spectral channels, thus predicting the performance of selected subsets of data channels in order to balance mosaic computation accuracy and speed. The characteristic noise tolerance of a given number of channels is shown to improve through selection of an optimal subset of channels that maximizes this model. We also demonstrate that the multichannel algorithm produces higher quality mosaics than the analogous single-channel methods in an empirical test case. To compensate for the increased data rate of hyperspectral video compared to single-channel systems, we employ parallel processing via GPUs to alleviate computational bottlenecks and to achieve real-time mosaicking even for video-rate multichannel systems anticipated in the future. This implementation paves the way for real-time multichannel mosaicking to accompany next-generation hyperspectral and multispectral video microscopy.

Illuminating the Numbers: Integrating Mathematical Models to Optimize Photomedicine Dosimetry and Combination Therapies.

Cancer photomedicine offers unique mechanisms for inducing local tumor damage with the potential to stimulate local and systemic anti-tumor immunity. Optically-active nanomedicine offers these features as well as spatiotemporal control of tumor-focused drug release to realize synergistic combination therapies. Achieving quantitative dosimetry is a major challenge, and dosimetry is fundamental to photomedicine for personalizing and tailoring therapeutic regimens to specific patients and anatomical locations. The challenge of dosimetry is perhaps greater for photomedicine than many standard therapies given the complexity of light delivery and light-tissue interactions as well as the resulting photochemistry responsible for tumor damage and drug-release, in addition to the usual intricacies of therapeutic agent delivery. An emerging multidisciplinary approach in oncology utilizes mathematical and computational models to iteratively and quantitively analyze complex dosimetry, and biological response parameters. These models are parameterized by preclinical and clinical observations and then tested against previously unseen data. Such calibrated and validated models can be deployed to simulate treatment doses, protocols, and combinations that have not yet been experimentally or clinically evaluated and can provide testable optimal treatment outcomes in a practical workflow. Here, we foresee the utility of these computational approaches to guide adaptive therapy, and how mathematical models might be further developed and integrated as a novel methodology to guide precision photomedicine.

Community Culinary Workshops as a Nutrition Curriculum in a Preventive Medicine Residency Program.

Introduction: Obesity and diabetes are common diagnoses in the primary care population, especially in urban settings. Physicians providing preventive culinary and nutrition education to patients may be able to uniquely address these medical issues; however, culinary and nutrition education among medical residency programs is insufficient. Methods: We describe a pilot of a novel interactive approach to culinary and nutrition education focused on preventive medicine residents who were trained to provide culinary and nutrition skills to community members in three separate workshops. We developed and implemented a series of three culinary education workshops with 11, eight, and nine preventive medicine residents in each respective workshop. A total of 16 residents were invited to participate. A physician-chef facilitated each workshop with the residents within a community church kitchen and meeting area. We evaluated self-reported data on confidence level with culinary education and resident attitudes toward effects of culinary education on patient behaviors, as well as frequency of home-cooked meals and personal cooking competency, as indicators of resident proficiency. Results: A significant increase was noted in self-reported cooking competency after culinary workshops when evaluating change from the first workshop to the final workshop ( p = .038). Increases in home-cooking frequency and belief that lifestyle medicine impacts patient behavior were also observed but did not achieve statistical significance. Discussion: Culinary workshops are a useful tool to enhance nutrition education in a residency curriculum and may be an effective way to improve resident perceptions regarding the impact of nutrition education in the community.

Ibuprofen Decreases Spontaneous Activity and Enhances Nerve-Evoked Contractions to Minimize Mitomycin C-Induced Bladder Dysfunction.

Inflammation may play a causal role in urological side effects reported following intravesical mitomycin C (MMC). Our aim was to investigate the effects of the nonsteroidal anti-inflammatory drug ibuprofen (IBU) on the cytotoxic potency of MMC and the potential for IBU to protect against bladder dysfunction. Malignant (RT4, T24) and normal (UROtsa) urothelial lines were treated with MMC followed by ibuprofen, with cell viability and caspase-3 activity assessed. Female C57BL/6JArc mice (Saline/Control, MMC, Saline + IBU, and MMC + IBU) received intravesical treatment (1 hour) with saline or MMC (2 mg/ml), with IBU (1 mg/ml) delivered in drinking water (for 7 days). Voiding pattern analysis was conducted prior to and following (1, 3, 7 days) treatment. A whole-bladder preparation was used to assess compliance, contractile responses, and urothelial-mediator release. Ibuprofen selectively increased the cytotoxic potency of MMC and caspase-3 activity in both malignant cells lines but not in UROtsa. MMC significantly increased voiding frequency at 24 hours and 3 days, whereas administration of ibuprofen significantly reduced this effect. MMC significantly increased the frequency of spontaneous contractions from 2.3 ± 0.5 contractions/min in saline controls to 4.8 ± 0.16 contractions/min, with ibuprofen protecting against this change. Interestingly, although nerve-evoked responses were not altered by MMC, they were increased in both IBU groups. Ibuprofen improved voiding dysfunction following MMC treatment by reducing spontaneous phasic activity and enhancing nerve-mediated contractions. Ibuprofen use in bladder cancer patients may help to minimize the urological adverse effects associated with intravesical MMC.

BINARY NEUTRON STAR MERGERS: A JET ENGINE FOR SHORT GAMMA-RAY BURSTS.

We perform magnetohydrodynamic simulations in full general relativity (GRMHD) of quasi-circular, equal-mass, binary neutron stars that undergo merger. The initial stars are irrotational, n = 1 polytropes and are magnetized. We explore two types of magnetic-field geometries: one where each star is endowed with a dipole magnetic field extending from the interior into the exterior, as in a pulsar, and the other where the dipole field is initially confined to the interior. In both cases the adopted magnetic fields are initially dynamically unimportant. The merger outcome is a hypermassive neutron star that undergoes delayed collapse to a black hole (spin parameter a/MBH ~ 0.74) immersed in a magnetized accretion disk. About 4000M ~ 60(MNS/1.625M⊙) ms following merger, the region above the black hole poles becomes strongly magnetized, and a collimated, mildly relativistic outflow-an incipient jet-is launched. The lifetime of the accretion disk, which likely equals the lifetime of the jet, is Δ t ~ 0.1 (MNS/1.625M⊙) s. In contrast to black hole-neutron star mergers, we find that incipient jets are launched even when the initial magnetic field is confined to the interior of the stars.

Minority Underrepresentation in Academia: Factors Impacting Careers of Surgery Residents.

BACKGROUND: Underrepresentation of minorities within academic surgery is an ever present problem with a profound impact on healthcare. The factors influencing surgery residents to pursue an academic career have yet to be formally investigated. We sought to elucidate these factors, with a focus on minority status. METHODS: A web-based questionnaire was sent to all administered to all ACGME-accredited general surgery programs in the United States. The main outcome was the decision to pursue a fully academic versus non-academic career. Multivariable logistic regression was used to identify characteristics impacting career choice. RESULTS: Of the 3,726 residents who received the survey, a total of 1,217 residents completed it - a response rate of 33%. Forty-seven percent planned to pursue non-academic careers, 35% academic careers, and 18% were undecided. There was no association between underrepresented minority status and academic career choice (Odds Ratio = 1.0, 95% Confidence Interval 0.6 - 1.6). Among all residents, research during training (OR=4.0, 95% CI 2.7-5.9), mentorship (OR=2.1, 95% CI 1.6-2.9), and attending a residency program requiring research (OR=2.3, 95% CI 1.5-3.4) were factors associated with choosing an academic career. When the analysis was performed among only senior residents (i.e., 4th and 5th year residents), a debt burden >$150,000 was associated with choosing a non-academic career (OR=0.4, 95% CI 0.1-0.9). CONCLUSIONS: Underrepresented minority status is not associated with career choice. Intentional recruitment of minorities into research-oriented training programs, increased mentorship and research support among current minority residents, and improved financial options for minorities may increase the number choosing an academic surgical career.

Combined Dependence of Nanoconfined Tg on Interfacial Energy and Softness of Confinement.

We employ molecular dynamics simulations of nanolayered polymers to systematically quantify the dependence of Tg nanoconfinement effects on interfacial energy and the "softness" of confinement. Results indicate that nanoconfined Tg depends linearly on interfacial adhesion energy, with a slope that scales exponentially with the ratio of the bulk Debye-Waller factors ⟨u2⟩ of the confined and confining materials. These trends, together with a convergence at low interfacial adhesion energy to the Tg of an equivalent freestanding film, are captured in a single functional form, with only three parameters explicitly referring to the confined state. The observed dependence on ⟨u2⟩ indicates that softness of nanoconfinement should be defined in terms of the relative high frequency shear moduli, rather than low frequency moduli or relaxation times, of the confined and confining materials.

Vitamin D deficiency among newborns in Amman, Jordan.

OBJECTIVE: Vitamin D deficiency is well recognized in selected Middle Eastern countries, but neonatal vitamin D status is not well studied in Jordan and other nearby countries. The aim of this study is to determine the prevalence of vitamin D deficiency in Jordanian newborns and risk factors associated with low levels. METHODS: This is a prospective cohort study of newborn infants who were delivered at the Al Bashir Government Hospital in Amman, Jordan, from January 31, 2010, to January 27, 2011. Heel stick blood samples for 25-hydroxyvitamin D [25(OH)D] levels were obtained within 96 hours of birth. Maternal dress pattern, vitamin supplementation, smoke exposure during pregnancy, mode of delivery, gestational age, and birth weight were documented. RESULTS: Samples were obtained from 3,731 newborns. Median gestational age was 39 weeks, median birth weight was 3.1 kilograms, median maternal age was 27 years, and median newborn 25(OH)D level was 8.6nmol/L. A total of 3,512 newborns (94.1%) in this study were vitamin D deficient (< 50 nmol/L). Lower gestational age, maternal smoke exposure, and birth during winter months were associated with lower infant vitamin D levels, while vitamin D supplementation and time spent outside during pregnancy were associated with higher vitamin D levels. CONCLUSIONS: The prevalence of severely low vitamin D levels in newborn infants in Amman, Jordan, is substantial, even in newborns born during the spring and summer months. Vitamin D supplementation is needed in this population.

Solitary waves in soybean induced by localized thermal stress.

Action potentials in higher plants are believed to be the information carriers in intercellular and intracellular communication in the presence of an environmental stressor. Plant electrophysiologists have recorded long distance electrical signaling in higher plants during the last two hundred years. Reproducing the duration, speed of propagation, and the shape of the action potential is challenging. Early measurements revealed that the speed of action potential propagation in plants is extremely slow - from 0.1 mm/s to 20 cm/s, although many faster plant responses to stress have been recorded as well. We hypothesized that this discrepancy is most likely due to the artifacts of aliasing from slow registration systems. In this study, we employ real time measurements using modern data acquisition techniques to detect ultra fast action potentials in green plants induced by localized heat stress. Thermal shock or heat stress is the most common environmental stress. Based on more sophisticated measuring techniques, we show that plants transmit solitary waves and that the speed of action potential propagation in green plants is similar to the speed of action potentials in mammalians, varying from a few meters per second up to 105 m/s. Possible pathways for electrical signal propagation in vascular plants are discussed.

Electrical signaling in Aloe vera induced by localized thermal stress.

Action potentials in higher plants are theorized as the information carriers in intercellular and intracellular communication in the presence of environmental stressors. Among the most common stressors is heat shock. Under stressful conditions, the response reactions of plant tissues and organs can be local or transmitted over long distances. In this article, the speeds of propagation of thermally induced action potentials in green plants are discussed, and their speeds were found to be comparable to those occurring in various mammalian species. These rapid action potentials in green plants were recorded in real time using modern data acquisition techniques. According to our measurements, a single application of localized heat stress induces fast action potentials in Aloe vera (67 m/s). Electrical signals propagated along all leaves of the A. vera plants were studied. Possible pathways for electrical signal propagation in vascular plants are also discussed.