IntroductionLarge-scale sero-prevalence studies with representation from all age groups are requi... more IntroductionLarge-scale sero-prevalence studies with representation from all age groups are required to estimate the true burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the community. Serial serological surveys in fixed cohorts enable study of dynamics of viral transmission and correlates of immune response over time in the context of gradual introduction of COVID-19 vaccines and repeated upsurge of cases during the pandemic.MethodsThis longitudinal study will involve follow-up of a cohort of 25,000 individuals (5,000 per site) aged 2 years and above recruited from five existing demographic surveillance sites in India. The cohort will be tested for the presence of IgG antibodies against S1/S2 spike protein subunits of SARS-CoV-2 in four rounds; once at baseline and subsequently, at intervals of 4 months for a year between January 2021 and January 2022. Neutralization assays will be carried out in a subset of seropositive samples in each round to...
Background: Six diverse Demographic Development and Environmental Surveillance System (DDESS) sit... more Background: Six diverse Demographic Development and Environmental Surveillance System (DDESS) sites were established in urban slum, urban resettlement, peri-urban, rural, and tribal areas located in Northern, North-East, Eastern, and Southern regions of India from June 2020 to March 2022. Understanding the community dynamics and engaging people in the community is critically important in the process of establishing DDESS. We ascertained the barriers, challenges, and facilitators during the establishment of multiple DDESS sites across India. Methods: This was a cross-sectional descriptive mixed-methods study. Results: Multiple barriers and challenges encountered were reported in the process of community engagement (CE), such as geographical inaccessibility, language barriers, adverse weather, non-responsiveness due to perceived lack of individual benefit or financial gain, fear of contracting COVID-19, COVID-19 vaccine hesitancy, etc. Facilitators in the CE process were pre-existing ...
Adolescents constitute 16% of the global population and are susceptible to adverse health and ill... more Adolescents constitute 16% of the global population and are susceptible to adverse health and illness from substance abuse, unhealthy diet, physical inactivity, and high-risk sexual behaviors. We conducted this study to assess the perceptions of good health, health-seeking behavior, and health service utilization among adolescents living in a low-income urban neighborhood after the second wave of the COVID-19 pandemic. A total of 23 adolescents, including 12 males and 11 females, were interviewed. Adolescents' perceived body image and size considerations apart from functioning at an optimum physical capacity as the principal attributes of good health, which was possible through the intake of a healthy diet and exercise. Adolescents were likely to be aware of the addiction potential and risk of cancer from using tobacco and alcohol, but attitudes towards eschewing their use were ambivalent. Adolescents perceived themselves as lacking access to reliable, adequate, and validated sources of sexual and reproductive health information. Knowledge and utilization of adolescent health services in this area were negligible, suggestive of the need to strengthen these services and improve the program outreach.
This explorative qualitative study assesses the health-seeking behaviour for childhood ailments i... more This explorative qualitative study assesses the health-seeking behaviour for childhood ailments in caregivers of under-five children in a low-income neighbourhood in Delhi, India during July-September 2021. A total of 17 caregivers (mothers) of eight male and nine female under-five children were enrolled, with the mother being the caregiver in most (94%) cases. Caregivers consulted on common childhood ailments from multiple sources, including family, neighbours, healthcare providers (both licensed and unlicensed), frontline workers, and local pharmacists. The internet was often used as a source of child health information due to its ease of access but often "confused" caregivers due to the presence of too much information. Health-seeking behaviour of caregivers for childhood ailments could range from self-medication, local pharmacist dispensing, and private and public healthcare providers. Factors that influenced preference for the healthcare facility or provider were accessibility issues (waiting time, queuing), perceived physician competence, and associated out-of-pocket expenses. Caregivers reported dissatisfaction with government health facilities because of shorter operational hours, overcrowding, suboptimal sanitation, queuing with limited seating arrangements, and occasionally discourteous health staff. Self-medication and over-thecounter use of antibiotics was high due to a lack of awareness of the challenges of antibiotic resistance or any perceived side effects. Preference for unlicensed practitioners for medical treatment was low and based on long-term familial beliefs and acceptance. However, traditional practitioners enjoyed a high level of trust in the community from shared cultural values, enjoining attenuation of the perceived non-biological agents of childhood illnesses through non-medical supernatural interventions.
IntroductionLarge-scale sero-prevalence studies with representation from all age groups are requi... more IntroductionLarge-scale sero-prevalence studies with representation from all age groups are required to estimate the true burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the community. Serial serological surveys in fixed cohorts enable study of dynamics of viral transmission and correlates of immune response over time in the context of gradual introduction of COVID-19 vaccines and repeated upsurge of cases during the pandemic.MethodsThis longitudinal study will involve follow-up of a cohort of 25,000 individuals (5,000 per site) aged 2 years and above recruited from five existing demographic surveillance sites in India. The cohort will be tested for the presence of IgG antibodies against S1/S2 spike protein subunits of SARS-CoV-2 in four rounds; once at baseline and subsequently, at intervals of 4 months for a year between January 2021 and January 2022. Neutralization assays will be carried out in a subset of seropositive samples in each round to...
Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countrie... more Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countries where it manifests as waterborne outbreaks and sporadic cases. Though generally self-limited with a low mortality rate, some cases progress to fulminant hepatic failure (FHF) with high mortality. With no identified predictive or diagnostic markers, the events leading to disease exacerbation are not known. Our aim is to use proteomic tools to identify biomarkers of acute and fulminant hepatitis E. Results: We analyzed proteins in the plasma and urine of hepatitis E patients and healthy controls by two-dimensional Differential Imaging Gel Electrophoresis (DIGE) and mass spectrometry, and identified over 30 proteins to be differentially expressed during acute hepatitis E. The levels of one plasma protein, transthyretin, and one urine protein, alpha-1-microglobulin (α1m), were then quantitated by enzyme immunoassay (EIA) in clinical samples from a larger group of patients and controls. The...
Background Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases ... more Background Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases and large waterborne outbreaks. The disease severity ranges from acute self-limited hepatitis with low mortality to fulminant hepatic failure with high mortality. It is believed that the host response plays an important role in determining the progression and outcome of this disease. We profiled the plasma peptidome from hepatitis E patients to discover suitable biomarkers and understand disease pathogenesis. Results The peptidome (< 10 kDa) fraction of plasma was enriched and analyzed by mass spectrometry. A comparative analysis of the peptide pattern of hepatitis E patients versus healthy controls was performed using ClinPro Tools. We generated a peptide profile that could be used for selective identification of hepatitis E cases. We have identified five potential biomarker peaks with m/z values of 9288.6, 7763.6, 4961.5, 1060.572 and 2365.139 that can be used to reliably differenti...
regions of the world, is largely an acute and self-limiting disease, but some patients have an in... more regions of the world, is largely an acute and self-limiting disease, but some patients have an increased susceptibility to develop fulminant hepatitis. The pathogenesis of hepatitis E in humans is poorly characterized. To understand the metabolic pathways involved in the pathophysiology of hepatitis E, we have used 1 H nuclear magnetic resonance spectroscopy to quantify various metabolites in the plasma and urine of the patients with hepatitis E. These were compared with specimens from patients with acute hepatitis B as disease controls and healthy volunteers. Data were analysed using chemometric statistical methods and metabolite databases. The main metabonomic changes found in patients with hepatitis E, but not in those with hepatitis B, included increased plasma levels of L-isoleucine, acetone, and glycerol, reduced plasma levels of glycine, and reduced urinary levels of imidazole, 3-aminoisobutanoic acid, 1-methylnicotina-mide, biopterin, adenosine, 1-methylhistidine, and salicyluric acid. Patients with hepatitis E or B both showed increased levels of plasma and urinary l-proline and decreased levels of various other metabolites. Pathway analysis tools suggest the involvement of glycolysis, tricarboxylic acid cycle, urea cycle, and amino acid metabolism in patients with acute hepatitis E. These findings may help better understand the clinical and biochemical manifestations in this disease and the underlying pathophysiologic processes. Based on our findings, it would be worthwhile determining whether patients with hepatitis E are more prone to develop lactic acidosis and ketosis compared with other forms of viral hepatitis.
Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end rel... more Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end releasing glucose and maltose in Escherichia coli. MalZ is a highly aggregation prone protein and molecular chaperonins GroEL and GroES assist in the folding of this protein to a substantial level. The N-terminal region of this enzyme appears to be a unique domain as seen in sequence comparison studies with other amylases as well as through homology modelling. The sequence and homology model analysis show a probability of disorder in the N-Terminal region of MalZ. The crystal structure of this enzyme has been reported in the present communication. Based on the crystallographic structure, it has been interpreted that the N-terminal region of the enzyme (Met1-Phe131) might be unstructured or flexible. To understand the role of the N-terminal region of MalZ in its enzymatic activity, and overall stability, a truncated version (Ala111-His616) of MalZ was created. The truncated version failed to...
Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end rel... more Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end releasing glucose and maltose in Escherichia coli. MalZ is a highly aggregation prone protein and molecular chaperonins GroEL and GroES assist in the folding of this protein to a substantial level. The N-terminal region of this enzyme appears to be a unique domain as seen in sequence comparison studies with other amylases as well as through homology modelling. The sequence and homology model analysis show a probability of disorder in the N-Terminal region of MalZ. The crystal structure of this enzyme has been reported in the present communication. Based on the crystallographic structure, it has been interpreted that the N-terminal region of the enzyme (Met1– Phe131) might be unstructured or flexible. To understand the role of the N-terminal region of MalZ in its enzymatic activity, and overall stability, a truncated version (Ala111-His616) of MalZ was created. The truncated version failed to fold into an active enzyme both in E. coli cytosol and in vitro even with the assistance of chaperonins GroEL and GroES. Furthermore, the refolding effort of N-truncated MalZ in the presence of isolated N-terminal domain didn't succeed. Our studies suggest that while the structural rigidity or orientation of the N-terminal region of the MalZ protein may not be essential for its stability and function, but the said domain is likely to play an important role in the formation of the native structure of the protein when present as an integral part of the protein.
Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countrie... more Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countries where it manifests as large waterborne outbreaks and sporadic cases. Though generally self-limited with a low mortality rate, some cases progress to fulminant hepatic failure with high mortality. Thus it is believed that the host response plays an important role in determining the progression and outcome of hepatitis E. With no identified predictive or diagnostic markers, the events leading to disease exacerbation are not known, and thus results in poor management of fulminant cases. Methods: For proteomics analysis of plasma and urine, a differential imaging (DIGE) based two dimensional gel electrophoresis platform was optimized, wherein the differentially expressed protein spots were selected and identified by mass spectrometry. The levels of one plasma protein, transthyretin, and one urine protein, alpha-1-microglobulin (1m), were validated by enzyme linked immunosorbent assay (ELI...
Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countrie... more Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countries where it manifests as waterborne outbreaks and sporadic cases. Though generally selflimited with a low mortality rate, some cases progress to fulminant hepatic failure (FHF) with high mortality. With no identified predictive or diagnostic markers, the events leading to disease exacerbation are not known. Our aim is to use proteomic tools to identify biomarkers of acute and fulminant hepatitis E.
Background: Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases... more Background: Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases and large waterborne outbreaks. The disease severity ranges from acute self-limited hepatitis with low mortality to fulminant hepatic failure with high mortality. It is believed that the host response plays an important role in determining the progression and outcome of this disease. We profiled the plasma peptidome from hepatitis E patients to discover suitable biomarkers and understand disease pathogenesis. Results: The peptidome (< 10 kDa) fraction of plasma was enriched and analyzed by mass spectrometry. A comparative analysis of the peptide pattern of hepatitis E patients versus healthy controls was performed using ClinPro Tools. We generated a peptide profile that could be used for selective identification of hepatitis E cases. We have identified five potential biomarker peaks with m/z values of 9288.6, 7763.6, 4961.5, 1060.572 and 2365.139 that can be used to reliably differentiate between hepatitis E patients and controls with areas under the receiver operating characteristic curve (AUROC) values of 1.00, 0.954, 0.989, 0.960 and 0.829 respectively. A number of proteins involved in innate immunity were identified to be differentially present in the plasma of patients compared to healthy controls. Conclusions: Besides the utility of this approach for biomarker discovery, identification of changes in endogenous peptides in hepatitis E patient plasma has increased our understanding of disease pathogenesis. We have identified peptides in plasma that can reliably distinguish hepatitis E patients from healthy controls. Results from this and an earlier proteomics study are discussed.
The hepatitis E virus (HEV) is a small RNA virus and the etiological agent for hepatitis E, a for... more The hepatitis E virus (HEV) is a small RNA virus and the etiological agent for hepatitis E, a form of acute viral hepatitis. The virus has a feco-oral transmission cycle and is transmitted through environmental contamination, mainly through drinking water. Recent studies on the isolation of HEV-like viruses from animal species also suggest zoonotic transfer of the virus. The absence of small animal models of infection and effi cient cell culture systems has precluded virological studies on the replication cycle and pathogenesis of HEV. A vaccine against HEV has undergone successful clinical testing and diagnostic tests are available. This review describes HEV epidemiology, clinical presentation, pathogenesis, molecular virology and the host response to HEV infection. The focus is on published literature in the past decade. [Chandra V, Taneja S, Kalia M and Jameel S 2008 Molecular biology and pathogenesis of hepatitis E virus; J. Biosci. 33 451-464] Vivek Chandra et al 454 Figure 2. HEV and its genotypes. Electron micrograph showing HEV particles from the stool of a hepatitis E patient visualized after aggregation with anti-HEV positive serum and negative staining. A phylogenetic tree showing the distribution of human and swine HEV isolates in four distinct genotypes number 1 to 4 and an outlier group containing avian HEV. Patil AP and Naik S 2007 T-cell epitope mapping of ORF2 and ORF3 proteins of human hepatitis E virus; J. Viral. Hepat. 14 283-292 Agrawal S, Gupta D and Panda S K 2001 The 3′ end of hepatitis E virus (HEV) genome binds specifi cally to the viral RNAdependent RNA polymerase (RdRp); Virology 282 87-101 Ansari I H, Nanda S K, Durgapal H, Agrawal S, Mohanty S K, Gupta D, Jameel S and Panda SK 2000 Cloning, sequencing, and expression of the hepatitis E virus (HEV) nonstructural open reading frame 1 (ORF1); J. Med. Virol. 60 275-283 Arankalle V A, Chobe L P, Joshi M V, Chadha M S, Kundu B and Walimbe A M 2002 Human and swine hepatitis E viruses from Western India belong to different genotypes; J. Hepatol. 36 417-425 Arankalle V A, Joshi M V, Kulkarni A M, Gandhe S S, Chobe L P, Rautmare S S, Mishra A C and Padbidri V S 2001 Prevalence of anti-hepatitis E virus antibodies in different Indian animal species; J.
Hepatitis E, which is endemic to resource-poor regions of the world, is largely an acute and self... more Hepatitis E, which is endemic to resource-poor regions of the world, is largely an acute and self-limiting disease, but some patients have an increased susceptibility to develop fulminant hepatitis. The pathogenesis of hepatitis E in humans is poorly characterized. To understand the metabolic pathways involved in the pathophysiology of hepatitis E, we have used 1 H nuclear magnetic resonance spectroscopy to quantify various metabolites in the plasma and urine of the patients with hepatitis E. These were compared with specimens from patients with acute hepatitis B as disease controls and healthy volunteers. Data were analysed using chemometric statistical methods and metabolite databases. The main metabonomic changes found in patients with hepatitis E, but not in those with hepatitis B, included increased plasma levels of L-isoleucine, acetone, and glycerol, reduced plasma levels of glycine, and reduced urinary levels of imidazole, 3-aminoisobutanoic acid, 1-methylnicotina-mide, biopterin, adenosine, 1-methylhistidine, and salicyluric acid. Patients with hepatitis E or B both showed increased levels of plasma and urinary l-proline and decreased levels of various other metabolites. Pathway analysis tools suggest the involvement of glycolysis, tricarboxylic acid cycle, urea cycle, and amino acid metabolism in patients with acute hepatitis E. These findings may help better understand the clinical and biochemical manifestations in this disease and the underlying pathophysiologic processes. Based on our findings, it would be worthwhile determining whether patients with hepatitis E are more prone to develop lactic acidosis and ketosis compared with other forms of viral hepatitis.
IntroductionLarge-scale sero-prevalence studies with representation from all age groups are requi... more IntroductionLarge-scale sero-prevalence studies with representation from all age groups are required to estimate the true burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the community. Serial serological surveys in fixed cohorts enable study of dynamics of viral transmission and correlates of immune response over time in the context of gradual introduction of COVID-19 vaccines and repeated upsurge of cases during the pandemic.MethodsThis longitudinal study will involve follow-up of a cohort of 25,000 individuals (5,000 per site) aged 2 years and above recruited from five existing demographic surveillance sites in India. The cohort will be tested for the presence of IgG antibodies against S1/S2 spike protein subunits of SARS-CoV-2 in four rounds; once at baseline and subsequently, at intervals of 4 months for a year between January 2021 and January 2022. Neutralization assays will be carried out in a subset of seropositive samples in each round to...
Background: Six diverse Demographic Development and Environmental Surveillance System (DDESS) sit... more Background: Six diverse Demographic Development and Environmental Surveillance System (DDESS) sites were established in urban slum, urban resettlement, peri-urban, rural, and tribal areas located in Northern, North-East, Eastern, and Southern regions of India from June 2020 to March 2022. Understanding the community dynamics and engaging people in the community is critically important in the process of establishing DDESS. We ascertained the barriers, challenges, and facilitators during the establishment of multiple DDESS sites across India. Methods: This was a cross-sectional descriptive mixed-methods study. Results: Multiple barriers and challenges encountered were reported in the process of community engagement (CE), such as geographical inaccessibility, language barriers, adverse weather, non-responsiveness due to perceived lack of individual benefit or financial gain, fear of contracting COVID-19, COVID-19 vaccine hesitancy, etc. Facilitators in the CE process were pre-existing ...
Adolescents constitute 16% of the global population and are susceptible to adverse health and ill... more Adolescents constitute 16% of the global population and are susceptible to adverse health and illness from substance abuse, unhealthy diet, physical inactivity, and high-risk sexual behaviors. We conducted this study to assess the perceptions of good health, health-seeking behavior, and health service utilization among adolescents living in a low-income urban neighborhood after the second wave of the COVID-19 pandemic. A total of 23 adolescents, including 12 males and 11 females, were interviewed. Adolescents' perceived body image and size considerations apart from functioning at an optimum physical capacity as the principal attributes of good health, which was possible through the intake of a healthy diet and exercise. Adolescents were likely to be aware of the addiction potential and risk of cancer from using tobacco and alcohol, but attitudes towards eschewing their use were ambivalent. Adolescents perceived themselves as lacking access to reliable, adequate, and validated sources of sexual and reproductive health information. Knowledge and utilization of adolescent health services in this area were negligible, suggestive of the need to strengthen these services and improve the program outreach.
This explorative qualitative study assesses the health-seeking behaviour for childhood ailments i... more This explorative qualitative study assesses the health-seeking behaviour for childhood ailments in caregivers of under-five children in a low-income neighbourhood in Delhi, India during July-September 2021. A total of 17 caregivers (mothers) of eight male and nine female under-five children were enrolled, with the mother being the caregiver in most (94%) cases. Caregivers consulted on common childhood ailments from multiple sources, including family, neighbours, healthcare providers (both licensed and unlicensed), frontline workers, and local pharmacists. The internet was often used as a source of child health information due to its ease of access but often "confused" caregivers due to the presence of too much information. Health-seeking behaviour of caregivers for childhood ailments could range from self-medication, local pharmacist dispensing, and private and public healthcare providers. Factors that influenced preference for the healthcare facility or provider were accessibility issues (waiting time, queuing), perceived physician competence, and associated out-of-pocket expenses. Caregivers reported dissatisfaction with government health facilities because of shorter operational hours, overcrowding, suboptimal sanitation, queuing with limited seating arrangements, and occasionally discourteous health staff. Self-medication and over-thecounter use of antibiotics was high due to a lack of awareness of the challenges of antibiotic resistance or any perceived side effects. Preference for unlicensed practitioners for medical treatment was low and based on long-term familial beliefs and acceptance. However, traditional practitioners enjoyed a high level of trust in the community from shared cultural values, enjoining attenuation of the perceived non-biological agents of childhood illnesses through non-medical supernatural interventions.
IntroductionLarge-scale sero-prevalence studies with representation from all age groups are requi... more IntroductionLarge-scale sero-prevalence studies with representation from all age groups are required to estimate the true burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the community. Serial serological surveys in fixed cohorts enable study of dynamics of viral transmission and correlates of immune response over time in the context of gradual introduction of COVID-19 vaccines and repeated upsurge of cases during the pandemic.MethodsThis longitudinal study will involve follow-up of a cohort of 25,000 individuals (5,000 per site) aged 2 years and above recruited from five existing demographic surveillance sites in India. The cohort will be tested for the presence of IgG antibodies against S1/S2 spike protein subunits of SARS-CoV-2 in four rounds; once at baseline and subsequently, at intervals of 4 months for a year between January 2021 and January 2022. Neutralization assays will be carried out in a subset of seropositive samples in each round to...
Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countrie... more Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countries where it manifests as waterborne outbreaks and sporadic cases. Though generally self-limited with a low mortality rate, some cases progress to fulminant hepatic failure (FHF) with high mortality. With no identified predictive or diagnostic markers, the events leading to disease exacerbation are not known. Our aim is to use proteomic tools to identify biomarkers of acute and fulminant hepatitis E. Results: We analyzed proteins in the plasma and urine of hepatitis E patients and healthy controls by two-dimensional Differential Imaging Gel Electrophoresis (DIGE) and mass spectrometry, and identified over 30 proteins to be differentially expressed during acute hepatitis E. The levels of one plasma protein, transthyretin, and one urine protein, alpha-1-microglobulin (α1m), were then quantitated by enzyme immunoassay (EIA) in clinical samples from a larger group of patients and controls. The...
Background Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases ... more Background Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases and large waterborne outbreaks. The disease severity ranges from acute self-limited hepatitis with low mortality to fulminant hepatic failure with high mortality. It is believed that the host response plays an important role in determining the progression and outcome of this disease. We profiled the plasma peptidome from hepatitis E patients to discover suitable biomarkers and understand disease pathogenesis. Results The peptidome (< 10 kDa) fraction of plasma was enriched and analyzed by mass spectrometry. A comparative analysis of the peptide pattern of hepatitis E patients versus healthy controls was performed using ClinPro Tools. We generated a peptide profile that could be used for selective identification of hepatitis E cases. We have identified five potential biomarker peaks with m/z values of 9288.6, 7763.6, 4961.5, 1060.572 and 2365.139 that can be used to reliably differenti...
regions of the world, is largely an acute and self-limiting disease, but some patients have an in... more regions of the world, is largely an acute and self-limiting disease, but some patients have an increased susceptibility to develop fulminant hepatitis. The pathogenesis of hepatitis E in humans is poorly characterized. To understand the metabolic pathways involved in the pathophysiology of hepatitis E, we have used 1 H nuclear magnetic resonance spectroscopy to quantify various metabolites in the plasma and urine of the patients with hepatitis E. These were compared with specimens from patients with acute hepatitis B as disease controls and healthy volunteers. Data were analysed using chemometric statistical methods and metabolite databases. The main metabonomic changes found in patients with hepatitis E, but not in those with hepatitis B, included increased plasma levels of L-isoleucine, acetone, and glycerol, reduced plasma levels of glycine, and reduced urinary levels of imidazole, 3-aminoisobutanoic acid, 1-methylnicotina-mide, biopterin, adenosine, 1-methylhistidine, and salicyluric acid. Patients with hepatitis E or B both showed increased levels of plasma and urinary l-proline and decreased levels of various other metabolites. Pathway analysis tools suggest the involvement of glycolysis, tricarboxylic acid cycle, urea cycle, and amino acid metabolism in patients with acute hepatitis E. These findings may help better understand the clinical and biochemical manifestations in this disease and the underlying pathophysiologic processes. Based on our findings, it would be worthwhile determining whether patients with hepatitis E are more prone to develop lactic acidosis and ketosis compared with other forms of viral hepatitis.
Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end rel... more Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end releasing glucose and maltose in Escherichia coli. MalZ is a highly aggregation prone protein and molecular chaperonins GroEL and GroES assist in the folding of this protein to a substantial level. The N-terminal region of this enzyme appears to be a unique domain as seen in sequence comparison studies with other amylases as well as through homology modelling. The sequence and homology model analysis show a probability of disorder in the N-Terminal region of MalZ. The crystal structure of this enzyme has been reported in the present communication. Based on the crystallographic structure, it has been interpreted that the N-terminal region of the enzyme (Met1-Phe131) might be unstructured or flexible. To understand the role of the N-terminal region of MalZ in its enzymatic activity, and overall stability, a truncated version (Ala111-His616) of MalZ was created. The truncated version failed to...
Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end rel... more Maltodextrin glucosidase (MalZ) hydrolyses short malto-oligosaccharides from the reducing end releasing glucose and maltose in Escherichia coli. MalZ is a highly aggregation prone protein and molecular chaperonins GroEL and GroES assist in the folding of this protein to a substantial level. The N-terminal region of this enzyme appears to be a unique domain as seen in sequence comparison studies with other amylases as well as through homology modelling. The sequence and homology model analysis show a probability of disorder in the N-Terminal region of MalZ. The crystal structure of this enzyme has been reported in the present communication. Based on the crystallographic structure, it has been interpreted that the N-terminal region of the enzyme (Met1– Phe131) might be unstructured or flexible. To understand the role of the N-terminal region of MalZ in its enzymatic activity, and overall stability, a truncated version (Ala111-His616) of MalZ was created. The truncated version failed to fold into an active enzyme both in E. coli cytosol and in vitro even with the assistance of chaperonins GroEL and GroES. Furthermore, the refolding effort of N-truncated MalZ in the presence of isolated N-terminal domain didn't succeed. Our studies suggest that while the structural rigidity or orientation of the N-terminal region of the MalZ protein may not be essential for its stability and function, but the said domain is likely to play an important role in the formation of the native structure of the protein when present as an integral part of the protein.
Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countrie... more Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countries where it manifests as large waterborne outbreaks and sporadic cases. Though generally self-limited with a low mortality rate, some cases progress to fulminant hepatic failure with high mortality. Thus it is believed that the host response plays an important role in determining the progression and outcome of hepatitis E. With no identified predictive or diagnostic markers, the events leading to disease exacerbation are not known, and thus results in poor management of fulminant cases. Methods: For proteomics analysis of plasma and urine, a differential imaging (DIGE) based two dimensional gel electrophoresis platform was optimized, wherein the differentially expressed protein spots were selected and identified by mass spectrometry. The levels of one plasma protein, transthyretin, and one urine protein, alpha-1-microglobulin (1m), were validated by enzyme linked immunosorbent assay (ELI...
Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countrie... more Background: Hepatitis E, caused by the hepatitis E virus (HEV), is endemic to developing countries where it manifests as waterborne outbreaks and sporadic cases. Though generally selflimited with a low mortality rate, some cases progress to fulminant hepatic failure (FHF) with high mortality. With no identified predictive or diagnostic markers, the events leading to disease exacerbation are not known. Our aim is to use proteomic tools to identify biomarkers of acute and fulminant hepatitis E.
Background: Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases... more Background: Hepatitis E is endemic to resource-poor regions, where it manifests as sporadic cases and large waterborne outbreaks. The disease severity ranges from acute self-limited hepatitis with low mortality to fulminant hepatic failure with high mortality. It is believed that the host response plays an important role in determining the progression and outcome of this disease. We profiled the plasma peptidome from hepatitis E patients to discover suitable biomarkers and understand disease pathogenesis. Results: The peptidome (< 10 kDa) fraction of plasma was enriched and analyzed by mass spectrometry. A comparative analysis of the peptide pattern of hepatitis E patients versus healthy controls was performed using ClinPro Tools. We generated a peptide profile that could be used for selective identification of hepatitis E cases. We have identified five potential biomarker peaks with m/z values of 9288.6, 7763.6, 4961.5, 1060.572 and 2365.139 that can be used to reliably differentiate between hepatitis E patients and controls with areas under the receiver operating characteristic curve (AUROC) values of 1.00, 0.954, 0.989, 0.960 and 0.829 respectively. A number of proteins involved in innate immunity were identified to be differentially present in the plasma of patients compared to healthy controls. Conclusions: Besides the utility of this approach for biomarker discovery, identification of changes in endogenous peptides in hepatitis E patient plasma has increased our understanding of disease pathogenesis. We have identified peptides in plasma that can reliably distinguish hepatitis E patients from healthy controls. Results from this and an earlier proteomics study are discussed.
The hepatitis E virus (HEV) is a small RNA virus and the etiological agent for hepatitis E, a for... more The hepatitis E virus (HEV) is a small RNA virus and the etiological agent for hepatitis E, a form of acute viral hepatitis. The virus has a feco-oral transmission cycle and is transmitted through environmental contamination, mainly through drinking water. Recent studies on the isolation of HEV-like viruses from animal species also suggest zoonotic transfer of the virus. The absence of small animal models of infection and effi cient cell culture systems has precluded virological studies on the replication cycle and pathogenesis of HEV. A vaccine against HEV has undergone successful clinical testing and diagnostic tests are available. This review describes HEV epidemiology, clinical presentation, pathogenesis, molecular virology and the host response to HEV infection. The focus is on published literature in the past decade. [Chandra V, Taneja S, Kalia M and Jameel S 2008 Molecular biology and pathogenesis of hepatitis E virus; J. Biosci. 33 451-464] Vivek Chandra et al 454 Figure 2. HEV and its genotypes. Electron micrograph showing HEV particles from the stool of a hepatitis E patient visualized after aggregation with anti-HEV positive serum and negative staining. A phylogenetic tree showing the distribution of human and swine HEV isolates in four distinct genotypes number 1 to 4 and an outlier group containing avian HEV. Patil AP and Naik S 2007 T-cell epitope mapping of ORF2 and ORF3 proteins of human hepatitis E virus; J. Viral. Hepat. 14 283-292 Agrawal S, Gupta D and Panda S K 2001 The 3′ end of hepatitis E virus (HEV) genome binds specifi cally to the viral RNAdependent RNA polymerase (RdRp); Virology 282 87-101 Ansari I H, Nanda S K, Durgapal H, Agrawal S, Mohanty S K, Gupta D, Jameel S and Panda SK 2000 Cloning, sequencing, and expression of the hepatitis E virus (HEV) nonstructural open reading frame 1 (ORF1); J. Med. Virol. 60 275-283 Arankalle V A, Chobe L P, Joshi M V, Chadha M S, Kundu B and Walimbe A M 2002 Human and swine hepatitis E viruses from Western India belong to different genotypes; J. Hepatol. 36 417-425 Arankalle V A, Joshi M V, Kulkarni A M, Gandhe S S, Chobe L P, Rautmare S S, Mishra A C and Padbidri V S 2001 Prevalence of anti-hepatitis E virus antibodies in different Indian animal species; J.
Hepatitis E, which is endemic to resource-poor regions of the world, is largely an acute and self... more Hepatitis E, which is endemic to resource-poor regions of the world, is largely an acute and self-limiting disease, but some patients have an increased susceptibility to develop fulminant hepatitis. The pathogenesis of hepatitis E in humans is poorly characterized. To understand the metabolic pathways involved in the pathophysiology of hepatitis E, we have used 1 H nuclear magnetic resonance spectroscopy to quantify various metabolites in the plasma and urine of the patients with hepatitis E. These were compared with specimens from patients with acute hepatitis B as disease controls and healthy volunteers. Data were analysed using chemometric statistical methods and metabolite databases. The main metabonomic changes found in patients with hepatitis E, but not in those with hepatitis B, included increased plasma levels of L-isoleucine, acetone, and glycerol, reduced plasma levels of glycine, and reduced urinary levels of imidazole, 3-aminoisobutanoic acid, 1-methylnicotina-mide, biopterin, adenosine, 1-methylhistidine, and salicyluric acid. Patients with hepatitis E or B both showed increased levels of plasma and urinary l-proline and decreased levels of various other metabolites. Pathway analysis tools suggest the involvement of glycolysis, tricarboxylic acid cycle, urea cycle, and amino acid metabolism in patients with acute hepatitis E. These findings may help better understand the clinical and biochemical manifestations in this disease and the underlying pathophysiologic processes. Based on our findings, it would be worthwhile determining whether patients with hepatitis E are more prone to develop lactic acidosis and ketosis compared with other forms of viral hepatitis.
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Papers by Shikha Taneja