Publications by authors named "Asok Biswas"

59 Publications

Silicon augments salt tolerance through modulation of polyamine and GABA metabolism in two indica rice (Oryza sativa L.) cultivars.

Plant Physiol Biochem 2021 May 26;166:41-52. Epub 2021 May 26.

Plant Physiology and Biochemistry Laboratory, Centre of Advanced Study, Department of Botany, Ballygunge Science College, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India. Electronic address:

Polyamines (PA) have multifarious roles in plant-environment interaction and stress responses. In conjunction with GABA shunt, they regulate induction of tolerance under salinity stress in plants. Here, we tested the hypothesis that silicon improves salt tolerance through mediating vital metabolic pathways rather than acting as a mere mechanical barrier. Seedlings of two rice (Oryza sativa L.) cultivars MTU 1010 (salt-sensitive) & Nonabokra (salt-tolerant) growing in hydroponic culture were treated with NaCl (0, 25, 50 & 100 mM) combined with or without Si (2 mM). NaCl stress enhanced PA synthesizing enzymes activity and PA production in salt tolerant cultivar Nonabokra, whereas in the sensitive cultivar, MTU 1010 both declined. Enhanced activities of GABA synthesizing enzymes along with a decline in the activities of GABA degrading enzymes under NaCl exposure led to GABA accumulation in both the cultivars. The interactive effects of silicon and NaCl also induced the activities of the enzymes related to polyamine biosynthesis and inhibited polyamine degrading enzymes that enhanced PA contents in the cultivars. Supplemental Si decreased endogenous GABA levels by modulating GABA metabolising enzymes under NaCl stress. On the basis of all tested parameters cv. MTU 1010 was proven to be more responsive towards silicon application than cv. Nonabokra. Such study of silicon-induced polyamine accretion and reduced GABA accumulation may lower oxidative damage in rice cultivars under NaCl stress and thereby form a successful strategy to boost tolerance.
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http://dx.doi.org/10.1016/j.plaphy.2021.05.030DOI Listing
May 2021

Solitary Polypoid Erythematous Skin Nodule: Challenge.

Am J Dermatopathol 2020 Dec;42(12):e161-e162

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001781DOI Listing
December 2020

Solitary Polypoid Erythematous Skin Nodule: Answer.

Am J Dermatopathol 2020 12;42(12):1004-1005

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001782DOI Listing
December 2020

Ultrasound in the diagnosis and monitoring of eosinophilic fasciitis.

Rheumatology (Oxford) 2021 03;60(3):e107-e108

Rheumatic Diseases Unit, Western General Hospital, Edinburgh, UK.

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http://dx.doi.org/10.1093/rheumatology/keaa498DOI Listing
March 2021

Silicon nutrition modulates arsenic-inflicted oxidative overload and thiol metabolism in wheat (Triticum aestivum L.) seedlings.

Environ Sci Pollut Res Int 2020 Dec 11;27(36):45209-45224. Epub 2020 Aug 11.

Plant Physiology and Biochemistry Laboratory, Centre for Advanced Study, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019, India.

A hydroponic experiment was conducted to establish the response of exogenous silicon [Si] in alleviating arsenate [As (V)] prompted alterations on antioxidant enzyme activities and thiol metabolism in wheat (Triticum aestivum L. cv PBW 343) seedlings. Objective of the work was to validate the hypothesis whether silicate may alleviate arsenate-provoked oxidative stress in wheat through diverse metabolic pathways with an endeavor to improve food safety and health. Arsenate treatment significantly enhanced oxidative stress and was associated with modifications in non-enzymatic and enzymatic antioxidants. The activities of arsenate reductase [AR] and the enzymes related to thiol metabolism revealed dose-dependent enhancements with increase in arsenate along with enhanced production of phytochelatins [PCs] in the cultivar. Simultaneous supplementations of silicate with arsenate in the nutrient formulation reduced arsenate uptake along with arsenate reductase activity and consequently lowered arsenite [As (III)] accumulation. The antioxidative defense was upregulated and phytochelatin production was lowered causing an appreciable revival from the arsenate-imposed consequences that eventually augmented growth.
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http://dx.doi.org/10.1007/s11356-020-10369-zDOI Listing
December 2020

Influence of sodium chloride on growth and metabolic reprogramming in nonprimed and haloprimed seedlings of blackgram (Vigna mungo L.).

Protoplasma 2020 Nov 9;257(6):1559-1583. Epub 2020 Jul 9.

Phytochemistry and Pharmacognosy Research Laboratory, Centre for Advanced Studies, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India.

Salinity hinders agricultural productivity worldwide by distressing plant metabolism. Growth of blackgram (Vigna mungo L. var. Sulata), an adverse climate-resistant pulse, is arrested under salinity. Present research integrates study of physio-biochemical parameters and non-targeted metabolomics approach to explore the alterations in metabolic pathway during adaptive responses of nonprimed and haloprimed blackgram seedlings grown hydroponically under NaCl stress. Salinity provoked accumulation of peroxides, compatible solutes and phenolics which increased free radical scavenging activities of nonprimed seedlings under salinity. Pre-germination seed halopriming abrogated NaCl-mediated adversities in haloprimed plantlets favouring better growth. Thus, farmers may adopt seed halopriming technique to improve blackgram productivity in saline-prone fields. Additionally, metabolomics study uncovered numerous metabolites amongst which 35 compounds altered significantly under salinity. The candidate metabolites were aspartic acid, L-glutamic acid, L-proline, L-asparagine, DL-isoleucine, L-homoserine, citrulline, L-ornithine, D-altrose, D-allose, N-acetyl-D-mannosamine, fructose, tagatose, sucrose, D-glucose, maltose, glycerol-1-phosphate, D-sorbitol, benzoic acid, shikimic acid, 4-hydroxycinnamic acid, arbutin, succinic acid, pipecolic acid, fumaric acid, nicotinic acid, L-pyroglutamic acid, oxalic acid, glyceric acid, maleamic acid, adenine, guanosine, lauric acid, stearic acid and porphine. Comparing metabolic responses of nonprimed and haloprimed seedlings, it was clear that efficient alteration in carbohydrate metabolism, phenolics accumulation, amino acid, organic acid and nucleic acid metabolism were the key places of metabolic reprogramming for tolerating salinity. Overall, we report, for the first time, 35 contributory candidate compounds that constituted core fundamental metabolome invoking salinity tolerance in nonprimed and haloprimed blackgram. These metabolites may be targeted by biotechnologists to produce high vigour salt-tolerant transgenic blackgram via genetic engineering.
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http://dx.doi.org/10.1007/s00709-020-01532-xDOI Listing
November 2020

Trichoblastic carcinosarcoma with panfollicular differentiation (panfollicular carcinosarcoma) and CTNNB1 (beta-catenin) mutation.

J Cutan Pathol 2021 Feb 20;48(2):309-313. Epub 2020 Jul 20.

Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands.

We present a case of trichoblastic carcinosarcoma with panfollicular differentiation. An 80-year-old man presented with a lesion on the left ear, which had been present for several months. Histopathology revealed a well-demarcated neoplasm in the dermis composed of intimately intermingled malignant epithelial and mesenchymal cells. The epithelial component showed multilineage follicular differentiation toward all of the elements of a normal hair follicle. Molecular analysis revealed identical molecular aberrations in both epithelial and mesenchymal components including CTNNB1 and SUFU mutations. To the best of our knowledge, this is the first report of panfollicular carcinosarcoma and of the presence of a CTNNB1 mutation in trichoblastic carcinosarcoma.
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http://dx.doi.org/10.1111/cup.13794DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7891381PMC
February 2021

Differential responses of photosynthetic parameters and its influence on carbohydrate metabolism in some contrasting rice (Oryza sativa L.) genotypes under arsenate stress.

Ecotoxicology 2020 Sep 27;29(7):912-931. Epub 2020 Jun 27.

Plant Physiology and Biochemistry Laboratory, Centre of Advanced Study, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019, India.

Influence of arsenic (As) in As tolerant and sensitive rice genotypes based chloroplastic pigments, leaf gas exchange attributes and their influence on carbohydrate metabolism were investigated in the present study. As retards growth of crop plants and increase several health ailments by contaminating food chain. Photosynthetic inhibition is known to be the prime target of As toxicity due to over-production of ROS. Hydroponically grown rice seedlings of twelve cultivars were exposed to 25, 50, and 75 μM arsenate (AsV) that exerted negative impact on plastidial pigments content and resulted into inhibition of Hill activity. Internal CO concentration lowered gradually due to interference of As with stomatal conductance and transpiration rate that subsequently led to drop in net photosynthesis. Twelve contrasting rice genotypes responded differentially to As(V) stress. Present study evaluated As tolerant and sensitive rice cultivars with respect to As(V) imposed alterations in pigments content, photosynthetic attributes along with sugar metabolism. Starch contents, the principle carbohydrate storage declined differentially among As(V) stressed test cultivars, being more pronounced in cvs. Swarnadhan, Tulaipanji, Pusa basmati, Badshabhog, Tulsibhog and IR-20 compared to cvs. Bhutmuri, Kumargore, Binni, Vijaya, TN-1 and IR-64. Therefore, the six former cultivars tried to adapt defensive mechanisms by accumulating higher levels of reducing and non-reducing sugars to carry out basal metabolism to withstand As(V) induced alterations in photosynthesis. This study could help to screen As tolerant and sensitive rice genotypes based on their photosynthetic efficiency in As polluted agricultural fields to reduce As contamination assisted ecotoxicological risk.
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http://dx.doi.org/10.1007/s10646-020-02241-0DOI Listing
September 2020

Desmoplastic stromal changes in cutaneous neural granular cell tumors: An under-recognized histopathologic feature of diagnostic and prognostic importance.

J Cutan Pathol 2020 May 30;47(5):431-438. Epub 2019 Dec 30.

Department of Pathology, Western General Hospital, Edinburgh, UK.

Background: Granular cell tumors (GCTs) are uncommon mucocutaneous and soft tissue neoplasms with distinctive histopathologic appearance but controversial histogenesis. Herein, we report a variant of cutaneous GCT featuring extensive desmoplastic stroma which may result in diagnostic difficulties with mesenchymal proliferations, particularly a dermatofibroma.

Methods: Following a recent case of GCT with prominent stromal desmoplasia, we reviewed all cases diagnosed as GCT during the past 10 years accessioned at the dermatopathology unit in a tertiary university hospital.

Results: Three additional cases with a similar excessive connective tissue were identified out of a total of 49 GCTs. Cytoplasmic granularity was often subtle and focal, S100 expression was weak, and nuclei had a tendency to show spindling in tumor cells entrapped within the desmoplastic areas. Of note, nuclear spindling is one of the criteria used to diagnose an atypical/malignant GCT.

Conclusion: We propose the term "desmoplastic GCT" for these tumors, which not only appropriately addresses the stromal changes but also raises an awareness of GCT being one of the cutaneous tumors which may show stromal desmoplasia. Differential diagnostic difficulties apart, awareness of this phenomenon is important so that desmoplasia and resultant spindling are not linked with potential aggressive behavior.
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http://dx.doi.org/10.1111/cup.13635DOI Listing
May 2020

A Rare Form of Acquired Telangiectasia With Distinctive Histopathologic Features: Answer.

Am J Dermatopathol 2019 Dec;41(12):950

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001240DOI Listing
December 2019

Asymptomatic Indurated Plaque in a 16-year-Old Girl: Answer.

Am J Dermatopathol 2019 Dec;41(12):948-949

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001221DOI Listing
December 2019

Evaluation of arsenic induced toxicity based on arsenic accumulation, translocation and its implications on physio-chemical changes and genomic instability in indica rice (Oryza sativa L.) cultivars.

Ecotoxicology 2020 Jan 17;29(1):13-34. Epub 2019 Nov 17.

Plant Physiology & Biochemistry Laboratory, Centre of Advanced Study, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India.

Arsenic (As) accumulation in rice is a principal route of As exposure for rice based population. We have tested physiochemical and molecular parameters together to identify low As accumulating rice cultivars with normal growth and vigor. The present study examined potential toxicity caused by arsenate (AsV) among four rice cultivars tested that varied with respect to accumulation of total arsenic, arsenite (AsIII) and their differential translocation rate which had deleterious impact on growth and metabolism. Intracellular homeostasis of rice cultivars viz., TN-1, IR-64, IR-20 and Tulaipanji was hampered by 21 days long As(V) treatment due to generation of reactive oxygen species (ROS) and inadequate activity of catalase (CAT; EC 1.11.1.6). Upregulation of oxidative stress markers viz., HO, proline and MDA along with alteration in enzymatic antioxidants profile were conspicuously pronounced in cv. Tulaipanji while cv. TN-1 was least affected under As(V) challenged environment. In addition to that genomic template stability and band sharing indices were qualitatively measured by DNA profiling of all tested cultivars treated with 25 μM, 50 μM, and 75 μM As(V). In rice cv. Tulaipanji genetic polymorphism was significantly detected with the application of random amplified polymorphic DNA (RAPD) tool and characterized as susceptible cultivar of As compared to cvs. TN-1, IR-64 and IR-20 that is in correlation with data obtained from cluster analysis. Hence, identified As tolerant cultivars viz., TN-1, IR64 and IR-20 especially TN-1 could be used in As contaminated agricultural field after appropriate field trial. This study could help to gather information regarding cultivar-specific tolerance strategy to avoid pollutant induced toxicity.
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http://dx.doi.org/10.1007/s10646-019-02135-wDOI Listing
January 2020

Spectrum of Melanocytic Proliferation/Differentiation in a Large Series of Cutaneous Neurofibromas: An Under-Recognized Histopathologic Phenomenon and Potential Clue for Neurofibromatosis Type 1.

Am J Dermatopathol 2020 Mar;42(3):165-172

Department of Pathology, Western General Hospital and The University of Edinburgh, Edinburgh, United Kingdom.

Aims: Neurofibromas (NFs) and melanocytic nevi share a common neuroectodermal origin and may occasionally show overlapping morphological features. The objective of this study was to assess the prevalence and spectrum of melanocytic proliferation/differentiation in NFs and also to test the hypothesis whether detection of this feature could be used as a potential clue for neurofibromatosis type 1 (NF-1).

Methods: This was a retrospective study of 229 syndromic and 239 sporadic cutaneous NFs. Each case was assessed for an associated melanocytic component, both within the tumor and the overlying epidermis. Melan A immunohistochemistry was used in selected cases to further characterize this feature, particularly in diffuse NFs.

Results: An associated melanocytic component was detected in 77/229 syndromic and 12/239 sporadic cases (P < 0.00001). This was in the form of a junctional proliferation (lentiginous melanocytic hyperplasia or junctional nevus) or dermal differentiation (diffuse spindle cell or dermal nests of pigmented epithelioid melanocytes).

Conclusions: Our study affirms that the spectrum of melanocytic proliferation/differentiation in NFs is broad and probably under-recognized. Awareness of this phenomenon is critical to avoid misdiagnosis of some diffuse NFs as primary melanocytic tumors, for example, desmoplastic melanomas. Given the strong link between dermal melanocytic differentiation and syndromic NFs, its detection could potentially serve as a useful clue for NF-1 in an appropriate clinical context.
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http://dx.doi.org/10.1097/DAD.0000000000001512DOI Listing
March 2020

Modulation of photosynthetic parameters, sugar metabolism, polyamine and ion contents by silicon amendments in wheat (Triticum aestivum L.) seedlings exposed to arsenic.

Environ Sci Pollut Res Int 2019 May 27;26(13):13630-13648. Epub 2019 Mar 27.

Plant Physiology and Biochemistry Laboratory, Centre for Advanced Study, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019, India.

The objective of the present investigation was to consider the effectiveness of exogenous silicate supplementation in reviving the arsenate imposed alterations on pigment content, Hill activity, photosynthetic parameters, sugar metabolism, polyamine, and ion contents in wheat (Triticum aestivum L. cv. PBW-343) seedlings. Experiments were conducted under different levels of arsenate (0, 25 μM, 50 μM, and 100 μM) in combination with silicate (0, 5 mM) in a hydroponic environment with modified Hoagland's solution for 21 days to determine the ameliorative role of silicon (Si). Arsenate exposure led to a decline in chlorophyll content by 28% and Hill activity by 30% on an average along with photosynthetic parameters. Activity of starch phosphorylase increased causing a subsequent decrease in starch contents by 26%. Degradation of starch enhanced sugar contents by 61% in the test cultivar. Dose-dependant increments in the activities of carbohydrate metabolizing enzymes viz., sucrose synthase, sucrose phosphate synthase, and acid invertase were also noted. Putrescine content was significantly enhanced along with a consequent decline in spermidine and spermine contents. The macro- and micronutrient contents declined proportionally with arsenate imposition. Conversely, silicate amendments irrespective of all arsenate concentrations brought about considerable alterations in all parameters tested with respect to arsenate treatment alone. Marked improvement in pigment content and Hill activity also improved the gas exchange parameters. Soluble sugar contents decreased and starch contents were enhanced. Increase in polyamine contents improved the ionic balance in the test cultivar as well. This study highlights the potentiality of silicon in ameliorating the ecotoxicological risks associated with arsenic pollution and the probable ability of silicon to offer an approach in mitigating arsenate-induced stress leading to restoration of growth and metabolism in wheat seedlings.
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http://dx.doi.org/10.1007/s11356-019-04896-7DOI Listing
May 2019

Exogenous silicon alters organic acid production and enzymatic activity of TCA cycle in two NaCl stressed indica rice cultivars.

Plant Physiol Biochem 2019 Mar 28;136:76-91. Epub 2018 Dec 28.

Plant Physiology and Biochemistry Laboratory, Centre of Advanced Study, Department of Botany, Ballygunge Science College, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India. Electronic address:

The activities of TCA cycle enzymes viz., pyruvate dehydrogenase, citrate synthase, isocitrate dehydrogenase, succinate dehydrogenase and malate dehydrogenase as well as levels of different organic acids viz., pyruvic acid, citric acid, succinic acid and malic acid were studied in two rice cultivars viz. cv. Nonabokra and cv. MTU 1010 differing in salt tolerance grown under 25, 50 and 100 mM NaCl salinity levels. A contrasting response to salt stress on enzyme activities of TCA cycle and accumulation of organic acid was observed between two cultivars during twenty-one days period of study. Salinity caused enhanced organic acid production and increase in all five enzyme activities in cv. Nonabokra whereas in cv. MTU 1010 decrease in both organic acid production and enzymes activities were noted. Joint application of exogenous silicon along with NaCl, altered the organic acids levels and activities of enzymes in both cultivars of rice seedlings conferring tolerance against salt induced stress. Rice cv. MTU 1010 showed better response to exogenous silicon on parameters tested compared to cv. Nonabokra.
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http://dx.doi.org/10.1016/j.plaphy.2018.12.026DOI Listing
March 2019

Modulation of growth, ascorbate-glutathione cycle and thiol metabolism in rice (Oryza sativa L. cv. MTU-1010) seedlings by arsenic and silicon.

Ecotoxicology 2018 Dec 8;27(10):1387-1403. Epub 2018 Nov 8.

Plant Physiology and Biochemistry Laboratory, Centre of Advanced Studies, Department of Botany, University of Calcutta, Kolkata, West Bengal, 700019, India.

Arsenic is a carcinogenic metalloid, exists in two important oxidation states-arsenate (As-V) and arsenite (As-III). The influence of arsenate with or without silicate on the growth and thiol metabolism in rice (Oryza sativa L. cv. MTU-1010) seedlings were investigated. Arsenate was more toxic for root growth than shoot growth where the root lengths were short, characteristically fragile and root tips turned brown. The multiple comparison analysis using Tukey's HSD (honest significant difference) tests indicated that the rate of arsenate accumulation and its conversion to arsenite by arsenate reductase were significantly increased in all arsenate treated seedlings while in seedlings treated jointly with arsenate and silicate, arsenate accumulation and its conversion to arsenite decreased. Silicate content was detected in the seedlings treated with silicate alone and under co-application of arsenate with silicate. In the test seedlings arsenic toxicity increased ascorbate and glutathione contents along with the activities of their regulatory enzymes, viz., ascorbate peroxidase, glutathione reductase, glutathione peroxidase and glutathione-s-transferase to reduce the toxicity level induced by arsenic whereas ascorbate oxidase activity was decreased to maintain sufficient ascorbate pool under arsenate treatment. Phytochelatins production were increased in both root and shoot of the test seedlings under arsenate exposure to alter the detrimental effects of arsenic by chelation with arsenite and their subsequent sequestration into vacuole. Thus, joint application of silicate along with arsenate showed significant alterations on all the parameters tested compared to arsenate treatment alone due to less availability of arsenic in the tissue leading to better growth and metabolism in rice seedlings. Thus use of silicon in arsenic contaminated medium may help to grow rice with improved vigour.
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http://dx.doi.org/10.1007/s10646-018-1994-5DOI Listing
December 2018

Concordance of somatic mutation profiles (BRAF,NRAS, and TERT) and tumoral PD-L1 in matched primary cutaneous and metastatic melanoma samples.

Hum Pathol 2018 12 16;82:206-214. Epub 2018 Aug 16.

Dermatopathology Section, VA Integrated Systems Network (VISN1), Department of Pathology and Laboratory Medicine, West Roxbury, MA 02132, USA. Electronic address:

Despite the efficacy of BRAF-targeted and PD-L1-related immune therapies in tackling metastatic melanoma, a significant number of patients exhibit resistance. Given this, the objective of the current study was to ascertain concordance of somatic mutations in BRAF/NRAS/TERT and immunohistochemical PD-L1 and CD8 in matched primary cutaneous and metastatic melanoma. A total of 43 archival paired samples with sufficient material for genetic and immunohistochemical analyses met the criteria for inclusion in the study. Immunohistochemistry was performed for PD-L1 and CD8 and direct-DNA Sanger sequencing for BRAF/NRAS/TERT promoter mutational analyses. Agreement between paired samples was assessed using Cohen κ. Poor concordance among primary and corresponding metastases was noted in BRAF (9/42 cases discordant, κ = 0.49; 95% confidence interval [CI], 0.21-0.77; P = .0013), TERT promoter mutations (13/41 cases discordant, κ = 0.33; 95% CI, 0.04-0.62; P = .033), tumoral PD-L1 immunoexpression (9/43 cases discordant, κ = 0.39; 95% CI, 0.07-0.72; P = .0099), and immunoexpression of CD8 T lymphocytes (12/43 cases discordant, κ = 0.44; 95% CI, 0.19-0.69; P = .002). Although NRAS1 and NRAS2 were highly concordant (42/43 and 39/43 cases, respectively), discordant NRAS2 mutational status was associated with a median time to metastasis of 90 versus 455 days for pairs with concordant status (P = .07). Although limited by sample size, our findings suggest that consideration be given to mutational analysis of metastatic tissue rather than the primary to guide BRAF-targeted therapy and question the roles of TERT promoter mutations and PD-L1 as predictive biomarkers in malignant melanoma.
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http://dx.doi.org/10.1016/j.humpath.2018.08.002DOI Listing
December 2018

An Unusual Vesiculopustular Eruption: Answer.

Am J Dermatopathol 2018 Sep;40(9):703

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001099DOI Listing
September 2018

Bilateral agminated skin-colored papules and nodules on the dorsum of the hands.

Indian J Dermatol Venereol Leprol 2019 Mar-Apr;85(2):192-194

Department of Pathology, Western General Hospital and University of Edinburgh, Edinburgh, UK.

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http://dx.doi.org/10.4103/ijdvl.IJDVL_160_17DOI Listing
June 2019

A Rare Form of Acquired Telangiectasia With Distinctive Histopathologic Features: Challenge.

Am J Dermatopathol 2019 Dec;41(12):e158-e159

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001241DOI Listing
December 2019

Identification of arsenic-tolerant and arsenic-sensitive rice (Oryza sativa L.) cultivars on the basis of arsenic accumulation assisted stress perception, morpho-biochemical responses, and alteration in genomic template stability.

Protoplasma 2019 Jan 31;256(1):193-211. Epub 2018 Jul 31.

Plant Physiology & Biochemistry Laboratory, Centre of Advanced Study, Department of Botany, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal, 700019, India.

Arsenic toxicity is the most commonly experienced challenge of rice plants due to irrigation with arsenic-polluted groundwater and their cultivation in water logging environment which poses threat to human health, particularly in Bangladesh and West Bengal (India). In the present study, hydroponically grown eight rice cultivars, viz., Bhutmuri, Kumargore, Binni, Vijaya, Tulsibhog, Badshabhog, Pusa basmati, and Swarnadhan, were screened for arsenic tolerance by using physiological and molecular parameters. Treatment with 25 μM, 50 μM, and 75 μM arsenate resulted in dosage-based retardation in growth and water content in all the tested cultivars due to accumulation of total arsenic along with the enhanced activity of arsenate reductase with more severe effects exhibited in cvs. Swarnadhan, Pusa basmati, Badshabhog, and Tulsibhog. Arsenic sensitivity of rice cultivars was evaluated in terms of oxidative stress markers generation, antioxidant enzyme activities, and level of genotoxicity. Under arsenate-challenged conditions, the levels of oxidative stress markers, viz., HO, MDA, and proline, and activities of antioxidant enzymes, viz., SOD and CAT, along with the level of genotoxicity analyzed by RAPD profiling were altered in variable levels in all tested rice cultivars and showed a significant alteration in band patterns in arsenate-treated seedlings of cvs. Swarnadhan, Pusa basmati, Badshabhog, and Tulsibhog in terms of appearance of new bands and disappearance of normal bands that were presented in untreated seedlings led to reduction in genomic template stability due to their high susceptibility to arsenic toxicity. Cultivar- and dose-dependent alteration of parameters tested including the rate of As accumulation showed that cvs. Kumargore, Binni, and Vijaya, specially Bhutmuri, were characterized as arsenate tolerant and could be cultivated in arsenic-prone areas to minimize level of toxicity and potential health hazards.
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http://dx.doi.org/10.1007/s00709-018-1290-5DOI Listing
January 2019

Asymptomatic Indurated Plaque in a 16-Year-Old Girl: Challenge.

Am J Dermatopathol 2019 Dec;41(12):e156-e157

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001220DOI Listing
December 2019

Fibrous Papule: A Histopathologic Review.

Am J Dermatopathol 2018 Aug;40(8):551-560

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

Fibrous papule (FP) is a common benign lesion located primarily in the nose. Although its histogenesis has been marred with controversies in the past, the dermal dendrocyte is now largely accepted to be the putative cell of origin. Histopathologic diagnosis of an FP is straightforward in most cases, which shows characteristics of an angiofibroma. Several histologic variants have been described, recognition of which is important to avoid a misdiagnosis and inappropriate treatment. This review presents a historical perspective into the histogenesis, discusses the histopathologic features and potential diagnostic pitfalls of classic FP, and lists the various histologic variants and their differential diagnoses.
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http://dx.doi.org/10.1097/DAD.0000000000001083DOI Listing
August 2018

Exogenous silicon alters ascorbate-glutathione cycle in two salt-stressed indica rice cultivars (MTU 1010 and Nonabokra).

Environ Sci Pollut Res Int 2018 Sep 12;25(26):26625-26642. Epub 2018 Jul 12.

Plant Molecular Cytogenetics Laboratory, Centre of Advanced Study, Department Of Botany, Ballygunge Science College, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, India.

Silicon is widely available in soil and is known to mitigate both biotic and abiotic stress in plants. Very low doses of silicon are becoming increasingly essential in rice for biofortification and preventing water loss. Soil salinity is a matter of grave concern in various parts of the world, and silicon is a suitable candidate to mitigate salinity-induced stress of important plants in affected areas. The present study investigates the protective capability of exogenously applied silicon in ameliorating NaCl-induced toxicity in two rice (Oryza sativa L.) cultivars, the salt-sensitive MTU 1010, and salt-tolerant Nonabokra. Rice seedlings were treated with three doses of NaCl (25, 50, and 100 mM), initially alone and subsequently in combination with 2 mM sodium silicate (NaSiO, 9HO). After 21 days, these plants were examined to determine levels of reduced glutathione, ascorbic acid, cysteine, and activities of different enzymes involved in the ascorbate-glutathione cycle, viz., glutathione reductase (GR), ascorbate peroxidase (APX), glutathione peroxidase (GPx), and glutathione S-transferase (GST). Though ROS levels increased in both the cultivars with increasing NaCl concentrations, cv. MTU 1010 accumulated comparatively higher amounts. A differential response of NaCl-induced toxicity on the two cultivars was observed with respect to the various enzymatic and non-enzymatic antioxidants. APX and GST activities, as well as, cysteine contents, increased concomitantly with salt concentrations, whereas GR activity declined at increasing salt concentrations, in both cultivars. Activity of GPx increased in cv. Nonabokra but declined in cv. MTU 1010, under similar NaCl concentrations. Reduced glutathione (GSH) contents decreased in both cultivars, whereas ascorbate contents declined in only the sensitive cultivar. Application of silicon, along with NaCl, in the test seedlings of both the cultivars, reduced ROS accumulation and boosted antioxidant defense mechanism, through enhancing ascorbate and GSH levels, and activities of ascorbate-glutathione cycle enzymes as well. However, amelioration of salt-induced damages in the sensitive cv. MTU 1010 was more pronounced upon silicon administration, than the tolerant cv. Nonabokra. Thus, cv. MTU 1010 was found to be more responsive to applied silicon. Hence, this study was instrumental in realizing a successful strategy in silicon-mediated amelioration of salinity stress in plants.
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http://dx.doi.org/10.1007/s11356-018-2659-xDOI Listing
September 2018

Metabolomics analysis of Cajanus cajan L. seedlings unravelled amelioration of stress induced responses to salinity after halopriming of seeds.

Plant Signal Behav 2018 11;13(7):e1489670. Epub 2018 Jul 11.

a Centre for Advanced Study, Department of Botany , University of Calcutta , Kolkata India.

Soil salinity has become a major concern for agriculture. Such constraints not only reinforce the urgent need to understand the underlying mechanisms by which plants cope during salt stress but also to develop cost-effective and farmer friendly halopriming technique to alleviate the adverse effects of salinity to some extent. Metabolomics approach was used to explore different responses to physiological metabolites and pathway variations that occur during salt stress responses in Cajanus cajan L. var. Rabi and to understand the role of halopriming in ameliorating stress at the level of metabolite. Seedlings raised from non-primed and haloprimed seeds, grown in hydroponic solution, were subjected to different concentrations of NaCl. After 21 days, metabolites were extracted, derivatized and analyzed by GC-MS. The data were analysed by different multivariate analyses. Chemometric study of the identified metabolites indicated that the leaves responded most to NaCl induced stress than the stem and root with production of beta-cyano-L-alanine and also increased level of different compatible solutes. O-Acetylsalicylic was also found to increase in all the parts upon facing stress but, such upregulated metabolite production was downregulated in the leaves when the seeds were haloprimed before germination, although many of the metabolites, including beta-cyanoalanine, showed a trend of increase with increase in salt concentrations. Important metabolites produced by C. cajan seedlings in response to salinity were unravelled. Pre-germination haloprimimg of seeds resulted in amelioration of NaCl induced stress, as the levels of stress induced metabolites were lowered.
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http://dx.doi.org/10.1080/15592324.2018.1489670DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6128681PMC
April 2019

An Unusual Vesiculopustular Eruption: Challenge.

Am J Dermatopathol 2018 Sep;40(9):e124-e125

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

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http://dx.doi.org/10.1097/DAD.0000000000001100DOI Listing
September 2018

A Longstanding Nodule on the Temple: A Quiz.

Acta Derm Venereol 2018 Apr;98(4):471-472

Department of Dermatology, Lauriston Building, Lauriston Place, EH3 9HA Edinburgh, Scotland.

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http://dx.doi.org/10.2340/00015555-2881DOI Listing
April 2018

Pseudomembranous changes in the dermis: A novel observation and potential clue for evolving lipodermatosclerosis?

J Cutan Pathol 2017 Dec 19;44(12):1070-1074. Epub 2017 Sep 19.

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, UK.

Lipodermatosclerosis (LDS) is a well-recognized form of fibrosing panniculitis. Although chronic cases are readily diagnosed, early and evolving lesions may be clinically mistaken for cellulitis and other forms of panniculitis. Most pathologists are familiar with a pseudomembranous type of fat necrosis as a useful feature of chronic LDS. Although nonspecific, this distinctive pattern of fat necrosis helps in supporting a diagnosis of LDS in the appropriate clinical context. The histopathologic features of early and evolving LDS and those involving the dermis are less well documented. We report a case of early LDS showing extensive pseudomembranous changes in the dermis on a superficial skin biopsy where progression to a classic established lesion was documented clinically. We suspect that this previously unreported and unusual finding may be a histopathologic clue for evolving lesions of LDS.
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http://dx.doi.org/10.1111/cup.13038DOI Listing
December 2017

Nicolau Syndrome (Embolia Cutis Medicamentosa): A Rare and Poorly Recognized Iatrogenic Cause of Cutaneous Thrombotic Vasculopathy.

Am J Dermatopathol 2018 Mar;40(3):212-215

Department of Pathology, Western General Hospital and the University of Edinburgh, Edinburgh, United Kingdom.

Nicolau syndrome is a rare form of iatrogenic cutaneous necrosis which affects injection sites. Although classically associated with intramuscular injections, it may develop after subcutaneous or other routes of parenteral drug administration. Clinically, it manifests as necrotic ulcers that often develop in a background of erythematous and livedoid reticular patches. The histopathologic characteristics of Nicolau syndrome are poorly documented in the dermatopathology literature and features only rarely as one of the obscure causes of cutaneous thrombotic vasculopathy. We report a case of Nicolau syndrome developing secondary to subcutaneous injection of cyclizine to familiarize the clinicians and pathologists to this unusual condition. Given that it is potentially avoidable, pathologists should alert the clinicians to the possibility of Nicolau syndrome when a skin biopsy from an injection site shows signs of extensive thrombotic vasculopathy.
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http://dx.doi.org/10.1097/DAD.0000000000000972DOI Listing
March 2018

Hailey-Hailey Disease With Coexistent Herpes Virus Infection: Insights Into the Diagnostic Conundrum of Herpetic/Pseudoherpetic Features in Cutaneous Acantholytic Disorders.

Am J Dermatopathol 2018 Oct;40(10):749-753

Department of Pathology, Western General Hospital, The University of Edinburgh, Edinburgh, United Kingdom.

The specific histopathologic diagnosis of a primary acantholytic disorder takes into account the distribution and extent of acantholysis, presence or absence of dyskeratosis, nature of the dermal inflammatory cell infiltrate, and immunofluorescence findings. Herpes virus infection is a common cause of secondary acantholysis where distinctive viral cytopathic changes aid in making it a clear-cut diagnosis in majority of cases. We present a case of coexistence of Hailey-Hailey disease and herpes simplex virus infection to compare and contrast their histopathologic features. This is imperative because acantholytic cells from primary acantholytic disorders may occasionally show cytological features traditionally associated with herpes virus infection (pseudoherpetic changes). The objective of this article is to create a greater awareness of pseudoherpetic changes and also to explore the clinical significance of coexistence of a primary acantholytic disorder and herpes virus infection, as in this case.
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http://dx.doi.org/10.1097/DAD.0000000000000902DOI Listing
October 2018
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