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Gurnani A, Sharma PK, Rautela RS, Bhattacharya A. Analgesia for acute musculoskeletal trauma: low-dose subcutaneous infusion of ketamine. Anaesth Intensive Care 1996; 24:32-6. [PMID: 8669651 DOI: 10.1177/0310057x9602400106] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Low-dose ketamine by subcutaneous infusion (0.1 mg/kg/h) was compared in double-blind fashion with intermittent morphine (0.1 mg/kg intravenously, four-hourly) as analgesic regimen in 40 ASA-I adults after acute musculoskeletal trauma. Pain was assessed using visual analogue scales and sedation was graded on a four point rank drowsiness score. Objective cardiovascular and respiratory parameters and patient acceptability in terms of supplementary analgesia and early mobilization were also recorded. Pain relief was better with the ketamine infusion than with intermittent morphine (P < 0.001). Patients were more awake and alert with ketamine infusion as evidenced by the drowsiness score (P < 0.001). Peak expiratory flow rate improved significantly with the ketamine infusion (P < 0.05). None of the patients in ketamine group required supplementary analgesia (P < 0.001) and the patients could be easily mobilized for traction/splintage as compared with patients in the control group (P < 0.001). The incidence of nausea and vomiting in the morphine group was high (P < 0.01). The study shows that subcutaneous infusion of ketamine provides safe and effective analgesia in acute musculoskeletal trauma.
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Yadav TP, Gupta VK, Mishra S, Gautam RK, Sharma PK. Hereditary onycho-osteo dysplasia syndrome. Indian J Dermatol Venereol Leprol 1995; 61:360-362. [PMID: 20953024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report a two and a half year old male child with dystrophy of all the nails, absent patellae and iliac horns. In addition he had dysmorphic facial features, sparing of lunula and bilateral hallux valgus deformity, hitherto not reported earlier.
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153
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Parsad D, Gautam RK, Jain RK, Sharma PK, Kar HK. Porokeratosis of mibelli in a family. Indian J Dermatol Venereol Leprol 1995; 61:371-372. [PMID: 20953029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The occurrence of porokeratosis of Mibelli in all members of a family when only one parent (mother) had the disease is reported. The 17 members of the third generation are still under 17 years of age and have not revealed any lesions of porokeratosis.
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154
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Gupta GS, Sharma PK. Molecular inactivation of testicular hyaluronidase in solid state after proton irradiation: a study based on target size, substrate binding and thermodynamic analysis of heat denaturation. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1995; 32:266-71. [PMID: 8713748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Dose response activity curve of testicular hyaluronidase (HDase) following proton irradiation in dry state follows complicated mechanisms which may involve multiple hits and multiple targets of variable sizes giving a constant G value of 1.66. Target analysis appears to be modified by slow recovery of activity when irradiated enzyme is brought to aqueous phase. However, pattern of irradiation at a dose of 1 x 10(5) to 8 x 10(5) Gy reveals that though binding affinity of enzyme to the substrate (hyaluronic acid) increases as shown by declining Km from 500 mg/l to 300-70 mg/l, the reaction rate of catalysis by irradiated HDase is decreased due to decrease in reaction velocity (Vmax: 266 versus 76 units at 8 x 10(5) Gy). Activation analysis of heat denaturation of nonirradiated HDase suggested the involvement of 78 kcal/mole of energy of activation (E*a) which declined to 63-52 k cal/mole after irradiation at 1 x 10(5) to 8 x 10(5) Gy for residual enzyme. The corresponding change in entropy of activation (delta S*) increased from a control value of -291 eu to -236 eu at 8 x 10(5) Gy. From thermodynamic analysis in association with recovery in aqueous phase, it is concluded that HDase is inactivated due to dissipation of proton energy among weak forces including H bonds associated with secondary/tertiary structure of molecules.
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155
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Tami TA, Sharma PK. Intralesional vinblastine therapy for Kaposi's sarcoma of the epiglottis. Otolaryngol Head Neck Surg 1995; 113:283-5. [PMID: 7675491 DOI: 10.1016/s0194-5998(95)70119-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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156
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Sharma PK. Depression manifesting as urticaria. Indian J Dermatol Venereol Leprol 1995; 61:325. [PMID: 20953010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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157
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Weber RE, Malte H, Braswell EH, Oliver RW, Green BN, Sharma PK, Kuchumov A, Vinogradov SN. Mass spectrometric composition, molecular mass and oxygen binding of Macrobdella decora hemoglobin and its tetramer and monomer subunits. J Mol Biol 1995; 251:703-20. [PMID: 7666421 DOI: 10.1006/jmbi.1995.0466] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The hexagonal bilayer hemoglobin (Hb) of the leech Macrobdella decora has an equilibrium sedimentation mass of 3544(+/- 80) kDa. Maximum entropy analysis of the electrospray ionization mass spectra of the Hb show three groups of peaks: two peaks of equal intensity at approximately 17 kDa, A (16,770.1 Da) and B (16,841.9 Da); three peaks at approximately 24 kDa, C (24,340.1 Da), D (24,398.6 Da) and E (24,420.0 Da) with relative intensities of 1:6:3, respectively; and three peaks of equal intensities at approximately 33 kDa, F (32,586.0 Da), G (32,714.5 Da) and H (32,849.9 Da). Although reduction with dithiothreitol does not affect the masses of peaks A through E, the approximately 33 kDa peaks give rise to four new peaks at approximately 16 kDa, P (16,052.2 Da), Q (16,537.3 Da), R (16,666.7 Da) and S (16,792.9 Da), indicating that F, G and H represent disulfide-bonded dimers of globin chains, P + Q, P + R and P + S, respectively. The relative intensities of the three groups of peaks are (A + B) to (C + D + E) to (F + G + H) = 0.39:0.26:0.32, and the globin to linker ratio 0.71:0.29 is in good agreement with the ratio 0.72:0.28 obtained by HPLC. The largest functional subunit obtained by dissociation at pH 7 in 4 M urea, is a subunit lacking linker chains with apparent mass 63(+/- 3) kDa. The equilibrium sedimentation profile of this subunit is fitted best as a monomer-dimer-tetramer equilibrium, with association constants K1,2 = 365 l g-1 and K1,4 = 8.1 x 10(5) l3 g-3. A model of the Hb consisting of a hexagonal bilayer of 36 tetramer and 42 linker subunits provides a total mass and globin to linker ratio closest to the experimental values. Equilibrium O2 binding measurements of the native Hb and its tetramer and monomer subunits were carried out over the pH range 6.6 to 8.0 at 10 and 25 degrees C, and in the absence and presence of Na+, Mg2+ and Ca2+. The Hb exhibits a moderately high O2 affinity, P50 = 4.4 torr at pH 7.5 and 25 degrees C, a high cooperativity (n50 approximately 3) and a substantial Bohr effect, phi = delta log P50/delta pH = -0.38. The tetramer subunit has a higher affinity, lower cooperativity and smaller Bohr effect, 1.9 torr, 1.3 to 1.5 and -0.30, respectively. The monomer subunit has a much higher affinity (P50 = 0.29 torr) and no cooperativity or Bohr effect.(ABSTRACT TRUNCATED AT 400 WORDS)
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Sharma PK, Gautam RK, Sharma AK. Eosinophilic cellulitis - A case study and management with griseofulvin. Indian J Dermatol Venereol Leprol 1995; 61:163-164. [PMID: 20952936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A 47 year old hypertensive and diabetic male patient suffering from eosinophilic cellulitis (Wells syndrome) is being reported. The patient responded very well to oral griseofulvin at the time of first presentation and subsequent three recurrences in a period of three years.
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159
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Sharma PK, Tami TA. AIDS: lessons from the last decade and prospects for the future. EAR, NOSE & THROAT JOURNAL 1995; 74:329-34, 336. [PMID: 7796740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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160
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Jain AK, Sharma PK, Bhattacharya A. Double burst stimulation for monitoring neuromuscular blockade for tracheal intubation. Anaesthesia 1995; 50:23-5. [PMID: 7702138 DOI: 10.1111/j.1365-2044.1995.tb04507.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Responses to double burst stimulation were palpated every 15 s after intravenous administration of vecuronium 0.2 mg.kg-1 in 60 adult patients under anaesthesia. Intubating conditions and neuromuscular responses to tracheal intubation were assessed at disappearance of one or both palpable responses to double burst stimulation in groups of 30 patients randomly divided, although in group A patients, tracheal intubation could be performed at disappearance of one palpable response to double burst stimulation; 27 out of 30 patients (90%) had mild to moderate bucking on intubation. In this group, only five patients (16.66%) had good intubating conditions. In group B, where tracheal intubation was attempted at disappearance of both palpable responses, intubating conditions were good in 28 out of 30 patients (93.33%) and there was no response to tracheal intubation in 26 out of 30 patients (86.66%). Palpation of evoked response to double burst stimulation can be used to predict intubating conditions and neuromuscular response to tracheal intubation with nondepolarising muscle relaxants such as vecuronium.
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Sharma PK, Richards GE, Hall DO, Singhal GS. Different sites of photodamage in chilling-sensitive (sorghum) and chilling-resistant (barley and wheat) plants. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1994; 31:459-63. [PMID: 7875714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The electron transport chain was affected to varying degrees by high light intensity at low temperature in different crop plants. The PS II was found to be the sensitive site while PS I showed very little change in its activity. Photoinhibition affected the oxidizing side of PS II in all three plants. However, the site of inhibition was different in chilling-sensitive and chilling-resistant plants. In sorghum, the water splitting reaction was damaged while in barley and wheat the damage occurred in the reaction centre itself. It appears that photoinhibition may affect different sites within the PS II in chilling-resistant and sensitive plants.
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Bhupathiraju VK, Oren A, Sharma PK, Tanner RS, Woese CR, McInerney MJ. Haloanaerobium salsugo sp. nov., a moderately halophilic, anaerobic bacterium from a subterranean brine. INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY 1994; 44:565-72. [PMID: 7520744 DOI: 10.1099/00207713-44-3-565] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A strictly anaerobic, moderately halophilic, gram-negative bacterium was isolated from a highly saline oil field brine. The bacterium was a non-spore-forming, nonmotile rod, appearing singly, in pairs, or occasionally as long chains, and measured 0.3 to 0.4 by 2.6 to 4 microns. The bacterium had a specific requirement for NaCl and grew at NaCl concentrations of between 6 and 24%, with optimal growth at 9% NaCl. The isolate grew at temperatures of between 22 and 51 degrees C and pH values of between 5.6 and 8.0. The doubling time in a complex medium containing 10% NaCl was 9 h. Growth was inhibited by chloramphenicol, tetracycline, and penicillin but not by cycloheximide or azide. Fermentable substrates were predominantly carbohydrates. The end products of glucose fermentation were acetate, ethanol, CO2, and H2. The major components of the cellular fatty acids were C14:0, C16:0, C16:1, and C17:0 cyc acids. The DNA base composition of the isolate was 34 mol% G+C. Oligonucleotide catalog and sequence analyses of the 16S rRNA showed that strain VS-752T was most closely related to Haloanaerobium praevalens GSLT (ATCC 33744), the sole member of the genus Haloanaerobium. We propose that strain VS-752 (ATCC 51327) be established as the type strain of a new species, Haloanaerobium salsugo, in the genus Haloanaerobium.
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163
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Gupta RC, Mathur AK, Sharma P, Vanjani RM, Sharma PK. Pancreatic xenograft survival in diabetic rabbits. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 1994; 42:526-8. [PMID: 7868519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Prolonged survival of pancreatic xenografts in the muscles of diabetic rabbits was achieved. The mean graft survival time (assessed by euglycemic status) in nonimmunosuppressed (Group A) was 10 days and in immunosuppressed (Group B) was 36 days (P < 0.05). Adequate immunosuppression helps pancreatic xenograft to normalize blood glucose level (BGL) by prolonging survival time. Our study demonstrates that xenotransplantation of islet cells in their natural environment (pancreatic tissue in four of thin slices) survive and function adequately in immunosuppressed recipients. This discordant Xenotransplantation model may be useful for future xenotransplantation studies.
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164
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Bhattacharya A, Gurnani A, Sharma PK, Sethi AK. Subcutaneous infusion of ketamine and morphine for relief of postoperative pain: a double-blind comparative study. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1994; 23:456-9. [PMID: 7979117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Low dose ketamine by subcutaneous infusion (0.1 mg.kg-1.h-1) was compared in a double-blind fashion with a similar infusion of morphine (0.03 mg.kg-1.h-1) for postoperative analgesia in 60 ASA-I adults after major abdominal surgery. Pain was assessed using visual analogue scales and sedation was graded on a four-point rank drowsiness score. Cardiovascular and respiratory parameters were also recorded. Pain relief was better with the ketamine infusion than with morphine infusion (P < 0.001). Both tidal and minute volume parameters improved better with ketamine (P < 0.001); patients were more awake and alert as evidenced by the drowsiness score (P < 0.001). Nine out of 30 patients who received morphine required catheterisation for urinary retention (P < 0.05). The study revealed higher analgesic efficacy of a low dose subcutaneous infusion of ketamine with lesser sedation and fewer side effects.
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165
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Sharma PK, McInerney MJ. Effect of Grain Size on Bacterial Penetration, Reproduction, and Metabolic Activity in Porous Glass Bead Chambers. Appl Environ Microbiol 1994; 60:1481-6. [PMID: 16349250 PMCID: PMC201506 DOI: 10.1128/aem.60.5.1481-1486.1994] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We determined the effects of grain size and nutritional conditions on the penetration rate and metabolic activity of
Escherichia coli
strains in anaerobic, nutrient-saturated chambers packed with different sizes of glass beads (diameters, 116 to 767 μm) under static conditions. The chambers had nearly equal porosities (38%) but different calculated pore sizes (range, 10 to 65 μm). Motile strains always penetrated faster than nonmotile strains, and nutrient conditions that resulted in faster growth rates (fermentative conditions versus nitrate-respiring conditions) resulted in faster penetration rates for both motile and nonmotile strains for all of the bead sizes tested. The penetration rate of nonmotile strains increased linearly when bead size was increased, while the penetration rate of motile strains became independent of the bead size when beads having diameters of 398 μm or greater were used. The rate of H
2
production and the final amount of H
2
produced decreased when bead size was decreased. However, the final protein concentrations were similar in chambers packed with 116-, 192-, and 281-μm beads and were only slightly higher in chambers packed with 398- and 767-μm beads. Our data indicated that conditions that favored faster growth rates also resulted in faster penetration times and that the lower penetration rates observed in chambers packed with small beads were due to restriction of bacterial activity in the small pores. The large increases in the final amount of hydrogen produced without corresponding increases in the final amount of protein made indicated that metabolism became uncoupled from cell mass biosynthesis as bead size increased, suggesting that pore size influenced the efficiency of substrate utilization.
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Vinogradov SN, Sharma PK. Preparation and characterization of invertebrate globin complexes. Methods Enzymol 1994; 231:112-24. [PMID: 8041246 DOI: 10.1016/0076-6879(94)31010-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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167
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Rashid KA, Haque M, Siddiqi AH, Stern MS, Sharma PK, Vinogradov SN, Walz DA. Purification and properties of the hemoglobins of the platyhelminth Isoparorchis hypselobagri (Trematoda: Isoparorchidae) and its host Wallagu attu (catfish). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1993; 106:993-8. [PMID: 8299358 DOI: 10.1016/0305-0491(93)90063-b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
1. The hemoglobins of the trematode Isoparorchis hypselobagri and of its host Wallagu attu (catfish) were isolated and purified. 2. SDS-polyacrylamide gel electrophoresis showed both to consist of single, 15-17 kDa chains, having different electrophoretic mobilities. 3. Isoelectric focusing showed the trematode hemoglobin to be homogeneous with a pI of 4.2 and the host hemoglobin to consist of several components. 4. Gel filtration of freshly prepared trematode hemoglobin revealed one peak corresponding to M(r) approximately 17 kDa; gel filtration of a preparation which had been stored for 2-3 months demonstrated the presence of two peaks, whose elution volumes corresponded to M(r) of ca 35 and 17 kDa, respectively. 5. Reversed-phase chromatography of carboxymethylated 35 and 17 kDa peaks on a C8 column, gave a single peak a and two peaks b and c, respectively. 6. Edman degradation of peaks a, b and c obtained provided identical sequences of 27 amino acid residues for peaks a and c and another sequence differing at 10 of the 27 positions, for peak b. Edman degradation of the freshly prepared Isoparorchis hemoglobin provided the first 15 amino acid residues found for peaks a and c. The host hemoglobin gave an N-terminal sequence completely different from the trematode sequences. 7. Since gel filtration of the 35 and 17 kDa peaks showed no sign of an interconversion equilibrium, it appears that the 35 kDa peak and peak a represent a disulfide-bonded dimer of a monomer globin chain which shares the 27 N-terminal residues with chain c, the major monomer globin component of the 17 kDa peak.(ABSTRACT TRUNCATED AT 250 WORDS)
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Zafar RS, Weber RE, Sharma PK, Vinogradov SN, Walz DA. Purification and characterization of recombinant polymeric hemoglobin P1 of Glycera dibranchiata. Protein Expr Purif 1993; 4:547-51. [PMID: 8286952 DOI: 10.1006/prep.1993.1072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The apoprotein of component P1 of the polymeric fraction of the intracellular hemoglobin of the marine polychaete Glycera dibranchiata has been expressed at a high level in Escherichia coli. The expressed globin was reconstituted with heme and purified. The N-terminal sequence of the recombinant P1 is identical to the cDNA-derived sequence of cloned P1 (Zafar et al., Biochem. Biophys. Acta, 1041, 117-123, 1990). Gel filtration, SDS-PAGE, optical spectra over the range 200-650 nm, and circular dichroism over the range 200-250 nm of the purified recombinant P1 were very similar to the polymeric fraction of native Glycera hemoglobin. The molar ellipticity at 222 nm provided an estimate of 77% for the alpha-helical content of the recombinant P1, in excellent agreement with that calculated from the crystal structure of Glycera monomeric component M-II. Although the oxygen binding affinity of the recombinant P1 is higher than that of the polymeric fraction of Glycera hemoglobin (3-4 torr vs 7-13 torr), which consists of at least six different single-chain hemoglobins, the Hill coefficient is lower (1.0-1.2 vs 1.2-1.4).
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Sharma PK, McInerney MJ, Knapp RM. In situ growth and activity and modes of penetration of Escherichia coli in unconsolidated porous materials. Appl Environ Microbiol 1993; 59:3686-94. [PMID: 8285677 PMCID: PMC182518 DOI: 10.1128/aem.59.11.3686-3694.1993] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Statistically reliable data on the in situ rates of growth, substrate consumption, and product formation are required to test the validity of the mathematical models developed for microbially enhanced oil recovery and in situ bioremediation processes. A simple, replicable porous-core system that could be aseptically divided into sections at various times was developed to follow the kinetics of microbial growth and metabolism in situ. This core system was used to study the kinetics of growth and the mode of penetration of strains of Escherichia coli through anaerobic, nutrient-saturated, fine Ottawa sand (permeability of 7.0 microns2 and porosity of 37%) under static conditions. The in situ rate of growth of a wild-type, motile, chemotactic strain, RW262, was two times slower inside cores than it was in liquid cultures. The mode of metabolism of galactose by strain RW262 was not altered inside cores, as acetate was the only product detected either inside the cores or in liquid cultures. Without applied advective force, strain RW262 grew exponentially and moved through cores at a rate of about 0.1 m/day. The cell population moved through cores in a band-like fashion, as the front of the moving cells consisted of high cell concentrations (greater than 10(5) cells per ml). Until the breakthrough of the cells occurred, galactose consumption and acetate production were observed only in the proximal sections of the core, showing that the cell propagation preceded the complete depletion of the substrate or the accumulation of large amounts of products.(ABSTRACT TRUNCATED AT 250 WORDS)
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170
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Gallucci JC, Sharma PK, Black SD, Rinderle SJ, Witiak DT. Structure of 6-fluoro-1,2,3,4,7,12-hexahydro-7-methyl-12-methylene- benz[a]anthracene. Acta Crystallogr C 1993; 49 ( Pt 10):1868-71. [PMID: 8297535 DOI: 10.1107/s0108270193003713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The X-ray analysis confirms the structure of the 12-methylene tautomer formed by the acid catalysis of 6-fluoro-1,2,3,4-tetrahydro-7,12-dimethylbenz[a]anthracene. The central C ring is in a boat conformation, with the result that the molecule is bent about a line through atoms C(7) and C(12) with a dihedral angle of 32.5 degrees. The cyclohexene A ring is in a half-chair conformation.
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171
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Gibson QH, Regan R, Olson JS, Carver TE, Dixon B, Pohajdak B, Sharma PK, Vinogradov SN. Kinetics of ligand binding to Pseudoterranova decipiens and Ascaris suum hemoglobins and to Leu-29-->Tyr sperm whale myoglobin mutant. J Biol Chem 1993; 268:16993-8. [PMID: 8349589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The kinetics of binding of O2, CO, and NO to the octameric, two-domain hemoglobins of the parasitic nematodes Pseudoterranova decipiens and Ascaris suum were determined on nanosecond and picosecond time scales using flash photolysis. The two nematode hemoglobins have very similar kinetic properties. On the picosecond time scale, they exhibit an unusual behavior in showing a geminate reaction with oxygen that is biphasic and dependent on the flash intensity. The geminate reaction with NO is also faster and more complete than for sperm whale myoglobin; however, in contrast to the O2 reaction, it is homogeneous. In addition, the oxygen dissociation rate of P. decipiens hemoglobin, 0.0035 s-1, is as low as that of A. suum hemoglobin, 0.004 s-1 (Gibson, Q. H., and Smith, M. H. (1965) Proc. R. Soc. Lond. B Biol. Sci. 163, 206-214). A mutant of sperm whale myoglobin suggested by sequence alignment of the nematode hemoglobins, Leu-29-->Tyr, did not have kinetic properties similar to them.
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Abstract
325 skulls were investigated in the present study. The absence of the floor of the carotid canal was found in only one skull, a condition which makes the internal carotid artery vulnerable during a surgical approach to this region.
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173
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Sharma PK, Singhal GS. Effect of water stress on primary photosynthetic process: interaction with light and temperature. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 1993; 30:10-4. [PMID: 8509121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Effect of water stress alone and in combination with light and temperature on chlorophyll fluorescence and photosynthetic electron transport have been studied in drought-resistant wheat. It was observed that water stress alone-did not modify the amplitude of variable fluorescence in leaf but showed slight decrease in photosynthetic electron transport. However, interaction with light caused significant decrease in the efficiency of photosynthesis. This was greater when photoinhibited at 30 degrees C than at 10 degrees C. Results suggest that water stress alone does not lead to significant damage to the primary photochemistry but photoinhibition causes both inhibition of electron transport activity and chlorophyll fluorescence. The damage was further enhanced by the combination of water stress and high temperature.
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174
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Dar GH, Anand RC, Sharma PK. Genetically engineered microorganisms to rescue plants from frost injury. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 1993; 50:1-19. [PMID: 8213308 DOI: 10.1007/bfb0007384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Ice nucleation active bacteria belonging to genera Pseudomonas, Xanthomonas and Erwinia contribute to frost damage to plants by initiating the formation of ice in plants that would otherwise supercool and avoid the damaging ice formation. The biological control of frost injury can be achieved by the application of non-ice nucleation active bacteria to the plant surfaces before they become colonized by Ice+ species. ice genes have been cloned from Pseudomonas and isogenic Ice- derivatives constructed via genetic manipulations. These genetically engineered microorganisms (GEMs) have been released into the environment to control the frost damage. The incidence of frost injury to the plants has, thereby, been reduced by 50-85% during natural frosts. These GEMs do not survive in soil and show no aerial dispersal in the environment.
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175
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Sharma PK, Kundu BS, Dogra RC. Molecular mechanism of host specificity in legume-rhizobium symbiosis. Biotechnol Adv 1993; 11:741-79. [PMID: 14538056 DOI: 10.1016/0734-9750(93)90002-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Rhizobium - legume symbiosis is a highly specific interaction between the two partners. Host specificity is evident at early stages of infection and results from multiple interactions involving signalling among bacteria and host plants. Host specific plant signals (flavanoids) convert the NodD protein to an active form and its binding with nod box initiates the transcription of inducible nod operons. Common nod genes (nodABC) code for an extracellular mitogenic Nod factor which is required for nodule organogenesis. Host specific genes (hsn) modify the Nod factor to induce root hair deformation on specific hosts. The structure of Nod factor controls host range distinction between species and biovars of rhizobia. Interactions of lectins and Exopolysaccharide/Lipopolysaccharide result in host specific attachment of Rhizobium and its subsequent invasion. Change in Expopolysaccharide structure by the transfer of hsn genes enables the Rhizobium to bind with heterologous host lectins. Conversely, changes in root lectins via gene manipulation enables the heterologous rhizobia to bind and initiate nodulation on heterologous hosts. Finally, host specific signals are required to initiate nitrogen fixation in nodules that are formed.
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