Occurrence, transport, and toxicity of microplastics in tropical food chains: perspectives view and way forward.

Microplastics, which have a diameter of less than 5 mm, are becoming an increasingly prevalent contaminant in terrestrial and aquatic ecosystems due to the dramatic increase in plastic production to 390.7 million tonnes in 2021. Among all the plastics produced since 1950, nearly 80% ended up in the environment or landfills and eventually reached the oceans. Currently, 82-358 trillion plastic particles, equivalent to 1.1-4.9 million tonnes by weight, are floating on the ocean's surface. The interactions between microorganisms and microplastics have led to the transportation of other associated pollutants to higher trophic levels of the food chain, where microplastics eventually reach plants, animals, and top predators. This review paper focuses on the interactions and origins of microplastics in diverse environmental compartments that involve terrestrial and aquatic food chains. The present review study also critically discusses the toxicity potential of microplastics in the food chain. This systematic review critically identified 206 publications from 2010 to 2022, specifically reported on microplastic transport and ecotoxicological impact in aquatic and terrestrial food chains. Based on the ScienceDirect database, the total number of studies with "microplastic" as the keyword in their title increased from 75 to 4813 between 2010 and 2022. Furthermore, various contaminants are discussed, including how microplastics act as a vector to reach organisms after ingestion. This review paper would provide useful perspectives in comprehending the possible effects of microplastics and associated contaminants from primary producers to the highest trophic level (i.e. human health).

Genome-wide identification and characterization of InDels and SNPs in Glycine max and Glycine soja for contrasting seed permeability traits.

BACKGROUND: Water permeability governed by seed coat is a major facet of seed crops, especially soybean, whose seeds lack physiological dormancy and experience rapid deterioration in seed viability under prolonged storage. Moreover, the physiological and chemical characteristics of soybean seeds are known to vary with seed coat color. Thus, to underpin the genes controlling water permeability in soybean seeds, we carried out an in-depth characterization of the associated genomic variation. RESULTS: In the present study, we have analyzed genomic variation between cultivated soybean and its wild progenitor with implications on seed permeability, a trait related to seed storability. Whole genome resequencing of G.max and G. soja, identified SNPs and InDels which were further characterized on the basis of their genomic location and impact on gene expression. Chromosomal density distribution of the variation was assessed across the genome and genes carrying SNPs and InDels were characterized into different metabolic pathways. Seed hardiness is a complex trait that is affected by the allelic constitution of a genetic locus as well as by a tricky web of plant hormone interactions. Seven genes that hold a probable role in the determination of seed permeability were selected and their expression differences at different stages of water imbibition were analyzed. Variant interaction network derived 205 downstream interacting partners of 7 genes confirmed their role in seed related traits. Interestingly, genes encoding for Type I- Inositol polyphosphate 5 phosphatase1 and E3 Ubiquitin ligase could differentiate parental genotypes, revealed protein conformational deformations and were found to segregate among RILs in coherence with their permeability scores. The 2 identified genes, thus showed a preliminary association with the desirable permeability characteristics. CONCLUSION: In the light of above outcomes, 2 genes were identified that revealed preliminary, but a relevant association with soybean seed permeability trait and hence could serve as a primary material for understanding the molecular pathways controlling seed permeability traits in soybean.

Development and validation of functional CAPS markers for the FAE genes in Brassica juncea and their use in marker-assisted selection.

Low erucic acid is a major breeding target to improve the edible oil quality in Brassica juncea. The single nucleotide polymorphism (SNP) in fatty acid elongase 1 (FAE1.1 and FAE1.2) gene was exploited to expedite the breeding program. The paralogs of FAE1 gene were sequenced from low erucic acid genotype Pusa Mustard 30 and SNPs were identified through homologous alignment with sequence downloaded from NCBI GenBank. Two SNPs in FAE1.1 at position 591 and 1265 and one in FAE1.2 at 237 were found polymorphic among low and high erucic acid genotypes. These SNPs either create or change the recognition site of restriction enzymes. Transition of a single nucleotide at position 591 and 1265 in FAE1.1, and at position 237 in FAE1.2, leads to a change in the recognition site of Hpy99I, BglII and MnlI restriction enzymes, respectively. Two CAPS markers for FAE1.1 and one for FAE1.2 were developed to differentiate low and high erucic acid genotypes. The efficiency of these CAPS markers was found 100 per cent when validated in Brassica juncea, and B. nigra genotypes and used in back-cross breeding. These CAPS markers will facilitate in marker-assisted selection for improvement of oil quality in Brassica juncea.

Effect of life skills training on physical activity patterns amongst school adolescents in Delhi: a non-randomized interventional study.

BACKGROUND: Effect of life skills on physical activity behavior of adolescents is little explored. OBJECTIVE: To assess impact of life-skills training on the level of physical activity amongst adolescents. METHODS: A nonrandomized interventional study with a control group. All students studying in Class IX and XI of two schools in Delhi were included. Data was collected at baseline, 15 days and 3 months after the life-skills training. Two life-skills training sessions were conducted for each standard following collection of baseline data. RESULTS: There were 180 students in the intervention and 183 students in the control group. A significant increase was noted in the level of light-moderate, vigorous physical activity, and stretching and strengthening exercises (p<0.001) in an intervention group over the period of 3 months following the training. The number of students enrolled in physical education classes also increased. CONCLUSIONS: A skills-based approach helped to improve the level of physical activity amongst the school adolescents.

Biogenic engineered zinc oxide nanoparticle for sulfur black dye removal from contaminated wastewater: comparative optimization, simulation modeling, and isotherms.

This research work aimed to isolate and culture the bacterium Bacillus paramycoides for biogenic fabrication of zinc oxide nanoparticles, specifically ZnO and ZnO-ME nanoparticles (nanoparticles fabricated from bacterial extracts only - ZnO, and from bacterial cell mass including extract - ZnO-ME). SEM investigation revealed the spherical-shaped NPs with 22.33 and 39 nm in size for ZnO and ZnO-ME, respectively. The Brunauer, Emmett, and Teller (BET) studies revealed mesoporous structure with pore diameters of 13.839 and 13.88 nm and surface area of 7.617 and 33.635 m2/gm for ZnO and ZnO-ME, respectively. Various parameters for the adsorption of sulfur black dye onto both ZnO and ZnO-ME were screened and optimized using Plackett-Burman Design (PBD), Full Factorial Design (FFD) and Central Composite Design (CCD). The results of the optimization modeling study revealed that FFD yielded the most predictable and best-fitting results among all the models studied, with R2 values of 0.998 for ZnO and 0.993 for ZnO-ME. Notably, ZnO-ME exhibited a greater dye removal efficiency 80% than ZnO i.e., 71%, it may be due to the presence of amorphous carbon on the surface of ZnO-ME. Among the various isothermal models, the Freundlich model displayed the strongest correlation with the dye removal data, confirming the multilayer adsorption of dye on both nanoparticles and supporting physisorption. Therefore, ZnO and ZnO-ME nanoparticles have been proven as potential tools for mitigating environmental impacts associated with dye-containing wastewater.

Sequestration of Ni (II), Pb (II), and Zn (II) utilizing biogenic synthesized Fe3O4/CLPC NCs and modified Fe3O4/CLPC@CS NCs: Process optimization, simulation modeling, and feasibility study.

The present study reports low-cost novel biogenic magnetite Citrus limetta peels carbon (Fe3O4/CLPC) nanocomposites and modified Fe3O4/CLPC@CS nanocomposites cross-linked with glutaraldehyde and subsequently employed in batch mode sequestration of heavy metals ions. Diverse techniques fully characterized them, and the influence of operating variables on adsorption reactions from aqueous solutions was investigated. The Brunauer, Emmett, and Teller (BET) surface areas of synthesized Fe3O4/CLPC and Fe3O4/CLPC@CS NCs were 53.91 and 32.16 m2/g, while the mesoporous diameters were 7.69 and 7.57 nm, respectively. The Langmuir isotherm and Pseudo second order kinetic were well-fitting and capable of explaining the adsorption reaction. The Langmuir-based monolayer adsorption (qmax) for Fe3O4/CLPC@CS NCs was 82.65, 95.24, and 64.10 mg/g, higher than Fe3O4/CLPC NCs, which were 70.92, 84.75, and 59.17 mg/g for Ni (II), Pb (II), and Zn (II), respectively. Each metal's pseudo second order correlation coefficient (R2 ≥ 0.99) reveals that nanocomposites surface binding functional groups controlled the adsorption rate via chemisorption. Further, thermodynamic results confirm that each studied metal ions' adsorption was spontaneous, endothermic, and characterized by an increase in randomness. In addition to magnetic separability, three ad-desorption cycles yielded exceptional adsorption efficacy and > 93% regenerability. The present study also reveals the effective utilization of Fe3O4/CLPC and Fe3O4/CLPC@CS NCs as cost-effective magnetic separable green adsorbents for heavy metals sequestration from electroplating wastewater.

Silicic and Humic Acid Priming Improves Micro- and Macronutrient Uptake, Salinity Stress Tolerance, Seed Quality, and Physio-Biochemical Parameters in Lentil (Lens culinaris spp. culinaris).

Lentil is an important grain legume crop which is mostly grown on marginal soils that hamper its productivity. Improvement of salt tolerance in lentils is considered to be a useful strategy of utilizing salt-affected lands in an economic manner. This study was conducted to evaluate the effectiveness of seed priming using silicic acid and humic acid both seperately and in combination to improve salt stress tolerance among three different lentil varieties: IPL-316 (tolerant), PSL-9, and PDL-1 (susceptible). The concentrations and durations of treatments were standardized under the normal condition and the salinity stress condition. Salt stress hindered seedling emergence and biomass production and accelerated Na+ toxicity and oxidative damage at the seedling stage in untreated seeds. Nevertheless, chemical priming improved early seedling emergence, increased root length, shoot length, and seed vigor index I and II, and reduced the mean germination time. A significant quantitative change in biochemical parameters under normal and salinity stress conditions was observed in IPL-316,viz. Specifically, for IPL-316, the following parameters were observed (values under the normal condition and values under salt stress conditions, respectively): chlorophyll-a (16 and 13 mg/g Fw), chlorophyll-b (25 and 16 mg/g FW), total chlorophyll content (42 and 30 mg/g FW), relative leaf water content (92% and 82%), total soluble sugars (26 and 33 ug/g FW), free amino acid (10 and 7 mg/g FW), total phenol (26 and 24 mg of GAE/g FW), total protein (35 and 29 mg/g FW), carbohydrate (208 and 173 mg/g FW), superoxide dismutase (SOD) (29 and 35 unit/min./g FW), proline (0.28 and 0.32 u mol/g FW), catalase (CAT) (84 and 196 unit/mL/g FW), and peroxidase (POX) (217 and 738 unit/mL/g FW). Furthermore, histochemical analysis of H2O2 and O2-, micronutrients, and macronutrients also increased, while malondialdehyde (MDA) (0.31 and 0.47 nmol/mL FW) content decreased using silicic and humic acid priming under salt stress conditions. The combination of silicic and humic acids improved seedling growth and reduced oxidative damage in lentil plants under salt stress conditions. The combination of silicic and humic acid priming hastened seedling emergence, seed quality parameters, and biochemical parameters under salt stress over respective control. To the best of our knowledge, this is the first report of integrated chemical priming in lentils for salinity stress. In conclusion, chemical priming using a combination of silicic and humic acid performed better in terms of seed quality due to enhanced antioxidant machinery, better membrane stability and osmolyte protection, and enhanced nutrient uptake under salt stress conditions.

Heat-Stress-Induced Changes in Physio-Biochemical Parameters of Mustard Cultivars and Their Role in Heat Stress Tolerance at the Seedling Stage.

In the era of global warming, heat stress, particularly at the seedling stage, is a major problem that affects the production and productivity of crops such as mustard that are grown in cooler climates. Nineteen mustard cultivars were exposed to contrasting temperature regimes-20 °C, 30 °C, 40 °C and a variable range of 25-40 °C-and evaluated for changes in physiological and biochemical parameters at the seedling stage to study their role in heat-stress tolerance. Exposure to heat stress showed detrimental effects on seedling growth as revealed by reduced vigor indices, survival percentages, antioxidant activity and proline content. The cultivars were grouped into tolerant, moderately tolerant and susceptible based on the survival percentage and biochemical parameters. All the conventional and three single-zero cultivars were found to be tolerant and moderately tolerant, respectively, while double-zero cultivars were reckoned to be susceptible except for two cultivars. Significant increases in proline content and catalase and peroxidase activities were found associated with thermo-tolerant cultivars. More efficient antioxidant system activity and proline accumulation were noticed in conventional along with three single-zero (PM-21, PM-22, PM-30) and two double-zero (JC-21, JC-33) cultivars that might have provided better protection to them under heat stress than the remaining one single- and nine double-zero cultivars. Tolerant cultivars also resulted in significantly higher values of most of the yield attributing traits. Heat-stress-tolerant cultivars could easily be selected based on the survival percentage, proline and antioxidants at the seedling stage and included as efficient cultivars in breeding programs.

Recent analytical techniques, and potential eco-toxicological impacts of textile fibrous microplastics (FMPs) and associated contaminates: A review.

Despite of our growing understanding of microplastic's implications, research on the effects of fibrous microplastic (FMPs) on the environment is still in its infancy. Some scientists have hypothesized the possibility of natural textile fibres, which may act as one of the emerging environmental pollutants prevalent among microplastic pollutants in the environment. Therefore, this review aims to critically evaluate the toxic effects of emerging FMPs, the presence, and sources of FMPs in the environment, identification and analytical techniques, and the potential impact or toxicity of the FMPs on the environment and human health. About175 publications (2011-2023) based on FMPs were identified and critically reviewed for transportation, analysis and ecotoxicological behaviours of FMPs in the environment. Textile industries, wastewater treatment plants, and household washing of clothes are significant sources of FMPs. In addition, various characterization techniques (e.g., FTIR, SEM, RAMAN, TGA, microscope, and X-Ray Fluorescence Spectroscopy) commonly used for the identification and analysis of FMPs are also discussed, which justifies the novelty aspects of this review. FMPs are pollutants of emerging concern due to their prevalence and persistence in the environment. FMPs are also found in the food chain, which is an alarming situation for living organisms, including effects on the nervous system, digestive system, circulatory system, and genetic alteration. This review will provide readers with a comparison of different analytical techniques, which will be helpful for researchers to select the appropriate analytical techniques for their study and enhance their knowledge about the harmful effects of FMPs.

Deciphering the Genetic Inheritance of Tocopherols in Indian Mustard (Brassica juncea L. Czern and Coss).

Tocopherol is vital for the nutritional value and stability of Indian mustard (Brassica juncea L. Czern and Coss) oil; nonetheless, the lack of information on genetic control is hampering its improvement. In this study, six populations (P1, P2, F1, F2, BC1P1, and BC1P2) of RLC3 × NPJ203 were evaluated in a family block design to evaluate the inheritance pattern, gene effects, and various other genetic parameters of tocopherol content (α, γ, and total), using generation mean analysis. The comparison of direct and reciprocal crosses indicated that the tocopherol content was not influenced by maternal inheritance. Negative directional heterosis showed that ATC, GTC, and TTC are governed by recessive genes. Potence ratio and degree of dominance highlighted an over-dominance type of gene interaction for GTC and TTC, whereas ATC was governed by epistatic interactions. Furthermore, the six-parameter model revealed a duplicate gene action for α-tocopherol content. Broad and narrow sense heritability coupled with genetic advances were high.

Immunogenicity and safety of an indigenously manufactured reconstituted pentavalent (DTwP-HBV+Hib) vaccine in comparison with a foreign competitor following primary and booster immunization in Indian children.

OBJECTIVE: An open label, controlled clinical study was conducted in Indian infants aged 6-14 weeks to compare the immunogenicity and safety of a reconstituted pentavalent vaccine (DTwP-HBV+Hib) of Serum Institute of India Ltd (SIIL) with TritanrixHB+Hiberix vaccine of Glaxo Smithkline (GSK). METHODS: Eligible infants were randomized to receive three doses of the study / comparator vaccine. The vaccines were reconstituted prior to administration, by mixing DTwP-HBV (liquid) with the Hib (lyophilized) vaccine. IgG antibody titres were assessed by ELISA at baseline and after one month following the 3-dose primary immunization schedule. Safety was evaluated after each dose. Further, safety and immunogenicity was also evaluated following a booster dose in the same cohort of children (aged between 15-24 months). SETTING: Tertiary-care hospitals in India Important outcome measures: Immunogenicity and safety following a 3-dose primary vaccination series and a booster vaccination. RESULTS: Post-primary immunization, 100% seroprotection was noted for Diphtheria, Tetanus, Hepatitis B and PRP-Hib components in both the vaccine groups. For pertussis, response was 96.1% in SIIL and 95.4% in GSK group. The overall safety profile as well as persistence of antibodies against all vaccine components up to the time of booster immunization was comparable between the SIIL and GSK groups. A marked rise of all antibody concentrations indicated effective priming. The booster dose was safe, well tolerated with a significant increase in antibody concentrations of all the vaccine antigens in both the groups. CONCLUSION: DTwP-HBV+Hib vaccine of SIIL was found to be safe and immunogenic. This Indian vaccine compared well with the licensed vaccine and is a cost-effective alternative for incorporating into the immunization schedule of various countries so as to control worldwide Hepatitis B and Hib infections.

Screening of Latent Tuberculous Infection (LTBI) before Starting Anti-Tumor Necrosis Factor Therapy in Patients with Psoriasis: A Primer for Clinical Dermatologist.

Anti-tumor necrosis agents are being increasingly used in the management of moderate to severe psoriasis. Therapy with antitumor necrosis factor alpha (TNF-α) agents is being fraught with reactivation of latent tuberculosis infection (LTBI). This paper addresses the intricate relation between LTBI and anti-TNF-α agents and provides working guidelines for screening of LTBI and its management before prescribing anti-TNF-α therapy in patients with psoriasis.

Association of DNA biosynthesis with planting value enhancement in hydroprimed maize seeds.

Inadequate plant stand establishment due to insufficient germination is an important bottleneck in achieving the potential yields, specifically under uncertain growing conditions. Hydropriming has been publicized as a useful tool to alleviate the stress-induced consequences. Association of DNA biosynthesis in hydroprimed seeds of maize; hybrid, PEHM 5 and its parental lines (CM150 and CM151) was studied. Seeds were hydroprimed at 25 °C for 30 h and half of them were surface dried while the other half were redried back to the original moisture contents. The treated and untreated seeds were evaluated for; germination test, mean germination time, vigour index and DNA levels in embryos of fully matured seeds. Both the treatment strategies significantly enhanced the planting value of maize seeds. Vigour index I revealed significant correlation with G2/G1 ratio whereas significant negative correlation between G2/G1 ratio and mean germination time was observed. Large amounts of 2C DNA signals in flow cytometric analysis divulged that most cells might had arrested in the cell cycle at the pre synthetic G1 phase of nuclear division. Augmentation of 4C signal in the embryonic region was noticed after imbibition that could be ascribed to cells entering the synthetic phase of nuclear division. The embryonic cells showed increased 4C:2C ratios after 30 h of imbibition. Apparently, DNA synthesis preceded germination. In dry seeds, DNA histograms revealed both a 2C signal and a considerable 4C peak. A priming period of 30 h in distilled water considerably enhanced the rate and uniformity of germination in both surface dried and redried treatment strategies. Upon priming, the ratio of 4C:2C increased during the 30 h priming period, though the level in case of redried seeds did not reach the level obtained after hydration in water without drying back. However, the 4C: 2C ratio was constant after redrying the seeds to the original moisture content, indicating that the chromosomal material in the embryonic cells had stably ceased cell cycle activity at the G2 phase. The present results indicate that the beneficial effects of priming on seedling performance could be associated with the action of replicative DNA synthesis processes prior to germination.

Association Between Neonatal Thyroid Stimulating Hormone Status and Maternal Urinary Iodine Status.

BACKGROUND: Maternal urinary iodine concentration (MUIC) and percentage of neonates with Thyroid stimulating hormone (TSH) >5 mIU/L are amongst the parameters suggested for assessing adequate iodine status. OBJECTIVE: To assess the correlation between MUIC and neonatal TSH levels. STUDY DESIGN: Cross-sectional. SETTINGS: Tertiary care center in Delhi, India, between November 2015 to November 2016. PARTICIPANTS: Postnatal mother-neonate dyads. METHODS: TSH levels assessed among neonatal samples were stratified as below and above 5 mIU/L. MUIC was measured in 544 mothers, 400 mother-neonate dyads with neonatal TSH levels >5 mIU/L (cases) and 144 mother-neonate newborn mother dyads with neonatal TSH <5 mIU/L (controls). RESULTS: Results: The percentage of mothers with iodine insufficiency (9.8% vs 5.6%) as well as iodine excess (54.3% vs 41.7%) were significant higher in cases than controls. Mean TSH was also higher (P=0.0002) in both the iodine deficient and iodine excess group. There was no correlation between neonatal TSH values and MUIC. CONCLUSION: Lack of correlation between neonatal TSH and MUIC is due to iodine excess together with iodine deficiency.

Tumor necrosis factor alpha and interleukin 6 in infants with sepsis.

Thirty-two infants above one month of age admitted to a tertiary care hospital with signs of infection and presumptive diagnosis of sepsis were included. Cytokine levels of tumor necrosis factor alpha (TNFmu) and interleukin-6 (IL 6) were estimated at admission and after 48 to 72 hr, and their relationship examined to the outcome. Significantly higher TNFalpha and IL-6 levels were seen in infants with sepsis compared to control. The TNFalpha levels significantly decreased in patients with sepsis, septic shock and the survivors, while the patients who did not survive, the levels showed no significant change after 48 hr. The initial levels of IL6 were comparatively higher in patients with septic shock and non-survivors, and increased at 48 hr of admission in patients with sepsis, septic shock and non-survivors.

Small for gestational age: growth and puberty issues.

CONTEXT: Small for gestational age infants have multifold increased risk of growth failure and adulthood disorders. Those who experience rapid catch up growth are at risk of developing metabolic syndrome, whereas those without catch up may end up with short stature. These children are also prone to an altered pubertal development. NEED AND PURPOSE: Scarcity of literature, lack of published guidelines on the follow-up and management plan of children born with small for gestational age. EVIDENCE ACQUISITION: Literature search in PubMed was conducted with regard to epidemiology, growth and puberty, comorbidities, its pathogenesis and management in small for gestational age, with particular relevance for developing countries. An algorithm for follow-up of these children is outlined, based on available empiric data. CONCLUSIONS: Being born small for gestational age predisposes to many metabolic and pubertal disorders. Special emphasis is needed for early detection and management through early surveillance in growth clinics, and regular follow-up to prevent associated comorbidities.

Effect of life skills training on dietary behavior of school adolescents in Delhi: a nonrandomized interventional study.

Skill-based education has been shown to reduce high-risk behavior among adolescents, but in India, life skills have often been looked at only from the reproductive health perspective. Therefore, the current study was undertaken to assess the effect of life skills training on dietary behavior of adolescents studying in grades 9 and 11 of 2 schools in Delhi. This was a nonrandomized interventional study with a control group. A self-administered questionnaire was used for assessment of dietary behavior at baseline, 15 days, and 3 months after the life skills training. Two life skills training sessions were imparted to the intervention group, focusing on the use of life skills in making healthy choices. Participants in the intervention group (n = 180) showed significant improvement in knowledge (P < .001), attitude (P = .007), and practices (P < .001) following the life skills training. To conclude, a skills-based approach does help improve the dietary behavior in adolescents.

Whole blood samples as an alternative to serum for detection of immunity to measles virus by ELISA.

The aim of this study was to evaluate enzyme linked immunosorbent assay (ELISA) as a testing strategy for detection of antibodies against measles virus from microquantities of blood soaked onto filter paper. We studied 165 healthy children in the age group of 1 to 2 years, attending the outpatient department of pediatrics. Two sets of samples were collected from each child. One by venipuncture and the other on Whatman filter paper-3 discs of 20 mm size by finger or heel prick so that each strip is completely soaked with blood on both sides. These were tested for measles virus antibodies by ELISA using Melotest measles IgG commercial ELISA kit manufactured by Melotec S. A. (Barcelona, Spain). The resulting sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the filter paper (FP) ELISA compared to serum ELISA was 100, 90, 97.8, and 100%, respectively. The correlation coefficient r = 0.93% (p < 0.001) and the agreement between the two techniques was 98% as calculated by the Kappa statistical method. The present study has found filter paper testing by ELISA to be a promising qualitative technique for detection of immunity against measles.

Comparative evaluation of measles, mumps & rubella vaccine at 9 & 15 months of age.

BACKGROUND & OBJECTIVES: Measles, mumps and rubella (MMR) contribute to significant amount of mortality and morbidity in our country. Though MMR vaccine has been a part of immunization schedule in the developed countries, it is yet to be included in our national immunization schedule. Hence this study was conducted to assess the serological status of measles, mumps and rubella in young children and to evaluate the seroconversion of measles, mumps and rubella vaccine at 9 and 15 months of age. METHODS: The cohort study was carried out at the out patient department of a tertiary care hospital in north India. A total of 240 normal children, 120 each in the age group 9-10 and 15-18 months attending the hospital for immunization were enrolled for the study. None of them had been vaccinated with MMR vaccine in the past, or gave any history of measles, mumps or rubella infection, or were on any immunosuppressive agent. The pre-vaccination blood sample was taken and each child was administered a single dose of trivalent MMR vaccine. The post-vaccination sample was taken 6-8 wk later. The paired serum samples were analysed for the presence of measles, mumps and rubella antibodies using commercially available ELISA kits. RESULTS: Of the 120 infants in the age group of 9-10 months, 102 (85%) were seronegative for measles and 96 (80%) were seronegative for both mumps and rubella. Following MMR vaccination, 102 infants came for post vaccination sampling of which 92 per cent were seropositive for measles, 100 per cent for mumps and 98 per cent for rubella. In the age group of 15-18 months, of the 120 children, 67 (56%) were seronegative for measles, 84 (70%) for mumps and 86 (71.6%) for rubella. In 50 per cent of the children, there was a history of measles immunization at 9 months of age. After MMR vaccination, 100 children came for post vaccination sampling and seropositivity of 92, 96 and 94 per cent was observed for measles, mumps and rubella, respectively. The rise in the pre- and post-immunization geometrical mean titre was significant (P < 0.05) for each component of the vaccine in both the age groups. INTERPRETATION & CONCLUSION: The MMR vaccine can be offered safely and with equal efficacy to children at 9 and 15 months of age.