Fostering innovation and sustainable thinking in surgery: an evaluation of a surgical hackathon.

INTRODUCTION: Surgery represents a major source of carbon emissions, with numerous initiatives promoting more sustainable practices. Healthcare innovation and the development of a digitally capable workforce are fundamental in leveraging technologies to tackle challenges, including sustainability in surgery. METHODS: A surgical hackathon was organised with three major themes: (1) how to make surgery greener, (2) the future of plastic surgery in 10 years, and (3) improving healthcare outcomes using machine learning. Lectures were given on sustainability and innovation using the problem, innovation, market size, strategy and team (PIMST) framework to support their presentations, as well as technological support to translate ideas into simulations or minimum viable products. Pre- and post-event questionnaires were circulated to participants. RESULTS: Most attendees were medical students (65%), although doctors and engineers were also present. There was a significant increase in delegates' confidence in approaching innovation in surgery (+20%, p < 0.001). Reducing waste packaging (70%), promoting recyclable material usage (56%) and the social media dimension of public perceptions towards plastic surgery (40%) were reported as the most important issues arising from the hackathon. The top three prizes went to initiatives promoting an artificial intelligence-enhanced operative pathway, instrument sterilisation and an educational platform to teach students research and innovation skills. CONCLUSIONS: Surgical hackathons can result in significant improvements in confidence in approaching innovation, as well as raising awareness of important healthcare challenges. Future innovation events may build on this to continue to empower the future workforce to leverage technologies to tackle healthcare challenges such as sustainability.

DNA sequence information resolves taxonomic ambiguity of the common mud crab species (Genus Scylla) in Indian waters.

For several years, mud crabs of genus Scylla have been misidentified owing to their high morphological plasticity and the absence of distinct morphological diagnostic characters. The taxonomic confusion of genus Scylla de Haan is considered to be a primary constraint to the development of aquaculture. Although genus Scylla was revised using morphological and genetic characteristics, taxonomy of Scylla species occurring in India is still not clear. In this study, partial sequences of two mitochondrial genes, 16S rRNA and CO1 (Cytochrome C oxidase subunit I) in populations of Scylla spp. obtained from eleven locations along the Indian coast were used to differentiate and resolve taxonomical ambiguity of the mud crab species in India. The sequences were compared with previously published sequences of Scylla spp. Both trees generated based on 16S rRNA and CO1 indicated that all S. tranquebarica morphotypes obtained during this study and S. tranquebarica sequences submitted previously from Indian waters reciprocally monophyletic with reference sequence of S. serrata. Both sequence data and morphological characters revealed that the species S. serrata (Forskal) is the most abundant followed by S. olivacea. Further, the 16S rRNA and COI haplotypes of Indian S. tranquebarica obtained in the study significantly differed with the known S. tranquebarica by 6.7% and 10.6% respectively whereas it differed with known S. serrata by 0.0-0.7% only, a difference that was not statistically significant. From these studies it is clear that "S. tranquebarica" commonly reported from India should be S. serrata (Forskal).

Gene expression profiling in gill tissues of White spot syndrome virus infected black tiger shrimp Penaeus monodon by DNA microarray.

White spot syndrome virus (WSSV) continues to be the most devastating viral pathogen infecting penaeid shrimp the world over. The genome of WSSV has been deciphered and characterized from three geographical isolates and significant progress has been made in developing various molecular diagnostic methods to detect the virus. However, the information on host immune gene response to WSSV pathogenesis is limited. Microarray analysis was carried out as an approach to analyse the gene expression in black tiger shrimp Penaeus monodon in response to WSSV infection. Gill tissues collected from the WSSV infected shrimp at 6, 24, 48 h and moribund stage were analysed for differential gene expression. Shrimp cDNAs of 40,059 unique sequences were considered for designing the microarray chip. The Cy3-labeled cRNA derived from healthy and WSSV-infected shrimp was subjected to hybridization with all the DNA spots in the microarray which revealed 8,633 and 11,147 as up- and down-regulated genes respectively at different time intervals post infection. The altered expression of these numerous genes represented diverse functions such as immune response, osmoregulation, apoptosis, nucleic acid binding, energy and metabolism, signal transduction, stress response and molting. The changes in gene expression profiles observed by microarray analysis provides molecular insights and framework of genes which are up- and down-regulated at different time intervals during WSSV infection in shrimp. The microarray data was validated by Real Time analysis of four differentially expressed genes involved in apoptosis (translationally controlled tumor protein, inhibitor of apoptosis protein, ubiquitin conjugated enzyme E2 and caspase) for gene expression levels. The role of apoptosis related genes in WSSV infected shrimp is discussed herein.

Recent insights into host-pathogen interaction in white spot syndrome virus infected penaeid shrimp.

Viral disease outbreaks are a major concern impeding the development of the shrimp aquaculture industry. The viral disease due to white spot syndrome virus (WSSV) observed in early 1990s still continues unabated affecting the shrimp farms and cause huge economic loss to the shrimp aquaculture industry. In the absence of effective therapeutics to control WSSV, it is important to understand viral pathogenesis and shrimp response to WSSV at the molecular level. Identification and molecular characterization of WSSV proteins and receptors may facilitate in designing and development of novel therapeutics and antiviral drugs that may inhibit viral replication. Investigations into host-pathogen interactions might give new insights to viral infectivity, tissue tropism and defence mechanism elicited in response to WSSV infection. However, due to the limited information on WSSV gene function and host immune response, the signalling pathways which are associated in shrimp pathogen interaction have also not been elucidated completely. In the present review, the focus is on those shrimp proteins and receptors that are potentially involved in virus infection or in the defence mechanism against WSSV. In addition, the major signalling pathways involved in the innate immune response and the role of apoptosis in host-pathogen interaction is discussed.

White spot syndrome virus (WSSV) genome stability maintained over six passages through three different penaeid shrimp species.

White spot syndrome virus (WSSV) replicates rapidly, can be extremely pathogenic and is a common cause of mass mortality in cultured shrimp. Variable number tandem repeat (VNTR) sequences present in the open reading frame (ORF)94, ORF125 and ORF75 regions of the WSSV genome have been used widely as genetic markers in epidemiological studies. However, reports that VNTRs might evolve rapidly following even a single transmission through penaeid shrimp or other crustacean hosts have created confusion as to how VNTR data is interpreted. To examine VNTR stability again, 2 WSSV strains (PmTN4RU and LvAP11RU) with differing ORF94 tandem repeat numbers and slight differences in apparent virulence were passaged sequentially 6 times through black tiger shrimp Penaeus monodon, Indian white shrimp Feneropenaeus indicus or Pacific white leg shrimp Litopenaeus vannamei. PCR analyses to genotype the ORF94, ORF125 and ORF75 VNTRs did not identify any differences from either of the 2 parental WSSV strains after multiple passages through any of the shrimp species. These data were confirmed by sequence analysis and indicate that the stability of the genome regions containing these VNTRs is quite high at least for the WSSV strains, hosts and number of passages examined and that the VNTR sequences thus represent useful genetic markers for studying WSSV epidemiology.

High salinity induced expression profiling of differentially expressed genes in shrimp (Penaeus monodon).

Four suppression subtractive hybridization (SSH) cDNA libraries were constructed to identify differentially expressed salinity stress responsive genes of black tiger shrimp, Penaeus monodon exposed to high (55 ppt) salinity conditions. One each of the forward and reverse SSH cDNA libraries were developed from the gill and gut tissues of shrimp and clones having inserts larger than 300 bp were unidirectionally sequenced. Based on the sequence homology search, the identified genes were categorized for their putative functions related to a wide range of biological roles, such as nucleic acid regulation and replication, immune response, energy and metabolism, signal transduction, cellular process, structural and membrane proteins, stress and osmoregulation. Gene expression levels in response to high salinity conditions at 2 weeks post salinity stress for some of the differentially expressed genes (Na(+)/K(+)-ATPase α-subunit, glutathione peroxidase, intracellular fatty acid binding protein, elongation factor 2, 14-3-3 like protein, penaeidin, translationally controlled tumor protein, transglutaminase and serine proteinase inhibitor B3) identified from SSH cDNA libraries were analysed by real-time RT-PCR. The highest gene expression levels was observed for Na(+)/K(+)-ATPase α-subunit in gill tissues (15.23-folds) and antennal glands (12.01-folds) and intracellular fatty acid binding protein in gut tissues (14.05-folds) respectively. The differential and significant levels of gene expression indicate the functional role of these genes in shrimp salinity stress adaptive mechanisms.

Association of dual viral infection with mortality of Pacific white shrimp (Litopenaeus vannamei) in culture ponds in India.

Pacific white shrimp, Litopenaeus vannamei has been introduced recently for culture practice in India. Though SPF stocks are imported for larval production and thereafter culture practice, these are prone to infection with the existing viruses in the environment. Here we report mortality of L.vannamei in several farms in India with minimum biosecurity. The shrimp were harvested early within 50-72 days of culture due to the onset of disease and consequent mortality. As per the analysis carried out, the shrimp were infected with two virus, white spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV). About 80 % of the samples collected had either or both of the viruses. A majority of these samples (60 %) had dual infection with WSSV and IHHNV. Infection of shrimp with WSSV and IHHNV could be detected both by PCR and histopathology. Some of the samples had either exclusively WSSV infection or IHHNV infection and were also harvested before the completion of the required culture period. All the samples analyzed were negative for taura syndrome virus, yellow head virus and infectious myonecrosis virus. While it is difficult to point out the exact etiological agent as the cause of mortality, strict biosecurity measures are advisable for the continuity of L. vannamei culture in India.

Identification and characterization of microsatellite markers for the population genetic structure in endemic red-tailed barb, Gonoproktopterus curmuca.

Gonoproktopterus curmuca is an endangered red tailed barb found in Southern part of Western Ghat, India. As a part of stock-specific, propagation assisted rehabilitation and management program, polymorphic microsatellites markers were used to study the genetic diversity and population structure of this species from the three River systems of Southern Western Ghats, such as Periyar River, the Chalakkudy River, and the Chaliyar River. From selected eight polymorphic microsatellite markers, the number of alleles per locus ranged from 2 to 8, and the average number of alleles among 3 populations ranged from 5.0 to 5.75. The mean observed (Hob) and expected (Hex) heterozygosity ranged from 0.5148 to 0.5360 and from 0.5996 to 0.6067, respectively. Significant deviations from Hardy-Weinberg Equilibrium expectation were found at majority of the loci (except Gcur MFW72 and Gcur MFW19) and in all three populations in which heterozygote deficits were apparent. The analysis of molecular variance indicates that the percent of variance among populations and within populations were 6.73 and 93.27, respectively. The pairwise FST values between populations indicate that there were significant deviations in genetic differentiations for the red-tailed barb populations from these three Rivers of the Western Ghats, India. The microsatellites methods reported a low degree of gene diversity and lack of genetic heterogeneity in the population of G. curmuca, which strongly emphasize the need of fishery management, conservation and rehabilitation of G. curmuca.

Molecular cloning and characterization of acyl-CoA binding protein (ACBP) gene from shrimp Penaeus monodon exposed to salinity stress.

Acyl-CoA binding protein (ACBP), a protein present ubiquitously in wide range of organisms play significant role in transport of acyl groups for macromolecular biosynthesis involved in various functional and regulatory processes. In crustaceans, ACBP has functional role in growth, reproduction and temperature tolerance. In the present study, two suppression subtractive hybridization (SSH) cDNA libraries were performed using gut tissues of shrimp Penaeus monodon exposed to low (3 ppt) and high (55 ppt) salinity stress conditions. SSH library resulted in identification of differentially expressed genes that belonged to various functional classes such as the nucleic acid regulation and replication, defence proteins, allergen protein, signal transduction pathways, apoptosis, energy and metabolism, cell cycle regulation and hypothetical proteins. ACBP was identified as one of the differentially expressed gene in both the SSH libraries of shrimp P. monodon subjected to low and high salinity stress. The full-length cDNA of P. monodon ACBP gene was isolated and the sequence revealed 273 bp open reading frame encoding 90 amino acids with molecular mass of 10 kDa and pI 6.8. The ORF showed presence of four phosphorylation sites, with absence of signal peptide sequence and glycosylation sites. The deduced amino acid sequence of ACBP exhibited high sequence identity (92%) with ACBP class of protein identified from Fenneropenaeus chinensis. Real time PCR analysis of shrimps subjected to 3 ppt salinity conditions after 2 weeks revealed an increase in expression of ACBP transcripts, in the gut (28.08-folds), gills (11.71-folds) and in the muscle tissues (1.70-folds). Whereas, shrimps exposed to 55 ppt salinity conditions after 2 weeks exhibited increased ACBP transcript levels in the gut (11.95-folds), gills (1.052-folds) and muscle tissues (7.35-folds). The significant increase in expression levels of ACBP in various tissues of shrimps suggests a functional role of this gene in salinity stress tolerance and adaptation.

Identification and expression analysis of differentially expressed genes from shrimp (Penaeus monodon) in response to low salinity stress.

Four suppression subtractive hybridization (SSH) cDNA libraries were constructed to identify differentially expressed salinity stress responsive genes of black tiger shrimp, Penaeus monodon exposed to low (3 ppt) salinity conditions. Forward and reverse SSH cDNA libraries were developed from the gill and gut tissues of shrimp and clones having inserts larger than 300 bp were unidirectionally sequenced. Based on the sequence homology search, the identified genes were categorized for their putative functions related to a wide range of biological roles, such as nucleic acid regulation and replication, immune response, energy and metabolism, cell signaling, cellular process, cytoskeleton and membrane structure, stress and osmoregulation. Gene expression levels in response to low salinity conditions at 2 weeks post salinity stress of thirteen selected differentially expressed genes identified from SSH cDNA libraries (14-3-3 like protein, crust in, lysozyme, arginine kinase, Naþ/Kþ-ATPase a-subunit, intracellular fatty acid binding protein, cathepsin B, anti-lipopolysaccharide factor, ferritin, ubiquitin conjugating enzyme E2, calreticulin, innexin 2 and heat shock protein 21) were analyzed by RT-PCR. The highest gene expression levels were observed for Naþ/Kþ-ATPase a-subunit (34.28-folds) in gill tissues, intracellular fatty acid binding protein (13.30-folds) in gut tissues and innexin 2 (14.43-folds) in muscle tissues respectively. The differential and significant levels of gene expression indicate the functional role of these genes in shrimp salinity stress adaptive mechanisms.

Identification, cloning and expression analysis of Catechol-O-methyltransferase (COMT) gene from shrimp, Penaeus monodon and its relevance to salinity stress.

O-methyltransferase (OMT), a protein present ubiquitously in wide range of organisms plays significant role in methylation of small macro molecules for various functional and regulatory purposes. In crustaceans, OMT has functional role in growth, reproduction, ovarian development and molting. In the present study, suppression subtractive hybridization (SSH) performed using gill tissues of low (3ppt) and high (55ppt) salinity stressed shrimp Penaeus monodon resulted in identification of differentially expressed genes involved in signal transduction pathways, metabolism, defense proteins, DNA repair and synthesis, apoptosis, cell cycle regulation along with unknown and hypothetical proteins. Catechol-O-methyltransferase (COMT) a type of OMT was identified by SSH as one of the differentially expressed genes of shrimp P. monodon subjected to low and high salinity stress. The full length cDNA of COMT was cloned from the gills of P. monodon which consisted an open reading frame of 666 bp, encoding 221 amino acids. The ORF revealed one each of N-glycosylation and O-glycosylation sites and nine phosphorylation sites. The deduced amino acid sequence of COMT exhibited high sequence identity (92%) with COMT class of protein from Fenneropenaeus chinensis. Real time PCR analysis of the shrimp samples exposed to low salinity conditions at 3ppt revealed significant increase in expression of COMT transcripts in the guts at 24 h, 48 h, 1 week and 2 weeks, gills at 24 h and in the muscle tissues at 48 h, with maximum expression of the COMT levels by 5 fold in guts (1 week), 1 fold in gills (24 h) and 1.5 fold in muscle (48 h) respectively. The increased expression level of COMT at different time intervals in different tissues suggests a possible role of this gene in salinity stress tolerance in shrimps under low salinity conditions.

Comparative assessment of genetic variability in the populations of endemic and endangered yellow catfish, Horabagrus brachysoma (Teleostei: Horabagridae), based on allozyme, RAPD, and microsatellite markers.

The comparative assessment of genetic diversity using allozymes, random amplified polymorphic DNA (RAPD), and microsatellite markers was conducted in endemic and endangered yellow catfish (Horabagrus brachysoma) sampled from three locations in Western Ghats river systems of India. Among the three markers, microsatellites show more polymorphism, having 100% polymorphic loci, whereas allozymes show the least (56%). In RAPD, 60.5% of fragments were polymorphic. Observed heterozygosity and F(ST) values were very high in microsatellites, compared with the other markers. Microsatellite and RAPD markers reported a higher degree of genetic differentiation than allozymes among the populations depicted by pairwise F(ST)/G(ST), AMOVA, Nei's genetic distance, and UPGMA dendrogram. The three classes of markers demonstrated striking genetic differentiation between pairs of H. brachysoma populations. The data emphasize the need for fishery management, conservation, and rehabilitation of this species.

Transcript Analysis of White spot syndrome virus Latency and Phagocytosis Activating Protein Genes in Infected Shrimp (Penaeus monodon).

Viral latency has been recently observed to be associated with White spot syndrome virus (WSSV) infection in shrimp. In the present study, shrimp samples (Penaeus monodon) surviving WSSV infection were examined for presence of WSSV in latent phase. Virus latency was observed in shrimp which were either experimentally challenged with WSSV and survived the infection or those which survived the natural infection. Three viral transcripts (ORFs 427, 151, 366) associated with latency were analyzed by real-time PCR. The shrimp surviving the natural WSSV infection on estimation with RT-PCR were found to have low grade of WSSV infection (less than 56 copies of WSSV). All the shrimp samples were RT-PCR negative for structural protein genes of WSSV, VP24 and VP28, indicating that these samples were harboring latent phase virus. RT-PCR of all the shrimp samples which survived WSSV infection revealed amplification of phagocytosis activating protein (PAP) gene (435 bp) with higher gene expression levels in experimentally challenged shrimp when compared to naturally infected shrimp. The expression of PAP in WSSV infected shrimp samples indicates its possible role in host response for resistance against WSSV infection. PAP was cloned and expressed as recombinant protein for protection studies. Shrimp were injected with three doses (5, 15 and 20 µg g(-1) body weight) of recombinant PAP. Relative percent survival of 10 % was observed in shrimp immunized with the dose of 15 µg g(-1) body weight of recombinant PAP. The expression of both WSSV latency associated and PAP genes obtained from shrimp surviving the WSSV infection, indicates the possible role of these genes in host-pathogen interaction.

Genetic variation and phylogenetic relationship between two species of yellow catfish, Horabagrus brachysoma and H. nigricollaris (Teleostei: Horabagridae) based on RAPD and microsatellite markers.

The two species of yellow catfish, Horabagrus brachysoma and H. nigricollaris are categorized as 'endangered' and 'critically endangered' respectively in their wild habitat. Proper knowledge of genetic structure and variability of these endangered species are highly essential for the management, conservation and improvement of fish stocks. Therefore, genetic variation and phylogenetic relationships between these species of yellow catfish sampled from Chalakkudy River in the hot spot of biodiversity-Western Ghats region, Kerala, India were analyzed by using Random amplified polymorphic DNA (RAPD) and microsatellite markers. 85 RAPD and five microsatellites loci were detected to analyze the genetic variation and phylogenetic relationships among these species. Out of 85 RAPD loci produced only 52.94% were polymorphic whereas in microsatellite, all 5 loci were polymorphic (100%). Species-specific RAPD bands were found in both species studied. In microsatellite, the number of alleles across the five loci ranged from 1 to 8. The observed heterozygosities in H. brachysoma and H. nigricollaris were 0.463 and 0.443, respectively. Here, both RAPD and microsatellite methods reported a low degree of gene diversity and lack of genetic heterogeneity in both species of Horabagrus which strongly emphasize the need of fishery management, conservation and rehabilitation of these species.

Development and characterization of RAPD and microsatellite markers for genetic variation analysis in the critically endangered yellow catfish Horabagrus nigricollaris (Teleostei: Horabagridae).

Random-amplified polymorphic DNA (RAPD) and microsatellite markers were developed and used for the analysis of genetic variability in the critically endangered yellow catfish Horabagrus nigricollaris, sampled from the Chalakkudy River, Kerala, India. Eight RAPD and five microsatellite markers were detected to genotype the species. In RAPD, the 73 fragments were 20.55% polymorphic, whereas 4 polymorphic loci (80%) were obtained in microsatellites. In microsatellites, the number of alleles across the 5 loci was 1-5, and the range of heterozygosity was 0.25-0.5. The mean observed number of alleles was 2.4, and the effective number was 1.775 per locus. The average heterozygosity across all investigated samples was 0.29, indicating a significant deficiency of heterozygotes in this species. RAPD and microsatellite methods report a low degree of gene diversity and lack of genetic heterogeneity in the population of H. nigricollaris, emphasizing the need for fishery management, conservation, and rehabilitation of this species.

Resource implications of bilateral autologous breast reconstruction--a single centre's seven year experience.

INTRODUCTION AND AIMS: Since the recent introduction of ''Payment by Results'' as part of NHS financial reforms, it has been noted that there is an imbalance between allocated Healthcare Resource Group tariffs and actual resource use for certain procedures. This study was undertaken to assess the impression that bilateral breast reconstruction using autologous flaps is under-funded. MATERIAL AND METHODS: Patients who underwent bilateral flap breast reconstruction following mastectomy between 2000 and 2006 at Addenbrooke's University Hospital were identified. Resource cost analysis for each patient was based on the following parameters: number of operating consultants, theatre running costs, and length of hospital stay. The estimated hospital costs were then compared to the national tariff for the Healthcare Resource Group ''Complex Breast Reconstruction using Flaps''. KEY RESULTS: Over the 7-year period 24 patients underwent bilateral flap breast reconstruction (7 paired latissimus dorsi and 17 paired abdominal flaps). The mean operative time was 9.4h (£4.5/min), the mean hospital stay was 10 days (£150/day) and ten patients required 2 consultants (£34/h) operating. The average total cost equated to £5 492. CONCLUSION: The allocated tariff of £4 053 is insufficient, even before the inclusion of hidden costs. Bilateral free flap breast reconstructions are grossly under-funded at present. With increasing financial pressures on NHS Trusts there may be a drive towards simpler operations, which receive proportionally greater remuneration.

Pharmacists' role in the post-discharge management of patients with heart failure: a literature review.

BACKGROUND AND OBJECTIVE: The incidence of heart failure is increasing in developed countries. In the aged population, heart failure is a common cause of hospitalization and hospital readmission, which in conjunction with post-discharge care, impose a significant cost burden. Inappropriate medication management and drug-related problems have been identified as major contributors to hospital readmissions. In order to enhance the care and clinical outcomes, and reduce treatment costs, heart failure disease management programmes (DMPs) have been developed. It is recommended that these programmes adopt a multi-disciplinary approach, and pharmacists, with their understanding and knowledge of medication management, can play a vital role in the post-discharge care of heart failure patients. The aim of this literature review was to assess the role of pharmacists in the provision of post-charge services for heart failure patients. METHOD: An extensive literature search was undertaken to identify published studies and review articles evaluating the benefits of an enhanced medication management service for patients with heart failure post-discharge. RESULTS: Seven studies were identified evaluating 'outpatient' or 'post-discharge' pharmacy services for patients with heart failure. In three studies, services were delivered prior to discharge with either subsequent telephone or home visit follow-up. Three studies involved the role of a pharmacist in a specialist heart failure outpatient clinic. One study focused on a home-based intervention. In six of these studies, positive outcomes, such as decreases in unplanned hospital readmissions, death rates and greater compliance and medication knowledge were demonstrated. One study did not show any difference in the number of hospitalizations between intervention and control groups. The quality of evidence of the randomized controlled trials was assessed using the Jadad scoring method. None of the studies achieved a score of more than 2, out of a maximum of 5, indicating the potential for bias. DISCUSSION: The DMPs carried out by pharmacists have contributed to positive patient outcomes, which has highlighted the value of extending the traditional roles of pharmacists from the provision of professional guidance to the delivery of continuity of care through a more holistic and direct approach. CONCLUSION: This review has demonstrated the effectiveness of pharmacists' interventions to reduce the morbidity and mortality associated with heart failure. However, there is an on-going need for the development and evaluation of pharmacy services for these patients.

In vivo sister chromatid differentiation and base line sister chromatid exchanges in Channa punctatus.

An in vivo system for differentially stained sister chromatids by incorporating 5' Bromo 2' deoxyuridine at two consecutive round of DNA replication has been developed in C. punctatus. The base line developed frequency of sister chromatid exchanges (SCEs) was found to be 0.038 SCE/chromosome. This low baseline frequency of SCEs could be useful in detecting genotoxicity of pollutants in aquatic medium.