Stigma of sickle cell disease among Indian tribal population: A multi-centric qualitative study

BACKGROUND

Sickle Cell Disease (SCD) is the most prevalent hemoglobinopathy, impacting around 5% of the global population. The Indian tribal population, which has been a key focus of the Indian SCD program, can experience health-related stigma due to the multidimensional impact of the disease. This preliminary qualitative inquiry delves into the lived experiences of individuals and synthesizes domains to identify the sources of stigma.

METHODOLOGY

The study's framework for developing the stigma tool was rooted in Bronfenbrenner's Ecology of Human Development. The study was implemented in five tribal-dominated districts of India and involved in-depth interviews with sickle cell disease (SCD) patients and their caregivers to explore their stigmatizing experiences.

RESULTS

The analysis revealed four overarching themes and several subthemes explaining the type of stigma, its source, and factors contributing to stigmatization. First, the study focused on elements associated with perceived stigma, such as disclosure, self-isolation/refusal to participate, and self-judgment. The second theme pertained to the internalization of stigma. The third theme addressed experienced stigma concerning the disease's impact on day-to-day events, and the fourth theme explored the support system patients needed. The framework highlighted the varying degrees of stigmatizing components within different aspects of patients' ecology.

CONCLUSION

Our study highlights the importance of addressing stigma at various levels. Policies, programs, and healthcare interventions must target stigma across these levels. Culturally adaptive tools for identifying stigma, implementing appropriate interventions, and improving healthcare participation are essential for enhancing the quality of life and reducing the disease burden.

COVID-19 vaccine acceptance and hesitancy in Indian context: a systematic review and meta-analysis

Vaccination against COVID-19 is vital for achieving herd immunity, and the Government of India has adopted several strategies to achieve coverage. Vaccine hesitancy was identified as a potential obstacle in combating COVID-19. This study aimed to review the COVID-19 vaccine acceptance and hesitancy, and factors associated with vaccine hesitancy based on studies conducted in Indian populations. The data sources (PubMed, Scopus, and Google Scholar) were searched by following PRISMA guidelines, and the search was done in September 2022. We performed a meta-analysis through a random effect model to estimate pooled hesitancy rate with 95% confidence intervals (CI). A total of 3,339 records were searched, of which 46 studies were found to be eligible for inclusion in the review. The included studies covered 65,551 respondents, 55% were female. Studies reported COVID-19 vaccine acceptance rate of 65.7% in January-February 2021, which increased to 92.8% in May-August 2021. Likewise, the rate of vaccine hesitancy in December 2020 was 37%, dropping to 12.1% through November 2021. The estimated pooled COVID-19 vaccine hesitancy was 31% [95% CI: 27% - 36%, I2 = 99.3%]. Most studies highlighted that fear of the vaccine's side effects, efficacy, and safety were major barriers to vaccine acceptance. However, as the review indicates, it is important to consider and address all factors contributing to vaccine hesitancy.

Strengthening Health System and Community Mobilization for Sickle Cell Disease Screening and Management among Tribal Populations in India: An Interventional Study

Sickle cell disease (SCD) affects 5% of the global population, with over 300,000 infants born yearly. In India, 73% of those with the sickle hemoglobin gene belong to indigenous tribes in remote regions lacking proper healthcare. Despite the prevalence of SCD, India lacked state-led public health programs until recently, leaving a gap in screening and comprehensive care. Hence, the Indian Council of Medical Research conducted implementation research to address this gap. This paper discusses the development and impact of the program, including screening and treatment coverage for SCD in tribal areas. With a quasi-experimental design, this study was conducted in six tribal-dominated districts in three phases - formative, intervention, and evaluation. The intervention included advocacy, partnership building, building the health system's capacity and community mobilization, and enabling the health systems to screen and manage SCD patients. The capacity building included improving healthcare workers' skills through training and infrastructure development of primary healthcare (PHC) facilities. The impact of the intervention is visible in terms of people's participation (54%, 76% and 93% of the participants participated in some intervention activities, underwent symptomatic screening and demanded the continuity of the program, respectively), and improvement in SCD-related knowledge of the community and health workers (with more than 50% of net change in many of the knowledge-related outcomes). By developing screening and treatment models, this intervention model demonstrated the feasibility of SCD care at the PHC level in remote rural areas. This accessible approach allows the tribal population in India to routinely seek SCD care at their local PHCs, offering great convenience. Nevertheless, additional research employing rigorous methodology is required to fine-tune the model. National SCD program may adopt this model, specifically for community-level screening and management of SCD in remote and rural areas.

Indian sickle cell disease registry for surveillance and patient management: Development and implementation

In India, sickle cell disease (SCD) predominantly occurs in indigenous (tribal) people, who are about 104 million. However, screening and diagnosis seldom happen. This situation necessitates developing a comprehensive SCD care model, including a registry. This paper describes the development and implementation of the Indian SCD registry (ISCDR) in six tribal-dominated districts of India. The ISCDR was created in two components-(i) an Android-based mobile/tablet application, (ii) a dashboard/admin panel for patients' data management and retrieval. Data capture involves two electronic case report forms (CRF), that is, the primary form (CRF-1) and the repeat visit form (CRF-2). CRF-1 is completed as soon as the patient is found positive and captures the patient's information, including medical history, diagnosis, symptoms, precipitating factors, hospitalisation history and treatment received. Issues related to quality, security and data-sharing were addressed. After the screening system was functional, ISCDR was initiated. In 12 months, data of 324 SCD patients and 1771 carriers were entered. The study demonstrates the feasibility of establishing an SCD registry in India. It collects systematic longitudinal data on SCD patients, which are essential for programme planning and management. Further, it is feasible to scale up and integrate with other health management databases.

Feasibility of population-based screening of sickle cell disease through the primary health care system in tribal areas of India

OBJECTIVE

To describe the development and implementation of a population-based screening programme for sickle cell disease (SCD) implemented in 12 SCD-endemic and tribal-dominated primary/community health centres (PHCs/CHCs) across six districts of India.

SETTING

India reports a huge burden of SCD, especially among indigenous (tribal) communities. However, there is no state-led SCD programme in many places, and systematic screening is absent. This situation necessitates developing a model of population screening.

METHODS

This programme was meant to screen all people and was carried out in three tiers. The first tier was a symptomatic survey carried out by community health workers. Regular health workers then screened those referred by sickle cell solubility test at sub-health centres as the second tier. The third tier was confirmation by haemoglobin electrophoresis at PHCs/CHCs. Communities were mobilised and prepared to accept the screening. Capacity building of health facilities was ensured through training and supply of equipment and material.

RESULTS

Initial observation based on six months' data revealed that out of the 110,754 tribal population of 12 PHCs/CHCs, 8418 (7.6%) were identified in the symptomatic survey. Subsequently, 9416 people, including the above 8418, underwent the solubility test, and 2607 (27.7%) were found to be positive. Of these, 1978 (78.9%) underwent electrophoresis. About 64.2% were found to be positive for sickle haemoglobin (233 (18.4%) SCD and 1036 (81.6%) SCD trait).

CONCLUSIONS

The study demonstrates the feasibility of establishing a population-based screening programme in the primary health care system. It is easy to implement in tribal habitations as part of the proposed national SCD/haemoglobinopathies programme.

Sickle cell disease treatment and management in India: a systematic review of interventional studies

Sickle cell disease (SCD) affects approximately 5% of the world's population, and India has been the second highest country in the numbers of predicted SCD births. Despite the high burden in India, there is no state-led public health programme, and very few interventions dealing with the treatment and management of SCD are available. This review highlights the dearth of SCD-related interventions, and demonstrates that these interventions effectively improve patients' conditions and are feasible to implement in India. We systematically searched three databases-PubMed/Medline, Google Scholar and Web of Science-for articles from India on SCD-related interventions. The PRISMA guidelines were followed during this review. We included 22 studies, of which 19 dealt with specific therapeutic interventions, and 3 with comprehensive SCD care. Hydroxyurea therapy was the main therapy in 15 studies and is efficacious. Three studies demonstrated the feasibility of comprehensive care in resource-limited settings. The low number of SCD-related intervention studies does not match the huge burden of SCD in India. Governments of endemic countries should consider the findings of available interventions and include them in their countries' programmes. Comprehensive care is feasible in India and other low-resource settings, from screening to treatment and psychosocial support.

Sickle cell disease-related knowledge and perceptions of traditional healers in tribal communities in India: implications on sickle cell disease programme

Sickle cell disease (SCD) is a progressively debilitating genetic disease, and India is the second most affected nation in the prevalence of births with SCD. This SCD prevalence is high among Indian indigenous tribal communities, whose healthcare is pluralistic. Traditional healers are an essential part of tribal pluralistic care. This study aimed to understand the extent of SCD-related knowledge and practices of traditional healers and their willingness to participate in the SCD programme, which is primarily meant to screen and treat SCD. Following the grounded theory approach, data were collected by in-depth interviews with 40 traditional healers selected from five SCD endemic districts. Text data were coded through a deductive approach, and thematic content analysis was carried out. A few healers knew about SCD. However, almost all are aware of anaemia and its symptoms. Most healers were unaware of the cause of SCD and mentioned that malnutrition and anaemia are reasons for the recurrence of SCD-related symptoms. Most of the traditional healers did not give any treatment. Some gave symptomatic treatment and provided herbal medicines along with some rituals. Though some healers treated some of the typical symptoms of SCD like spleen enlargement, jaundice, swelling and pains in joints, they did not link them with SCD. All traditional healers expressed concern and said they support the government-run SCD programme. The programme should recognise the role and importance of traditional healers. Necessary education on SCD may be given to the healers. Such involvement and education empower the healers in appropriately guiding the people concerning SCD care.

A Comprehensive in Silico Analysis for Identification of Immunotherapeutic Epitopes of HPV-18

Human papillomavirus (HPV) remains the major cause of cervical cancer, globally. High risk HPV (Hr-HPV) 16 and 18 together account for more than 70% of cervical cancer cases, whereas the hr-HPV-18 is the second most prevalent hr-HPV type, causing about 5.2% of all cancers worldwide. Considering the high prevalence and mortality rate, cervical cancer remains a noteworthy health problem among women. As of now, no registered immunotherapies are available after the HPV infection. Thus, developing an immunotherapeutic candidate against hr-HPV would be of major clinical benefit. Nowadays, the T-and B-cell peptide based targeted vaccines have been considered as the best candidate for vaccine development against viral infections. In this study, both prophylactic and therapeutic vaccine candidates against hr-HPV-18 were predicted. To achieve this, the prediction of T-and B-cell epitopes of major histocompatibility complex (MHC) were accomplished, that can be used for HPV immunotherapy. For MHC-I, a maximum number (20) of potent peptides were found, against HLA-B*51:01 (L1 = 9, L2 = 6, E2 = 4, and E4 = 1) having percentile value < 1 and, immunogenicity scores higher than 0.5, followed by HLA-A*11:01 (L1 = 8, E2 = 7 L2 = 2, and E6 = 1, E7 = 1); 19 epitopes. For MHC-II, the highest number of peptides found, against the HLA-DRB1*04:01 (L2 = 10, E5 = 7, and E4 = 4), HLA-DRB1*04:05 (E5 = 7, E2 = 5, E4 = 5, and L1 = 4) HLA-DPA1*01:03/DPB1*04:01 (E7 = 7, E6 = 5, L2 = 5, and E2 = 2), HLA-DRB5*01:01(E6 = 6, L1 = 6, and L2 = 6); peptides 21, 21, 19 and 18 respectively. For B-cell, total 94, 16 amino acid long B-cell epitopes were predicted. In conclusion, these predicted epitopes can be valuable candidates for in vitro or in vivo therapeutic vaccine studies against hr-HPV-18 associated cancer.

Inadequate community knowledge about sickle cell disease among the Indian tribal population: a formative assessment in a multicentric intervention study

BACKGROUND

Sickle cell disease (SCD) is a serious public health problem, with >300 000 affected births worldwide each year. About 73% of the SCD-affected people in India belong to the tribal population. The Government of India is planning to implement a programme for SCD and hence people's knowledge of SCD is crucial. This paper reports the SCD-related knowledge among the Indian tribal population.

METHODS

As part of a formative assessment before an intervention, data were collected from 9837 adults from 24 primary health centre areas of six states. Each community's knowledge of SCD was elicited through an interviewer-administered pretested questionnaire. Univariate and multivariate analyses were conducted.

RESULTS

Overall, 32.1% (CI 31.2 to 33.1%) of participants had heard of SCD, 7.9% (CI: 7.3 to 8.4%) knew that SCD is hereditary, 19.4% (CI: 18.7 to 20.3%) knew that a blood test can diagnose SCD and 23.9% (CI: 23.1 to 24.8%) knew that SCD is treatable. Only 13.1% (CI: 12.4 to 13.8%) knew that SCD can be prevented. No more than 16% knew about any SCD symptoms. Multiple logistic regression revealed some predictors of basic knowledge (i.e. had heard of SCD).

CONCLUSIONS

There is a gross inadequacy of knowledge about SCD in the Indian tribal population. This study warrants implementing a health education programme as a part of the SCD programme.

Potential applications of peptide nucleic acid in biomedical domain

Peptide Nucleic Acid (PNA) are DNA/RNA synthetic analogs with 2-([2-aminoethyl] amino) acetic acid backbone. They partake unique antisense and antigene properties, just due to its inhibitory effect on transcription and translation; they also undergo complementary binding to RNA/DNA with high affinity and specificity. Hence, to date, many methods utilizing PNA for diagnosis and treatment of various diseases namely cancer, AIDS, human papillomavirus, and so on, have been designed and developed. They are being used widely in polymerase chain reaction modulation/mutation, fluorescent in-situ hybridization, and in microarray as a probe; they are also utilized in many in-vitro and in-vivo assays and for developing micro and nano-sized biosensor/chip/array technologies. Earlier reviews, focused only on PNA properties, structure, and modifications related to diagnostics and therapeutics; our review emphasizes on PNA properties and synthesis along with its potential applications in diagnosis and therapeutics. Furthermore, prospects in biomedical applications of PNAs are being discussed in depth.

Cloning, characterization and transmission blocking potential of midgut carboxypeptidase A in Anopheles stephensi

Transmission-blocking vaccines (TBV) interrupt malaria parasite transmission and hence form an important component for malaria eradication. Mosquito midgut exopeptidases such as aminopeptidase N & carboxypeptidase B have demonstrated TBV potential. In the present study, we cloned and characterized carboxypeptidase A (CPA) from the midgut of an important malarial vector, Anopheles stephensi. ClustalW amino acid alignment and in silico 3-dimensional structure analysis of CPA predicted the presence of active sites involved in zinc and substrate binding that are conserved among all the known mosquito species. Real-time PCR analysis demonstrated that CPA is predominantly expressed in the midgut throughout the mosquito life cycle and that this gene is significantly elevated in P. berghei-infected mosquitoes compared to uninfected blood-fed controls. The high midgut CPA activity correlated with the prominent mRNA levels observed. Peptide-based anti-CPA antibodies were raised that cross-reacted specifically to ∼48kDa and ∼37kDa bands, which correspond to zymogen and active forms of CPA. Further, the addition of CPA-directed antibodies to P. berghei-containing blood meal significantly reduced the mosquito infection rate in the test group compared to control and blocked the parasite development in the midgut. These results support further development of A. stephensi CPA as a candidate TBV.

Identification of a standard AI based technique for credit risk analysis

Purpose

– Credit risk assessment has gained importance in recent years due to global financial crisis and credit crunch. Financial institutions therefore seek the support of credit rating agencies to predict the ability of creditors to meet financial persuasions. The purpose of this paper is to construct neural network (NN) and fuzzy support vector machine (FSVM) classifiers to discriminate good creditors from bad ones and identify a best classifier for credit risk assessment.

Design/methodology/approach

– This study uses artificial neural network, the most popular AI technique used in the field of financial applications for classification and prediction and the new machine learning classification algorithm, FSVM to differentiate good creditors from bad. As membership value on data points influence the classification problem, this paper presents the new FSVM model. The instances membership is computed using fuzzy c-means by evolving a new membership. The FSVM model is also tested on different kernels and compared and the classifier with highest classification accuracy for a kernel is identified.

Findings

– The paper identifies a standard AI model by comparing the performances of the NN model and FSVM model for a credit risk data set. This work proves that that FSVM model performs better than back propagation-neural network.

Practical implications

– The proposed model can be used by financial institutions to accurately assess the credit risk pattern of customers and make better decisions.

Originality/value

– This paper has developed a new membership for data points and has proposed a new FCM-based FSVM model for more accurate predictions.

Early exposure of 17α-ethynylestradiol and diethylstilbestrol induces morphological changes and alters ovarian steroidogenic pathway enzyme gene expression in catfish, Clarias gariepinus

Environmental estrogens are major cause of endocrine disruption in vertebrates, including aquatic organisms. Teleosts are valuable and popular models for studying the effects of endocrine disrupting chemicals (EDCs) in the environment. In the present study, we investigated the changes caused by exposure to the synthetic estrogens 17α-ethynylestradiol (EE2 ) and diethylstilbesterol (DES) during early stages of growth and sex differentiation of air-breathing catfish, Clarias gariepinus, at the morphological, histological, and molecular levels. Catfish hatchlings, 0 day post hatch (dph) were exposed continuously to sublethal doses of EE2 (50 ng/L) and DES (10 ng/L) until 50 dph and subsequently monitored for ovarian structural changes and alteration in the gene expression of steroidogenic enzymes till adulthood. Treated fish exhibited morphological deformities such as spinal curvature, stunted growth, and yolk-sac fluid retention. In addition to ovarian atrophy, DES-treated fish showed either rudimentary or malformed ovaries. Detailed histological studies revealed precocious oocyte development as well as follicular atresia. Further, transcript levels of various steroidogenic enzyme and transcription factor genes were altered in response to EE2 and DES. Activity of the rate-limiting enzyme of estrogen biosynthesis, aromatase, in the ovary as well as the brain of treated fish was in accordance with transcript level changes. These developmental and molecular effects imparted by EE2 and DES during early life stages of catfish could demonstrate the deleterious effects of estrogen exposure and provide reliable markers for estrogenic EDCs exposure in the environment.

Effect of juvenile hormone analog, methoprene on H-fibroin regulation during the last instar larval development of Corcyra cephalonica

Juvenile hormone (JH) and 20-hydroxyecdysone (20E), co-ordinately orchestrate insect growth and development. The process of silk synthesis and secretion in lepidopteran insects is known to be under hormonal control. However, the role of JH in this process has not been demonstrated hitherto. The present study is aimed to elucidate the role of JH in H-fibroin regulation in Corcyra cephalonica, a serious lepidopteran pest. Reiterated amino acid stretches and the large molecular weight of H-fibroin render its cloning and characterization cumbersome. To address this, a commercially synthesized short amino acid peptide conjugated with a carrier protein was used to generate antibodies against the N-terminal region of H-fibroin. ELISA and immunoblot experiments demonstrated the sensitivity and specificity of antibody. Further, immunohistochemical analyses revealed the antibody's cross-reactivity with H-fibroins of C. cephalonica and Bombyx mori in the silk gland lumen. Quantitative RT-PCR and Western blot analysis demonstrated the tissue-specificity and developmental expression of H-fibroin. Hormonal studies revealed that JH alone does not alter the expression of H-fibroin. However, in the presence 20E, JH reverses the declined expression caused by 20E administration to normal levels. This study provides molecular evidence for the regulation of H-fibroin by the cumulative action of JH and 20E.

Endosulfan and flutamide, alone and in combination, target ovarian growth in juvenile catfish, Clarias batrachus

Juvenile Catfish(es), Clarias batrachus of 50 days post hatch (dph) were exposed to endosulfan (2.5 parts per billion [ppb]) and flutamide (33 ppb), alone and in combination for 50 days to access their impact on ovarian development. The doses used in this study were nominal considering pervious reports. Sampling was done at 100 dph to perform histology and measurement of various transcripts, estradiol-17β and aromatase activity. In general, treatments enhanced expression of ovary-specific transcription factors, steroidogenic enzymes steroidogenic acute regulatory protein and aromatases while transcripts of tryptophan hydroxylase2 (tph2) and catfish gonadotropin-releasing hormone declined in the brain of all treated groups with maximum reduction in the endosulfan group. Significant reduction of tph2 immunoreactivity in the forebrain/telencephalon-preoptic area endorsed our results. Increased number of pre-vitellogenic and less immature oocytes in the treated groups indicated hastened ovarian growth. Elevated ovarian aromatase activity and plasma estradiol-17β levels were noticed in the treated groups with maximum being in the endosulfan group. These data together demonstrate that the exposure of endosulfan causes synchronous precocious ovarian development better than flutamide, alone or in combination. Our results suggest that both endosulfan and flutamide alter ovarian growth by triggering precocious development in catfish.

Expression and immunolocalization of 20β-hydroxysteroid dehydrogenase during testicular cycle and after hCG induction, in vivo in the catfish, Clarias gariepinus

The maturation inducing hormone, 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP) is required for the meiotic maturation and is produced from the precursor 17α-hydroxyprogesterone by the enzyme 20β-hydroxysteroid dehydrogenase (20β-HSD) in several teleosts. Central role of 20β-HSD in ovarian cycle and final oocyte maturation is well studied when compared to spermatogenesis. In the present study, we investigated the localization and expression of 20β-HSD in testicular cycle and gonadotropin induced sperm maturation. During testicular ontogeny, 20β-HSD expression was detectable at 50 and 100 days post-hatch (dph), while the expression was high at 150 dph. In testicular cycle, highest levels of mRNA and protein of 20β-HSD were observed during spawning phase. Intraperitoneal injection of human chorionic gonadotropin (hCG) to prespawning catfish elevated both 20β-HSD transcripts and protein levels when compared to saline treated controls in a time-dependent manner. Serum 17α,20β-DP levels, measured during different phases of testicular cycle as well as following the treatment of hCG, showed a positive correlation with the expression of 20β-HSD. Immunolocalization revealed the presence of 20β-HSD protein predominantly in interstitial cells and spermatogonia/spermatocytes while 20β-HSD was undetectable in haploid cells (spermatids/sperm). These results together with high expression during spawning phase of testicular cycle and after hCG treatment in the prespawning catfish suggests a pivotal role for 20β-HSD during testicular recrudescence leading to sperm maturation. Further studies using various fish models on testicular 20β-HSD may provide interesting details to understand its importance in teleostean spermatogenesis.

Cloning and differential expression of FOXL2 during ovarian development and recrudescence of the catfish, Clarias gariepinus

FOXL2 is a member of the forkhead/HNF-3-related family of transcription factors which provides tissue-specific gene regulation. It is known to regulate ovarian aromatase, (cyp19a1a) which plays a crucial role in ovarian differentiation. To understand the role of FOXL2 in gonads and brain during ovarian development and recrudescence, we cloned the full-length cDNA of FOXL2 and analyzed its spatio-temporal expression both at transcript and protein levels in the air-breathing catfish, Clarias gariepinus. Based on its deduced amino acid sequence, an antigenic peptide conjugated with a carrier protein was synthesized which was then used for raising antibody that reacted specifically with FOXL2. Tissue distribution pattern of FOXL2 revealed its presence prominently in ovary and female brain with sexual dimorphism. Highest expression of FOXL2 was observed in ovary and brain during prespawning phase indicating an important role for this correlate in ovarian recrudescence. Human chorionic gonadotropin (hCG) treatment, in vitro and in vivo, induced FOXL2 expression in the ovary during preparatory and prespawning phases. Similar type of enhanced expression was evident in brain after hCG-induction during the prespawning phase. The ontogeny of FOXL2 showed sexual dimorphic expression pattern both in gonads and brain. Based on our previous studies, the expression pattern of FOXL2 was found to be synchronous not only with that of ovarian cyp19a1a but also with brain cyp19a1b. Present study substantiates the role of FOXL2 in the regulation of aromatase in teleosts and also designates FOXL2 as a potential ovary and brain marker during female sex development in catfish.

Dimorphic expression of various transcription factor and steroidogenic enzyme genes during gonadal ontogeny in the air-breathing catfish, Clarias gariepinus

In the present study the expression of 13 genes known to be involved in sex differentiation and steroidogenesis in catfish was analyzed during gonadal ontogeny by quantitative real-time RT-PCR. Dmrt1 and sox9a showed exclusive expression in male gonads while ovarian aromatase (cyp19a1) and foxl2 were abundant in differentiating female gonads. Most of the genes related to steroidogenesis were expressed only after gonadal differentiation. However, genes coding for 3β-hydroxysteroid dehydrogenase (3β-hsd), 17α-hydroxylase/C17-20 lyase type 1 (cyp17) and steroidogenic acute regulatory protein (star) were barely detectable during gonadal differentiation. Ovarian aromatase, cyp19a1, which is responsible for estradiol-17β biosynthesis in females, was expressed very early in the undifferentiated gonads of catfish, around 30-40 days post hatch (dph). The steroidogenic enzyme, 11β-hydroxylase (cyp11b1) required for the production of 11-ketotestosterone (11-KT) was expressed only after differentiation of testis. These results suggest that estradiol-17β has a critical role in ovarian differentiation, while the role of 11-KT in testicular differentiation is doubtful. In conclusion, dimorphic expression of dmrt1 and sox9a in gonads during early development is required for testicular differentiation, and sex-specific expression of cyp19a1 and foxl2 in females plays a critical role in ovarian development. Our study reveals that the critical period of gonadal differentiation in catfish starts around 30-40 dph when sex-specific genes showed differential expression.

20-Hydroxyecdysone regulation of H-fibroin gene in the stored grain pest Corcyra cephalonica, during the last instar larval development

20-Hydroxyecdysone (20E) controls molting, metamorphosis and reproduction of insects. It binds to a heterodimeric complex of ecdysone receptor (EcR) and ultraspiracle (USP), and regulates the transcription of genes containing ecdysone response elements (EcREs). However, the 20E regulation of silk fibroin genes is largely unexplored. In most lepidopteran larvae, the silk fibroin primarily consists of a large protein, heavy chain fibroin (H-fibroin) that is associated with two small proteins, L-chain fibroin and P25. In the present study, we demonstrate that 20E regulates the expression of H-fibroin gene in Corcyra cephalonica, in a dose-dependent manner during the last instar larval development. Semi-quantitative and real-time PCR studies reveal that physiological doses of 20E do not alter the normal expression, whereas higher doses cause a significant decline in the expression. Luciferase activity assays and gel shift experiments further confirm the presence of a functional EcRE in the upstream region of H-fibroin which regulates the ecdysteroid dependent transcriptional activity of fibroin gene through EcR. In vitro treatment with 20E mimicking insecticides, RH-5849 and RH-5992 decreases the expression of H-fibroin in isolated salivary glands. Insects fed with similar concentrations of these insecticides, metamorphose abnormally. Differences are also observed in the ultrastructure of the silk fibers of control and insecticide fed insects providing additional insight into the disruptive effects of these non-steroidal ecdysteroid agonists.

Cytochrome P450 aromatases: Impact on gonadal development, recrudescence and effect of hCG in the catfish, Clarias gariepinus

Present study analyzed the importance of two forms of aromatases during ovarian development and recrudescence of north African/air-breathing catfish. We cloned both CYP19A1 (1941bp; ovarian form) and CYP19A2 (1786bp; brain form), which showed 47% homology between the two forms. Characterization of encoded proteins in non-steroidogenic COS-7 cells illustrated that both isoforms efficiently catalyzed the aromatization reaction by producing estradiol-17beta (E(2)) from testosterone. Tissue distribution pattern revealed preferential expression of CYP19A2 in brain while CYP19A1 predominated in ovary with trace amounts detected in other tissues including brain. Relative real-time PCR analysis revealed high transcript levels of both isoforms in the prespawning phase of ovarian cycle, which is in accordance with serum E(2) level. Aromatase activity in brain was comparatively lower than ovary, indicating the predominant requirement of aromatase in ovary. Ontogeny studies displayed sexual dimorphism, with early expression of CYP19A1 and CYP19A2 in ovary and brain, respectively. Phase-dependent rise of expression and enzyme activity of aromatase after hCG treatment revealed the stimulatory role of gonadotropin during preparatory and prespawning phases, preferentially to promote vitellogenesis. Lack of influence of hCG treatment during spawning phase endorses it further. A good correlation of expression, enzyme activity and serum E(2) levels suggests a crucial role of CYP19A1 during ovarian differentiation and ovarian cycle of catfish. Likewise, CYP19A2 might also be involved in these processes either indirectly or directly.

Comparison of Newcastle disease vaccines by serology using serum, tears and feather pulp samples

Seroconversion of 3 lentogenic commercial Newcastle disease (ND) vaccines and experimental V4 vaccines was compared based on the haemagglutination inhibition (HI) test against ND. It was found that for primary vaccination all the vaccines produced similar response but for vaccinations V4 and LaSota were better than RDVF. Eight-five samples each of serum, tears and feather pulp were collected from respective birds and antibody assessment was done against ND by HI test. The geometric mean HI titres (GMT) of serum samples were highest followed by tears and feather pulp samples before vaccination and 3 weeks after vaccination by oculonasal route and the difference was statistically significant (p < 0.01). Three weeks after booster vaccination by oculonasal route, however, the GMT of serum samples were highest followed by feather pulp and tear samples. The ease of collection of feather pulp samples and their role in ND serology is discussed.