1
|
Gill US, Peppa D, Micco L, Singh HD, Carey I, Foster GR, Maini MK, Kennedy PTF. Interferon Alpha Induces Sustained Changes in NK Cell Responsiveness to Hepatitis B Viral Load Suppression In Vivo. PLoS Pathog 2016; 12:e1005788. [PMID: 27487232 PMCID: PMC4972354 DOI: 10.1371/journal.ppat.1005788] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 07/05/2016] [Indexed: 12/16/2022] Open
Abstract
NK cells are important antiviral effectors, highly enriched in the liver, with the potential to regulate immunopathogenesis in persistent viral infections. Here we examined whether changes in the NK pool are induced when patients with eAg-positive CHB are 'primed' with PegIFNα and importantly, whether these changes are sustained or further modulated long-term after switching to nucleos(t)ides (sequential NUC therapy), an approach currently tested in the clinic. Longitudinal sampling of a prospectively recruited cohort of patients with eAg+CHB showed that the cumulative expansion of CD56bright NK cells driven by 48-weeks of PegIFNα was maintained at higher than baseline levels throughout the subsequent 9 months of sequential NUCs. Unexpectedly, PegIFNα-expanded NK cells showed further augmentation in their expression of the activating NK cell receptors NKp30 and NKp46 during sequential NUCs. The expansion in proliferating, functional NK cells was more pronounced following sequential NUCs than in comparison cohorts of patients treated with de novo NUCs or PegIFNα only. Reduction in circulating HBsAg concentrations, a key goal in the path towards functional cure of CHB, was only achieved in those patients with enhancement of NK cell IFNγ and cytotoxicity but decrease in their expression of the death ligand TRAIL. In summary, we conclude that PegIFNα priming can expand a population of functional NK cells with an altered responsiveness to subsequent antiviral suppression by NUCs. Patients on sequential NUCs with a distinct NK cell profile show a decline in HBsAg, providing mechanistic insights for the further optimisation of treatment strategies to achieve sustained responses in CHB.
Collapse
Affiliation(s)
- Upkar S. Gill
- Hepatology, Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine & Dentistry, QMUL, London, United Kingdom
- Department of Hepatology, The Royal London Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Dimitra Peppa
- Division of Infection & Immunity, UCL, London, United Kingdom
| | - Lorenzo Micco
- Division of Infection & Immunity, UCL, London, United Kingdom
| | | | - Ivana Carey
- Institute of Liver Studies, Kings College Hospital, London, United Kingdom
| | - Graham R. Foster
- Hepatology, Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine & Dentistry, QMUL, London, United Kingdom
- Department of Hepatology, The Royal London Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Mala K. Maini
- Division of Infection & Immunity, UCL, London, United Kingdom
- * E-mail: (MKM); (PTFK)
| | - Patrick T. F. Kennedy
- Hepatology, Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine & Dentistry, QMUL, London, United Kingdom
- Department of Hepatology, The Royal London Hospital, Barts Health NHS Trust, London, United Kingdom
- * E-mail: (MKM); (PTFK)
| |
Collapse
|
2
|
Schurich A, Pallett LJ, Lubowiecki M, Singh HD, Gill US, Kennedy PT, Nastouli E, Tanwar S, Rosenberg W, Maini MK. The third signal cytokine IL-12 rescues the anti-viral function of exhausted HBV-specific CD8 T cells. PLoS Pathog 2013; 9:e1003208. [PMID: 23516358 PMCID: PMC3597507 DOI: 10.1371/journal.ppat.1003208] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 01/14/2013] [Indexed: 12/20/2022] Open
Abstract
Optimal immune activation of naïve CD8 T cells requires signal 1 mediated by the T cell receptor, signal 2 mediated by co-stimulation and signal 3 provided by pro-inflammatory cytokines. However, the potential for signal 3 cytokines to rescue anti-viral responses in functionally exhausted T cells has not been defined. We investigated the effect of using third signal cytokines IL-12 or IFN-α to rescue the exhausted CD8 T cell response characteristic of patients persistently infected with hepatitis B virus (HBV). We found that IL-12, but not IFN-α, potently augmented the capacity of HBV-specific CD8 T cells to produce effector cytokines upon stimulation by cognate antigen. Functional recovery mediated by IL-12 was accompanied by down-modulation of the hallmark inhibitory receptor PD-1 and an increase in the transcription factor T-bet. PD-1 down-regulation was observed in HBV but not CMV-specific T cells, in line with our finding that the highly functional CMV response was not further enhanced by IL-12. IL-12 enhanced a number of characteristics of HBV-specific T cells important for viral control: cytotoxicity, polyfunctionality and multispecificity. Furthermore, IL-12 significantly decreased the pro-apoptotic molecule Bim, which is capable of mediating premature attrition of HBV-specific CD8 T cells. Combining IL-12 with blockade of the PD-1 pathway further increased CD8 functionality in the majority of patients. These data provide new insights into the distinct signalling requirements of exhausted T cells and the potential to recover responses optimised to control persistent viral infections. Persistent viral infections continue to cause major morbidity and mortality; chronic hepatitis B virus infection alone accounts for more than a million deaths annually. Such infections are characterised by a failure of viral control perpetuated by exhaustion of the T cell response. Here we show that the cytokine IL-12 can act as a potent “third signal” to rescue antiviral function in exhausted T cells. IL-12 has previously been shown to enhance naïve T cell responses but this is the first demonstration of its capacity to boost the disabled antiviral response in a persistent viral infection. IL-12 was able to down-regulate PD-1, a key inhibitory receptor driving T cell exhaustion, resulting in the recovery of hepatitis B virus-specific responses able to mediate multiple antiviral functions. Control responses in the same patients directed against the well-controlled cytomegalovirus did not require IL-12 to function efficiently. Our findings therefore elucidate a role for IL-12 in re-programming functionally exhausted T cells in persistent viral infections.
Collapse
Affiliation(s)
- Anna Schurich
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Laura J. Pallett
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Marcin Lubowiecki
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Harsimran D. Singh
- Division of Infection and Immunity, University College London, London, United Kingdom
- Centre for Hepatology, University College London, London, United Kingdom
| | - Upkar S. Gill
- Centre for Digestive Disease, Barts and the London School for Medicine and Dentistry, London, United Kingdom
| | - Patrick T. Kennedy
- Centre for Digestive Disease, Barts and the London School for Medicine and Dentistry, London, United Kingdom
| | - Eleni Nastouli
- Department of Clinical Microbiology and Virology, University College London Hospital, London, United Kingdom
| | - Sudeep Tanwar
- Centre for Hepatology, University College London, London, United Kingdom
| | - William Rosenberg
- Centre for Hepatology, University College London, London, United Kingdom
| | - Mala K. Maini
- Division of Infection and Immunity, University College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
3
|
Peppa D, Gill US, Reynolds G, Easom NJW, Pallett LJ, Schurich A, Micco L, Nebbia G, Singh HD, Adams DH, Kennedy PTF, Maini MK. Up-regulation of a death receptor renders antiviral T cells susceptible to NK cell-mediated deletion. ACTA ACUST UNITED AC 2012; 210:99-114. [PMID: 23254287 PMCID: PMC3549717 DOI: 10.1084/jem.20121172] [Citation(s) in RCA: 250] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hepatic NK cells eliminate HBV-specific T cells dependent on TRAIL and TRAIL-R2 interactions to limit antiviral immunity in chronic infection. Antiviral T cell responses in hepatotropic viral infections such as hepatitis B virus (HBV) are profoundly diminished and prone to apoptotic deletion. In this study, we investigate whether the large population of activated NK cells in the human liver contributes to this process. We show that in vitro removal of NK cells augments circulating CD8+ T cell responses directed against HBV, but not against well-controlled viruses, in patients with chronic hepatitis B (CHB). We find that NK cells can rapidly eliminate HBV-specific T cells in a contact-dependent manner. CD8+ T cells in the liver microcirculation are visualized making intimate contact with NK cells, which are the main intrahepatic lymphocytes expressing TNF-related apoptosis-inducing ligand (TRAIL) in CHB. High-level expression of the TRAIL death receptor TRAIL-R2 is found to be a hallmark of T cells exposed to the milieu of the HBV-infected liver in patients with active disease. Up-regulation of TRAIL-R2 renders T cells susceptible to caspase-8–mediated apoptosis, from which they can be partially rescued by blockade of this death receptor pathway. Our findings demonstrate that NK cells can negatively regulate antiviral immunity in chronic HBV infection and illustrate a novel mechanism of T cell tolerance in the human liver.
Collapse
Affiliation(s)
- Dimitra Peppa
- Division of Infection and Immunity and Centre for Sexual Health and HIV Research, University College London, London NW3 2PF, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Nebbia G, Peppa D, Schurich A, Khanna P, Singh HD, Cheng Y, Rosenberg W, Dusheiko G, Gilson R, ChinAleong J, Kennedy P, Maini MK. Upregulation of the Tim-3/galectin-9 pathway of T cell exhaustion in chronic hepatitis B virus infection. PLoS One 2012; 7:e47648. [PMID: 23112829 PMCID: PMC3480425 DOI: 10.1371/journal.pone.0047648] [Citation(s) in RCA: 209] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 09/14/2012] [Indexed: 12/26/2022] Open
Abstract
The S-type lectin galectin-9 binds to the negative regulatory molecule Tim-3 on T cells and induces their apoptotic deletion or functional inactivation. We investigated whether galectin-9/Tim-3 interactions contribute to the deletion and exhaustion of the antiviral T cell response in chronic hepatitis B virus infection (CHB). We found Tim-3 to be expressed on a higher percentage of CD4 and CD8 T cells from patients with CHB than healthy controls (p<0.0001) and to be enriched on activated T cells and those infiltrating the HBV-infected liver. Direct ex vivo examination of virus-specific CD8 T cells binding HLA-A2/peptide multimers revealed that Tim-3 was more highly upregulated on HBV-specific CD8 T cells than CMV-specific CD8 T cells or the global CD8 T cell population in patients with CHB (p<0.001) or than on HBV-specific CD8 after resolution of infection. T cells expressing Tim-3 had an impaired ability to produce IFN-γ and TNF-α upon recognition of HBV-peptides and were susceptible to galectin-9-triggered cell death in vitro. Galectin-9 was detectable at increased concentrations in the sera of patients with active CHB-related liver inflammation (p = 0.02) and was strongly expressed by Kupffer cells within the liver sinusoidal network. Tim-3 blockade resulted in enhanced expansion of HBV-specific CD8 T cells able to produce cytokines and mediate cytotoxicity in vitro. Blocking PD-1 in combination with Tim-3 enhanced the number of patients from whom functional antiviral responses could be recovered and/or the strength of responses, indicating that these co-inhibitory molecules play a non-redundant role in driving T cell exhaustion in CHB. Patients taking antivirals able to potently suppress HBV viraemia continued to express Tim-3 on their T cells and respond to Tim-3 blockade. In summary, both Tim-3 and galectin-9 are increased in CHB and may contribute to the inhibition and deletion of T cells as they infiltrate the HBV-infected liver.
Collapse
Affiliation(s)
- Gaia Nebbia
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Dimitra Peppa
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Anna Schurich
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Pooja Khanna
- Division of Infection and Immunity, University College London, London, United Kingdom
- Centre for Hepatology, University College London, London, United Kingdom
| | - Harsimran D. Singh
- Centre for Hepatology, University College London, London, United Kingdom
| | - Yang Cheng
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - William Rosenberg
- Centre for Hepatology, University College London, London, United Kingdom
| | - Geoffrey Dusheiko
- Centre for Hepatology, University College London, London, United Kingdom
| | - Richard Gilson
- Centre for Sexual Health and HIV, University College London, London, United Kingdom
| | - Joanne ChinAleong
- Centre for Digestive Diseases, Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, London, United Kingdom
| | - Patrick Kennedy
- Centre for Digestive Diseases, Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, London, United Kingdom
| | - Mala K. Maini
- Division of Infection and Immunity, University College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
5
|
Sharma A, Unni BG, Singh HD. A novel fed-batch digestion system for biomethanation of plant biomasses. J Biosci Bioeng 1999; 87:678-82. [PMID: 16232537 DOI: 10.1016/s1389-1723(99)80133-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/1998] [Accepted: 12/07/1998] [Indexed: 11/16/2022]
Abstract
Plant biomasses, which in the absence of adequate pretreatment pose serious operational problems in biogas production using conventional domestic flow-through digesters, can be successfully digested in a novel fedbatch digestion system that produces a steady rate of biogas. Basically, the system is a batch digestion operated with a regular input of a calculated amount of feed based on first order decay kinetics in order to maintain a regular biogas production rate. For nearly three years the system was tested in a laboratory-scale fed-batch digester (10 l) using dried water hyacinth as feed providing the desired biogas production rate. A field-scale domestic digester of masonry construction with a working volume of 10 m3 was designed and tested for about 9 months by feeding a mixture of dried water hyacinth or banana stem along with sugarcane press mud, yielding an average biogas production of 90-100% of the expected rate calculated on the basis of the feed rate.
Collapse
Affiliation(s)
- A Sharma
- Biochemistry Division, Regional Research Laboratory, Jorhat-785006, Assam, India
| | | | | |
Collapse
|
6
|
Singh HD, Subrahmanyam S, Varagunan M. A comparison of peak expiratory flow rates obtained with the Morgan Spirocheck and a Mini Peak Flow Meter. Indian J Physiol Pharmacol 1997; 41:91-3. [PMID: 10225042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
To examine whether the normal Indian standards of Peak Expiratory Flow Rate (PEF) established with the peak flow meter were applicable to PEF values obtained with the Morgan Spirocheck, a comparison was made of PEF(S) measured with the Spirocheck with PEF (M) obtained with a Mini Peak Flow Meter. Data were obtained in 92 subjects (53 males between 20 and 84 years of age and 39 females between 21 and 75 years), comprising staff of the institute, patients undergoing treatment for chronic arthritis, and the accompanying relatives. There was a highly significant correlation between the two values. The values were identical in 14 subjects; the differences between the values were within 10% in 54 subjects, and in excess of 10% in only 20 subjects. In the whole group, the mean and standard error were 363.5 +/- 14.7 and 384 +/- 15.2 lit/min for PEF (S) and PEF (M) respectively. The regression equation PEF (M) = 0.961 x PEF (S) + 34.9 will enable estimation of expected value of PEF (M) corresponding to the observed value of PEF (S) when a standard obtained with a Peak Flow Meter in used assess abnormality in a patient.
Collapse
|
7
|
Singh HD. An easy method of spirometry. J Assoc Physicians India 1993; 41:770. [PMID: 8005957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
8
|
Abstract
Plasmid-harbouring, sterol-decomposing organism Arthrobacter oxydans 317 was treated with sodium dodecylsulphate to obtain a plasmid-cured strain A. oxydans 317 A1 incapable of utilizing 4-androstene-3,17-dione (AD). The strain 317 A1 was unable to degrade beta-sitosterol side chain completely to form AD but could carry out partial degradation as shown by the accumulation of 3-oxochol-4-en-24-oic acid as a major metabolite and 27-norcholest-4-en-3,24-dione as a minor metabolite. The strain could form 1,4-androstadiene-3,17-dione (ADD) from 3-oxo-23,24-bisnorchol-1,4-dien-22- oic acid (BNC) to a limited extent. The existence of metabolic blocks in the conversion of 3-oxochol-4-en-24-oic acid to 3-oxo-23,24-bis-norchol-4-en-22-oic acid and further conversion to AD by the plasmid-cured strain 317 A1 was suggested. Neither the formation of ADD from AD nor the conversion of AD and ADD to 9 alpha-hydroxy derivatives leading to steroid ring opening could be done by the plasmid-cured strain but the 17 beta-reduction of AD and ADD and 1(2)-reduction of ADD were not affected by the absence of the plasmid. It was proposed that plasmid determines 1(2)-dehydrogenation and 9 alpha-hydroxylation of steroid ring structure in this organism.
Collapse
Affiliation(s)
- R K Dutta
- Biochemistry Division, Regional Research Laboratory, Jorhat, Assam, India
| | | | | |
Collapse
|
9
|
Goswami PC, Singh HD, Baruah JN. Factors limiting the microbial conversion of sterols to 17-ketosteroids in the presence of metal chelate inhibitors. Folia Microbiol (Praha) 1984; 29:209-16. [PMID: 6745816 DOI: 10.1007/bf02877310] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Bioconversion of sterols to 17-ketosteroids by an Arthrobacter species occurred in the presence of hydrophobic metal-chelating agents but the production of 17-ketosteroids (17-KS) was seriously limited by the rapid loss of the viability of cells in the presence of these inhibitors. Besides, the conversion was inhibited by 17-KS at concentrations of 500 ppm or more. The 17-KS formed consisted exclusively of 1,4-androstadiene-3,17-dione (ADD) and 4-androstene-3,17-dione (AD) and these were found in the extracellular medium predominantly in bound form or as molecular aggregates which may limit their accumulation. It was concluded that enhanced production of 17-KS could be achieved by protecting the viability of cells and by removing the steroid metabolites from the site of inhibition.
Collapse
|
10
|
Goswami PC, Singh HD, Hazarika AK, Baruah JN. Isolation and characterisation of sterol metabolites formed by an Arthrobacter species. Indian J Biochem Biophys 1982; 19:367-9. [PMID: 7184854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
11
|
Singh HD, Krishnamurthi G. Mean expiratory flow volume curve. Indian J Physiol Pharmacol 1981; 25:85-88. [PMID: 7275272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|
12
|
Singh HD, Peri S. Peak expiratory flow rate in South Indian adults. Indian J Physiol Pharmacol 1979; 23:315-20. [PMID: 528035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Peak Expiratory Flow Rate (PEFR) was measured with a Wright Peak Flow Meter in 851 healthy men and women of two categories; Group I--students and staff of the Medical College constituting the middle income group, and Group II--healthy individuals from the poorer class with an income of less than Rs.200/-per month, forming the lower income group. In both categories women had much lower values than men, and in both sexes the values in the subjects of the poor income group was significantly lower. The PEFR was found to correlate best with height in subjects below 30 years, and with age in older subjects. The mean values, standard deviations and regression equations are given for the different groups. Present values are also compared with some western and Indian data.
Collapse
|
13
|
Roy PK, Singh HD, Baruah JN. Metabolism of n-alkane in Endomycopsis lipolytica (Saccharomycopsis lipolytica): Part IV--Characteristics of lipid formation from n-alkanes by non-proliferating cells. Indian J Biochem Biophys 1978; 15:456-61. [PMID: 753745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
14
|
Singh HD, Peri S. Peak expiratory flow rates in South Indian children and adolescents. Indian Pediatr 1978; 15:473-8. [PMID: 721263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
15
|
Abstract
A study of menarcheal age was carried out in southern India. A logit method of analysis was applied to status quo data on 1267 Tamil and Telugu speaking girls aged 9 to 18 years in 3 schools catering for different socio-economic groups. There appears to be no relationship of menarcheal age with dietary pattern classified simply as vegetarian and non-vegetarian. Differences in median age at menarche between schools correspond well with the socio-economic differences between them. The median age in the most advantaged school (12-86 years) is comparable with that in recent studies in southern and eastern Europe, and may perhaps be in advance of some recent north-west European samples.
Collapse
|
16
|
Singh HD, Meenakshi K. Expiratory flow rates in boys. Indian J Pediatr 1976; 43:83-7. [PMID: 977071 DOI: 10.1007/bf02749275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
17
|
|
18
|
Roy PK, Singh HD, Baruah JN. Metabolism of n-alkane in Endomycopsis lipolytica (Saccharomycopsis lipolytica): Part III. Formation of carbohydrates from hydrocarbons. Indian J Biochem Biophys 1974; 11:279-86. [PMID: 4478836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
19
|
Lonsane BK, Barua PK, Singh HD, Mathur RK, Baruah JN, Iyengar MS. Formation of salicylic acid from naphthalene by microorganisms: Part I. Studies on isolation, characterization & growth of bacterial isolates utilizing naphthalene. Indian J Exp Biol 1974; 12:158-61. [PMID: 4215747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
20
|
Singh HD, Lonsane BK, Barua PK, Baruah JN, Iyengar MS. Formation of salicylic acid from naphthalene by microorganisms: Part II. Factors affecting salicylic acid accumulation. Indian J Exp Biol 1974; 12:162-5. [PMID: 4215748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
21
|
Lonsane BK, Vadalkar K, Nigam JN, Singh HD, Baruah JN, Iyengar MS. Growth characteristics of the strains of Saccharomycopsis lipolytica on hydrocarbons. Indian J Exp Biol 1973; 11:413-6. [PMID: 4793250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
22
|
Amin PM, Nigam JN, Lonsane BK, Baruah B, Singh HD, Baruah JN, Iyengar MS. Microbial biomass production of solid hydrocarbons. Folia Microbiol (Praha) 1973; 18:49-55. [PMID: 4569084 DOI: 10.1007/bf02884249] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
23
|
Pillai KR, Bhagat SD, Vadalkar K, Singh HD, Baruah JN, Iyengar MS. Metabolism of n-alkane in Endomycopsis lipolytica. II. Formation of fatty acids from n-alkanes and their derivatives. Indian J Biochem Biophys 1972; 9:321-4. [PMID: 4662215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
24
|
Singh HD, Barua PK, Pillai KR, Baruah JN, Iyengar MS. Metabolism of n-alkanein Endomycopsis lipolytica. I. Studies on the oxidation of n-alkanes and their derivatives. Indian J Biochem Biophys 1972; 9:315-20. [PMID: 4662214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
25
|
|
26
|
Meenakshi K, Singh HD. Measurement of flow rates over the third quarter and middle litre of maximal forced expiration as indices of ventilatory function. J Indian Med Assoc 1972; 59:51-3. [PMID: 4645680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
27
|
Lonsane BK, Singh HD, Baruah JN, Iyengar MS. Ascospore formation in yeasts during active growth on hydrocarbons. Arch Mikrobiol 1972; 87:41-6. [PMID: 5086058 DOI: 10.1007/bf00424777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
28
|
Lonsane BK, Singh HD, Baruah JN, Iyengar MS. Simple method for inducing ascospore formation in yeasts. Appl Microbiol 1972; 23:161-3. [PMID: 4110425 PMCID: PMC380296 DOI: 10.1128/am.23.1.161-163.1972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A new method for inducing ascospore formation in yeasts is described and compared with conventional methods for its performance. The method has the advantage of simplicity, reproducibility, and saving of time.
Collapse
|
29
|
Singh HD, Bageerathi KS, Meenakshi K. Spirometric studies in schoolboys. Indian Pediatr 1971; 8:822-6. [PMID: 5141875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
30
|
Singh HD, Meenakshi K, Bageerathi KS. Assessing the nutritional status of children. Lancet 1970; 2:1358-9. [PMID: 4098924 DOI: 10.1016/s0140-6736(70)92377-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
31
|
Barua PK, Bhagat SD, Pillai KR, Singh HD, Baruah JN, Iyengar MS. Comparative utilization of paraffins by a Trichosporon species. Appl Microbiol 1970; 20:657-61. [PMID: 5530273 PMCID: PMC377020 DOI: 10.1128/am.20.5.657-661.1970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Utilization of normal and isoparaffins, separately and in mixtures, by a Trichosporon sp. was investigated. From a mixture of normal paraffins and isoparaffins, the organism consumed straight-chain paraffins, leaving the branched paraffins relatively unchanged. When offered separately, the highest utilization of n-alkanes by the organism was obtained in the range of undecane to octadecane; n-pentadecane was poorly utilized. From a mixture of n-alkanes, the rate of consumption of shorter-chain alkanes, n-decane to n-dodecane, was found to be relatively faster and more uniform than that of longer-chain alkanes.
Collapse
|
32
|
|
33
|
Singh HD, Abraham DL, Antony NJ. Expiratory flow rates and timed expiratory capacities in South Indian men. J Indian Med Assoc 1970; 54:412-5. [PMID: 5506298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
34
|
|
35
|
Satyavati GV, Prasad DN, Das PK, Singh HD. Anti-inflammatory activity of Semecarpus anacardium Linn. A preliminary study. Indian J Physiol Pharmacol 1969; 13:37-45. [PMID: 4982025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
36
|
Singh HD. Peak flow rate in Indians. Indian J Physiol Pharmacol 1967; 11:129-130. [PMID: 5620319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|
37
|
|