101
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102
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Sachar RK, Verma J, Dhawan S, Prakash V, Chopra A, Adlaka R. Sex bias in health and medical care allocation. INDIAN JOURNAL OF MATERNAL AND CHILD HEALTH : OFFICIAL PUBLICATION OF INDIAN MATERNAL AND CHILD HEALTH ASSOCIATION 1990; 1:63-5. [PMID: 12319234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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103
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Sachar RK, Verma J, Prakash V, Dhawan S, Sachar U. Childhood malnutrition and development -- a paradox. INDIAN JOURNAL OF MATERNAL AND CHILD HEALTH : OFFICIAL PUBLICATION OF INDIAN MATERNAL AND CHILD HEALTH ASSOCIATION 1990; 1:8-11. [PMID: 12319243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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104
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Abstract
A study of ocular changes in reactions in leprosy was undertaken to assign these changes, their proper place in the wide spectrum of ocular morbidity in leprosy. 76.1% of eyes of Type I reaction and 89.7% of eyes with Type II reaction showed some ocular involvement. Corneal hypoaesthesia, superficial punctate keratitis, a decrease of corneal film break up time (BUT), prominent corneal nerves, pigment on the endothelium of the cornea and a pigmented trabecular meshwork were the common ocular findings. The incidence of iridocyclitis in Type II reactions was low (8.1%). The significance of the ocular involvement in reactions in leprosy and the pathogenesis of iridocyclitis in Type II reactions is discussed.
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105
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Dhawan S, Chandra M, Pandya SN, Singh BN. Non-Q-wave myocardial infarction-current status. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 1988; 36:726-8. [PMID: 3235435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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106
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Taneja DK, Singhal PK, Dhawan S. Superstitions in pediatric illnesses among rural mothers. Indian Pediatr 1988; 25:447-52. [PMID: 3229814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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107
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Dhawan S, Singhal PK, Taneja DK. Diarrhea beliefs and practices among rural mothers of Delhi. Indian Pediatr 1988; 25:195-7. [PMID: 3246400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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108
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Dhawan S, Duong LT, Ornberg RL, Fleming PJ. Subunit exchange between membranous and soluble forms of bovine dopamine beta-hydroxylase. J Biol Chem 1987; 262:1869-75. [PMID: 3805054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Dopamine beta-hydroxylase is present in the bovine adrenal medulla in two forms: soluble and membrane-bound. In a previous study, it was shown that the tetrameric, soluble form of the enzyme undergoes dissociation into two identical dimeric subunits and that this subunit dissociation is dependent on pH and ADP binding (Dhawan, S., Hensley, P., Osborne, J. C., Jr., and Fleming, P. J. (1986) J. Biol. Chem. 261, 7680-7684). Here we report the effect of pH and ADP on the dissociation of the membranous form of dopamine beta-hydroxylase into two nonidentical subunits. Negative stain electron microscopy of purified membranous hydroxylase showed largely tetrameric species together with occasional dimeric species. The tetrameric images of membranous hydroxylase were similar to, but clearly different from, previously published negative stain images of soluble hydroxylase (Duong, L. T., Fleming, P. J., and Ornberg, R. L. (1985) J. Biol. Chem. 260, 2393-2398). Quantitative binding of ADP to the membranous hydroxylase revealed the existence of two binding sites per dimeric subunit. ADP binding and low pH both promote dissociation of a hydrophilic, catalytically active subunit from the membranous enzyme reconstituted onto phospholipid vesicles. Kinetic analyses of reconstituted membranous hydroxylase activity were consistent with the existence of tetrameric and dimeric catalytic species in equilibrium. All of the hydrophilic subunits of the purified soluble hydroxylase bind to the hydrophobic subunits of the reconstituted membranous hydroxylase. We propose that, in the chromaffin granules, the soluble hydroxylase subunits are in equilibrium association with the membrane-bound hydroxylase subunits and that the hydrophilic subunits of both soluble and membranous hydroxylase are identical.
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109
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Dhawan S, Duong LT, Ornberg RL, Fleming PJ. Subunit exchange between membranous and soluble forms of bovine dopamine beta-hydroxylase. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(19)75720-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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110
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Dhawan S, Hensley P, Osborne JC, Fleming PJ. Adenosine 5'-diphosphate-dependent subunit dissociation of bovine dopamine beta-hydroxylase. J Biol Chem 1986; 261:7680-4. [PMID: 3711102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In a previous study, it was shown that purified soluble bovine dopamine beta-hydroxylase exhibits pH-dependent reversible tetramer-dimer dissociation (Saxena, A., Hensley, P., Osborne, J. C., Jr., and Fleming, P. J. (1985) J. Biol. Chem. 260, 3386-3392). Here we report evidence for the dissociation of this enzyme by magnesium-adenosine diphosphate independent of pH in the pH range 5-7. Quantitative binding of ADP to dopamine beta-hydroxylase revealed that there are two binding sites/dimeric species of hydroxylase and that ADP is tightly bound with a KD less than 10(-8) M. Kinetic data obtained at pH 5.5, the pH inside the chromaffin granule, shows that the apparent Km values for both the substrates tyramine and ascorbate are lowered by the presence of ADP without affecting the Vmax of the enzyme. The ADP-dependent lowering of apparent Km values results from a dissociation of the enzyme to the dimeric species which has inherently lower apparent Km values for substrates.
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111
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Dhawan S, Reynolds JA. Interaction of apolipoprotein B from human serum low-density lipoprotein with egg yolk phosphatidylcholine and cholesterol. Biochemistry 1983; 22:3660-4. [PMID: 6684478 DOI: 10.1021/bi00284a019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Binary and ternary complexes of apolipoprotein B (apo B) with egg yolk lecithin and with lecithin plus cholesterol have been formed from detergent-lipid-protein mixed micelles. These particles appear to be spherical by negative-stain electron microscopy and contain 510 000 g of protein (2 mol of apo B) complexed with apparent maximum molar ratios of 780:2 (egg yolk lecithin:apo B) and 1300:280:2 (egg yolk lecithin:cholesterol:apo B). The secondary structure as reflected in the circular dichroic spectra is similar to that of holo-LDL2 when only lecithin is bound, but is significantly altered when cholesterol is also present in the complex, suggesting that the molecular organization of the ternary complex formed in the absence of neutral lipids is significantly different from that of the native lipoprotein. A part of the protein (presumably uncharged) has to be incorporated with the lipid acyl chains in a hydrophobic "core" of the spherical particle. However, the relative amounts of apo B exposed to the aqueous solvent and to the hydrophobic interior of the recombined particles depend on the lipid content and also appear to differ from those in LDL2. The results suggest that the manner in which apo B folds is continuously variable, a result consistent with its ability to bind varying amounts of lipid in vivo.
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112
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Bali A, Dhawan S, Gupta CM. Stability of liposomes in circulation is markedly enhanced by structural modification of their phospholipid component. FEBS Lett 1983; 154:373-7. [PMID: 6832376 DOI: 10.1016/0014-5793(83)80185-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Replacement of the C-2 ester group in phosphatidylcholine by the carbamyloxy function rendered its liposomes completely stable and longer living in the circulation of rats.
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113
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Shirkot CK, Mann D, Dhawan S, Gupta AK, Gupta KG. Effect of dithiocarbamates on cellulase activity in culture filtrates of Trichoderma reesei. Biotechnol Bioeng 1982; 24:1233-40. [PMID: 18546422 DOI: 10.1002/bit.260240602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Different concentrations of tetramethylthiuram disulfide (TMTD), sodium dimethyldithiocarbamate (NaDDC), and zinc dimethyldithiocarbamate (ZnDDC) affected the amount of cellulase(s) activity in the culture of Trichoderma reesei. After eight days incubation at 28 degrees C the greatest increase in Avicelase, CMCase, and beta-glucosidase over the control were observed at 0.1 ppm (TMTD) and 0.4 ppm (NaDDC and ZnDCC). There was decrease in the growth in the ZnDDC, but beta-glucosidase activity was reduced considerably. Total protein in the culture filtrate increased with the increase in cellulase(s) activity. No change in pH was observed at eight days incubation but pH increased (not exceeding 5.9) at 12 days incubation.
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114
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Dhawan S, Nityanand S, Kapoor NK, Singh S. Conformational transitions in serum high density apoproteins of hypercholesterolemic monkeys. Atherosclerosis 1982; 41:81-6. [PMID: 7073796 DOI: 10.1016/0021-9150(82)90072-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Conformational transitions in serum high density apolipoproteins of normal and hypercholesterolemic monkeys have been studied by circular dichroism. This study has revealed that under hypercholesterolemic conditions the secondary structure of apolipoproteins suffers permanent changes which could be observed even after a lengthy procedure of isolation, purification and delipidation of high density lipoprotein.
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115
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Gupta CM, Bali A, Dhawan S. Modification of phospholipid structure results in greater stability if liposomes in serum. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 648:192-8. [PMID: 7306536 DOI: 10.1016/0005-2736(81)90034-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Previous studies have revealed that the replacement of the C-2 ester group in phosphatidylcholine by the carbamyloxy function renders the resulting lipids, without affecting the properties of the liposomes, resistant to hydrolysis by phospholipase A2 (Gupta, C.M. Bali, A. (1981) Biochim. Biophys, Acta 663, 506-515). As an extension of this work, the effect of serum on the stability of liposomes, prepared from 1-palmitoyl-2-heptadec-10-cis-enylcarbamyloxyphosphatidylcholine (carbamylphosphatidylcholine), has been examined. The stability has been measured in terms of (a) bilayer permeability to solutes, and (b) the lipid transfer to serum proteins. Replacement of egg phosphatidylcholine in liposomes by the carbamyl analog prevented serum-induced leakage of the entrapped solutes and also inhibited the lipid (phospholipid and cholesterol) transfer. Manipulation of the cholesterol content of the liposomes had no effect on the stability. These observations indicate that the interaction of serum proteins with liposomes probably involves a highly specific binding of the proteins to the liposome surface.
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116
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Dhawan S, Nityanand S, Kappoor NK, Singh S. Conformational transitions in serum HDL apoproteins of hyperlipidaemic rabbits. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1981; 18:326-8. [PMID: 7341410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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117
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Malik N, Sharma SK, Nagi B, Joshi SK, Dhawan S, Jain S, Sodhi JS. Transcatheter therapeutic arterial embolization of renal tumours. Indian J Cancer 1981; 18:218-21. [PMID: 7309127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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118
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Sehgal SC, Dhawan S, Chhiber S, Sharma M, Talwar P. Frequency and significance of fungal isolations from conjunctival sac and their role in ocular infections. Mycopathologia 1981; 73:17-9. [PMID: 7219508 DOI: 10.1007/bf00443007] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Five hundred conjunctival swabs, from 150 males and 100 females with no history of ocular infections, were collected and cultured for the isolations of fungi. Eighty (16%) of the total specimens yielded positive fungal isolations. The isolation rate was more from the males than the females subjects. Mycelial fungi were predominant than the yeast organisms. Aspergillus species were the commonest isolates with A. flavus taking the lead in the isolations being positive 16 of the total 24 Aspergillus species isolated. A variable rate of fungal isolations was observed in different months of the year. The percentage of the isolations increases after the local use of Efcorlin-N. Nineteen of the 20 eyes studied did not yield the same fungal species in the repeated samples.
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119
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Vohra RM, Shirkot CK, Dhawan S, Gupta KG. Effect of lignin and some of its components on the production and activity of cellulase(s) by Trichoderma reesei. Biotechnol Bioeng 1980. [DOI: 10.1002/bit.260220714] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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120
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Gupta KG, Singh J, Sahni G, Dhawan S. Production of phenyl acetyl carbinol by yeasts. Biotechnol Bioeng 1979. [DOI: 10.1002/bit.260210614] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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121
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Kapoor NK, Dhawan S, Nityanand S. Isoproterenol induced myocardial necrosis & biogenic amine levels in rats. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1979; 17:292-4. [PMID: 223979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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122
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Gupta KG, Yadav NK, Dhawan S. Laboratory-scale production of acetoin plus diacetyl by Enterobacter cloacae ATCC 27613. Biotechnol Bioeng 1978; 20:1895-901. [PMID: 728550 DOI: 10.1002/bit.260201206] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Conditions for the laboratory-scale production of acetoin plus diacetyl by Enterobacter cloacae ATCC 27613 were studied. Thirty-five g acetoin plus diacetyl/50 g sucrose were obtained when fermentation was carried out in 2.5 liter medium containing 12.5 g peptone and 12.5 g yeast extract, at pH 7.0, in a 5 liter conical flask on a shaker (240 rpm) at 28-30 degrees C for 48 hr. Recovery of pure diacetyl was 85% of the total acetoin plus diacetyl.
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123
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Dhawan S, Kapoor NK, Nityanand S. Effect of isoprenaline on lipid profile & cardiac enzymes in rats. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1978; 16:376-8. [PMID: 680844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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124
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Rai JN, Dhawan S. Production of polymethyl-galacturonase and cellulase and its relationship with virulence in isolates of sclerotinia sclerotiorum (Lib.) de bary. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1976; 14:196-7. [PMID: 992750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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125
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Dass A, Mukhopadahyay P, Dhawan S. Termination of midtrimester pregnancies by intra-amniotic injection of hypertonic saline. J Obstet Gynaecol India 1975; 25:323-30. [PMID: 1164975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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126
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Jain A, Dass A, Dhawan S. Cervical factor in fertility. J Obstet Gynaecol India 1973; 23:332-6. [PMID: 4802855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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127
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Dass A, Jain A, Dhawan S. Hysterosalpingography versus tubal insufflation in sterility. J Obstet Gynaecol India 1973; 23:337-41. [PMID: 4802813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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128
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Dass A, Dhawan S, Chhibber HJ. Pregnanediol estimations in threatened miscarriage. J Obstet Gynaecol India 1973; 23:247-52. [PMID: 4802916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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129
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Dhawan S, Tandon GC, Tandon R, Dhawan IK, Talwar JR. Anaesthesia following coronary artery occlusion. Indian J Med Res 1972; 60:1638-42. [PMID: 4654634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
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