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1.
BMC Chem ; 18(1): 119, 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38937800

ABSTRACT

In an attempt to develop potent anti-cancer agents, a new 1,3,4-substituted-thiadiazole derivatives (8b-g), starting from 4-substituted-thiazol-2-chloroacetamides (4b-g), were synthesized and evaluated for their cytotoxic effects on multiple human cancer cell lines, including the hepatocellular carcinoma (HEPG-2), human lung carcinoma (A549), human breast carcinoma (MCF-7) and pseudo-normal human embryonic liver (L02) cancer cell lines by an MTT assay. Among all synthesized compounds, compound 8d showed the potent anti-cancer activities with GI50 values of 2.98, 2.85 and 2.53 µM against MCF-7, A549 and HepG-2 cell lines respectively as compared to standard drug Doxorubicin. Furthermore, molecular modelling studies have spotlighted the anchoring role of 1,3,4-substituted-thiadiazole moiety in bonding and hydrophobic interaction with the key amino acid residues. Therefore, these results can provide promising starting points for further development of best anti-cancer agents.

2.
Am J Infect Control ; 50(1): 8-14, 2022 01.
Article in English | MEDLINE | ID: mdl-34718069

ABSTRACT

BACKGROUND: There are concerns regarding immunogenicity with coronavirus disease 2019 (COVID-19) mRNA vaccines among persons with prior history of COVID-19 (PHC). This study was to analyze the short-term side effects of mRNA vaccines among health care workers (HCWs) with and without PHC. METHODS: A cross-sectional study was performed using an independent online survey questionnaire that gathered responses from HCWs. RESULTS: Among 1,475 HCWs, 1268 (85.97%) completed the survey, 102/1268 (44/447 in Moderna group and 58/821 in Pfizer-BioNTech group) reported PHC during pre-vaccination period. Symptoms of flushing/P = .05, brain fogging/P= .005, vertigo/P= .041, numbness/P= .023, diarrhea/P= .047, hives/P= .028, itching/P= .028, swelling of lips/mouth/P= .001, shortness of breath/P= .022, and anxiety/P= .048 have greater occurrence among Pfizer-BioNtech group with PHC when compared to Pfizer-BioNtech group with no PHC. Symptoms of chills/P= .027, flushing/P= .045, tremor/P= .05, muscle spasm/P= .039, vomiting/P= .031, diarrhea/P= .015, and cough/P= .011 have higher occurrence among Moderna group with PHC when compared to Moderna group with no PHC. CONCLUSIONS: Few short-term side effects among mRNA vaccine recipients with PHC may have necessitated transient time-off from work. The PHC can be considered as a predictor for severity of side effects. While the vaccination program continues in the United States, a future COVID legislation that mandates vaccination among employees along with paid time off provision may help with higher compliance and acceptance.


Subject(s)
COVID-19 , mRNA Vaccines , Cross-Sectional Studies , Humans , SARS-CoV-2 , United States , Vaccines, Synthetic
3.
Sci Rep ; 11(1): 21331, 2021 10 29.
Article in English | MEDLINE | ID: mdl-34716361

ABSTRACT

Left atrial (LA) features are altered when diastolic dysfunction (DD) is present. The relations of LA features to the DD severity and to adverse outcomes remain unclear using CMR images. We sought to compare LA features including volumes, emptying fraction, and strains as predictors of left ventricular (LV) DD and adverse outcomes. We compared four groups including normal controls (n = 32), grade I DD (n = 69), grade II DD (n = 42), and grade III DD (n = 21). DD was graded by echocardiography following the current ASE guidelines. Maximum LA volume (LAVmax), minimum LA volume (LAVmin), and LA emptying fraction (LAEF) were assessed using CMR cine images. Phasic LA strains including reservoir, conduit, and booster pump strain were assessed by feature tracking. The outcome was a composite of hospital admissions for heart failure and all-cause mortality analyzed using Cox proportional hazard models. LAVmax and LAVmin were progressively larger while LAEF and LA strain measures were lower with worsening degree of DD (all p < 0.001). Among 132 patients with DD, 61 reached the composite outcome after on average 36-months of follow-up. Each of the LA parameters except for LA conduit strain was an independent predictor of the outcome in the adjusted Cox proportional hazard models (all p < 0.001). They remained significant outcome predictors after the model additionally adjusted for LV longitudinal strain. The AUC of outcome prediction was highest by LAEF (0.760) followed by LA reservoir strain (0.733) and LAVmin (0.725). Among all the LA features, increased LA volumes, reduced LAEF, reduced LA reservoir and booster pump strains were all associated with DD and DD severity. While LA strains are valuable, conventional parameters such as LAEF and LAVmin remain to be highly effective in outcome prediction with comparable performance.


Subject(s)
Atrial Function, Left , Magnetic Resonance Imaging, Cine/methods , Ventricular Dysfunction, Left/diagnostic imaging , Adult , Aged , Cause of Death , Echocardiography , Female , Heart Failure/epidemiology , Humans , Male , Middle Aged , Predictive Value of Tests
4.
Trop Anim Health Prod ; 53(3): 407, 2021 Jul 22.
Article in English | MEDLINE | ID: mdl-34291320

ABSTRACT

Infectious bursal disease (IBD) is considered as menace as it affects poultry industry globally causing immunosuppression, high mortality and heavy economic loss. Outbreaks of IBD were reported in many states of India including Kerala. VP1 gene acts as an important factor in the process of virus encapsidation and its involvement in viral virulence and viral replication indicates its importance in infectious bursal disease virus (IBDV). The present study was conducted to carry out the molecular characterization of VP1 gene of virulent IBDV in Kerala. A total of 42 samples were processed for the detection and analysis of VP1 gene of IBDV. Out of 42 samples, 21 samples were positive for VP1 gene of IBD. The phylogenetic analysis of the partial VP1 gene sequences reveals the clustering of IBDV isolates into very virulent IBDV (vvIBDV) and non-virulent IBDV (vIBDV). Eighteen isolates (11 isolates from vaccinated flock and 7 from non-vaccinated flocks) clustered with very virulent strains. Three isolates (2 isolates were from vaccinated flock and 1 from non-vaccinated flock) clustered with non-virulent IBDV strains, showing more evolutionarily similarity to south Indian strain VCN14/ABT/MVC/India. It is observed that vvIBDV isolates from this study have common ancestor with the south Indian strain PY12 but showed 9-10% divergence from this strains. The amino acid analysis of these 21 isolates revealed that 17 isolates possessed the characteristic vvIBDV TDN amino acid triplet, while the three isolates had non-vIBDV NEG amino acid triplet at 145/146/147 position. The remaining isolate 1/CVASP/IBDV/VP1 shows unique PDN triplet instead of TDN. Two vvIBDV isolates (15/CVASP/IBDV/VP1 and 18/CVASP/IBDV/VP1) showed 100% nucleotide and amino acid similarity with intermediate plus vaccine strain. Four vvIBDV isolates showed neutral amino acid substitution K251R which was earlier reported in Indian strains but first time in south Indian isolates. The most common unique amino acid substitution observed in our study was neutral E269D amino acid substitution in 12 isolates, neutral amino acid substitution T329S in five isolates, neutral T174N and non-polar to polar amino acid substitution A178T in isolate 10/CVASP/IBDV/VP1, non-polar to polar amino acid substitution P360R in isolate 17/CVASP/IBDV/VP1 and non-polar to polar amino acid substitution P188S in isolate 1/CVASP/IBDV/VP1. These novel mutations in our study reveal the role of genetic drift in the evolution of vvIBDV strains. The isolate 2/CVASP/IBDV/VP1 from non-vaccinated flock shows VP1 gene of non-vIBDV, but possessing VP2 of vvIBDV type indicates this is evolved by genetic shift of segments A and B. This is the first genetic characterization study of field VP1 gene of IBDV isolates in Kerala, India.


Subject(s)
Birnaviridae Infections , Infectious bursal disease virus , Poultry Diseases , Animals , Birnaviridae Infections/epidemiology , Birnaviridae Infections/veterinary , Chickens , Disease Outbreaks/veterinary , India/epidemiology , Infectious bursal disease virus/genetics , Phylogeny , Poultry Diseases/epidemiology , Viral Structural Proteins/genetics
6.
Cureus ; 13(5): e15065, 2021 May 16.
Article in English | MEDLINE | ID: mdl-34141509

ABSTRACT

Steroids are one of the most commonly used drugs and known to be associated with several side effects. There have been case reports about the associated sinus bradycardia with pulse dose corticosteroids administration both IV and oral. We present a case of asymptomatic sinus bradycardia associated with oral prednisone 40 mg. A 69-year-old male was admitted to the ICU for sepsis and subsequently was found to have gastrointestinal (GI) bleed. He developed an acute gout attack during hospitalization and was treated with prednisone 40 mg. Over the next 24 hours, the patient's heart rate dropped to 30s to 40s beats/minute while other vitals have remained stable. He was monitored on telemetry and review of the rhythm strips, as well as a 12-lead electrocardiogram (EKG), that showed sinus bradycardia; no pauses or atrio-ventricular (AV) nodal blocks were identified. The patient was not on any beta blocker or other therapies commonly associated with sinus bradycardia. His steroids were stopped while all other medications were continued. His heart rate slowly started to improve over the next 24 hours. He was not found to have any further episodes of bradycardia. Our case is unusual as we noted transient asymptomatic bradycardia with oral prednisone 40 mg dose. While bradycardia is reversible and may go unnoticed, it is important for the clinician to be aware of this adverse effect and include it in the list of potential differentials for bradycardia.

7.
J Med Virol ; 93(7): 4420-4429, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33822361

ABSTRACT

There are concerns regarding the side effects of the new coronavirus disease 2019 (COVID-19) mRNA-1273 vaccine among healthcare workers (HCWs) in the United States. The objective of the study was to investigate the side effects of the mRNA-1273 vaccine with detailed review of organ systems. A randomized, cross-sectional study using an independent online survey questionnaire was conducted to collect responses from HCWs. Of all participants, 87.8% (1116/1271) provided complete responses. Of them, 38.7% (432/1116) received the mRNA-1273 vaccine, among which, 89.35% were females; 425 of these 432 mRNA-1273 vaccine recipients (98.34%) reported at least one or more symptoms. The results were classified based on the frequency of symptoms reported postvaccination. Of these, 254/432 (58.8%) were able to continue their daily routine activities. 108/432 (25%) temporarily had trouble to perform daily activities, 120/432 (27.78%) required transient time off from work, 17/432 (3.94%) required help from an outpatient provider, 1/432 (0.23%) required help from emergency department, and none of them were hospitalized. Despite the wide array of self-reported symptoms, 97.02% of the HCWs did not intend to skip the second dose of vaccine. Among all the symptoms reported, localized pain, generalized weakness, headache, myalgia, chills, fever, nausea, joint pains, sweating, localized swelling at the injection site, dizziness, itching, rash, decreased appetite, muscle spasm, decreased sleep quality, and brain fogging were the most commonly reported symptoms (in descending order of occurrence). Most of the symptoms reported were nonlife threatening. Despite the wide array of self-reported symptoms, there appears to be a higher acceptance for this vaccine.


Subject(s)
COVID-19 Vaccines/adverse effects , COVID-19/prevention & control , Health Personnel/psychology , Injection Site Reaction/pathology , 2019-nCoV Vaccine mRNA-1273 , Activities of Daily Living , Adult , Aged , Anaphylaxis/pathology , COVID-19/immunology , COVID-19 Vaccines/immunology , Cross-Sectional Studies , Female , Fever , Humans , Male , Middle Aged , SARS-CoV-2/immunology , Self Report , Sick Leave/statistics & numerical data , Surveys and Questionnaires , Young Adult
8.
Virusdisease ; 31(4): 554-559, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33381628

ABSTRACT

Group A rotaviruses (GAR) are an important cause of diarrhoea in infants and newborn animals especially pigs. In this paper, we report the detection, G and P typing and phylogenetic analysis of GAR of pigs in Kerala. A total of 100 fecal samples from diarrhoeic piglets were collected from organized farms in Wayanad, Ernakulam, Thrissur, and Palakkad districts of Kerala. The samples were tested for the presence of GAR employing reverse transcriptase polymerase chain reaction (RT-PCR) targeting VP6 gene. Positive samples were tested by G and P genotyping primers and representative amplicons were sequenced. Of the 100 samples, 12 were positive for GAR. The G and P types detected were G2, G4, G5, G6, G9, P[6] and P[19]. An untypable P type (P21-5 like) was also detected. In some of the samples more than one G type was detected. The nucleotide sequences of G2, G4 and G5 types were similar to those seen in pigs and that of G6 was similar to bovine sequences. G9, P[6] and P[19] sequences showed similarity to human rotavirus sequences. The findings of this study provide the first information on the G and P genotypes of GAR of pigs in Kerala.

9.
Virusdisease ; 31(4): 560-565, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33381629

ABSTRACT

Porcine reproductive and respiratory syndrome (PRRS) caused by an arterivirus is characterised by reproductive disorders in sows, and post-weaning pneumonia and growth reduction in piglets. Though the virus has been detected in Kerala, no systematic study has been carried out to ascertain its genotype and molecular epidemiology. In the present study, 7 PRRS virus (PRRSV) positive samples collected from incidences of PRRS in Kerala during 2017-2019 were subjected to ORF5, ORF7 and Nsp2 gene based reverse transcription polymerase chain reaction and the specific amplicons generated were sequenced. On BLAST analysis it was revealed that all the sequences were of genotype 2 (North American genotype). Phylogenetic analysis of ORF5 sequences, grouped them under subgenotype 4 with close clustering with other isolates from Kerala, Mizoram and Assam. Nsp2 gene sequence based phylogenetic analysis grouped the isolates under subgenotype 3 with similarities to isolates from Mizoram. Phylogenetic analysis based on ORF7, clustered the isolates under study with PRRSV isolates from Mizoram and Meghalaya. In Nsp2 sequences, a 30 amino acid discontinuous deletion was observed. On analysis of amino acid sequences of ORF5 of Kerala isolates and those from India, it was seen that the Kerala isolates showed closer similarity to PRRSV isolates from Assam than to the other Indian isolates. The study reveals that PRRSV strains prevalent in Kerala share close relationship with other PRRSV isolates in India. This may be due to spread of the virus from these regions to Kerala due to animal movement. Concerted efforts should be undertaken to check unauthorized animal movement to control spread of this economically important disease.

10.
Theranostics ; 10(13): 5736-5748, 2020.
Article in English | MEDLINE | ID: mdl-32483415

ABSTRACT

Background: Elevated glutamate production and release from glial cells is a common feature of many CNS disorders. Inhibitors of glutaminase (GLS), the enzyme responsible for converting glutamine to glutamate have been developed to target glutamate overproduction. However, many GLS inhibitors have poor aqueous solubility, are unable to cross the blood brain barrier, or demonstrate significant toxicity when given systemically, precluding translation. Enhanced aqueous solubility and systemic therapy targeted to activated glia may address this challenge. Here we examine the impact of microglial-targeted GLS inhibition in a mouse model of Rett syndrome (RTT), a developmental disorder with no viable therapies, manifesting profound central nervous system effects, in which elevated glutamatergic tone, upregulation of microglial GLS, oxidative stress and neuroimmune dysregulation are key features. Methods: To enable this, we conjugated a potent glutaminase inhibitor, N-(5-{2-[2-(5-amino-[1,3,4]thiadiazol-2-yl)-ethylsulfanyl]-ethyl}-[1,3,4]thiadiazol-2-yl)-2-phenyl-acetamide (JHU29) to a generation 4 hydroxyl PAMAM dendrimer (D-JHU29). We then examined the effect of D-JHU29 in organotypic slice culture on glutamate release. We also examined GLS activity in microglial and non-microglial cells, and neurobehavioral phenotype after systemic administration of D-JHU29 in a mouse model of RTT. Results: We report successful conjugation of JHU29 to dendrimer resulting in enhanced water solubility compared to free JHU29. D-JHU29 reduced the excessive glutamate release observed in tissue culture slices in a clinically relevant Mecp2-knockout (KO) RTT mouse. Microglia isolated from Mecp2-KO mice demonstrated upregulation of GLS activity that normalized to wild-type levels following systemic treatment with D-JHU29. Neurobehavioral assessments in D-JHU29 treated Mecp2-KO mice revealed selective improvements in mobility. Conclusion: These findings demonstrate that glutaminase inhibitors conjugated to dendrimers are a viable mechanism to selectively inhibit microglial GLS to reduce glutamate production and improve mobility in a mouse model of RTT, with broader implications for selectively targeting this pathway in other neurodegenerative disorders.


Subject(s)
Dendrimers/pharmacology , Glutaminase/metabolism , Microglia/metabolism , Animals , Dendrimers/chemical synthesis , Dendrimers/metabolism , Disease Models, Animal , Female , Glutamic Acid/metabolism , Glutaminase/antagonists & inhibitors , Glutaminase/genetics , Glutamine/metabolism , Male , Mice , Mice, Knockout , Microglia/drug effects , Neuroglia , Neuroimmunomodulation/physiology , Oxidative Stress/physiology , Rett Syndrome/metabolism , Rett Syndrome/physiopathology
11.
J Am Soc Echocardiogr ; 33(2): 161-170, 2020 02.
Article in English | MEDLINE | ID: mdl-31836269

ABSTRACT

BACKGROUND: Left ventricular diastolic dysfunction (DD) and myocardial scar are important contributors to cardiovascular morbidity and mortality. The aim of this study was to test the hypothesis that myocardial scar is a substrate of DD and that collectively they contribute to increased risk for all-cause mortality. METHODS: The study included 607 consecutive patients who underwent echocardiography and cardiac magnetic resonance imaging within 1 week. DD was assessed by echocardiography according to the contemporary guidelines and myocardial scar by late gadolinium enhancement (LGE). All-cause mortality was the main outcome. RESULTS: Scar prevalence was significantly higher comparing no DD with mild and advanced DD (25%, 61%, and 80%, respectively; P < .001), and scar burden was greater by semiquantitative LGE scores (1.4 ± 3.4, 4.8 ± 6.3, and 6.8 ± 8.8, respectively; P < .001). After 10 years of follow-up, 50 patients (8.2%) had died. The mortality incidence was significantly higher comparing no DD with mild and advanced DD (2.5, 17.3, and 55.7 deaths per 1,000 person-years, respectively; P < .001). It was also higher in patients with higher LGE scores (4.3, 22.7, and 35.2 deaths per 1,000 person-years in groups with LGE scores of 0, 1-6, and ≥7, respectively; P < .001). The risk for death was higher among patients with both DD and scar. The additive interaction of DD and scar for mortality was significant (P < .001). In the multivariate Cox proportional-hazards analysis, DD and scar were associated with mortality (P < .001). CONCLUSIONS: There is a strong link between the echocardiographic findings of DD and the morphologic changes of myocardial tissue. DD assessed according to contemporary guidelines effectively differentiates mortality risk. The additive interaction of DD and scar on mortality risk highlights the pivotal role of myocardial tissue characterization in patients with DD.


Subject(s)
Cicatrix/diagnosis , Echocardiography/methods , Heart Ventricles/diagnostic imaging , Magnetic Resonance Imaging, Cine/methods , Myocardial Infarction/complications , Ventricular Dysfunction, Left/physiopathology , Cause of Death/trends , Cicatrix/complications , Female , Follow-Up Studies , Heart Ventricles/physiopathology , Humans , Male , Middle Aged , Myocardial Infarction/mortality , Myocardial Infarction/physiopathology , New York/epidemiology , Retrospective Studies , Survival Rate/trends , Ventricular Dysfunction, Left/diagnosis , Ventricular Dysfunction, Left/mortality
12.
Trop Anim Health Prod ; 52(3): 989-997, 2020 May.
Article in English | MEDLINE | ID: mdl-31705355

ABSTRACT

Recurrent infectious bursal disease (IBD) outbreaks were reported in different regions of Kerala, India. This paper reports the comparative genetic analysis of the hypervariable region of the VP2 gene of IBD virus isolates from the field outbreaks in Kerala. In phylogenetic analysis, the obtained field isolates fall into genogroup 1 and 3. In genogroup 3, all vvIBDV isolates shared a common ancestor with other south Indian isolates but isolates 9/CVASP/IBDV, 10/CVASP/IBDV, 12/CVASP/IBDV, 14/CVASP/IBDV and 17/CVASP/IBDV are most recently evolved and are diverged from the south Indian isolates. The amino acid sequence of 22 isolates was analysed, out of which 18 had conserved amino acids which were characteristic of vvIBDV. All the vvIBDV isolates obtained in the study had phenylalanine and valine at the position 240 and 294, respectively, similar to recently evolved Indian IBDV isolate (MDI14). But we observed T269A and S299N mutations in the isolate 6/CVASP/IBDV, and it is the first report of such mutations at these positions in India IBDV isolates. The isolate 11/CVASP/IBDV had a unique mutation of V225A which is not yet reported in IBDV isolates. Two isolates (15/CVASP/IBDV and 18/CVASP/IBDV) were 100% amino acid similar to intermediate plus vaccine strain. The isolates 8/CVASP/IBDV/VP2 and 19/CVASP/IBDV had amino acids unique for the intermediate vaccine with mutations observed at H253Q and V256I in 19/CVASP/IBDV, T270A and novel mutation N279Y in isolate 8/CVASP/IBDV. These two isolates had non-virulent classical heptapeptide sequence 'SWSARGS'; nevertheless, they produce field outbreaks of IBD. This is the first report of genetic characterisation of IBDV in Kerala, India.


Subject(s)
Birnaviridae Infections/veterinary , Chickens , Infectious bursal disease virus/genetics , Poultry Diseases/virology , Animals , Base Sequence , Birnaviridae Infections/epidemiology , Birnaviridae Infections/virology , Disease Outbreaks , Genotype , India/epidemiology , Phylogeny , Poultry Diseases/epidemiology
13.
Analyst ; 142(1): 118-122, 2016 12 19.
Article in English | MEDLINE | ID: mdl-27874898

ABSTRACT

A combination of donor-acceptor and electrostatic interactions in a three-component supramolecular system has been shown to form the basis for selective and sensitive detection of peptides. Different substituents in the polymer and the detection matrix were compared to demonstrate that the favorable donor-acceptor interactions explain the observed signal enhancement. The ternary supramolecular interactions discovered in this work are enabled by the self-packing behavior of amphiphilic homopolymers and their ability to mediate interactions between the detection matrix and peptide that facilitate sensitive detection of peptides.


Subject(s)
Chemistry Techniques, Analytical , Peptides/analysis , Polymers/chemistry , Hydrophobic and Hydrophilic Interactions , Limit of Detection , Static Electricity
14.
Virusdisease ; 27(3): 311-314, 2016 Sep.
Article in English | MEDLINE | ID: mdl-28466045

ABSTRACT

Porcine parvovirus (PPV) is a DNA virus of the genus Parvovirus of family Parvoviridae. It is the causative agent of many disease problems in pigs such as maternal reproductive failure, stillbirth, mummification, embryonic or fetal death, infertility, abortion and neonatal death. A study was conducted to assess the incidence of the virus in pigs in Kerala State in South India. A total of 38 samples were collected from domestic and wild pigs from different districts of the State. Polymerase chain reaction targeting a 265 bp fragment of the NS1 gene of the virus was carried out. Of the samples tested, 2 (5.26 %) were found to be positive for PPV virus genome, one of which was from a wild pig. One of the positive samples was sequenced and the nucleotide sequence obtained was compared with other sequences of PPV from India and abroad. The results revealed that the sequence had very close similarity to PPV sequences previously reported from India and to that of Chinese isolates. This is the first report of the existence of PPV in domestic and wild pigs in Kerala, India. The study highlights the need to test for the presence of PPV in addition to other infectious agents in diagnosis of cases of reproductive disorders in pigs.

15.
Virusdisease ; 26(4): 260-6, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26645036

ABSTRACT

Classical swine fever (CSF) is an economically important disease of pigs caused by CSF virus (CSFV) belonging to the genus Pestivirus within the family Flaviviridae. The disease is endemic in many countries including India. A comprehensive study was carried out to assess the type of CSFV circulating in the South Indian state of Kerala. During the period 2013-2014, clinical samples were collected from 19 suspected CSF outbreaks of domestic pigs in different districts of Kerala. The samples were tested using nested reverse transcription PCR (RT-PCR) targeting the E2 gene and RT-PCR for 5'UTR of the virus. Partial 5' UTR and E2 gene regions of six CSFV isolates were sequenced. Phylogenetic analysis revealed that all the CSFV isolates belonged to subgroup 2.2. The isolates showed close resemblance to the other CSFV isolates circulating in India. It was also observed that the CSFV viruses from Kannur district were distinct from those circulating in the other districts as evidenced by their divergence from other Kerala isolates in the phylogenetic tree. Close relationship was seen to the CSFV isolates from South East Asian countries.

17.
Polym Chem ; 6(33): 6083-6087, 2015 Sep 07.
Article in English | MEDLINE | ID: mdl-26779289

ABSTRACT

Zwitterionic amphiphilic homopolymers can be conveniently prepared in one-pot using activated ester-based polymer precursors. We show that these zwitterionic polymers can (i) spontaneously self-assemble to form micelle-like and inverse micelle-like assemblies depending on the solvent environment; (ii) act as hydrophilic and hydrophobic nanocontainers in apolar and polar solvents respectively; (iii) undergo pH-responsive surface charge and size variations; (iv) exhibit least cytotoxicity compared to structurally analogous amphiphilic homopolymers.

18.
Chemistry ; 19(48): 16374-81, 2013 Nov 25.
Article in English | MEDLINE | ID: mdl-24151036

ABSTRACT

Supramolecular nano-assemblies that reduce nonspecific interactions with biological macromolecules, such as proteins, are of great importance for various biological applications. Recently, zwitterionic materials have been shown to reduce nonspecific interactions with biomolecules, owing both to their charge neutrality and their ability to form a strong hydration layer around zwitterions via electrostatic interactions. Here, new triazole-based zwitterionic moieties are presented that are incorporated as the hydrophilic functionalities in facially amphiphilic dendrons. The amphiphilic zwitterionic dendrons spontaneously self-assemble in aqueous solutions forming micelle-type aggregates, which were confirmed by DLS, TEM, and fluorescence techniques. The structural and functional characteristics of the zwitterionic dendrons are also compared with the corresponding charge-neutral PEG-based dendrons and anionic carboxylate-based dendrons. Surface-charge measurements, temperature sensitivity and evaluation of interactions of these assemblies with proteins form the bases for these comparisons.


Subject(s)
Dendrimers/chemistry , Micelles , Proteins/chemistry , Triazoles/chemistry , Hydrophobic and Hydrophilic Interactions , Molecular Structure , Polyethylene Glycols/chemistry , Temperature
19.
J Am Chem Soc ; 135(38): 14179-88, 2013 Sep 25.
Article in English | MEDLINE | ID: mdl-23971726

ABSTRACT

Supramolecular assemblies formed by amphiphilic homopolymers with negatively charged groups in the hydrophilic segment have been designed to enable high labeling selectivity toward reactive side chain functional groups in peptides. The negatively charged interiors of the supramolecular assemblies are found to block the reactivity of protonated amines that would otherwise be reactive in aqueous solution, while maintaining the reactivity of nonprotonated amines. Simple changes to the pH of the assemblies' interiors allow control over the reactivity of different functional groups in a manner that is dependent on the pKa of a given peptide functional group. The labeling studies carried out in positively charged supramolecular assemblies and free buffer solution show that, even when the amine is protonated, labeling selectivity exists only when complementary electrostatic interactions are present, thereby demonstrating the electrostatically controlled nature of these reactions.


Subject(s)
Peptides/chemistry , Polymers/chemistry , Amyloid beta-Peptides/chemistry , Benzoates/chemistry , CDC2 Protein Kinase/chemistry , Diethyl Pyrocarbonate/chemistry , Hydrogen-Ion Concentration , Micelles , Oligopeptides/chemistry , Peptide Fragments/chemistry , Quaternary Ammonium Compounds/chemistry , Static Electricity , Succinimides/chemistry , Tandem Mass Spectrometry
20.
J Am Chem Soc ; 135(24): 8947-54, 2013 Jun 19.
Article in English | MEDLINE | ID: mdl-23692369

ABSTRACT

Oligo(ethylene glycol)-decorated supramolecular assemblies have been of great interest due to their charge-neutral character and thus their propensity to avoid nonspecific interactions. These systems are known to exhibit a macroscopic temperature-sensitive transition, where the assembly phase-separates from the aqueous phase at higher temperatures. While this so-called lower critical solution temperature (LCST) behavior has been well-studied, there have been no studies on the fate of these supramolecular assemblies below this transition temperature. The work here brings to light the presence of a second, sub-LCST transition, observed well below the LCST of oligo(ethylene glycol) (OEG)-based dendrons, where the host-guest properties of the assembly are significantly altered. This sub-LCST transition is accompanied by changes in the guest encapsulation stability and dynamics of host exchange.


Subject(s)
Delayed-Action Preparations/chemistry , Ethylene Glycol/chemistry , Transition Temperature , Phase Transition
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