Ferrets are widely used as animal models for studying influenza A viral pathogenesis and transmissibility. Human-adapted influenza A viruses primarily target the upper respiratory tract in humans ...(infection of the lower respiratory tract is observed less frequently), while in ferrets, upon intranasal inoculation both upper and lower respiratory tract are targeted. Viral tropism is governed by distribution of complex sialylated glycan receptors in various cells/tissues of the host that are specifically recognized by influenza A virus hemagglutinin (HA), a glycoprotein on viral surface. It is generally known that upper respiratory tract of humans and ferrets predominantly express α2→6 sialylated glycan receptors. However much less is known about the fine structure of these glycan receptors and their distribution in different regions of the ferret respiratory tract. In this study, we characterize distribution of glycan receptors going beyond terminal sialic acid linkage in the cranial and caudal regions of the ferret trachea (upper respiratory tract) and lung hilar region (lower respiratory tract) by multiplexing use of various plant lectins and human-adapted HAs to stain these tissue sections. Our findings show that the sialylated glycan receptors recognized by human-adapted HAs are predominantly distributed in submucosal gland of lung hilar region as a part of O-linked glycans. Our study has implications in understanding influenza A viral pathogenesis in ferrets and also in employing ferrets as animal models for developing therapeutic strategies against influenza.
Avian influenza subtypes such as H5, H7 and H9 are yet to adapt to the human host so as to establish airborne transmission between humans. However, lab-generated reassorted viruses possessing ...hemagglutinin (HA) and neuraminidase (NA) genes from an avian H9 isolate and other genes from a human-adapted (H3 or H1) subtype acquired two amino acid changes in HA and a single amino acid change in NA that confer respiratory droplet transmission in ferrets. We previously demonstrated for human-adapted H1, H2 and H3 subtypes that quantitative binding affinity of their HA to α2→6 sialylated glycan receptors correlates with respiratory droplet transmissibility of the virus in ferrets. Such a relationship remains to be established for H9 HA. In this study, we performed a quantitative biochemical characterization of glycan receptor binding properties of wild-type and mutant forms of representative H9 HAs that were previously used in context of reassorted viruses in ferret transmission studies. We demonstrate here that distinct molecular interactions in the glycan receptor-binding site of different H9 HAs affect the glycan-binding specificity and affinity. Further we show that α2→6 glycan receptor-binding affinity of a mutant H9 HA carrying Thr-189→Ala amino acid change correlates with the respiratory droplet transmission in ferrets conferred by this change. Our findings contribute to a framework for monitoring the evolution of H9 HA by understanding effects of molecular changes in HA on glycan receptor-binding properties.
The 2009 H1N1 influenza A virus continues to circulate among the human population as the predominant H1N1 subtype. Epidemiological studies and airborne transmission studies using the ferret model ...have shown that the transmission efficiency of 2009 H1N1 viruses is lower than that of previous seasonal strains and the 1918 pandemic H1N1 strain. We recently correlated this reduced transmission efficiency to the lower binding affinity of the 2009 H1N1 hemagglutinin (HA) to α2→6 sialylated glycan receptors (human receptors). Here we report that a single point mutation (Ile219→Lys; a base pair change) in the glycan receptor-binding site (RBS) of a representative 2009 H1N1 influenza A virus, A/California/04/09 or CA04/09, quantitatively increases its human receptor-binding affinity. The increased human receptor-affinity is in the same range as that of the HA from highly transmissible seasonal and 1918 pandemic H1N1 viruses. Moreover, a 2009 H1N1 virus carrying this mutation in the RBS (generated using reverse genetics) transmits efficiently in ferrets by respiratory droplets thereby reestablishing our previously observed correlation between human receptor-binding affinity and transmission efficiency. These findings are significant in the context of monitoring the evolution of the currently circulating 2009 H1N1 viruses.
Abstract Aim To validate the stability of glycated haemoglobin (HbA1c) measurements in blood samples stored at − 20 °C for up to one month. Methods The study group comprised 142 type 2 diabetic ...subjects visiting a tertiary centre for diabetes at Chennai city in south India. The HbA1c assay was done on a fasting blood sample using the Bio-Rad Variant machine on Day 0 (day of blood sample collection). Several aliquots were stored at − 20 °C and the assay was repeated on the 3rd, 7th, 15th, and 30th day after the sample collection. Bland–Altman plots were constructed and variation in the HbA1c levels on the different days was compared with the day 0 level. Results The median differences between HbA1c levels measured on Day 0 and the 3rd, 7th, 15th, and 30th day after blood collection were 0.0%, 0.2%, 0.3% and 0.5% respectively. Bland–Altman plot analysis showed that the differences between the day ‘0’ and the different time points tend to get larger with time, but these were not clinically significant. Conclusions HbA1c levels are relatively stable up to 2 weeks, if blood samples are stored at − 20 °C.
To describe the clinical profile, maternal and fetal outcomes, and the conversion rates to diabetes in women with gestational diabetes mellitus (GDM) seen at a tertiary care diabetes center in urban ...south India.
Clinical case records of 898 women with GDM seen between 1991 and 2011 were extracted from the Diabetes Electronic Medical Records (DEMR) of a tertiary care diabetes center in Chennai, south India and their clinical profile was analyzed. Follow-up data of 174 GDM women was available. To determine the conversion rates to diabetes, oral glucose tolerance test (OGTT) was done in these women. Glucose tolerance status postpartum was classified based on World Health Organization (WHO) 2006 criteria.
The mean maternal age of the women was 29 ± 4 years and mean age of gestation at first visit were 24 ± 8.4 weeks. Seventy percent of the women had a family history of diabetes. Seventy-eight percent of the women delivered full-term babies and 65% underwent a cesarean section. The average weight gain during pregnancy was 10.0 ± 4.2 kg. Macrosomia was present in 17.9% of the babies, hypoglycemia in 10.4%, congenital anomalies in 4.3%, and the neonatal mortality rate was 1.9%. Mean follow-up duration of the 174 women of whom outcome data was available was 4.5 years. Out of the 174, 101 women who were followed-up developed diabetes, of whom half developed diabetes within 5 years and over 90%, within 10 years of the delivery.
Progression to type 2 diabetes mellitus (T2DM) in Indian women with GDM is rapid. There is an urgent need to develop standardized protocols for GDM care in India that can improve the maternal and fetal outcomes and help prevent future diabetes in women with GDM.
The glycoprotein HA (haemagglutinin) on the surface of influenza A virus plays a central role in recognition and binding to specific host cell-surface glycan receptors and in fusion of viral membrane ...to the host nuclear membrane during viral replication. Given the abundance of HA on the viral surface, this protein is also the primary target for host innate and adaptive immune responses. Although addition of glycosylation sites on HA are a part of viral evolution to evade the host immune responses, there are specific glycosylation sites that are conserved during most of the evolution of the virus. In the present study, it was demonstrated that one such conserved glycosylation site at Asn(91) in H1N1 HA critically governs the glycan receptor-binding specificity and hence would potentially impinge on the host adaptation of the virus.
Design and Development of Smart Farming using ML and IoT in India Chatterjee, Alakananda; Viswanathan, Harini; Giridharan, Varsha ...
2023 International Conference on Recent Advances in Science and Engineering Technology (ICRASET),
2023-Nov.-23
Conference Proceeding
IoT is used to find massive amounts of data whereas ML easily identifies trends and patterns and gives more insights into the data that we want for farming. Focuses on improving the productivity of ...farming in many aspects by building a recommendation model trained by supervised and unsupervised model ML algorithms for smart greenhouse agricultural systems and optimizes work done by farmers as it involves no human intervention. REES52 IoT kit will be used for overall implementation. The proposed model employs logistic regression and a k-means algorithm to predict the kind of crop that will grow followed by deploying a flask module that will help display the results user-friendly through a web application.
Aim To validate the stability of glycated haemoglobin (HbA1c) measurements in blood samples stored at -20 degree C for up to one month. Methods The study group comprised 142 type 2 diabetic subjects ...visiting a tertiary centre for diabetes at Chennai city in south India. The HbA1c assay was done on a fasting blood sample using the Bio-Rad Variant machine on Day 0 (day of blood sample collection). Several aliquots were stored at -20 degree C and the assay was repeated on the 3rd, 7th, 15th, and 30th day after the sample collection. Bland-Altman plots were constructed and variation in the HbA1c levels on the different days was compared with the day 0 level. Results The median differences between HbA1c levels measured on Day 0 and the 3rd, 7th, 15th, and 30th day after blood collection were 0.0%, 0.2%, 0.3% and 0.5% respectively. Bland-Altman plot analysis showed that the differences between the day '0' and the different time points tend to get larger with time, but these were not clinically significant. Conclusions HbA1c levels are relatively stable up to 2weeks, if blood samples are stored at -20 degree C.
Avian influenza subtypes such as H5, H7 and H9 are yet to adapt to the human host so as to establish airborne transmission between humans. However, lab-generated reassorted viruses possessing ...hemagglutinin (HA) and neuraminidase (NA) genes from an avian H9 isolate and other genes from a human-adapted (H3 or H1) subtype acquired two amino acid changes in HA and a single amino acid change in NA that confer respiratory droplet transmission in ferrets. We previously demonstrated for human-adapted H1, H2 and H3 subtypes that quantitative binding affinity of their HA to alpha 2 arrow right 6 sialylated glycan receptors correlates with respiratory droplet transmissibility of the virus in ferrets. Such a relationship remains to be established for H9 HA. In this study, we performed a quantitative biochemical characterization of glycan receptor binding properties of wild-type and mutant forms of representative H9 HAs that were previously used in context of reassorted viruses in ferret transmission studies. We demonstrate here that distinct molecular interactions in the glycan receptor-binding site of different H9 HAs affect the glycan-binding specificity and affinity. Further we show that alpha 2 arrow right 6 glycan receptor-binding affinity of a mutant H9 HA carrying Thr-189 arrow right Ala amino acid change correlates with the respiratory droplet transmission in ferrets conferred by this change. Our findings contribute to a framework for monitoring the evolution of H9 HA by understanding effects of molecular changes in HA on glycan receptor-binding properties.
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