The role of chemical fractionation in risk assessment of toxic metals: a review

The identification of highly toxic metals like Cd, Ni, Pb, Cr, Co or Cu in ambient particulate matter (PM) has garnered a lot of interest recently. Exposure to toxic metals, including carcinogenic ones, at levels above recommended limits, can significantly affect human health. Prolonged exposure to even trace amounts of toxic or essential metals can also have negative health impacts. In order to assess significant risks, it is crucial to govern the concentrations of bioavailable/bio-accessible metals that are available in PM. Estimating the total metal concentrations in PM is only an approximation of metal toxicity. This review provides an overview of various procedures for extracting soluble toxic metals from PM and the importance of chemical fractionation in risk assessment. It is observed that the environmental risk indices such as bioavailability index (BI), contamination factor (CF) and risk assessment code (RAC) are specifically influenced by the concentration of these metals in a particular fraction. Additionally, there is compelling evidence that health risks assessed using total metal concentrations may be overestimated, therefore, the metal toxicity assessment is more accurate and more sensitive to the concentration of the bioavailable/bio-accessible fraction than the total metal concentrations. Hence, chemical fractionation of toxic metals can serve as an effective tool for developing environmental protection laws and improving air quality monitoring programs for public health.

Arabidopsis plants overexpressing additional copies of heat shock protein Hsp101 showed high heat tolerance and endo-gene silencing

Hsp101 chaperone is vital for survival of plants under heat stress. We generated transgenic Arabidopsis thaliana (Arabidopsis) lines with extra copies of Hsp101 gene using diverse approaches. Arabidopsis plants transformed with rice Hsp101 cDNA driven by Arabidopsis Hsp101 promoter (IN lines) showed high heat tolerance while the plants transformed with rice Hsp101 cDNA driven by CaMV35S promoter (C lines) were like wild type plants in heat stress response. Transformation of Col-0 plants with 4633 bp Hsp101 genomic fragment (GF lines) from A. thaliana containing both its coding and the regulatory sequence resulted in mostly over-expressor (OX) lines and a few under-expressor (UX) lines of Hsp101. OX lines showed enhanced heat tolerance while the UX lines were overly heat sensitive. In UX lines, silencing of not only Hsp101 endo-gene was noted but also transcript of choline kinase (CK2) was silenced. Previous work established that in Arabidopsis, CK2 and Hsp101 are convergent gene pairs sharing a bidirectional promoter. The elevated AtHsp101 protein amount in most GF and IN lines was accompanied by lowered CK2 transcript levels under HS. We observed increased methylation of the promoter and gene sequence region in UX lines; however, methylation was lacking in OX lines.

Insights into genomic variations in rice Hsp100 genes across diverse rice accessions

The Hsp101 gene is present across all sequenced rice genomes. However, as against Japonica rice, Hsp101 protein of most indica and aus rice contain insertion of glutamic acid at 907th position. The understanding of the heat stress response of rice plants is important for worldwide food security. We examined the presence/absence variations (PAVs) of heat shock proteins (Hsps)/heat shock transcription factor (Hsf) genes in cultivated rice accessions. While 53 Hsps/Hsfs genes showed variable extent of PAVs, 194 genes were the core genes present in all the rice accessions. ClpB1/Hsp101 gene, which is critically important for thermotolerance in plants, showed 100% distribution across the rice types. Within the ClpB1 gene sequence, 40 variation sites consisting of nucleotide polymorphisms (SNPs) and short insertion/deletions (InDels) were discerned. An InDel in ClpB1 leading to an in-frame insertion of 3 nucleotides (TCC) thereby an additional amino acid (glutamic acid) at 907th amino acid position was noted in most of the indica and aus as against japonica rice types. Three rice types namely Moroberekan (japonica), IR64 (indica) and N22 (aus) were further analyzed to address the question of ClpB1 genomic variations and its protein levels with the heat tolerance phenotype. The growth profiling analysis in the post heat stress (HS) period showed that N22 seedlings were most tolerant, IR64 moderately tolerant and Moroberekan highly sensitive. Importantly, the ClpB1 protein sequences of these three rice types showed distinct differences in terms of SNPs. As the ClpB1 protein levels accumulated post HS were generally higher in Moroberekan than N22 seedlings in our study, it is proposed that some additional gene loci in conjunction with ClpB1 regulate the overall rice heat stress response.

Heat-induced proteomic changes in anthers of contrasting rice genotypes under variable stress regimes

Heat stress drastically affects anther tissues resulting in poor plant fertility, necessitating an urgent need to determine the key proteome regulation associated with mature anther in response to heat stress. We identified several genotype - specific protein alterations in rice anthers of Moroberekan (Japonica, heat sensitive), IR64 (Indica, moderately heat tolerant), and Nagina22 (Aus, heat tolerant) in the short-term (ST_HS; one cycle of 42°C, 4 hours before anthesis) and long-term (LT_HS; 6 cycles of 38°C, 6 hours before anthesis) heat stress. The proteins upregulated in long-term heat stress in Nagina22 were enriched in biological processes related to unfolded protein binding and carboxylic acid metabolism, including amino acid metabolism. In short-term heat stress, Nagina22 anthers were enriched in proteins associated with vitamin E biosynthesis and GTPase activator activity. In contrast, downregulated proteins were related to ribosomal proteins. The expression of different Hsp20 and DnaJ was genotype specific. Overall, the heat response in Nagina22 was associated with its capacity for adequate metabolic control and cellular homeostasis, which may be critical for its higher reproductive thermotolerance. This study improves our understanding of thermotolerance mechanisms in rice anthers during anthesis and lays a foundation for breeding thermotolerant varieties via molecular breeding.

Prevalence of anxiety and depression in patients with tinnitus

Background: Tinnitus is phantom sound sensation in absence of external source of sound. A close association has been demonstrated between tinnitus and comorbid psychological disorders. In patients suffering from tinnitus a higher prevalence of anxiety and depression has been reported. Aims and Objectives: The aim of this study was to assess prevalence of depression and anxiety in patients suffering from tinnitus. Materials and Methods: It was cross sectional study conducted at a tertiary care hospital of Punjab. The study recruited 50 patients with history of tinnitus of time period more than twelve months of duration after taking written informed consent. The inclusion criteria was Patients over the age of 18, Patients having tinnitus for past 1 year duration. Patients with prior history of psychiatric illness were excluded. Depression was assessed by using Hamilton rating scale for depression(HRSD) and anxiety by Hamilton anxiety rating scale [18] (HAM-A). Appropiate statistical analysis was done. Results and Conclusion: Most of the study sample [27 (54%)] were in the age group of 41-50. Females outnumbered males. Majority of patients were suffering from tinnitus from last 1-5 years (33). Out of 50 subjects, depression was present in 43 patients and anxiety in 14 patients. There was strong correlation between female gender and depression and anxiety.

Early Community based Ayu-Emergency Intervention in Psychiatric Emergencies: A Community Based Participatory Research

Introduction

Psychiatry emergencies in India is major challenge for emergency service providers due to rapid growth of various behavioural, higher morbidity and mortality rate. Despite, psychiatry conditions are neglected area related to stigma, share, lack of awareness, and superstitious beliefs. There is an urgent need for specialist psychiatric emergency services, which can fill the huge gap between policymakers and health service providers joined together.

Objectives

Present feasibility study has been undertaken to evaluate the safety and efficacy of combined emergency and Ayurveda medicine management of psychiatric emergencies in community-based settings.

Methods

Ayu-Emergency Care project was developed in partnership with policy makers, researchers and health care providers, a collaborative platform of emergency medicine and Ayurveda medicine (Indian Traditional Medicine) for developing whole-system perspective, where providers work in a coordinated and joined-up way. Twenty trained care providers in psychiatry emergency and Ayurveda management worked in partnership with community-based organisation.

Results

Patients with major clinical difficulties, in the acute phase were treated and managed by Ayu-Emergencypractitioners. Severe Agitation and violence relating to substance abuse, anxiety disorder and psychosis were the most common admission diagnoses. 2-weeks results indicate that Ayurveda intervention can reduce anxiety(p<0.01), aggression (p< 0.001) and agitation (p<0.01) significantly with no side effects reported. Intervention found to be clinically beneficial and cost-efficient alternative to out-of-home placements (i.e., Incarceration, psychiatric hospitalisation).

Conclusions

The study’s findings highlight safety, efficacy and feasibility of intervention. Patients both prefer and seem to benefit from community-based ayu-psychiatric care, and early-intervention community program could be a good model for such care.

Disclosure

No significant relationships.

N-hydroxypipecolic acid-induced transcription requires the salicylic acid signaling pathway at basal SA levels

Systemic acquired resistance (SAR) is a plant immune response established in uninfected leaves after colonization of local leaves with biotrophic or hemibiotrophic pathogens. The amino acid-derived metabolite N-hydroxypipecolic acid (NHP) travels from infected to systemic leaves, where it activates salicylic acid (SA) biosynthesis through the isochorismate pathway. The resulting increased SA levels are essential for induction of a large set of SAR marker genes and full SAR establishment. In this study, we show that pharmacological treatment of Arabidopsis thaliana with NHP induces a subset of SAR-related genes even in the SA induction-deficient2 (sid2/isochorismate synthase1) mutant, which is devoid of NHP-induced SA. NHP-mediated induction is abolished in sid2-1 NahG plants, in which basal SA levels are degraded. The SA receptor NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) and its interacting TGACG SEQUENCE-SPECIFIC BINDING PROTEIN (TGA) transcription factors are required for the NHP-mediated induction of SAR genes at resting SA levels. Isothermal titration analysis determined a KD of 7.9 ± 0.5 µM for the SA/NPR1 complex, suggesting that basal levels of SA would not bind to NPR1 unless yet unknown potentially NHP-induced processes increase the affinity. Moreover, the nucleocytoplasmic protein PHYTOALEXIN DEFICIENT4 is required for a slight NHP-mediated increase in NPR1 protein levels and NHP-induced expression of SAR-related genes. Our experiments have unraveled that NHP requires basal SA and components of the SA signaling pathway to induce SAR genes. Still, the mechanism of NHP perception remains enigmatic.

Temporoparietal and Infratemporal fossa abscess as a complication of dental extraction – a rare and potentially lethal condition

Abscesses of the infratemporal fossa are rare in clinical practice. Usually it occurs as a complication of odontogenic infections, dental extraction, sinusitis and trauma. The initial signs & symptoms of this condition may be very non-specific in nature. If treatment is delayed, the abscess may extend superiorly to involve the temporoparietal region and only then it can be appreciated clinically. A middle aged male patient presented to us with the complaint of restricted mouth opening along with extensive swelling of the temporoparietal region. There was past history of tooth extraction. MRI scan confirmed it to be a case of temporoparietal & infratemporal fossa abscess with features of osteomyelitis of the ramus and adjacent body of the mandible on the right side. The patient was started on parenteral antibiotics and subsequently the abscess was drained by combined external and intraoral approach. The patient had an uneventful recovery. A thorough review of the literature has been done in relation to this condition and its management. A delay in diagnosis of this condition can lead to a number of potentially lethal complications. CT scan and MRI scan are the best modalities for confirming the diagnosis in suspected cases. Prompt drainage of the abscesses under antibiotic cover is the cornerstone of management. Isolated abscess of the infratemporal fossa may be drained intraorally or endoscopically by trans-maxillary approach. However if the temporoparietal region is also involved, a combined approach with a separate incision over the temporal region is indicated.Asian Journal of Medical Sciences Vol.9(4) 2018 57-60