Journal of primary care & community health, Jan 31, 2016
Physical activity in later years of life is not only essential to healthy aging and independent f... more Physical activity in later years of life is not only essential to healthy aging and independent functioning, but it also helps prevent chronic diseases. We aimed this cross-sectional study to assess the prevalence of physical activity and associated factors among rural elderly Thais. We conducted this study on a sample of 300 elderly in 2 rural districts of Phranakornsiayutthaya province in Thailand. The mean age of participants were 67.5±6 years and 42% of them did not perform physical activity. Prevalence of vigorous and moderate intensity physical activity was 43.7% and 48.7%, respectively. About 43.7% elderly used any active transport and spent 2.81 hours on sedentary activities, daily. Females and those with enough income were 3.64 and 0.59 times, respectively, less likely to be physically active (P < .05). Our study concluded that almost half of the rural Thai elderly were physically inactive. Also male and wealthy elderly were less likely to be engaged in physical activity...
Activation-induced cytidine deaminase (AID) is the key mutagenic enzyme that initiates somatic hy... more Activation-induced cytidine deaminase (AID) is the key mutagenic enzyme that initiates somatic hypermutation (SH) and class switch recombination (CSR) by deaminating cytosine to uracil. The targeting of AID and therefore SH and CSR to Ig genes is a central process of the immune system, but the trans-acting factors mediating the specific targeting have remained elusive. Here we show that defective calmodulin inhibition of the transcription factor E2A after activation of the B cell receptor (BCR) leads to reduced BCR, IL4 plus CD40 ligand stimulated CSR to IgE and instead CSR to other Ig classes. AID that initiates CSR is shown to be in a complex with the transcription factors E2A, PAX5 and IRF4 on key sequences of the Igh locus. Calmodulin shows proximity with each of them after BCR stimulation. BCR signaling reduces binding of the proteins to some of the target sites on the Igh locus, and calmodulin resistance of E2A blocks these reductions. AID binds directly to the bHLH domain of E2A and to the PD domain of PAX5. E2A, AID, PAX5 and IRF4 are components of a CSR complex that is redistributed on the Igh locus by BCR signaling through calmodulin binding.
Russian Journal of Coordination Chemistry, Mar 1, 2010
The condensation reaction of succinyldihydrazide with glyoxal in the presence of divalent metal i... more The condensation reaction of succinyldihydrazide with glyoxal in the presence of divalent metal ions (1 : 1 : 1) results in the formation of the complexes of type [M(C 6 H 8 N 4 O 2 )X 2 ], where M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and X = Cl -, NO 3 -, CH 3 COO -. The complexes have been characterized with the aid of elemental analyses, conductance measurements and electronic, NMR, infrared spectral studies. On the basis of these studies, a six coordinated distorted octahedral geometry in which two nitrogen and two carbonyl oxygen atoms are suitably placed for coordination toward metal ion, has been proposed for all the complexes. The complexes were tested for their in vitro antibacterial activity. Some of the complexes showed remarkable antibacterial activities against some selected bacterial strains.
Proceedings of the National Academy of Sciences, May 1, 1986
We have cloned multiple copies of 72-base-pair (bp) repeat transcriptional enhancer element from ... more We have cloned multiple copies of 72-base-pair (bp) repeat transcriptional enhancer element from simian virus 40 in plasmid vectors upstream from the bacterial chloramphenicol acetyltransferase gene under the control of the simian virus 40 early promoter. Two copies of the 72-bp repeat provided efficient activation of gene expression. Increasing the number of linked 72-bp units to four substantially improved the activation of gene expression, but further addition of enhancers diminished the activation of gene expression proportionally to the number of enhancers added. Enhancer regions containing 10 or more copies of the 72-bp sequence were very inefficient in gene activation. Plasmids containing such expanded enhancer regions also competed less efficiently in vivo for trans-acting enhancer-binding factors. These effects are specific for the enhancer element and are not produced by reiterations of the 21-bp promoter element. Multiple enhancer units placed upstream do not interfere with the accuracy of mRNA initiation directed by the simian virus 40 early promoter in these plasmid constructs but do severely inhibit the initiation of replication at the neighboring simian virus 40 origin of replication that overlaps the early promoter region. These results are consistent with the hypothesis that the structural alterations induced in the DNA by a large number of copies of the enhancer are not favorable for the activation of a linked gene or for the binding of factors believed to mediate the enhancement effect.
Transgenic swine expressing human HbA contained only one of two types of the anticipated interspe... more Transgenic swine expressing human HbA contained only one of two types of the anticipated interspecies hybrids, namely H alpha 2 P beta 2 (H = human, P = swine). In an attempt to establish whether the absence of the swine alpha and human beta (P alpha 2 H beta 2) hybrid in vivo is a reflection of the lack of complementarity between the interspecies chains to generate appropriate interfaces, we have undertaken the in vitro assembly of swine alpha and human beta chimeric tetramer. In contrast to the in vivo transgenic swine system, in vitro the hybrid of swine alpha human beta chain is assembled readily and the hybrid exhibits normal cooperative oxygen binding. Both the swine alpha human beta and the human alpha swine beta interspecies hybrids are stable around neutral pH and do not segregate into parent tetramers even when mixed together. On the other hand, nearly complete exchange of P alpha chain of P alpha 2 H beta 2 hybrid occurs in the presence of H alpha chain at pH 6.0 and room temperature, resulting in the formation of HbA. However, very little of such an exchange reaction takes place at pH 7.0. These results suggest that the thermodynamic stability of P alpha 2 H beta 2 hybrid is lower compared to that of HbA. In contrast, P beta chain of H alpha 2 P beta 2 hybrid is refractory to exchange with H beta chain at pH 7.0 as well as at pH 6.0, suggesting that the stability of H alpha 2 P beta 2 is higher compared to that of HbA (H alpha 2 H beta 2). The swine alpha human beta chimeric Hb undergoes subunit exchange reaction with human alpha-chain in the presence of 0.9 M MgCl2, at pH 7.0. This demonstrates the lower thermodynamic stability of the intradimeric interactions of the heterodimer even at neutral pH. A synergistic coupling of the intra- and interdimeric interactions of the swine alpha and human beta chain heterodimer is essential for the thermodynamic stability of the chimeric Hb under the physiological conditions. Accordingly, we speculate that the lower thermodynamic stability of P alpha H beta heterodimer (compared to the homodimers H alpha H beta and P alpha P beta) facilitates its segregation into the homodimers by subunit exchange reaction involving either H alpha or P beta. This molecular aspect by itself or possibly along with other cellular aspects of the swine system results in the absence of P alpha 2 H beta 2 hybrid in transgenic swine expressing HbA.
International Journal of Computer Network and Information Security, Aug 14, 2012
An efficient threshold signature scheme solves the difficulties of the receiver to proof the appr... more An efficient threshold signature scheme solves the difficulties of the receiver to proof the approval of the document from the sender as well as detecting if the file has been altered by illegitimate parties. In these days there are plenty of signature schemes such as (t,n) threshold proxy signature scheme. The network is a shared medium so that the weakness security attacks such as eavesdropping, replay attack and modification attack. Thus, we have to establish a common key for encrypting/decrypting our communications over an insecure network. In this scheme, a (t,n) threshold proxy signature scheme based on RSA, any t or more proxy signers can cooperatively generate a proxy signature while t-1 or fewer of them can"t do it. The threshold proxy signature scheme uses the RSA cryptosystem to generate the private and the public key of the signers. Comparison is done on the basis of time complexity, space complexity and communication overhead. We compare the performance of four schemes: Hwang et al., Wen et al., Geng et al. and Fengying et al. with the performance of a scheme that has been proposed by the authors of this article earlier. In the proposed scheme, both the combiner and the secret share holder can verify the correctness of the information that they are receiving from each other. Therefore, the enhanced threshold proxy signature scheme is secure and efficient against notorious conspiracy attacks.
Interspecies hybrid HbS (α2Pβ2S), has been assembled in vitro from pig α-globin and human βS-chai... more Interspecies hybrid HbS (α2Pβ2S), has been assembled in vitro from pig α-globin and human βS-chain. The α2Pβ2S retains normal tetrameric structure (α2β2) of human Hb and an O2 affinity comparable to that of HbS in 50 mM Hepes buffer; but, its O2 affinity is slightly higher than that of HbS in the presence of allosteric effectors (chloride, DPG and phosphate). The 1H-NMR spectroscopy detected distinct differences between the heme environments and α1β1 interfaces of pig Hb and HbS, while their α1β2 interfaces appear very similar. The interspecies hybrid α2Hβ2P resembles pig Hb; the pig β-chain dictated the conformation of the heme environment of the human α-subunit, and to the α1β1 interfaces of the hybrid. In the α2Pβ2S hybrid, βS-chain dictated the conformation of human heme environment to the pig α-chain in the hybrid; but the conformation of α1β1 interface of this hybrid is close to, but not identical to that of HbS. On the other hand, the α1β2 interface conformation is identical to that of HbS. More important, the α2Pβ2S does not polymerize when deoxygenated; pig α-chain completely neutralizes the βS-chain dependent polymerization. The polymerization inhibitory propensity of pig α-chain is higher when it is present in the cis αPβS dimer relative to that in a trans αPβA dimer. The semisynthetically generated chimeric pig-human and human-pig α-chains by exchanging the α1–30 segments of human and pig α-chains have established that the sequence differences of pig α31–141 segment can also completely neutralize the polymerization. Comparison of the electrostatic potential energy landscape of the α-chain surfaces of HbS and α2Pβ2S suggests that the differences in electrostatic potential energy surfaces on the α-chain of α2Pβ2S relative to that in HbS, particularly the ones involving CD region, E-helix and EF-corner of pig α-chain are responsible for the polymerization neutralization activity. The pig and human-pig chimeric α-chains can serve as blueprints for the design of a new generation of variants of α-chain(s) suitable for the gene therapy of sickle cell disease.
International Journal of Farm Sciences, Feb 8, 2012
Thirty five diverse genotypes of European radishes procured from Crop Genetic Resources (CG)the N... more Thirty five diverse genotypes of European radishes procured from Crop Genetic Resources (CG)the Netherlands and India, including two checks were evaluated for yield and quality characteristics. Analysis of variance showed highly significant differences among genotypes for all the characters under study. Genotype CGN-17290 gave 50.94 per cent more yield over check White Icicle and also performed better for other characters. Genotype CGN-23811, CGN-11997 and CGN-11994 performed better than both the checks for total soluble solids, ascorbic acid and total sugar, respectively. On the basis of results obtained in the present investigations, it was concluded that CGN-17290 proved as the best genotype followed by CGN-23811, CGN-11997 and CGN-11994 in yield and quality characters.
Journal of Microbiology and Biotechnology, Jun 1, 2011
A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showe... more A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showed high-level of radiation-resistant property and survived upto 12.5 kGy dose of gamma radiation. The 16S rDNA sequence of this strain was examined, identified as Bacillus sp. strain HKG 112, and was submitted to the NCBI GenBank (Accession No. GQ925432). The mechanism of radiation resistance and gene level expression were examined by proteomic analysis of whole-cell extract. Two proteins, 38 kDa and 86.5 kDa excised from SDS-PAGE, which showed more significant changes after radiation exposure, were identified by MALDI-TOF as being flagellin and S-layer protein, respectively. Twenty selected 2-DE protein spots from the crude extracts of Bacillus sp. HKG 112, excised from 2-DE, were identified by liquid chromatography mass spectrometry (LC-MS) out of which 16 spots showed significant changes after radiation exposure and might be responsible for the radiation resistance property. Our results suggest that the different responses of some genes under radiation for the expression of radiation-dependent proteins could contribute to a physiological advantage and would be a significant initial step towards a fullsystem understanding of the radiation stress protection mechanisms of bacteria in different environments.
The Pediatric Infectious Disease Journal, Aug 1, 1994
Although rotavirus is the most common cause of diarrhea in children older than 3 months of age, n... more Although rotavirus is the most common cause of diarrhea in children older than 3 months of age, neonatal infections, which are asymptomatic, have rarely been surveyed and have been identified in only a few discrete nosocomial outbreaks. After such a nosocomial outbreak of rotavirus infection among newborns at a hospital in Delhi, we screened infants born at five other nurseries in the immediate area to assess the prevalence of neonatal infections and to determine whether the unique neonatal rotavirus strain, 116E, previously identified in Delhi, was present in other settings. Infection was documented in 43 to 78% of hospitalized infants between 4 and 6 days of life born at five of the six hospitals. Infection with strains related to 116E were the most common, but other unusual strains and no strains common in the community were detected. In addition a shift in genotype was observed among specimens collected from two of these hospitals during a 2-year period. Our observation that neonatal rotavirus infections are more common than recognized previously would encourage the administration of rotavirus vaccines during the newborn period and suggests that the low efficacy of vaccines observed during trials in developing countries may be caused by early natural exposure of infants before immunization. The extraordinary predisposition of neonates for unusual rotavirus strains not commonly found in the community should encourage others to screen neonates for this infection, characterize the strains more fully and attempt to understand at a molecular level the unique relationship between the infecting strain type and the age of the host.
Journal of primary care & community health, Jan 31, 2016
Physical activity in later years of life is not only essential to healthy aging and independent f... more Physical activity in later years of life is not only essential to healthy aging and independent functioning, but it also helps prevent chronic diseases. We aimed this cross-sectional study to assess the prevalence of physical activity and associated factors among rural elderly Thais. We conducted this study on a sample of 300 elderly in 2 rural districts of Phranakornsiayutthaya province in Thailand. The mean age of participants were 67.5±6 years and 42% of them did not perform physical activity. Prevalence of vigorous and moderate intensity physical activity was 43.7% and 48.7%, respectively. About 43.7% elderly used any active transport and spent 2.81 hours on sedentary activities, daily. Females and those with enough income were 3.64 and 0.59 times, respectively, less likely to be physically active (P < .05). Our study concluded that almost half of the rural Thai elderly were physically inactive. Also male and wealthy elderly were less likely to be engaged in physical activity...
Activation-induced cytidine deaminase (AID) is the key mutagenic enzyme that initiates somatic hy... more Activation-induced cytidine deaminase (AID) is the key mutagenic enzyme that initiates somatic hypermutation (SH) and class switch recombination (CSR) by deaminating cytosine to uracil. The targeting of AID and therefore SH and CSR to Ig genes is a central process of the immune system, but the trans-acting factors mediating the specific targeting have remained elusive. Here we show that defective calmodulin inhibition of the transcription factor E2A after activation of the B cell receptor (BCR) leads to reduced BCR, IL4 plus CD40 ligand stimulated CSR to IgE and instead CSR to other Ig classes. AID that initiates CSR is shown to be in a complex with the transcription factors E2A, PAX5 and IRF4 on key sequences of the Igh locus. Calmodulin shows proximity with each of them after BCR stimulation. BCR signaling reduces binding of the proteins to some of the target sites on the Igh locus, and calmodulin resistance of E2A blocks these reductions. AID binds directly to the bHLH domain of E2A and to the PD domain of PAX5. E2A, AID, PAX5 and IRF4 are components of a CSR complex that is redistributed on the Igh locus by BCR signaling through calmodulin binding.
Russian Journal of Coordination Chemistry, Mar 1, 2010
The condensation reaction of succinyldihydrazide with glyoxal in the presence of divalent metal i... more The condensation reaction of succinyldihydrazide with glyoxal in the presence of divalent metal ions (1 : 1 : 1) results in the formation of the complexes of type [M(C 6 H 8 N 4 O 2 )X 2 ], where M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and X = Cl -, NO 3 -, CH 3 COO -. The complexes have been characterized with the aid of elemental analyses, conductance measurements and electronic, NMR, infrared spectral studies. On the basis of these studies, a six coordinated distorted octahedral geometry in which two nitrogen and two carbonyl oxygen atoms are suitably placed for coordination toward metal ion, has been proposed for all the complexes. The complexes were tested for their in vitro antibacterial activity. Some of the complexes showed remarkable antibacterial activities against some selected bacterial strains.
Proceedings of the National Academy of Sciences, May 1, 1986
We have cloned multiple copies of 72-base-pair (bp) repeat transcriptional enhancer element from ... more We have cloned multiple copies of 72-base-pair (bp) repeat transcriptional enhancer element from simian virus 40 in plasmid vectors upstream from the bacterial chloramphenicol acetyltransferase gene under the control of the simian virus 40 early promoter. Two copies of the 72-bp repeat provided efficient activation of gene expression. Increasing the number of linked 72-bp units to four substantially improved the activation of gene expression, but further addition of enhancers diminished the activation of gene expression proportionally to the number of enhancers added. Enhancer regions containing 10 or more copies of the 72-bp sequence were very inefficient in gene activation. Plasmids containing such expanded enhancer regions also competed less efficiently in vivo for trans-acting enhancer-binding factors. These effects are specific for the enhancer element and are not produced by reiterations of the 21-bp promoter element. Multiple enhancer units placed upstream do not interfere with the accuracy of mRNA initiation directed by the simian virus 40 early promoter in these plasmid constructs but do severely inhibit the initiation of replication at the neighboring simian virus 40 origin of replication that overlaps the early promoter region. These results are consistent with the hypothesis that the structural alterations induced in the DNA by a large number of copies of the enhancer are not favorable for the activation of a linked gene or for the binding of factors believed to mediate the enhancement effect.
Transgenic swine expressing human HbA contained only one of two types of the anticipated interspe... more Transgenic swine expressing human HbA contained only one of two types of the anticipated interspecies hybrids, namely H alpha 2 P beta 2 (H = human, P = swine). In an attempt to establish whether the absence of the swine alpha and human beta (P alpha 2 H beta 2) hybrid in vivo is a reflection of the lack of complementarity between the interspecies chains to generate appropriate interfaces, we have undertaken the in vitro assembly of swine alpha and human beta chimeric tetramer. In contrast to the in vivo transgenic swine system, in vitro the hybrid of swine alpha human beta chain is assembled readily and the hybrid exhibits normal cooperative oxygen binding. Both the swine alpha human beta and the human alpha swine beta interspecies hybrids are stable around neutral pH and do not segregate into parent tetramers even when mixed together. On the other hand, nearly complete exchange of P alpha chain of P alpha 2 H beta 2 hybrid occurs in the presence of H alpha chain at pH 6.0 and room temperature, resulting in the formation of HbA. However, very little of such an exchange reaction takes place at pH 7.0. These results suggest that the thermodynamic stability of P alpha 2 H beta 2 hybrid is lower compared to that of HbA. In contrast, P beta chain of H alpha 2 P beta 2 hybrid is refractory to exchange with H beta chain at pH 7.0 as well as at pH 6.0, suggesting that the stability of H alpha 2 P beta 2 is higher compared to that of HbA (H alpha 2 H beta 2). The swine alpha human beta chimeric Hb undergoes subunit exchange reaction with human alpha-chain in the presence of 0.9 M MgCl2, at pH 7.0. This demonstrates the lower thermodynamic stability of the intradimeric interactions of the heterodimer even at neutral pH. A synergistic coupling of the intra- and interdimeric interactions of the swine alpha and human beta chain heterodimer is essential for the thermodynamic stability of the chimeric Hb under the physiological conditions. Accordingly, we speculate that the lower thermodynamic stability of P alpha H beta heterodimer (compared to the homodimers H alpha H beta and P alpha P beta) facilitates its segregation into the homodimers by subunit exchange reaction involving either H alpha or P beta. This molecular aspect by itself or possibly along with other cellular aspects of the swine system results in the absence of P alpha 2 H beta 2 hybrid in transgenic swine expressing HbA.
International Journal of Computer Network and Information Security, Aug 14, 2012
An efficient threshold signature scheme solves the difficulties of the receiver to proof the appr... more An efficient threshold signature scheme solves the difficulties of the receiver to proof the approval of the document from the sender as well as detecting if the file has been altered by illegitimate parties. In these days there are plenty of signature schemes such as (t,n) threshold proxy signature scheme. The network is a shared medium so that the weakness security attacks such as eavesdropping, replay attack and modification attack. Thus, we have to establish a common key for encrypting/decrypting our communications over an insecure network. In this scheme, a (t,n) threshold proxy signature scheme based on RSA, any t or more proxy signers can cooperatively generate a proxy signature while t-1 or fewer of them can"t do it. The threshold proxy signature scheme uses the RSA cryptosystem to generate the private and the public key of the signers. Comparison is done on the basis of time complexity, space complexity and communication overhead. We compare the performance of four schemes: Hwang et al., Wen et al., Geng et al. and Fengying et al. with the performance of a scheme that has been proposed by the authors of this article earlier. In the proposed scheme, both the combiner and the secret share holder can verify the correctness of the information that they are receiving from each other. Therefore, the enhanced threshold proxy signature scheme is secure and efficient against notorious conspiracy attacks.
Interspecies hybrid HbS (α2Pβ2S), has been assembled in vitro from pig α-globin and human βS-chai... more Interspecies hybrid HbS (α2Pβ2S), has been assembled in vitro from pig α-globin and human βS-chain. The α2Pβ2S retains normal tetrameric structure (α2β2) of human Hb and an O2 affinity comparable to that of HbS in 50 mM Hepes buffer; but, its O2 affinity is slightly higher than that of HbS in the presence of allosteric effectors (chloride, DPG and phosphate). The 1H-NMR spectroscopy detected distinct differences between the heme environments and α1β1 interfaces of pig Hb and HbS, while their α1β2 interfaces appear very similar. The interspecies hybrid α2Hβ2P resembles pig Hb; the pig β-chain dictated the conformation of the heme environment of the human α-subunit, and to the α1β1 interfaces of the hybrid. In the α2Pβ2S hybrid, βS-chain dictated the conformation of human heme environment to the pig α-chain in the hybrid; but the conformation of α1β1 interface of this hybrid is close to, but not identical to that of HbS. On the other hand, the α1β2 interface conformation is identical to that of HbS. More important, the α2Pβ2S does not polymerize when deoxygenated; pig α-chain completely neutralizes the βS-chain dependent polymerization. The polymerization inhibitory propensity of pig α-chain is higher when it is present in the cis αPβS dimer relative to that in a trans αPβA dimer. The semisynthetically generated chimeric pig-human and human-pig α-chains by exchanging the α1–30 segments of human and pig α-chains have established that the sequence differences of pig α31–141 segment can also completely neutralize the polymerization. Comparison of the electrostatic potential energy landscape of the α-chain surfaces of HbS and α2Pβ2S suggests that the differences in electrostatic potential energy surfaces on the α-chain of α2Pβ2S relative to that in HbS, particularly the ones involving CD region, E-helix and EF-corner of pig α-chain are responsible for the polymerization neutralization activity. The pig and human-pig chimeric α-chains can serve as blueprints for the design of a new generation of variants of α-chain(s) suitable for the gene therapy of sickle cell disease.
International Journal of Farm Sciences, Feb 8, 2012
Thirty five diverse genotypes of European radishes procured from Crop Genetic Resources (CG)the N... more Thirty five diverse genotypes of European radishes procured from Crop Genetic Resources (CG)the Netherlands and India, including two checks were evaluated for yield and quality characteristics. Analysis of variance showed highly significant differences among genotypes for all the characters under study. Genotype CGN-17290 gave 50.94 per cent more yield over check White Icicle and also performed better for other characters. Genotype CGN-23811, CGN-11997 and CGN-11994 performed better than both the checks for total soluble solids, ascorbic acid and total sugar, respectively. On the basis of results obtained in the present investigations, it was concluded that CGN-17290 proved as the best genotype followed by CGN-23811, CGN-11997 and CGN-11994 in yield and quality characters.
Journal of Microbiology and Biotechnology, Jun 1, 2011
A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showe... more A Gram-positive bacterium was isolated from the saline soils of Jangpura (U.P.), India, and showed high-level of radiation-resistant property and survived upto 12.5 kGy dose of gamma radiation. The 16S rDNA sequence of this strain was examined, identified as Bacillus sp. strain HKG 112, and was submitted to the NCBI GenBank (Accession No. GQ925432). The mechanism of radiation resistance and gene level expression were examined by proteomic analysis of whole-cell extract. Two proteins, 38 kDa and 86.5 kDa excised from SDS-PAGE, which showed more significant changes after radiation exposure, were identified by MALDI-TOF as being flagellin and S-layer protein, respectively. Twenty selected 2-DE protein spots from the crude extracts of Bacillus sp. HKG 112, excised from 2-DE, were identified by liquid chromatography mass spectrometry (LC-MS) out of which 16 spots showed significant changes after radiation exposure and might be responsible for the radiation resistance property. Our results suggest that the different responses of some genes under radiation for the expression of radiation-dependent proteins could contribute to a physiological advantage and would be a significant initial step towards a fullsystem understanding of the radiation stress protection mechanisms of bacteria in different environments.
The Pediatric Infectious Disease Journal, Aug 1, 1994
Although rotavirus is the most common cause of diarrhea in children older than 3 months of age, n... more Although rotavirus is the most common cause of diarrhea in children older than 3 months of age, neonatal infections, which are asymptomatic, have rarely been surveyed and have been identified in only a few discrete nosocomial outbreaks. After such a nosocomial outbreak of rotavirus infection among newborns at a hospital in Delhi, we screened infants born at five other nurseries in the immediate area to assess the prevalence of neonatal infections and to determine whether the unique neonatal rotavirus strain, 116E, previously identified in Delhi, was present in other settings. Infection was documented in 43 to 78% of hospitalized infants between 4 and 6 days of life born at five of the six hospitals. Infection with strains related to 116E were the most common, but other unusual strains and no strains common in the community were detected. In addition a shift in genotype was observed among specimens collected from two of these hospitals during a 2-year period. Our observation that neonatal rotavirus infections are more common than recognized previously would encourage the administration of rotavirus vaccines during the newborn period and suggests that the low efficacy of vaccines observed during trials in developing countries may be caused by early natural exposure of infants before immunization. The extraordinary predisposition of neonates for unusual rotavirus strains not commonly found in the community should encourage others to screen neonates for this infection, characterize the strains more fully and attempt to understand at a molecular level the unique relationship between the infecting strain type and the age of the host.
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Papers by Ramesh Kumar