RUTIN, a widely consumed flavonoid, that commonly induces hormetic effects

Rutin is a flavonoid present in numerous fruits and vegetables and therefore widely consumed by humans. It is also a popular dietary supplement of 250-500 mg/day. There is considerable consumer interest in rutin due to numerous reports in the biomedical literature of its multi-system chemo-preventive properties. The present paper provides the first assessment of rutin-induced hormetic concentration/dose responses, their quantitative features and mechanistic basis, along with their biological, biomedical, clinical, and public health implications. The findings indicate that rutin-induced hormetic dose responses are widespread, being reported in numerous biological models and cell types for a wide range of endpoints. Of critical importance is that the optimal hormetic findings shown in in vitro systems are currently not achievable for human populations due to low gastrointestinal tract bioavailability. These findings have the potential to strengthen future experimental studies with rutin, particularly concerning study design parameters.

Taurine induces hormesis in multiple biological models: May have transformative implications for overall societal health

This paper represents the first integrative assessment and documentation of taurine-induced hormetic effects in the biological and biomedical areas, their dose response features, mechanistic frameworks, and possible public health, therapeutic and commercial applications. Taurine-induced hormetic effects are documented in a wide range of experimental models, cell types and for numerous biological endpoints, with most of these experimental findings being reported within the past five years. It is suggested that the concept of hormesis may have a transformative effect on taurine research and its public health and therapeutic applications.

Flavonoids commonly induce hormetic responses

The present paper provides a new perspective of previously published findings by Siwak (Food Chem 141:1227-1241, 2013) which showed that 15 structurally diverse flavonoids reduced toxicity (i.e., enhanced cell viability) from hypochlorite using the MTT assay within a pre-conditioning experimental protocol, with each agent showing a similar biphasic concentration response relationship. We use this Commentary to point out that each of the concentration response relationships are consistent with the hormetic dose response. The paper of Siwak (Food Chem 141:1227-1241, 2013) is unique in that it provides a comparison of a relatively large number of agents using the identical experimental protocol.

Hormesis determines lifespan

This paper addresses how long lifespan can be extended via multiple interventions, such as dietary supplements [e.g., curcumin, resveratrol, sulforaphane, complex phytochemical mixtures (e.g., Moringa, Rhodiola)], pharmaceutical agents (e.g., metformin), caloric restriction, intermittent fasting, exercise and other activities. This evaluation was framed within the context of hormesis, a biphasic dose response with specific quantitative features describing the limits of biological/phenotypic plasticity for integrative biological endpoints (e.g., cell proliferation, memory, fecundity, growth, tissue repair, stem cell population expansion/differentiation, longevity). Evaluation of several hundred lifespan extending agents using yeast, nematode (Caenorhabditis elegans), multiple insect and other invertebrate and vertebrate models (e.g., fish, rodents), revealed they responded in a manner [average (mean/median) and maximum lifespans] consistent with the quantitative features [i.e., 30-60% greater at maximum (Hormesis Rule)] of the hormetic dose response. These lifespan extension features were independent of biological model, inducing agent, endpoints measured and mechanism. These findings indicate that hormesis describes the capacity to extend life via numerous agents and activities and that the magnitude of lifespan extension is modest, in the percentage, not fold, range. These findings have important implications for human aging, genetic diseases/environmental stresses and lifespan extension, as well as public health practices and long-term societal resource planning.

Quercetin induces its chemoprotective effects via hormesis

Quercetin is a polyphenol present in numerous fruits and vegetables and therefore widely consumed by humans with average daily dietary intakes of 10-20 mg/day. It is also a popular dietary supplement of 250-1000 mg/day. However, despite the widespread consumer interest in quercetin, due to its possible chemopreventive properties, the extensively studied quercetin presents a highly diverse and complex array of biological effects. Consequently, the present paper provides the first assessment of quercetin-induced hormetic concentration/dose responses, their quantitative features and mechanistic foundations, and their biological, biomedical, clinical, and public health implications. The findings indicate that quercetin-induced hormetic dose responses are widespread, being independent of biological model, cell type, and endpoint. These findings have the potential to enlighten future experimental studies with quercetin especially with respect to study design parameters and may also affect the appraisal of possible public health benefits and risks associated with highly diverse consumer consumption practices.

Polyamines and hormesis: Making sense of a dose response dichotomy

The diverse biological effects of polyamines (putrescine, spermidine and spermine) were reviewed in the context of hormesis in an integrative manner for the first time. The findings illustrate that each of these polyamines commonly induces hormetic dose responses in a wide range of biological models and types of cells for multiple endpoints in numerous plant species and animal models. Plant research emphasized preconditioning experimental studies in which the respective polyamines conferred some protection against the damaging effects of a broad range of environmental stressors such as drought, salinity, cold/heat, heavy metals and UV-damage in an hormetic manner. Polyamine-based animal hormesis studies emphasized biomedical endpoints such as longevity and neuroprotection. These findings have important biological and biomedical implications and should guide experimental designs of low dose investigations.

Naringin commonly acts via hormesis

The present paper provides the first integrative assessment of the capacity of naringin and its metabolite, naringenin, to induce hormetic dose responses within a broad range of experimental biomedical models. The findings indicate that these agents commonly induced protective effects that are typically mediated via hormetic mechanisms leading to biphasic dose-response relationships. The maximum protective effects are generally modest, 30-60 % greater than control group values. The range of experimental findings with these agents has been reported for models with various neurodegenerative diseases, nucleus pulpous cells (NPCs) located within intravertebral discs, several types of stem cells (i.e., bone marrow, amniotic fluid, periodontal, endothelial) as well as cardiac cells. These agents also were effective within preconditioning protocols protecting against environmental toxins such as ultraviolet radiation (UV), cadmium, and paraquat. The mechanism(s) by which the hormetic responses mediates these biphasic dose responses is complex but commonly involves the activation of nuclear factor erythroid 2-related factor (Nrf2), an increasingly recognized regulator of cellular resistance to oxidants. Nrf2 appears to play a role in controlling the basal and induced expression of an array of antioxidant response element-dependent genes to regulate oxidant exposure's physiological and pathophysiological outcomes. Hence its importance in the assessment of toxicologic and adaptive potential is likely to be significant.

Moringa induces its beneficial effect via hormesis

Moringa oleifera, a traditional Indian herb, is widely known for its capacity to induce antioxidant, anti-inflammatory and other chemoprotective effects in a broad range of biomedical models. These perspectives have led to an extensive number of studies using various moringa extracts to evaluate its capacity to protect biological systems from oxidative stress and to explore whether it could be used to slow the onset of numerous age-related conditions and diseases. Moringa extracts have also been applied to prevent damage to plants from oxidative and saline stresses, following hormetic dose–response patterns. The present paper provides the first integrated and mechanistically based assessment showing that moringa extracts commonly induce hormetic dose responses and that many, perhaps most, of the beneficial effects of moringa are due to its capacity to act as an hormetic agent.

Hormesis, biological plasticity, and implications for clinical trial research

The present paper identifies a critical factor that leads to false negative results (i.e., failing to indicate efficacy when beneficial results did occur) in randomized human drug trials. The paper demonstrates that human performance can only be enhanced by a maximum of 30-60% as described by the hormetic dose response which defines the limits of biological plasticity. However, human epidemiological/clinical trials typically contain such extensive variability that often requires responses greater than 2-3 times control group responses to show statistical significance. Thus, many potentially beneficial agents may be missed because the clinical trial fails to recognize and take into consideration the limits of biological plasticity. The paper proposes that this hormesis-biological plasticity-clinical trial conundrum can be addressed successfully via the use of a weight-of-evidence methodology similar to that used by regulatory agencies such as EPA in environmental assessment of chemical toxicity.

Protective effects of alpha lipoic acid (ALA) are mediated by hormetic mechanisms

The endogenous and dietary agent, alpha lipoic acid (ALA) is evaluated for its capacity to induce a broad spectrum of adaptive responses via hormetic dose responses and their underlying mechanisms. ALA was shown to induce hormetic effects in a wide range of experimental models within in vitro and in vivo experimental settings which included direct exposure and pre- and post-conditioning experimental protocols. The hormetic effects occur in a broad range of organ systems, including the brain, heart, kidney and other tissues, with possible public health and clinical/therapeutic applications linked to reducing the onset and progression of neurogenerative diseases and also in the preservation of sperm health and functionality during cryopreservation. This paper provides the first integrated assessment of ALA-induced hormetic dose responses. Underlying mechanisms that mediated the occurrence of ALA-induced hormetic effects involved the induction of low levels of ROS that activate key cell signaling antioxidant (e.g. Nrf2) pathways.

Rhodiola rosea and Salidroside commonly induce hormesis, with particular focus on longevity and neuroprotection

The biological effects of Rhodiola rosea extracts and one of its major constituents, Salidroside, were evaluated for their capacity to induce hormesis/hormetic effects. The findings indicate that the Rhodiola rosea extracts and Salidroside commonly induce hormetic dose responses within a broad range of biological models, cell types and across a broad range of endpoints, with particular emphasis on longevity and neuroprotective endpoints. This paper represents the first integrative documentation and assessment of Rhodiola rosea extracts and Salidroside induction of hormetic effects. These findings have important biomedical applications and should have an important impact with respect to critical study design, dose selection and other experimental features.

Nitric oxide and hormesis

This present paper provides an assessment of the occurrence of nitric oxide (NO)-induced hormetic-biphasic dose/concentration relationships in biomedical research. A substantial reporting of such NO-induced hormetic effects was identified with particular focus on wound healing, tumor promotion, and sperm biology, including mechanistic assessment and potential for translational applications. Numerous other NO-induced hormetic effects have been reported, but require more development prior to translational applications. The extensive documentation of NO-induced biphasic responses, across numerous organs (e.g., bone, cardiovascular, immune, intestine, and neuronal) and cell types, suggests that NO-induced biological activities are substantially mediated via hormetic processes. These observations are particularly important because broad areas of NO biology are constrained by the quantitative features of the hormetic response. This determines the amplitude and width of the low dose stimulation, affecting numerous biomedical implications, study design features (e.g., number of doses, dose spacing, sample sizes, statistical power), and the potential success of clinical trials.

Lithium and hormesis: Enhancement of adaptive responses and biological performance via hormetic mechanisms

Biomedical and consumer interest in the health-promoting properties of pure single entities of known or unknown chemical constituents and mixtures has never been greater. Since its "rediscovery" in the 1950s, lithium is an example of such a constituent that represents an array of scientific and public health challenges and medical potentials that may now be understood best when seen through the lens of the dose-response paradigm known as hormesis. The present paper represents the first review of the capacity of lithium to induce hormetic dose responses in a broad range of biological models, organ systems, and endpoints. Of significance is that the numerous hormetic findings occur with extensive concentration/dose response evaluations with the optimal dosing being similar across multiple organ systems. The particular focus of these hormetic dose-response findings was targeted to research with a broad spectrum of stem cell types and neuroprotective effects. These findings suggest that lithium may have critically valuable systemic effects with respect to those therapeutically treated with lithium as well as for exposures that may be achieved via dietary intervention.

Boron enhances adaptive responses and biological performance via hormetic mechanisms

Boron is shown in the present review to induce hormetic dose responses in a broad range of biological models, organ systems and endpoints. Of particular importance is that numerous hormetic findings have been reported with whole animal studies, with extensive dose response evaluations with the optimal dosing being similar across multiple organ systems. These findings appear to be underappreciated and suggest that boron may have clinically significant systemic effects beyond that of its putative and more subtle essentiality functions. The re-exploration of boron's bioactivity as seen through hormetic mechanisms may also underscore the value of this approach to the assessment of micronutrient effects in human health and disease.

Hormesis mediates platelet-rich plasma and wound healing

Platelet-rich plasma (PRP) has become an accepted and general wound healing approach with an extremely wide range of applications. Despite considerable diversity in the composition of platelet-rich plasma products that are applied in specific wound healing usage, it is widely recognised that such diverse platelet-rich plasma complex mixtures routinely display hormetic-like biphasic concentrations that are independent of the tissue treated and endpoints measured. The present paper is the first to place the area of platelet-rich plasma-biomedical research and applications within an hormetic framework. The platelet-rich plasma area is also unique as it represents the application of the hormetic concept to the issue of complex biological mixtures.

Hormesis: Wound healing and keratinocytes

Hormetic dose responses (i.e., a biphasic dose/concentration response characterized by a low dose stimulation and a high dose inhibition) are shown herein to be commonly reported in the dermal wound healing process, with the particular focus on cell viability, proliferation, and migration of human keratinocytes in in vitro studies. Hormetic responses are induced by a wide range of substances, including endogenous agents, numerous drug and nanoparticle preparations and especially plant derived extracts, including many well-known dietary supplements as well as physical stressor agents, such as low-level laser treatments. Detailed mechanistic studies have identified common signaling pathways and their cross-pathway communications that mediate the hormetic dose responses. These findings suggest that the concept of hormesis plays a fundamental role in wound healing, with important potential implications for agent screening and evaluation, as well as clinical strategies.

Hormesis and neural stem cells

This paper provides a detailed identification and assessment of hormetic dose responses in neural stem cells (NSCs) as identified in a number of animal models and human tissues, with particular emphasis on cell proliferation and differentiation. Hormetic dose responses were commonly observed following administration of a number of agents, including dietary supplements [e.g., berberine, curcumin, (-)-epigallocatechin-3-gallate (EGCG), Ginkgo Biloba, resveratrol], pharmaceuticals (e.g., lithium, lovastatin, melatonin), endogenous ligands [e.g., hydrogen sulfide (H₂S), magnesium, progesterone, taurine], environmental contaminants (e.g., arsenic, rotenone) and physical agents [e.g., hypoxia, ionizing radiation, electromagnetic radiation (EMF)]. These data indicate that numerous agents can induce hormetic dose responses to upregulate key functions of such as cell proliferation and differentiation in NSCs, and enhance resilience to inflammatory stresses. The paper assesses both putative mechanisms of hormetic responses in NSCs, and the potential therapeutic implications and application(s) of hormetic frameworks in clinical approaches to neurological injury and disease.

Human dental pulp stem cells and hormesis

This paper represents the first assessment of hormetic dose responses by human dental pulp stem cells (hDPSCs) with particular emphasis on cell renewal (proliferation) and differentiation. Hormetic dose responses were commonly reported in this model, encompassing a broad range of chemicals, including principally pharmaceuticals (e.g., metformin and artemisinin), dietary supplements/extracts from medicinal plants (e.g., berberine, N-acetyl-L-cysteine, and ginsenoside Rg1) and endogenous agents (e.g., ATP, TNF-α). The paper assesses mechanistic foundations of the hDPSCs hormetic dose responses for both cell proliferation and cell differentiation, study design considerations, and therapeutic implications.

Metformin-enhances resilience via hormesis

The present paper demonstrates that metformin (MF) induced a broad spectrum of hormetic biphasic dose responses in a wide range of experimental studies, affecting multiple organ systems, cell types, and endpoints enhancing resilience to chemical stresses in preconditioning and co-current exposure protocols. Detailed mechanistic evaluations indicate that MF-induced hormetic-adaptive responses are mediated often via the activation of adenosine monophosphate-activated kinase (AMPK) protein and its subsequent upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2). Hormesis-induced protective responses by MF are largely mediated via a vast and highly integrated anti-inflammatory molecular network that enhances longevity and delays the onset and slows the progression of neurodegenerative and other chronic diseases.

Low-dose radiation therapy (LDRT) for COVID-19 and its deadlier variants

Coronavirus variants are gaining strongholds throughout the globe. Despite early signals that SARS-CoV-2 coronavirus case numbers are easing up in the United States and during the middle of a (not so easy) vaccination roll out, the country has passed a grim landmark of 600,000 deaths. We contend that these numbers would have been much lower if the medical community undertook serious investigations into the potential of low doses of radiation (LDRT) as a mainstream treatment modality for COVID-19 pneumonia. LDRT has been posited to manifest anti-infectious and anti-inflammatory properties at doses of 0.3-1.0 Gy via the activation of the Nrf-2 pathway. Although some researchers are conducting well-designed clinical trials on the potential of LDRT, the deep-rooted, blind, and flawed acceptance of the Linear No-Threshold (LNT) model for ionizing radiation has led to sidelining of this promising therapy and thus unimaginable numbers of deaths in the United States.

Luteolin and hormesis

The present paper provides the first integrated assessment of the capacity of luteolin to induce hormetic dose responses. It was shown that luteolin induced hormetic responses in multiple biological systems, including enhancing neuroprotection in various experimental model disease systems, improving wounding healing, especially in experimental models of high-risk population subgroups, such as diabetics, as well as enhancing osteogenesis in models of osteoporosis. The mechanistic basis for the luteolin-induced hormetic dose responses has been demonstrated to commonly involve the upregulation of the nuclear factor erythroid-derived 2-like 2 (Nrf2), which mediates the extensive range of anti-inflammatory effects induced by luteolin in multiple cell types and organ systems.

Low-dose radiation therapy for osteoarthritis and enthesopathies: a review of current data

BACKGROUND

Osteoarthritis (OA), the most common degenerative joint disease, is associated with severe functional limitation and impairment of quality of life. Numerous reports have documented the clinical efficacy of low-dose radiotherapy (LD-RT) in the management of various inflammatory disorders, including OA. In this paper, we assessed the clinical literature involving the use of LD-RT in the treatment of OA, its dose-response features, possible underlying mechanistic features, and optimal therapeutic dose range.

METHODS

We carried out a systematic review based on the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements and evaluated articles meeting the inclusion criteria for this review.

RESULTS

A total of 361 articles were identified from databases, such as Scopus, PubMed, Embase, and Science Direct out of which 224 articles were duplicates and were discarded. Of the remaining 137 articles, 74 articles were un-related, 27 articles were review articles, eight were conference abstracts, three were letters, two were editorials, two were notes, and one was a book chapter. Finally, 20 articles met all the inclusion criteria and were included in this systematic review.

DISCUSSION

Several single-arm retrospective/prospective studies showed advantages for LD-RT in the management of OA in terms of pain relief, improvement of mobility and function, and showed minimal side effects. Mechanistic considerations involve positive subcellular effects mediated by the activation of a nuclear factor erythroid 2-related transcription factor (Nrf2) mediated antioxidant response. Further research on both the short- and long-term effects of LD-RT on OA and other inflammatory disorders is recommended.

Nrf2 activation putatively mediates clinical benefits of low-dose radiotherapy in COVID-19 pneumonia and acute respiratory distress syndrome (ARDS): Novel mechanistic considerations

Novel mechanistic insights are discussed herein that link a single, nontoxic, low-dose radiotherapy (LDRT) treatment (0.5–1.0 Gy) to (1) beneficial subcellular effects mediated by the activation of nuclear factor erythroid 2-related transcription factor (Nrf2) and to (2) favorable clinical outcomes for COVID-19 pneumonia patients displaying symptoms of acute respiratory distress syndrome (ARDS). We posit that the favorable clinical outcomes following LDRT result from potent Nrf2-mediated antioxidant responses that rebalance the oxidatively skewed redox states of immunological cells, driving them toward anti-inflammatory phenotypes. Activation of Nrf2 by ionizing radiation is highly dose dependent and conforms to the features of a biphasic (hormetic) dose–response. At the cellular and subcellular levels, hormetic doses of <1.0 Gy induce polarization shifts in the predominant population of lung macrophages, from an M1 pro-inflammatory to an M2 anti-inflammatory phenotype. Together, the Nrf2-mediated antioxidant responses and the subsequent shifts to anti-inflammatory phenotypes have the capacity to suppress cytokine storms, resolve inflammation, promote tissue repair, and prevent COVID-19-related mortality. Given these mechanistic considerations—and the historical clinical success of LDRT early in the 20th century—we opine that LDRT should be regarded as safe and effective for use at almost any stage of COVID-19 infection. In theory, however, optimal life-saving potential is thought to occur when LDRT is applied prior to the cytokine storms and before the patients are placed on mechanical oxygen ventilators. The administration of LDRT either as an intervention of last resort or too early in the disease progression may be far less effective in saving the lives of ARDS patients.

Molecular and Genetic Characterization of Natural Variants of HIV-1 Nef Gene from North India and its Functional Implication in Down-Regulation of MHC-I and CD-4

BACKGROUND

HIV-1 Nef is an important accessory protein with multiple effector functions. Genetic studies of the HIV-1 Nef gene show extensive genetic diversity and the functional studies have been carried out mostly with Nef derived from regions dominated by subtype B (North America & Europe).

OBJECTIVE

This study was carried out to characterize genetic variations of the Nef gene from HIV-1 infected individuals from North India and to find out their functional implications.

METHODS

The unique representative variants were sub-cloned in a eukaryotic expression vector and further characterized with respect to their ability to downregulate cell surface expression of CD4 and MHC-1 molecules.

RESULTS

The phylogenetic analysis of Nef variants revealed sequence similarity with either consensus subtype B or B/C recombinants. Boot scan analysis of some of our variants showed homology to B/C recombinant and some to wild type Nef B. Extensive variations were observed in most of the variants. The dN/dS ratio revealed 80% purifying selection and 20% diversifying selection implying the importance of mutations in Nef variants. Intracellular stability of Nef variants differed greatly when compared with wild type Nef B and C. There were some variants that possessed mutations in the functional domains of Nef and responsible for its differential CD4 and MHC-1 downregulation activity.

CONCLUSION

We observed enhanced biological activities in some of the variants, perhaps arising from amino acid substitutions in their functional domains. The CD4 and MHC-1 down-regulation activity of Nef is likely to confer immense survival advantage allowing the most rare genotype in a population to become the most abundant after a single selection event.

Chloroquine commonly induces hormetic dose responses

The use of chloroquine in the treatment of COVID-19 has received considerable attention. The recent intense focus on this application of chloroquine stimulated an investigation into the effects of chloroquine at low doses on highly biologically-diverse models and whether it may induce hormetic-biphasic dose response effects. The assessment revealed that hormetic effects have been commonly induced by chloroquine, affecting numerous cell types, including tumor cell lines (e.g. human breast and colon) and non-tumor cell lines, enhancing viral replication, sperm motility, various behavioral endpoints as well as decreasing risks of convulsions, and enhancing a spectrum of neuroprotective responses within a preconditioning experimental framework. These diverse and complex findings indicate that hormetic dose responses commonly occur with chloroquine treatment with a range of biological models and endpoints. These findings have implications concerning study design features including the number and spacing of doses, and suggest a range of possible clinical concerns and opportunities depending on the endpoint considered.

Preparation and Characterization of Nb-1Zr-0.1C Alloy Suitable for Liquid Metal Coolant Channels of High Temperature Reactors

A novel process comprising of aluminothermic coreduction of mixed oxides followed by arc and electron beam melt refining was developed for preparation of Nb-1Zr-0.1C alloy. The parameters of the process were optimized by considering the thermodynamic (heat) and mass balance phenomenon. The ingots of the homogenized alloy produced after electron beam melt consolidation were further extruded into tubes. The alloy was vacuum annealed at 1350–1800 °C to study the stability of Nb2C and Nb(Zr)C carbide precipitates in the microstructure. Compression creep tests conducted at 900 and 1000 °C revealed a stress exponent value of 2 and activation energy of 508 kJ/mol. NbSi2-based coatings were developed on the Nb-1Zr-0.1C alloy tubes using pack siliconizing process. The coated alloy was tested for oxidation at 1250 °C, and corrosion in liquid lead-bismuth eutectic (LBE) alloy at 875 °C for prolonged duration. The silicide-coated alloy showed superior oxidation and LBE corrosion resistance at high temperatures. The alloy was found to be a promising material for coolant channels of high temperature reactors.

Neurofilament results for the phase II neuroprotection study of phenytoin in optic neuritis

BACKGROUND

A randomized trial of phenytoin in acute optic neuritis (ON) demonstrated a 30% reduction in retinal nerve fiber layer (RNFL) loss with phenytoin versus placebo. Here we present the corresponding serum neurofilament analyses.

METHODS

Eighty-six acute ON cases were randomized to receive phenytoin (4-6 mg/kg/day) or placebo for 3 months, and followed up for 6 months. Serum was collected at baseline, 3 and 6 months for analysis of neurofilament heavy chain (NfH) and neurofilament light chain (NfL).

RESULTS

Sixty-four patients had blood sampling. Of these, 58 and 56 were available at 3 months, and 55 and 54 were available at 6 months for NfH and NfL, respectively. There was no significant correlation between serum NfH and NfL at the time points tested. For NfH, the difference in mean placebo - phenytoin was -44 pg/ml at 3 months (P = 0.019) and -27 pg/ml at 6 months (P = 0.234). For NfL, the difference was 1.4 pg/ml at 3 months (P = 0.726) and -1.6 pg/ml at 6 months (P = 0.766).

CONCLUSIONS

At 3 months, there was a reduction in NfH, but not NFL, in the phenytoin versus placebo group, while differences at 6 months were not statistically significant. This suggests a potential neuroprotective role for phenytoin in acute ON, with the lower NfH at 3 months, when levels secondary to degeneration of the anterior visual pathway are still elevated, but not at 6 months, when levels have normalized.

Feasibility of Treatment Planning System in Localizing the COVID-19 Pneumonia Lesions and Evaluation of Volume Indices of Lung Involvement

Background and purpose

To assess the feasibility of a treatment planning system in localizing, contouring, and targeting lung lesions along with an evaluation of volume indices of lung involvement in patients with COVID-19 pneumonia.

Methods

We evaluated 10 patients with PCR-confirmed COVID-19 pneumonia. The CT images were imported into the ISOgray® treatment planning system to anatomically define and contour the volumes of the pulmonary lesions, the lungs, and other nearby organs.

Results

The ratio of lung lesion volume to lung volume in this study was 0.11 ± 0.13 (11.13%). The highest mean biosynthesis ratio of lung lesions was 0.36. The ratio of lesion volume in the left lung of patients with the highest volume of involvement, was 0.44, and the ratio of lesion volume in the right lung of these patients was 0.27 (approximately 1.5 times more in the left lung than the right lung). On average, CTDIvol and DLP for all patients studied in our study were 11.22 ± 2.47 mGy and 354.20 ± 65.11 mGy.cm.

Conclusion

We reported the feasibility of using a treatment planning system in localizing COVID-19 pulmonary lesions and its validity in the volumetric assessment of infected lung regions.

Hormesis: A potential strategic approach to the treatment of neurodegenerative disease

This review describes neuroprotective effects mediated by pre- and post-conditioning-induced processes that act via the quantitative features of the hormetic dose response. These lead to the development of acquired resilience that can protect neuronal systems from endogenous and exogenous stresses and insult. Particular attention is directed to issues of dose optimization, inter-individual variation, and potential ways to further study and employ hormetic-based preconditioning approaches in medical and public health efforts to treat and prevent neurodegenerative disease.

Low dose radiation therapy as a potential life saving treatment for COVID-19-induced acute respiratory distress syndrome (ARDS)

The new coronavirus COVID-19 disease caused by SARS-CoV-2 was declared a global public health emergency by WHO on Jan 30, 2020. Despite massive efforts from various governmental, health and medical organizations, the disease continues to spread globally with increasing fatality rates. Several experimental drugs have been approved by FDA with unknown efficacy and potential adverse effects. The exponentially spreading pandemic of COVID-19 deserves prime public health attention to evaluate yet unexplored arenas of management. We opine that one of these treatment options is low dose radiation therapy for severe and most critical cases. There is evidence in literature that low dose radiation induces an anti-inflammatory phenotype that can potentially afford therapeutic benefit against COVID-19-related complications that are associated with significant morbidity and mortality. Herein, we review the effects and putative mechanisms of low dose radiation that may be viable, useful and of value in counter-acting the acute inflammatory state induced by critical stage COVID-19.

Effect of prophylactic granulocyte-colony stimulating factor (G-CSF) on acute hematological toxicity in medulloblastoma patients during craniospinal irradiation (CSI)

OBJECTIVES

Haematological toxicity and treatment breaks are common during cranio-spinal irradiation (CSI) due to irradiation of large volume of bone marrow. We conducted this study to see the effect of prophylactic granulocyte colony stimulating factor (GCSF) in reducing treatment breaks.

PATIENTS AND METHODS

The study was conducted over a period of 15 months from August 2017 to November 2018. Histopathologically proven Medulloblastoma patients received prophylactic GCSF during CSI. Acute hematological toxicities and treatment breaks were noted and effect of age and pretreatment blood counts were analyzed by SPSS (Statistical Package for Social Sciences) version 23.

RESULTS

A total of 28 patients were included in the study. During CSI, hematological toxicity leading to treatment breaks was observed in 11 (39.3 %) patients, of which grade 3 and 2 toxicities were seen in ten and one patients respectively. Younger age (<10 years) at diagnosis was significantly associated with the development of hematological toxicity (p = 0.028, Chi-Square). No correlation was found with pre-treatment blood counts.

CONCLUSION

Prophylactic use of GCSF may be effective in preventing radiation induced hematological toxicity and treatment breaks.

Factors Associated With Cerebral Edema at Admission in Indian Children with Diabetic Ketoacidosis

OBJECTIVE

To evaluate the time course and predictors of cerebral edema in diabetic ketoacidosis (DKA).

METHODS

Review of hospital records of 107 episodes of DKA between January 2013 to March 2019.

RESULTS

Cerebral edema was identified in 26 (24.3%; 22 at presentation and 4 during treatment). Cerebral edema at presentation was associated with lower (<10 mmHg) arterial carbon dioxide (OR 3.6, 95% CI 1.0,12.7; P=0.04), prior fluid treatment (OR 4.7, 95% CI 1.8,12.7; P=0.001) and new onset diabetes (OR 3.5, 95% CI 1.1,11.1; P=0.03). Prior fluid was the only significant predictor on multivariate analysis (P=0.013). Cerebral edema resulted in a longer ICU stay [4.1 (2.3) vs 1.8 (0.9) d; P<0.001].

CONCLUSIONS

Cerebral edema at admission is common in Indian children with DKA and should be suspected with severe metabolic acidosis and inappropriate prior fluid treatment.

FDG-PET response and outcome from anti-PD-1 therapy in metastatic melanoma

Background

Immune checkpoint inhibitor therapy has resulted in impressive and durable clinical activity for many cancers including melanoma; however, there remain few reliable predictors for long-term response. This study investigated whether [18F]2-fluoro-2-deoxy-D-glucose (FDG-PET) imaging may better predict long-term outcomes compared with standard computed tomography (CT) response criteria.

Patients and methods

Retrospective analysis of metastatic melanoma patients treated with anti-PD-1-based immunotherapy with baseline and 1-year FDG-PET and CT imaging at Melanoma Institute Australia. One-year response was determined using RECIST for CT and EORTC criteria for PET, coded as complete response (CR or CMR), partial response (PR or PMR), stable disease (SD or SMD) or progressive disease (PD or PMD). Progression-free survival (PFS) was determined from the 1-year landmark.

Results

Patients (n = 104) were evaluated with median follow-up 30.1 months and 98% remain alive. Most received anti-PD-1 as monotherapy (67%) or combined with ipilimumab (31%). At 1 year, 28% had CR, 66% had PR and 6% had SD on CT, while 75% had CMR, 16% PMR and 9% SMD/PMD on PET. CMR was observed in 68% of patients with PR on CT. RECIST PFS post 1-year landmark was similar in patients with CR versus PR/SD, but improved in patients with CMR versus non-CMR {median not reached [NR] versus 12.8 month; hazard ratio [HR] 0.06 [95% confidence interval (CI) 0.02-0.23]; P < 0.01}. In patients with PR on CT, PFS was improved in patients with PR + CMR versus PR + non-CMR (median NR versus 12.8 months; HR 0.07 [95% CI 0.02-0.27]; P < 0.01). In the 78 CMR patients, 78% had discontinued treatment and 96% had ongoing response.

Conclusions

Whilst only a small proportion of patients have a CR at 1 year, most patients with a PR have CMR on PET. Almost all patients with CMR at 1 year have ongoing response to therapy thereafter. PET may have utility in predicting long-term benefit and help guide discontinuation of therapy.