1
|
Rajendran KV, Sood N, Rao BM, Valsalam A, Bedekar MK, Jeena K, Pradhan PK, Paria A, Swaminathan TR, Verma DK, Sood NK. Widespread occurrence of Tilapia parvovirus in farmed Nile tilapia Oreochromis niloticus from India. J Fish Dis 2023. [PMID: 37818735 DOI: 10.1111/jfd.13871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/19/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
Tilapia parvovirus (TiPV) has been associated with heavy mortalities in tilapia as a single infection or in co-infection with Tilapia lake virus (TiLV). In this study, TiPV was detected in farmed Nile tilapia, Oreochromis niloticus, from two geographical regions of India, Maharashtra and Uttar Pradesh. TiPV-specific polymerase chain reaction (PCR) reported earlier was used in the screening. Tilapia collected from Maharashtra showed characteristic clinical signs, and TiPV was detected along with TiLV and/or Aeromonas spp. However, fish from Uttar Pradesh were apparently healthy and only TiPV could be detected in these samples. A high prevalence of TiPV was recorded from both the geographical locations, Maharashtra and Uttar Pradesh (59.6% and 95.0% respectively). The virus could be detected in tissues such as the spleen, liver, kidney, brain and mucus. The spleen appeared to be the best tissue for detecting TiPV in apparently healthy tilapia. The presence of TiPV was further confirmed through sequencing the PCR products, isolation of the virus in the cell line and electron microscopy. Sequences of the NS1 gene of the two TiPV isolates showed similarity to the earlier reported TiPV isolates. The virus could be successfully propagated in O. niloticus Liver (OnL) cell line, and cytopathic effect was observed as early as 3 days post-infection. Furthermore, the presence of non-enveloped icosahedral to round virus particles measuring about 26-35 nm could be demonstrated in the cytoplasm and nucleus of infected OnL cells in transmission electron microscopy. With this confirmation of the presence of the virus, India is the third country to report TiPV after China and Thailand. The detection of TiPV in co-infection cases with TiLV and in apparently healthy Nile tilapia suggests its wide distribution and potential synergistic effect in co-infection cases. Therefore, this emerging virus needs holistic attention to understand its virulence, host-specificity and epidemiological risk factors.
Collapse
Affiliation(s)
| | - Neeraj Sood
- ICAR-National Bureau of Fish Genetic Resources, Uttar Pradesh, Lucknow, India
| | - B Madhusudhana Rao
- ICAR-Central Institute of Fisheries Education, Maharashtra, Mumbai, India
| | - Anisha Valsalam
- ICAR-Central Institute of Fisheries Education, Maharashtra, Mumbai, India
| | - Megha K Bedekar
- ICAR-Central Institute of Fisheries Education, Maharashtra, Mumbai, India
| | - Kezhedath Jeena
- ICAR-Central Institute of Fisheries Education, Maharashtra, Mumbai, India
| | | | - Anutosh Paria
- ICAR-National Bureau of Fish Genetic Resources, Uttar Pradesh, Lucknow, India
| | | | - Dev Kumar Verma
- ICAR-National Bureau of Fish Genetic Resources, Uttar Pradesh, Lucknow, India
| | - Naresh Kumar Sood
- Guru Angad Dev Veterinary and Animal Sciences University, Punjab, Ludhiana, India
| |
Collapse
|
2
|
Tripathi A, Ranjan MR, Verma DK, Singh Y, Shukla SK, Rajput VD, Minkina T, Mishra PK, Garg MC. Author Correction: ANN-GA based biosorption of As(III) from water through chemo-tailored and iron impregnated fungal biofilter system. Sci Rep 2022; 12:13228. [PMID: 35918382 PMCID: PMC9345897 DOI: 10.1038/s41598-022-17593-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- A Tripathi
- Amity Institute of Environmental Sciences, Amity University Uttar Pradesh, Noida-125, Gautam Buddha Nagar, U.P., 201303, India.
| | - M R Ranjan
- Amity Institute of Environmental Sciences, Amity University Uttar Pradesh, Noida-125, Gautam Buddha Nagar, U.P., 201303, India
| | - D K Verma
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, U.P., 221005, India
| | - Y Singh
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, U.P., 221005, India
| | - S K Shukla
- Department of Transport Science and Technology, School of Engineering and Technology, Central University of Jharkhand, Ranchi, Jharkhand, 835222, India
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia, 344090
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia, 344090
| | - P K Mishra
- Department of Chemical Engineering, IIT BHU, Varanasi, U.P., 221005, India
| | - M C Garg
- Amity Institute of Environmental Sciences, Amity University Uttar Pradesh, Noida-125, Gautam Buddha Nagar, U.P., 201303, India
| |
Collapse
|
3
|
Tripathi A, Ranjan MR, Verma DK, Singh Y, Shukla SK, Rajput VD, Minkina T, Mishra PK, Garg MC. ANN-GA based biosorption of As(III) from water through chemo-tailored and iron impregnated fungal biofilter system. Sci Rep 2022; 12:12414. [PMID: 35858932 PMCID: PMC9300712 DOI: 10.1038/s41598-022-14802-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 06/13/2022] [Indexed: 11/22/2022] Open
Abstract
The iron impregnated fungal bio-filter (IIFB) discs of luffa sponge containing Phanerochaete chrysosporium mycelia have been used for the removal of As(III) from water. Two different forms of same biomass viz. free fungal biomass (FFB) and modified free fungal biomass (chemically modified and iron impregnated; CFB and IIFB) have been simultaneously investigated to compare the performance of immobilization, chemo-tailoring and iron impregnation for remediation of As(III). IIFB showed highest uptake capacity and percentage removal of As(III), 1.32 mg/g and 92.4% respectively among FFB, CFB and IIFB. Further, the application of RSM and ANN-GA based mathematical model showed a substantial increase in removal i.e. 99.2% of As(III) was filtered out from water at optimised conditions i.e. biomass dose 0.72 g/L, pH 7.31, temperature 42 °C, and initial As(III) concentration 1.1 mg/L. Isotherm, kinetic and thermodynamic studies proved that the process followed monolayer sorption pattern in spontaneous and endothermic way through pseudo-second order kinetic pathway. Continuous mode of As(III) removal in IIFB packed bed bioreactor, revealed increased removal of As(III) from 76.40 to 88.23% with increased column height from 5 to 25 cm whereas the removal decreased from 88.23 to 69.45% while increasing flow rate from 1.66 to 8.30 mL/min. Moreover, the IIFB discs was regenerated by using 10% NaOH as eluting agent and evaluated for As(III) removal for four sorption–desorption cycles, showing slight decrease of their efficiency by 1–2%. SEM–EDX, pHzpc, and FTIR analysis, revealed the involvement of hydroxyl and amino surface groups following a non-electrostatic legend exchange sorption mechanism during removal of As(III).
Collapse
Affiliation(s)
- A Tripathi
- Amity Institute of Environmental Sciences, Amity University Uttar Pradesh, Noida-125, Gautam Buddha Nagar, U.P., 201303, India.
| | - M R Ranjan
- Amity Institute of Environmental Sciences, Amity University Uttar Pradesh, Noida-125, Gautam Buddha Nagar, U.P., 201303, India
| | - D K Verma
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, U.P., 221005, India
| | - Y Singh
- School of Biochemical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, U.P., 221005, India
| | - S K Shukla
- Department of Transport Science and Technology, School of Engineering and Technology, Central University of Jharkhand, Ranchi, Jharkhand, 835222, India
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia, 344090
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-on-Don, Russia, 344090
| | - P K Mishra
- Department of Chemical Engineering, IIT BHU, Varanasi, U.P., 221005, India
| | - M C Garg
- Amity Institute of Environmental Sciences, Amity University Uttar Pradesh, Noida-125, Gautam Buddha Nagar, U.P., 201303, India
| |
Collapse
|
4
|
Shirin M, Al-Azad S, Zubery MH, Rahman FB, Rashid N, Verma DK. Correlation between HRCT Findings of Symptomatic COVID-19 Patient with RT-PCR Test in a Tertiary Hospital of Bangladesh. Mymensingh Med J 2022; 31:200-207. [PMID: 34999703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The COVID-19 pandemic has turned into a global calamity and affected millions of lives around the world. Even though the vaccination efforts have started, they are yet to have an effective impact on the lower to middle-income countries. Early detection and isolation are still the best way to control the spread of the virus. The standard practice for detecting COVID-19 is the RT-PCR (Reverse Transcription Polymerase Chain Reaction) test but this test has a high probability of producing false-negative results plus lack of availability at all the time due to shortage of kit. Since COVID-19 is a respiratory disease affecting the lungs and the imaging patterns caused by COVID-19 can be observed in chest HRCT (High Resolution Computed Tomography) scans. As a result, HRCT can be used as an alternative diagnostic modality for any suspected cases of COVID-19. In this cross-sectional study was carried out in the Department of Radiology and Imaging, BSMMU, Dhaka, Bangladesh from May 12, 2020 to August 10, 2020. Chest HRCT scans of 284 suspected patients irrespective of age and sex who had done RT-PCR test either positive or negative test result having symptoms suggesting COVID pneumonia were enrolled in this study. Patients who had not done RT-PCR and who were not willing to do HRCT chest were excluded. According to the study, ground glass opacity is the most common feature and found in 89.44% of patients. The other predominant features were including consolidation, crazy paving, fibrotic density and vascular enlargement. The diagnostic performance of the CT scan was also evaluated using the RT-PCR test result as the gold standard and the sensitivity, specificity, and accuracy of the CT scan diagnosis were found to be 83.2%, 50% and 79.9% respectively. The severity of the five lung lobes has also been studied. The right middle lobe and the left upper lobe seemed to be in more severe condition for most of the patients compared to the other lung lobes.
Collapse
Affiliation(s)
- M Shirin
- Dr Mahbuba Shirin, Associate Professor, Department of Radiology and Imaging, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh; E-mail:
| | | | | | | | | | | |
Collapse
|
5
|
Verma DK, Sood N, Paria A, Swaminathan TR, Mohan CV, Rajendran KV, Pradhan PK. Reassortment and evolutionary dynamics of tilapia lake virus genomic segments. Virus Res 2021; 308:198625. [PMID: 34780882 DOI: 10.1016/j.virusres.2021.198625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/02/2021] [Accepted: 11/06/2021] [Indexed: 02/03/2023]
Abstract
The tilapia lake virus (TiLV), a highly infectious negative-sense single-stranded segmented RNA virus, has caused several outbreaks worldwide since its first report from Israel in 2014, and continues to pose a major threat to the global tilapia industry. Despite its economic importance, little is known about the underlying mechanisms in the genomic evolution of this highly infectious viral pathogen. Using phylogenomic approaches to the genome sequences of TiLV isolates from various geographic regions, we report on the pervasive role of reassortment, selection, and mutation in TiLV evolution. Our findings provided the evidence of genome-wide reassortment in this newly discovered RNA virus. The rate of non-synonymous (dN) to synonymous (dS) substitutions was less than one (dN/dS = 0.076 to 0.692), indicating that each genomic segment has been subjected to purifying selection. Concurrently, the rate of nucleotide substitution for each genomic segment was in the order of 1-3 × 10-3 nucleotide substitutions per site per year, which is comparable to the rate of other RNA viruses. Collectively, in line with the results of the previous studies, our results demonstrated that reassortment is the dominant force in the evolution and emergence of this highly infectious segmented RNA virus.
Collapse
Affiliation(s)
- Dev Kumar Verma
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh 226002, India
| | - Neeraj Sood
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh 226002, India
| | - Anutosh Paria
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh 226002, India
| | - T R Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, Kerala 682018, India
| | | | - K V Rajendran
- ICAR-Central Institute of Fisheries Education, Versova, Andheri (W), Mumbai, Maharashtra 400061, India
| | - P K Pradhan
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh 226002, India.
| |
Collapse
|
6
|
Ahsan M, Choudhury S, Razi RM, Verma DK. Bilateral Renal Angiomyolipoma with Hidden Tuberous Sclerosis Complex: A Case Report. Mymensingh Med J 2021; 30:850-854. [PMID: 34226479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Angiomyolipomas (AML) are benign tumor of kidney also referred as renal hamartoma composed of varying amounts of mature adipose tissue, smooth muscle, and blood vessels. It is seen in two distinct clinical forms, a sporadic (isolated) form and 55-80% seen in association with Tuberous sclerosis complex (TSC). If the lesion grows to a large size, a series of clinical manifestations and serious complications may occur. Here we present a case of 26 years lady who presented in the Department Radiology & Imaging of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with chief complaints of bilateral loin pain and occasional hematuria for 2 months. Ultrasound abdomen and contrast enhanced computed tomography shows bilateral renal angiomyolipoma (left>right). In order to look for tuberous sclerosis features, we followed her with plain computed tomography of head which shows subependymal calcifications.
Collapse
Affiliation(s)
- M Ahsan
- Dr Mainul Ahsan, Associate Professor, Department of Radiology & Imaging, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh; E-mail:
| | | | | | | |
Collapse
|
7
|
Sood N, Verma DK, Paria A, Yadav SC, Yadav MK, Bedekar MK, Kumar S, Swaminathan TR, Mohan CV, Rajendran KV, Pradhan PK. Transcriptome analysis of liver elucidates key immune-related pathways in Nile tilapia Oreochromis niloticus following infection with tilapia lake virus. Fish Shellfish Immunol 2021; 111:208-219. [PMID: 33577877 DOI: 10.1016/j.fsi.2021.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Nile tilapia (Oreochromis niloticus) is one of the most important aquaculture species farmed worldwide. However, the recent emergence of tilapia lake virus (TiLV) disease, also known as syncytial hepatitis of tilapia, has threatened the global tilapia industry. To gain more insight regarding the host response against the disease, the transcriptional profiles of liver in experimentally-infected and control tilapia were compared. Analysis of RNA-Seq data identified 4640 differentially expressed genes (DEGs), which were involved among others in antigen processing and presentation, MAPK, apoptosis, necroptosis, chemokine signaling, interferon, NF-kB, acute phase response and JAK-STAT pathways. Enhanced expression of most of the DEGs in the above pathways suggests an attempt by tilapia to resist TiLV infection. However, upregulation of some of the key genes such as BCL2L1 in apoptosis pathway; NFKBIA in NF-kB pathway; TRFC in acute phase response; and SOCS, EPOR, PI3K and AKT in JAK-STAT pathway and downregulation of the genes, namely MAP3K7 in MAPK pathway; IFIT1 in interferon; and TRIM25 in NF-kB pathway suggested that TiLV was able to subvert the host immune response to successfully establish the infection. The study offers novel insights into the cellular functions that are affected following TiLV infection and will serve as a valuable genomic resource towards our understanding of susceptibility of tilapia to TiLV infection.
Collapse
Affiliation(s)
- Neeraj Sood
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Dev Kumar Verma
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Anutosh Paria
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Shrish Chandra Yadav
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Manoj Kumar Yadav
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India
| | - Megha Kadam Bedekar
- ICAR-Central Institute of Fisheries Education, Versova, Andheri (W), Mumbai, 400 061, Maharashtra, India
| | - Saurav Kumar
- ICAR-Central Institute of Fisheries Education, Versova, Andheri (W), Mumbai, 400 061, Maharashtra, India
| | - Thangaraj Raja Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, 682 018, Kerala, India
| | | | - K V Rajendran
- ICAR-Central Institute of Fisheries Education, Versova, Andheri (W), Mumbai, 400 061, Maharashtra, India
| | - Pravata Kumar Pradhan
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, 226002, Uttar Pradesh, India.
| |
Collapse
|
8
|
Verma DK, Peruzza L, Trusch F, Yadav MK, Ravindra, Shubin SV, Morgan KL, Mohindra V, Hauton C, van West P, Pradhan PK, Sood N. Transcriptome analysis reveals immune pathways underlying resistance in the common carp Cyprinus carpio against the oomycete Aphanomyces invadans. Genomics 2020; 113:944-956. [PMID: 33127583 DOI: 10.1016/j.ygeno.2020.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/30/2020] [Accepted: 10/25/2020] [Indexed: 12/13/2022]
Abstract
Infection with Aphanomyces invadans is a serious fish disease with major global impacts. Despite affecting over 160 fish species, some of the species like the common carp Cyprinus carpio are resistant to A. invadans infection. In the present study, we investigated the transcriptomes of head kidney of common carp experimentally infected with A. invadans. In time course analysis, 5288 genes were found to be differentially expressed (DEGs), of which 731 were involved in 21 immune pathways. The analysis of immune-related DEGs suggested that efficient processing and presentation of A. invadans antigens, enhanced phagocytosis, recognition of pathogen-associated molecular patterns, and increased recruitment of leukocytes to the sites of infection contribute to resistance of common carp against A. invadans. Herein, we provide a systematic understanding of the disease resistance mechanisms in common carp at molecular level as a valuable resource for developing disease management strategies for this devastating fish-pathogenic oomycete.
Collapse
Affiliation(s)
- Dev Kumar Verma
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Luca Peruzza
- School of Ocean and Earth Science, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH, United Kingdom; Present address: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy
| | - Franziska Trusch
- International Centre for Aquaculture Research and Development, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom; Present address: University of Dundee, School of Life Sciences, Department of Plant Sciences (@ James Hutton Institute), Invergowrie, Dundee DD2 5DA, Scotland, United Kingdom
| | - Manoj Kumar Yadav
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Ravindra
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Sergei V Shubin
- College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, United Kingdom
| | - Kenton L Morgan
- The Institute of Veterinary Science, University of Liverpool, Leahurst Campus, Neston, CH64 7TE, Liverpool, United Kingdom
| | - Vindhya Mohindra
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Chris Hauton
- School of Ocean and Earth Science, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH, United Kingdom
| | - Pieter van West
- International Centre for Aquaculture Research and Development, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom
| | - P K Pradhan
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Neeraj Sood
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India.
| |
Collapse
|
9
|
Yadav MK, Rastogi A, Criollo Joaquin MP, Verma DK, Rathore G, Swaminathan TR, Paria A, Pradhan PK, Sood N. Establishment and characterization of a continuous cell line from heart of Nile tilapia Oreochromis niloticus and its susceptibility to tilapia lake virus. J Virol Methods 2020; 287:113989. [PMID: 33035566 DOI: 10.1016/j.jviromet.2020.113989] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 10/23/2022]
Abstract
In the present study, we have developed a continuous cell line from the heart tissue of the Oreochromis niloticus and used for studying susceptibility to tilapia lake virus (TiLV). The cell line, designated as OnH, has been subcultured up to 82 passages. The optimal growth of OnH cells was observed at 28-32 °C in iL-15 medium supplemented with 20 % fetal bovine serum. Karyotype analysis revealed that the modal chromosome number of OnH cells was 44. Partial amplification and sequencing of 16S rRNA gene confirmed the origin of OnH cell line from O. niloticus. Immunophenotyping revealed that OnH cells were of epithelial origin. These cells were successfully transfected with pAcGFP1-N1 mammalian expression vector. OnH cells showed cytopathic effects following inoculation with TiLV. The virus titration study indicated that the cells were highly susceptible to TiLV with TCID50 value of 105.3/mL. The qRT-PCR studies revealed that the optimal temperature for TiLV replication in OnH cells was 28 °C. Further, transmission electron microscopy of TiLV-infected OnH cells showed a number of electron-dense virus particles measuring 60-90 nm diameter, which were enclosed in the vesicles in the cytoplasm. Therefore, the newly established OnH cell line provides a valuable tool for isolation of viruses from disease cases suspected to be of viral etiology in this candidate species' and also for transgenic and genetic manipulation studies.
Collapse
Affiliation(s)
- Manoj Kumar Yadav
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India
| | - Aakriti Rastogi
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India
| | - Mónica Paola Criollo Joaquin
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India; Tumbes National University, Tumbes, 24001, Peru
| | - Dev Kumar Verma
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India
| | - Gaurav Rathore
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India
| | - Thangaraj Raja Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, Kerala, 682 018, India
| | - Anutosh Paria
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India
| | - Pravata Kumar Pradhan
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India
| | - Neeraj Sood
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow, Uttar Pradesh, 226 002, India.
| |
Collapse
|
10
|
Sood N, Pradhan PK, Verma DK, Yadav MK, Dev AK, Swaminathan TR, Sood NK. Candidatus Actinochlamydia pangasiae sp. nov. (Chlamydiales, Actinochlamydiaceae), a bacterium associated with epitheliocystis in Pangasianodon hypophthalmus. J Fish Dis 2018; 41:281-290. [PMID: 28940578 DOI: 10.1111/jfd.12711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 08/01/2017] [Accepted: 08/02/2017] [Indexed: 06/07/2023]
Abstract
Chlamydial infections are recognised as causative agent of epitheliocystis, reported from over 90 fish species. In the present study, the farmed striped catfish Pangasianodon hypophthalmus (14-15 cm, 70-90 g) with a history of cumulative mortality of about 23% during June and July 2015, were brought to the laboratory. The histopathological examination of gills from the affected fish revealed presence of granular basophilic intracellular inclusions, mostly at the base of the interlamellar region and in gill filaments. A concurrent infection with Trichodina spp., Ichthyobodo spp. and Dactylogyrus spp. was observed in the gills. The presence of chlamydial DNA in the gills of affected fish was confirmed by amplification and sequencing of 16S rRNA gene. BLAST-n analysis of these amplicons revealed maximum similarity (96%) with Candidatus Actinochlamydia clariae. On the basis of phylogenetic analysis, it was inferred that the epitheliocystis agents from striped catfish were novel and belonged to the taxon Ca. Actinochlamydia. It is proposed that epitheliocystis agents from striped catfish will be named as Ca. Actinochlamydia pangasiae. The 16S rRNA gene amplicons from novel chlamydiae were labelled and linked to inclusions by in situ hybridisation. This is the first report of epitheliocystis from India in a new fish host P. hypophthalmus.
Collapse
Affiliation(s)
- N Sood
- ICAR-National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, India
| | - P K Pradhan
- ICAR-National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, India
| | - D K Verma
- ICAR-National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, India
| | - M K Yadav
- ICAR-National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, India
| | - A K Dev
- ICAR-National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, India
| | - T R Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, Kochi, Kerala
| | - N K Sood
- Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| |
Collapse
|
11
|
Verma DK, Rathore G. New host record of five Flavobacterium species associated with tropical fresh water farmed fishes from North India. Braz J Microbiol 2016; 46:969-76. [PMID: 26691454 PMCID: PMC4704649 DOI: 10.1590/s1517-838246420131081] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 08/04/2014] [Indexed: 11/22/2022] Open
Abstract
Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38) of three farmed fish species i.e. Labeo rohita, Catla catla and Cyprinus carpio. Among them, only twelve bacterial isolates (13.18%) were identified as Flavobacterium spp. on the basis of morphological, biochemical tests, partial 16S rDNA gene sequencing and phylogenetic analysis. On the basis of 16S rDNA gene sequencing, all the 12 isolates were 97.6-100% similar to six different formally described species of genus Flavobacterium. The 16S rDNA based phylogenetic analysis grouped these strains into six different clades. Of the 12 isolates, six strains (Fl9S1-6) grouped with F. suncheonense, two strains (Fl6I2, Fl6I3) with F. indicum and the rest four strains (Fl1A1, Fl2G1, Fl3H1 and Fl10T1) clustered with F. aquaticum, F. granuli, F. hercynium and F. terrae, respectively. None of these species except, F. hercynium were previously reported from fish. All the isolated Flavobacterium species possessed the ability of adhesion and biofilm formation to colonize the external surface of healthy fish. The present study is the first record of tropical freshwater farmed fishes as hosts to five environmentally associated species of the Flavobacterium.
Collapse
|
12
|
Verma DK, Rathore G, Pradhan PK, Sood N, Punia P. Isolation and characterization of Flavobacterium columnare from freshwater ornamental goldfish Carassius auratus. J Environ Biol 2015; 36:433-439. [PMID: 25895267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Filamentous bacteria overlaying ulcerated area on the body surface were observed in the wet-mout preparation from a moribund goldfish with saddle back appearance. The causative agent was identified as Flavobacterium columnrae, on the basis of biochemical test, species-specific polymerase chain reaction (PCR) and sequencing of 16S rDNA gene with the universal bacterial primers. Furthermore, the strain (ING-1) attributed to genomovar II in 16S rDNA PCR-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis. In phylogenetic analysis, the strain ING-1, produced typical columnaris disease symptoms in rohu (Labeo rohita) fingerlings within 10 days. This is a new record about molecular detection and identification of Flavobacterium columnare, occurring naturally on a new host Carassius auratusin India.
Collapse
|
13
|
Verma DK, Thelekkat Y, Bansal S. Metastatic calcification of floor of the mouth secondary to chronic renal failure-report of a rare case with atypical presentation. Dentomaxillofac Radiol 2015; 44:20140023. [PMID: 25556563 DOI: 10.1259/dmfr.20140023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Soft-tissue calcification is always pathological. Metastatic calcification is calcification of soft tissues owing to hyperphosphataemia with or without hypercalcaemia. Metastatic calcification of oral cavity is extremely rare. A case report of metastatic calcification of the floor of the mouth with atypical radiologic and clinical picture is presented here along with a review of earlier reports. A chance finding of the granular oral mucosa on palpation led to a radiographic examination revealing granular calcifications of the floor of the mouth. Blood chemistry and hormone analysis revealed chronic renal failure and hyperparathyroidism. A diagnosis of metastatic calcification secondary to renal failure was made and the treatment was aimed at correcting the renal failure without any intervention for the asymptomatic calcifications. Key differences between the present case and other cases reported in the literature are outlined.
Collapse
Affiliation(s)
- D K Verma
- 1 Department of Oral and Maxillofacial Surgery, Surendera Dental College and Research Institute, Rajasthan, India
| | | | | |
Collapse
|
14
|
Rathore G, Verma DK. [Identification of hypervariable regions within the 16S-23S rRNA intergenic spacer region of Flavobacterium columnare and its application in assigning genomovar group to an individual strain]. Mol Biol (Mosk) 2014; 48:640-647. [PMID: 25842847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Flavobacterium columnare is an important bacterial pathogen of fish with wide ge- netic variability within species. This intraspecies diversity has been termed as genomovars and genomovar groups on the basis of Restriction Fragment Length Polymorphisms of 16S rDNA and 16S-23S rDNA Intergenic Spacer Region (ISR), respectively. In this study, we demonstrate the source of genetic heterogeneity in the F. columnare by sequence analysis of ISR. Length of ISR sequences of different genomovars varied from 553 to 592 nucleotides, while the similarity among sequences ranged from 76.1 to 92.6%. A common ISR structure with tRNAAa and tRNAne embedded within the sequence was identified in all the genomovars ofF. columnare. The results show that strains of F. columnare can be categorized into five genomovar groups based on the heterogeneity in the ISR sequences. Of these, strains belonging to Genomovar I and II can be sub-divided into two groups each; while strains of Genomovar III belonged to one group. Sequence similarity between genomovar groups was lower for ISR (76.1-92.6%) as compared to 16S rDNA (96.1-99.4%) indicating its ability to resolve closely related groups within the genomovars of F. columnare. The main source of variation between genomovar groups is the presence of three hyper variable regions (V1, V2 & V3) in the ISR Of the three, V3 was found to be the most heterogeneous region and was found to be useful in assigning genomovar group to an individual strain of F. columnare.
Collapse
|
15
|
Singh NK, Rai UN, Verma DK, Rathore G. Kocuria flava induced growth and chromium accumulation in Cicer arietinum L. Int J Phytoremediation 2014; 16:14-28. [PMID: 24912212 DOI: 10.1080/15226514.2012.723065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In the present investigation a chromate tolerant rhizobacterium Kocuria flava was isolated and inoculated to the Cicer arietinum L to evaluate its effects on growth and chromium accumulation upon exposure of different concentration of chromium (1-10 microg ml(-1)) as Cr (VI) for 24 d. K. flava inoculated plant of C. arietinum demonstrated luxuriant growth as compared to non inoculated plant at respective concentration of Cr (VI). K. flava found to ameliorate chromium induced phytotoxicity in terms of chlorophylls, carotenoid and protein contents and thus helps the plant in acquiring higher biomass with high chromium concentration. After 24 d, maximum concentration of chromium recorded in root of C. arietinum (4892.39 microg g(-1) dw) inoculated with K. flava as compared to non inoculated plant (1762.22 microg g(-1) dw) upon exposure of 5 microg ml(-1) Cr (VI). Therefore, application of C. arietinum in association with K. flava could be more efficient in decontamination of chromium polluted site. Moreover, K. flava may be used as a bioresource for developing microbes assisted phytoremediation system due to its compatibility.
Collapse
|
16
|
Kumar Verma D, Rathore G. Molecular characterization of Flavobacterium columnare isolated from a natural outbreak of columnaris disease in farmed fish, Catla catla from India. J GEN APPL MICROBIOL 2013; 59:417-24. [DOI: 10.2323/jgam.59.417] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
17
|
Dash C, Routray P, Tripathy S, Verma DK, Guru BC, Meher PK, Nandi S, Eknath AE. Derivation and characterization of embryonic stem-like cells of Indian major carp Catla catla. J Fish Biol 2010; 77:1096-1113. [PMID: 21039493 DOI: 10.1111/j.1095-8649.2010.02755.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Embryonic stem (ES)-like cells were derived from mid-blastula stage embryos of a freshwater fish, catla Catla catla, under feeder-free condition and designated as CCES cells. The conditioned media was optimized with 10% foetal bovine serum (FBS), fish embryo extract (FEE) having 100 µg ml(-1) protein concentration, 15 ng ml(-1) basic fibroblast growth factor (bFGF) and basic media containing Leibovitz-15, DMEM with 4·5 g l(-1) glucose and Ham's F12 (LDF) in 2:1:1 ratio using a primary culture of CCES cells. Cells attached to gelatin-coated plates after 24 h of seeding and ES-like colonies were obtained at day 5 onwards. A stable cell culture was obtained after passage 10 and further maintained up to passage 44. These cells were characterized by their typical morphology, high alkaline phosphatase activity, positive expression of cell-surface antigen SSEA-1, transcription factor Oct4, germ cell marker vasa and consistent karyotype up to extended periods. The undifferentiated state was confirmed by their ability to form embryoid bodies and their differentiation potential.
Collapse
Affiliation(s)
- C Dash
- Division of Aquaculture Production and Environment, Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar 751002, India
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Glass DC, Armstrong TW, Pearlman ED, Verma DK, Schnatter AR, Rushton L. Ensuring comparability of benzene exposure estimates across three nested case-control studies in the petroleum industry in support of a pooled epidemiological analysis. Chem Biol Interact 2009; 184:101-11. [PMID: 19914227 DOI: 10.1016/j.cbi.2009.11.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 10/30/2009] [Accepted: 11/03/2009] [Indexed: 11/17/2022]
Abstract
BACKGROUND Three case-control studies each nested within a cohort of petroleum workers assessed exposure to benzene in relation to risk of haematopoietic cancers. These studies have each been updated and the cases will be pooled to derive a more powerful study. The benzene exposure of new leukemia cases and controls was estimated in accordance with each respective study's original methods. An essential component of the process of pooling the data was comparison and rationalisation of the exposure estimates to ensure accuracy and consistency of approach. This paper describes this process and presents comparative estimates before and after appropriate revision took place. The original petroleum industry studies, in Canada, the UK and Australia, were conducted at different points in time by different study teams, but the industry used similar technology in similar eras in each of these countries. METHODS A job history for each subject giving job title, dates of starting and leaving the job and location of work, was assembled. For each job or task, the average benzene exposure (Base Estimate (BE) in ppm) was derived from measurements collected at applicable worksites. Estimates of exposure intensity (workplace exposure estimates (WE)) were then calculated for each line of work history by adjusting the BEs for site- and era-specific exposure-related variables such as loading technology and percentage benzene in the product. To ensure that the exposure estimates were comparable among the studies, the WEs were allocated to generic Job Categories, e.g. Tanker Driver (by technology used e.g. bottom loading), Motor Mechanic. The WEs were stratified into eras, reflecting technological changes in the industry. The arithmetic mean (AM), geometric mean (GM) and range of the stratified WEs were calculated, by study, for each generic Job Category. These were then compared. The AMs of the WEs were regarded as substantially similar if they were within 20% in all three studies in one era or for at least two studies in two eras. If the AM of the WE group differed by more than 20%, the data were examined to see whether the difference was justified by differences in local exposure conditions, such as an enclosure versus open work area. Estimates were adjusted in the absence of justification for the difference. RESULTS Reconciliation of differences resulted in changes to a small number of underlying BEs, particularly the background values, also the BEs attributed to some individuals and changes to the allocation of jobs between Job Categories. Although the studies covered some differing sectors of the industry and different time periods, for 22 Job Categories there was sufficient overlap, particularly in the downstream distribution sector, to make comparisons possible. After adjustment 12 Job Categories were judged to be similar and 10 were judged to be justifiably different. Job-based peak and skin exposure estimates were applied in a uniform way across the studies and a single approach to scoring the certainty of the exposure estimates was identified. CONCLUSIONS The revised exposure estimates will be used in the pooled analysis to examine the risk of haematopoietic cancers and benzene exposure. This exercise provided an important quality control check on the exposure estimates and identified similarly exposed Job Categories that could be grouped for risk assessment analyses.
Collapse
Affiliation(s)
- D C Glass
- Department of Epidemiology & Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, The Alfred Hospital, Melbourne, Monash Centre for Occupational and Environmental Health, VIC 3004, Australia.
| | | | | | | | | | | |
Collapse
|
19
|
Sood G, Sood A, Jindal A, Verma DK, Dhiman DS. Ultrasound guided percutaneous nephrostomy for obstructive uropathy in benign and malignant diseases. Int Braz J Urol 2006; 32:281-6. [PMID: 16813670 DOI: 10.1590/s1677-55382006000300004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2006] [Indexed: 11/21/2022] Open
Abstract
OBJECTIVE Analyze the success rate, complications and overall benefit of ultrasound guided percutaneous nephrostomy (PCN) for the relief of obstructive uropathy in benign and malignant diseases. MATERIALS AND METHODS PCN was performed in 50 kidneys of 32 patients. It was performed in emergency rooms totally under ultrasound guidance by general surgeons. Seldinger technique was used in all cases. Changes in renal function after the procedure were analyzed using paired t-test. RESULTS The procedure was successfully completed in 42 out of 50 kidneys (84%). There has been no major complication and 28% minor complications. The renal function improved significantly when PCN was performed for benign conditions (mean creatinine 3.52 mg/dL before and 2.18 mg/dL after PCN), however in malignancy there has been no significant improvement in renal function (before PCN mean creatinine 6.39 mg/dL and after PCN 5.41 mg/dL). CONCLUSION We conclude that PCN can be effectively performed under ultrasound guidance and should be the initial procedure in acutely obstructed kidneys with pyonephrosis and poor renal function. In malignant cases, however, improvement in renal function is possible only if the procedure is carried out at an early stage.
Collapse
Affiliation(s)
- G Sood
- Department of Surgery, Indira Gandhi Medical College Shimla H.P., India.
| | | | | | | | | |
Collapse
|
20
|
|
21
|
Abstract
BACKGROUND Failure of eruption of human permanent molars has been attributed to opercular lesions, although comparisons with specimens from normally erupting teeth are scarce. The aim of this study was to quantitatively analyse opercula associated with normal and delayed tooth eruption. METHOD Twenty opercula covering permanent molars delayed in eruption were obtained from 13 patients aged 7.3-18.1 years. Six opercula from normally erupting molars of five 7.3-17.5-year-old subjects served as controls. Specimens were analysed light and electron microscopically and morphometrically. RESULTS In addition to features recognized previously, prominent numbers of nerves, high endothelial-like venules and mast cells were observed. Ultrastructurally, large multinucleated cells did not reveal cell boundaries running between the nuclei, and mast cells seemed belonging to the MC(TC)-type. None of the features differed significantly between opercula from cases of delayed and normal tooth eruption. CONCLUSIONS Disturbances of tooth eruption that are attributed to opercular lesions may represent retentions resulting from the failure of the eruption mechanism, rather than impactions because of a physical barrier.
Collapse
Affiliation(s)
- D K Verma
- Institute of Oral Biology, Section of Orofacial Structures and Development, Center of Dental and Oral Medicine, University of Zurich, Zurich, Switzerland
| | | | | |
Collapse
|
22
|
Abstract
AIMS To study mortality in a cohort of members of the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada and to compare results with two previous proportional mortality studies. METHODS A cohort of 25,285 workers who entered the trade after 1949 was assembled from records of the international head office. Mortality was ascertained by linkage to the Canadian Mortality Registry at Statistics Canada. Standardised mortality ratios were computed using Ontario general population mortality rates as the reference. RESULTS There were significant increases in lung cancer mortality rates (SMR 1.27; 95% CI 1.13 to 1.42). Increased lung cancer risk was observed among plumbers, pipefitters, and sprinkler fitters. Increased risk was observed among workers joining the Union as late as the 1970s. A random effects meta-analysis of this study and the two PMR studies found significant increases in oesophageal (RR 1.24; 95% CI 1.00 to 1.53), lung (RR 1.31; 95% CI 1.19 to 1.44), and haematological/lymphatic (RR 1.21; 95% CI 1.08 to 1.35) malignancies. CONCLUSIONS The mortality pattern is consistent with the effects of occupational exposure to asbestos. Increased risk due to other respiratory carcinogens such as welding fume cannot be excluded. There are substantial amounts of asbestos in place in industrial and commercial environments. The education and training of workers to protect themselves against inhalation hazards will be necessary well into the future.
Collapse
Affiliation(s)
- M M Finkelstein
- Program in Occupational Health and Environmental Medicine, McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5.
| | | |
Collapse
|
23
|
Abstract
BACKGROUND The clinical features of chronic beryllium disease (CBD) are similar to many other chronic lung diseases. In particular, it may be difficult to distinguish it from pulmonary sarcoidosis since the two conditions may be very alike in clinical, pathological and radiological features. Aim To determine if the amount of beryllium found in the lungs could be used to differentiate CBD from sarcoidosis and controls. METHODS Analyses for beryllium in the autopsied lung tissues of 29 cases and controls were carried out. The cases included one CBD, three confirmed sarcoidosis and 25 controls. Blocks of formalin-fixed tissues were analysed by an atomic absorption spectrophotometer equipped with a graphite furnace. A method for analysis of beryllium in air was modified to permit tissue analysis. RESULTS The CBD case had a much higher average beryllium level, but some individual results were similar to controls and patients with sarcoidosis. CONCLUSION The CBD case had beryllium levels within the range of values reported in the literature. The differentiation between CBD and sarcoidosis could not be made with reasonable assurance based only on the analytic result. Occupational history is very important in making a diagnosis of CBD, along with the analysis of tissues. Tissue analysis helped confirm the diagnosis of compensatable CBD in this particular case.
Collapse
Affiliation(s)
- D K Verma
- Program in Occupational Health and Environmental Medicine and the Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada.
| | | | | |
Collapse
|
24
|
Abstract
BACKGROUND Primary cutaneous amoebiasis is a rare clinical entity. The lesions can be successfully treated if suspected and correctly diagnosed. We report an interesting case with review of the literature. METHODS A 25-year-old man presenting with primary cutaneous amoebiasis with extensive involvement of the anterior abdominal wall is described. Correct diagnosis eluded us for 2 years. Clinical suspicion and a simple bedside test (wet drop preparation examination) were sufficient to diagnose the lesion. Successful treatment was achieved with oral Metronidazole followed by split skin grafting. Only six cases of primary cutaneous amoebiasis could be traced in the literature. CONCLUSIONS Primary cutaneous amoebiasis is extremely rare. Diagnosis is usually not suspected because of its rarity. Cutaneous amoebiasis responds readily to proper treatment, yet, if unrecognized and neglected, produces significant morbidity and may be fatal.
Collapse
|
25
|
Affiliation(s)
- D K Verma
- Program in Occupational Health and Environmental Medicine, McMaster University, 1200 Main Street West, HSC-3H50, Hamilton, Ontario, Canada L8N 3Z5.
| | | | | |
Collapse
|
26
|
Verma DK, Shaw DS. A comparison of international silica (alpha-quartz) calibration standards by Fourier transform-infrared spectrophotometry. Ann Occup Hyg 2001; 45:429-35. [PMID: 11513792 DOI: 10.1016/s0003-4878(00)00083-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Seven international silica (alpha-quartz) standards were examined for relative purity to the US National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 1878 Respirable alpha-quartz by Fourier Transform-Infrared Spectrophotometry (FT-IR). The standards examined have been used in North America, the UK, Australia and Germany. The 189 samples analyzed included NIST-SRM 1878, Min-U-Sil 5, Ottawa Silica Sand, Sikron F-600, A9950 (AUST 1), DQ12-Robock, DQ12-Bergbau. Size distributions of the standards were determined by Coulter Counter to be broadly similar with equivalent spherical volume median diameter ranging between 1.2 and 3 microm. The results showed the standards to differ by as much as 30% in relative purity. Consequently, an internationally agreed upon calibration standard is urgently needed. Min-U-Sil 5 based NIST-SRM 1878 or Sikron F-600 are the two most likely candidates. Any agreed standard must have a well characterized size distribution and closely match the respirable dust criteria. It should also be studied by both infrared spectrophotometry and X-ray diffraction techniques.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada.
| | | |
Collapse
|
27
|
Verma DK, Saunders GA, Cheng WK. A laboratory evaluation of the accuracy and precision of the photovac snapshot portable gas chromatograph and the Dräger Chip Measurement System monitor for benzene in air measurements. Appl Occup Environ Hyg 2001; 16:832-40. [PMID: 11504361 DOI: 10.1080/10473220119911] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A laboratory evaluation of the accuracy and precision of two field instruments, the Photovac Snapshot Gas Chromatograph and the Dräger Chip Measurement System (CMS) Monitor, both capable of specific determination of benzene, was carried out. The evaluation was based on the generation of a test atmosphere of known concentration of benzene in a stainless steel calibration chamber and simultaneous sampling of the test atmosphere by each instrument. At the same time, the chamber atmosphere was continuously monitored by one or two data logging photoionization detector (PID) hydrocarbon analysers. A series of six, 10-minute charcoal tube air samples of the test atmosphere was also collected over the 1-hour run and analyzed by gas chromatography. Nine different concentrations ranging from 0.25 ppm to 8 ppm were used. Accuracy was evaluated using National Institute for Occupational Safety and Health (NIOSH) criteria. The Photovac GC consistently met the NIOSH recommended accuracy criteria of +/- 25 percent at or below 1 ppm of benzene, whereas the Drager CMS results generally fell slightly outside this criteria. Compared against less stringent accuracy criteria of +/- 35 percent, all Photovac GC results were acceptable but about 40 percent of Drager CMS results were not. The precision of Photovac GC (CV +/- 10%) is better than Drager CMS (CV = +/- 20% to 40%). Both instruments are, however, good field instruments provided their limitations are taken into account in their use.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | | | |
Collapse
|
28
|
Abstract
A common problem faced by industrial hygienists is the selection of a valid way of dealing with those samples reported to contain nondetectable values of the contaminant. In 1990, Hornung and Reed compared a maximum likelihood estimation (MLE) statistical method and two methods involving the limit of detection, L. The MLE method was shown to produce unbiased estimates of both the mean and standard deviation under a variety of conditions. That method, however, was complicated, requiring difficult mathematical calculations. Two simpler alternatives involved the substitution of L/2 or L/square root of 2 for each nondetectable value. The L/square root of 2 method was recommended when the data were not highly skewed. Although the MLE method produces the best estimates of the mean and standard deviation of an industrial hygiene data set containing values below the detection limit, it was not practical to recommend this method in 1990. However, with advances in desktop computing in the past decade the MLE method is now easily implemented in commonly available spreadsheet software. This article demonstrates how this method may be implemented using spreadsheet software.
Collapse
Affiliation(s)
- M M Finkelstein
- Program in Occupational Health and Environmental Medicine, McMaster University, 1200 Main St. West, Hamilton, Ontario, L8N 3Z5, Canada
| | | |
Collapse
|
29
|
Abstract
A review of studies, including both articles published in peer-reviewed journals and reports that were not peer reviewed, regarding occupational exposure to benzene and total hydrocarbons in the downstream petroleum industry operations was performed. The objective was to provide a broad estimate of exposures by compiling exposure data according to the following categories: refinery, pipeline, marine, rail, bulk terminals and trucks, service stations, underground storage tanks, tank cleaning, and site remediations. The data in each category was divided into personal occupational long-term and short-term samples. The summarized data offers valuable assistance to hygienists by providing them with an estimate and range of exposures. The traditional 8-hour time-weighted average (TWA) exposure and the 40-hour workweek do not generally coincide with exposure periods applicable to workers in marine, pipeline, railcar, and trucking operations. They are more comparable with short-term exposure or task-based exposure assessments. The marine sector has a large number of high exposures. Although relatively few workers are exposed, their exposures to benzene and total hydrocarbons are sometimes an order of magnitude higher than the respective exposure limits. It is recommended that in the future, it would be preferable to do more task-based exposure assessments and fewer traditional TWA long-term exposure assessments within the various sectors of the downstream petroleum industry.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, 1200 Main St. West, Hamilton, Ontario, L8N 3Z5, Canada
| | | | | | | |
Collapse
|
30
|
Allan LM, Verma DK, Yang F, Chau YK, Maguire RJ. A method for the analysis of butyltin chlorides in air by gas chromatography with atomic emission detection. AIHAJ 2000; 61:820-4. [PMID: 11192214 DOI: 10.1080/15298660008984592] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
An initial screening test compared the use of tropolone (2-hydroxy-2,4-6-cycloheptatrienone) in acetic acid with sodium diethyldithiocarbamate (NaDDC) as chelating agents for the extraction of butyltin chlorides from glass fiber filters and XAD-2 resin tube. NaDDC was chosen for subsequent analyses. Mono-, di-, and tributyltin chloride were spiked onto glass fiber filters and XAD-2 resin, extracted in toluene with NaDDC and derivatized with pentylmagnesium bromide. Derivatized butyltin species were determined by gas chromatography with plasma atomic emission detection. Glass fiber filters and XAD-2 resin were found to provide high retention of butyltin compounds during sampling and efficient recovery of butyltin compounds by extraction with NaDDC.
Collapse
Affiliation(s)
- L M Allan
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | |
Collapse
|
31
|
Abstract
A review of literature relating to the issue of adjustments of occupational exposure limits for unusual work shifts and unusual work schedules is described. The important issues relating to various adjustment models are discussed, and a number of conclusions are drawn. Tables of adjustment factors for 34 specific contaminants for 2 unusual schedules are given. A simple approach for use by industrial hygienists is proposed.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
32
|
Abstract
Occupational exposures to benzene and total hydrocarbons (THC) in the Canadian upstream petroleum industry are described in this article. A total of 1547 air samples taken by 5 oil companies in various sectors (i.e., conventional oil/gas, conventional gas, heavy oil processing, drilling and pipelines) were evaluated and summarized. The data includes personal long- and short-term samples and area long-term samples. The percentage of samples over the occupational exposure limit (OEL) of 3.2 mg/m3 or one part per million for benzene, for personal long-term samples ranges from 0 to 0.7% in the different sectors, and area long-term samples range from 0 to 13%. For short-term personal samples, the exceedance for benzene is at 5% with respect to the OEL of 16 mg/m3 or five parts per million in the conventional gas sector and none in the remaining sectors. THC levels were not available for all sectors and had limited data points in others. The percentage exceedance of the OEL of 280 mg/m3 or 100 parts per million for THC as gasoline ranged from 0 to 2.6% for personal long-term samples. It is recommended that certain operations such as glycol dehydrators be carefully monitored and that a task-based monitoring program be included along with the traditional long- and short-term personal exposure sampling.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | | | |
Collapse
|
33
|
Verma DK, Shaw L, Julian J, Smolynec K, Wood C, Shaw D. A comparison of sampling and analytical methods for assessing occupational exposure to diesel exhaust in a railroad work environment. Appl Occup Environ Hyg 1999; 14:701-14. [PMID: 10561882 DOI: 10.1080/104732299302332] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Methods of assessing occupational exposure to diesel exhaust were evaluated in a railroad work environment. The American Conference of Governmental Industrial Hygienists (ACGIH)-recommended elemental carbon and respirable combustible dust methods of sampling and analysis for assessing diesel exhaust were included in the study. A total of 215 personal and area samples were collected using both size-selective (nylon cyclone and Marple) and non-size-selective samplers. The results demonstrate that the elemental carbon method is suitable for the railroad environment and the respirable combustible dust method is not. All elemental carbon concentrations measured were below the proposed ACGIH Threshold Limit Value (TLV) of 0.15 mg/m3. The concentrations of oxides of nitrogen (nitric oxide and nitrogen dioxide) were also found to be below their respective TLVs. There is no correlation between elemental carbon or respirable combustible dust and the oxides of nitrogen. The elemental carbon as fraction of total carbon is about 13 percent, except for onboard locomotives where it is about 24 percent. Comparison of elemental carbon and respirable combustible dust measurements showed consistent relationships for most sampling locations, with respirable combustible dust concentrations 12 to 53 times higher than the elemental carbon levels.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
34
|
Verma DK, des Tombe K. Measurement of benzene in the workplace and its evolution process, Part I: Overview, history, and past methods. Am Ind Hyg Assoc J 1999; 60:38-47. [PMID: 10028615 DOI: 10.1080/00028899908984421] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Benzene and its measurement continues to be important in the field of industrial hygiene. This two-part article reviews the history of occupational and environmental sampling and analysis of benzene from the early 1900s to the present. Part I provides an overview and details of the methods used in the past; history of the American Conference of Governmental Industrial Hygienists' threshold limit values for benzene; and reviews portable, grab, and integrated sampling methods as well as the various analytical methods. It is important to review and understand the past in order to predict future trends.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | |
Collapse
|
35
|
Verma DK, des Tombe K. Measurement of benzene in the workplace and its evolution process, Part II: Present methods and future trends. Am Ind Hyg Assoc J 1999; 60:48-56. [PMID: 10028616 DOI: 10.1080/00028899908984422] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This article (the second of a two-part series) provides a discussion of currently accepted methodology and possible future happenings regarding measurement of benzene in workplaces. The gap between occupational and environmental monitoring is becoming narrow. Environmental levels will always be lower than the occupational, but as the push for lower threshold limit values continues, the focus should be on the environmental aspect as the ultimate limiting factor with respect to measurement. The charcoal tube/carbon disulfide desorption procedure is slowly being stretched to its limit with respect to benzene. It may be time for serious consideration in North America regarding adoption of the proven European procedure of thermal desorption using a porous polymer tube for analysis of benzene.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | |
Collapse
|
36
|
Verma DK, Pagotto JG, Shaw DS, Destombe K, Nieboer E. Assessment of triethylamine and diethylamine emission from military gas mask canisters. Ann Occup Hyg 1998; 42:325-30. [PMID: 9729920 DOI: 10.1016/s0003-4878(98)00042-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A study was undertaken to evaluate the suitability of four types of amine modified charcoal filter canisters (cartridge) for use with gas masks (respirators) by measuring emissions of triethylamine (TEA) and diethylamine (DEA). Sampling and analysis methods for TEA and DEA were validated and optimized to ensure accurate measurement at low levels. A total of 88 air samples were taken by the validated methods to measure concentrations of TEA and DEA emitted from gas mask canisters during simulated use in an environmental chamber. Samples were collected on a mannequin equipped with a breather pump and also on human volunteers. Very low levels of TEA and moderately low levels of DEA emissions were measured during the simulations. The C7 (KOH-TEA-BPL/ASC3T) gas mask canister giving the lowest emission has been selected for use by the Canadian Forces. The potential health hazard from TEA and DEA for soldiers using the gas masks, under normal conditions, based on estimated use of one to two days per month, for a maximum of 4 hours/day for a normal working lifetime, was considered to be minimal and acceptable.
Collapse
Affiliation(s)
- D K Verma
- Occupational and Environmental Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | |
Collapse
|
37
|
Verma DK, Sass-Kortsak AM, Gaylor DH. Evaluation of professional competency in occupational hygiene in Canada--the CRBOH program. Canadian Registration Board of Occupational Hygienists. Am Ind Hyg Assoc J 1994; 55:364-9. [PMID: 8209843 DOI: 10.1080/15428119491019023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The Canadian Registration Board of Occupational Hygienists (CRBOH) was established in 1986 to provide a registration system for professional occupational hygienists in Canada. It was decided that registration would be based on a competency examination following an appropriate combination of academic qualification and relevant professional experience. While the examination was being developed hygienists who met certain educational and experience requirements and who held other certifications by examination (such as those of the American Board of Industrial Hygiene, the British Examining and Board in Occupational Hygiene, or the Conseil d'Accrediation en Hygiene Industrielle du Quebec) were registered. In 1989 CRBOH, after much deliberation and review of other existing certification examinations, selected a two-part scheme consisting of both written and oral examinations. The written examination includes both multiple choice and essay style questions. Only those candidates successfully completing the written examination are eligible for the oral examination. The first group of candidates was examined in the fall of 1990. The authors outline the strengths and weaknesses of various forms of evaluation of professional competency. The rationale for the selection of the CRBOH examination format is discussed in relation to forms of evaluation currently being used in the United States and the United Kingdom. The implication of CRBOH registration on the training and education of occupational hygienists in Canada is highlighted.
Collapse
Affiliation(s)
- D K Verma
- Canadian Registration Board of Occupational Hygienists, Mississauga, Ontario
| | | | | |
Collapse
|
38
|
Abstract
Occupational exposures to the 55 hydrocarbon components of gasoline and petroleum products were measured at the bulk terminals and agencies of six Ontario petroleum companies during the summer of 1986. A total of 82 long-term (full-shift) and 111 short-term personal samples were taken over 3 months. The data, expressed as concentrations in milligrams per cubic meter, were highly variable and appeared to fit the lognormal distribution well. Full-shift exposures of bulk terminal drivers, agency drivers, and plantmen to total hydrocarbons (THC), computed as an n-hexane equivalent, and other hydrocarbon components for which exposure limits exist can be expected to exceed their respective 1986-1987 threshold limit value-time-weighted average (TLV-TWA) no greater than 1% of the time on the basis of the lognormal model. The short-term THC exposures of agency truck drivers can be expected to exceed the 1986-1987 TLV-short-term exposure limits about 7% of the time while top-loading and more than 17% while off-loading. For benzene, the short-term exceedance percentages are 1% and 4% for top- and off-loading operations, respectively. For long-term benzene exposures, up to 69% of the assessments can be expected to exceed the 1990-1991 proposed TLV-TWA of 0.3 mg/m3 (0.1 ppm). The full-shift hydrocarbon exposures of agency drivers were significantly higher than those for bulk terminal drivers. At the bulk terminals, the short-term hydrocarbon exposures during top-loading were significantly higher than during bottom-loading.
Collapse
Affiliation(s)
- D K Verma
- Occupational Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
39
|
Verma DK, Julian JA, Roberts RS, Muir DC, Jadon N, Shaw DS. Polycyclic aromatic hydrocarbons (PAHs): a possible cause of lung cancer mortality among nickel/copper smelter and refinery workers. Am Ind Hyg Assoc J 1992; 53:317-24. [PMID: 1609742 DOI: 10.1080/15298669291359717] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A retrospective industrial hygiene investigation was undertaken to explain the cause of a statistically significant excess lung cancer mortality observed in a subset of a large cohort of nickel workers involved in mining, smelting, and refining of nickel and copper in Ontario. The focus of this paper is to demonstrate how an industrial hygiene follow-up assessment of an epidemiologic finding can help to identify a likely cause. Polycyclic aromatic hydrocarbons (PAHs) alone or in association with particulate and gaseous contaminants (e.g., SO2) were likely the causative agents of the excess lung cancer observed among the lead welders, cranemen, and arc furnace workers of the copper refinery.
Collapse
Affiliation(s)
- D K Verma
- Occupational Health Program, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
40
|
Abstract
Industrial hygiene surveys were conducted at three hot dip galvanizing plants to determine occupational exposure to nickel, zinc, and lead. All three plants employed the "dry process" and used 2% nickel, by weight, in their zinc baths. A total of 32 personal and area air samples were taken. The air samples were analyzed for nickel, zinc, and lead. Some samples were also analyzed for various species of nickel (i.e., metallic, soluble, and oxidic). The airborne concentrations observed for nickel and its three species, zinc, and lead at the three plants were all well below the current and proposed threshold limit values recommended by the American Conference of Governmental Industrial Hygienists (ACGIH).
Collapse
Affiliation(s)
- D K Verma
- Occupational Health Laboratory, McMaster University, Hamilton, Ontario, Canada
| | | |
Collapse
|
41
|
Chong JP, Haines AT, Verma DK. A pragmatic approach to standard setting--the example of coal tar products and asphalt. Ann Occup Hyg 1989; 33:197-208. [PMID: 2667421 DOI: 10.1093/annhyg/33.2.197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This article will outline a pragmatic approach directed to incorporating key elements of a scientific review of the literature and derive a proposal for an occupational exposure standard for coal tar, coal tar pitch, creosote, petroleum pitch, bitumen and asphalt, six substances which contain polynuclear aromatic hydrocarbons. Five approaches to the standard setting process are reviewed and their strengths and weaknesses discussed. Unfortunately there does not exist an acceptable epidemiological data set, other than the coke oven emission studies, on which to base a valid and reliable risk assessment model. Based on comparative potency experiments of complex mixtures, consideration of the state-of-the-art sampling and analytical methods, prevention of acute human health effects, and current existing standards for these substances throughout the world, a set of recommended exposure standards are derived for health policy makers.
Collapse
|
42
|
Verma DK, Sebestyen A, Julian JA, Muir DC, Schmidt H, Bernholz CD, Shannon HS. Silica exposure and silicosis among Ontario hardrock miners: II. Exposure estimates. Am J Ind Med 1989; 16:13-8. [PMID: 2750747 DOI: 10.1002/ajim.4700160104] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
An epidemiological investigation was carried out to determine the relationship between silicosis in hardrock miners in Ontario and cumulative exposure to silica (free crystalline silica--alpha quartz) dust. This second report describes a side-by-side air-sampling program used to derive a konimeter/gravimetric silica conversion curve. A total of 2,360 filter samples and 90,000 konimeter samples were taken over 2 years in two mines representing the ore types gold and uranium, both in existing conditions as well as in an experimental stope in which dry drilling was used to simulate the high dust conditions of the past. The method of calculating cumulative respirable silica exposure indices for each miner is reported.
Collapse
Affiliation(s)
- D K Verma
- Occupational Health Program, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
43
|
Muir DC, Julian JA, Shannon HS, Verma DK, Sebestyen A, Bernholz CD. Silica exposure and silicosis among Ontario hardrock miners: III. Analysis and risk estimates. Am J Ind Med 1989; 16:29-43. [PMID: 2750748 DOI: 10.1002/ajim.4700160105] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
An epidemiological investigation was undertaken to determine the relationship between silicosis in hardrock miners in Ontario and cumulative exposure to silica (free crystalline silica--alpha quartz) dust. This report describes the analytic method and presents the risk estimates.
Collapse
Affiliation(s)
- D C Muir
- Occupational Health Program, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
44
|
Abstract
An epidemiological investigation was undertaken to determine the relationship between silicosis in hardrock miners in Ontario and cumulative exposure to silica (crystalline silica--alpha quartz) dust. This first report describes the cohort, the method of classifying the radiographs, and the identification of a case of silicosis.
Collapse
Affiliation(s)
- D C Muir
- Occupational Health Program, McMaster University, Hamilton, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
45
|
Abstract
A historical prospective study of cancer in lamp manufacturing workers in one plant was conducted. All men and women who worked for a total of at least 6 months and were employed at some time between 1960 and 1975 were included. Work histories were abstracted and subjects were divided according to whether they had worked in the coiling and wire drawing area (CWD). Cancer morbidity from 1964 to 1982 was ascertained via the provincial registry, and was compared with the site-specific incidence in Ontario, adjusting for age, sex and calendar period. Of particular interest were primary breast and gynecological cancers in women. The cancers of a priori concern were significantly increased in women in CWD, but not elsewhere in the plant. The excess was greatest in those with more than 5 yr exposure (in CWD) and more than 15 yr since first working in CWD, with eight cases of breast and gynecological cancers observed in this category compared with 2.67 expected. Only three cancers occurred in men in CWD. Environmental measurements had not been made in the past and little information was available on substances used in the 1940s and 1950s, the period when the women with the highest excess began employment. It is known that methylene chloride and trichlorethylene have been used, but not enough is known about the dates and patterns of use to draw any conclusions about their relationship with the increase in disease.
Collapse
Affiliation(s)
- H S Shannon
- Occupational Health Program, McMaster University Medical Centre, Hamilton, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
46
|
Verma DK, Shannon HS, Muir DC, Nieboer E, Haines AT. Multi-disciplinary, problem-based, self-directed training in occupational health. J Soc Occup Med 1988; 38:101-4. [PMID: 3236836 DOI: 10.1093/occmed/38.4.101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
47
|
|
48
|
McQueen MJ, Greer J, Nazir DJ, Strickland RD, Verma DK. Mercury exposure: an evaluation. Dimens Health Serv 1983; 60:22-4. [PMID: 6832513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
49
|
Verma DK, Muir DC, Cunliffe S, Julian JA, Vogt JH, Rosenfeld J, Chovil A. Polycyclic aromatic hydrocarbons in Ontario foundry environments. Ann Occup Hyg 1982; 25:17-25. [PMID: 7092013 DOI: 10.1093/annhyg/25.1.17] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
50
|
Abstract
Studies of airborne asbestos fiber concentrations associated with various operations of the drywall taping process have been undertaken in the province of Alberta, Canada. The results show that mixing, sanding and sweeping created high levels of airborne asbestos dust. The measured concentrations were frequently in excess of occupational health standards. Sanding in particular was assessed the most hazardous operation. The results are discussed in light of present and proposed Occupational Health Standards, and in terms of its implications for other workers, household contacts, and consumer's risk. Measures to reduce and control the health hazards associated with the process are described.
Collapse
|