551
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Cahay M, McLennan M, Datta S. Conductance of an array of elastic scatterers: A scattering-matrix approach. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 37:10125-10136. [PMID: 9944440 DOI: 10.1103/physrevb.37.10125] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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552
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Popitz-Bergez F, Datta S, Ostheimer GW. Intravascular epinephrine may not increase heart rate in patients receiving metoprolol. Anesthesiology 1988; 68:815-6. [PMID: 3369730 DOI: 10.1097/00000542-198805000-00036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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553
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Datta S, Kumar VM, Chhina GS, Singh B. Interrelationship of thermal and sleep-wakefulness changes elicited from the medial preoptic area in rats. Exp Neurol 1988; 100:40-50. [PMID: 3350096 DOI: 10.1016/0014-4886(88)90199-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The study investigated the possible interrelationship between changes in sleep-wakefulness and body temperature, primarily induced by manipulation of the noradrenergic system in the medial preoptic area. Saline, norepinephrine, and its alpha- and beta-blockers were injected in the medial preoptic area and in some control areas of rats, during their sleeping and active periods. 5-Hydroxytryptamine was injected in the medial preoptic area in another group of animals. Simultaneous changes in sleep-wakefulness and the body temperature were continuously recorded. Norepinephrine produced hypothermia and arousal, whereas alpha-adrenergic blockers induced hyperthermia and sleep. These changes in body temperature and in sleep-wakefulness did not follow an identical time course. 5-Hydroxytryptamine induced hyperthermia without affecting sleep-wakefulness. It is suggested that there are different neuronal mechanisms in the medial preoptic area that bring about the drug-induced changes in temperature and sleep-wakefulness.
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554
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Li WH, Tanimura M, Luo CC, Datta S, Chan L. The apolipoprotein multigene family: biosynthesis, structure, structure-function relationships, and evolution. J Lipid Res 1988. [DOI: 10.1016/s0022-2275(20)38532-1] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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555
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Datta S, Firtel RA. An 80-bp cis-acting regulatory region controls cAMP and development regulation of a prestalk gene in Dictyostelium. Genes Dev 1988; 2:294-304. [PMID: 2897942 DOI: 10.1101/gad.2.3.294] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have analyzed an 80-bp region containing the cis-acting sequences necessary for regulation of the Dictyostelium discoideum prestalk gene pst-cathepsin at the appropriate stage during multicellular development and in response to cAMP in single-cell culture. The region lies between approximately -280 and -200 bp upstream from the Cap site and contains two intertwined G/C-rich sequences, including a palindromic sequence and a direct repeat of the 3' portion of the palindrome. In a previous set of experiments, we showed that the direct repeat, or G-box, is important in the regulation of pst-cath expression. In this paper, we use a series of nested internal deletions to define other regions within the promoter required for cAMP and developmental expression, to further examine the importance of the two G-boxes, and to examine the functional relationship of the G-boxes with respect to the other regulatory sequences. Analysis of the expression of these constructs in transformed cells showed that both the 5' portion of the palindrome and the two G-boxes are required for promoter function and are capable of developmentally regulating pst-cath expression. An A/T-rich sequence located 5' to the G/C-rich sequence is also essential for maximal expression, whereas insertion of a linker 5' to this region suggests the presence of a negative element functional during multicellular development. The spacing between the G-box sequences proved to be important for the full induction of gene expression. Constructs containing the G-boxes at wild-type spacing or closer show wild-type or near wild-type levels of expression, whereas expansion of the region between the G-boxes leads to a substantial drop in the level of gene expression in response to cAMP. Insertion of an oligonucleotide containing one of the G-boxes and surrounding sequences can partially complement deletions in which this region has been removed. Analysis of the expression of the cassette constructs, in some cases, revealed significant differences in the quantitative level of expression under the two developmental conditions. This suggests that there are either qualitative or quantitative differences in the factors controlling the expression of this gene under these two conditions.
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556
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Li WH, Tanimura M, Luo CC, Datta S, Chan L. The apolipoprotein multigene family: biosynthesis, structure, structure-function relationships, and evolution. J Lipid Res 1988; 29:245-71. [PMID: 3288703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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557
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Datta S, Luo CC, Li WH, VanTuinen P, Ledbetter DH, Brown MA, Chen SH, Liu SW, Chan L. Human hepatic lipase. Cloned cDNA sequence, restriction fragment length polymorphisms, chromosomal localization, and evolutionary relationships with lipoprotein lipase and pancreatic lipase. J Biol Chem 1988; 263:1107-10. [PMID: 2447084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Human hepatic lipase is an important enzyme in high density lipoprotein (HDL) metabolism, being implicated in the conversion of HDL2 to HDL3. Three human hepatic lipase cDNA clones were identified in two lambda gt11 libraries from human liver. The cDNA-derived amino acid sequence predicts a protein of 476 amino acid residues, preceded by a 23-residue signal peptide. Four potential N-glycosylation sites are identified, two of which are conserved in rat hepatic lipase. On alignment with human, mouse, and bovine lipoprotein lipase, the same two sites were also conserved in lipoprotein lipase in all three species. Stringent conservation of the cysteine residues was also evident. Comparative analysis of amino acid sequences shows that hepatic lipase evolves at a rapid rate, 2.07 x 10(-9) substitutions/site/year, about four times that in lipoprotein lipase and half that in pancreatic lipase. Further, hepatic lipase and pancreatic lipase appear to be evolutionarily closer to each other than either of them is to lipoprotein lipase. Southern blot analysis revealed high frequency restriction fragment length polymorphisms of the hepatic lipase gene for the enzymes HindIII and MspI. these polymorphisms will be useful for haplotype and linkage analysis of the hepatic lipase gene. Using cloned human hepatic lipase cDNA as a hybridization probe, we performed Southern blot analysis of a panel of 13 human-rodent somatic cell hybrids. Concordance analysis of the various hybrid clones indicates that the hepatic lipase gene is located on the long arm of human chromosome 15. Analysis of hybrids containing different translocations of chromosome 15 localized the gene to the region 15q15----q22.
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558
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Hjorth A, Datta S, Khanna NC, Firtel RA. Analysis of cis and trans elements involved in cAMP-inducible gene expression in Dictyostelium discoideum. DEVELOPMENTAL GENETICS 1988; 9:435-54. [PMID: 2907423 DOI: 10.1002/dvg.1020090422] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Expression of the Dictyostelium discoideum pst-cath (CP2) gene is transcriptionally regulated during multicellular development, and the gene is inducible in competent single cells following administration of exogenous cAMP. The 5' flanking region of pst-cath (CP2) that extends from -313 to the Cap site (+1) has previously been shown to contain sufficient cis-acting regulatory elements for proper developmental and cAMP-inducible expression of a foreign gene [Datta and Firtel, 1987, Mol Cell Biol 7:149-159]. The -283 to -201 region includes two exceptional "G-boxes" centered at -233 and -217 respectively, and this approximately 80 bp region is essential for basal as well as regulated expression of the pst-cath (CP2) gene. Here we summarize results obtained from a detailed analysis of a series of linker-scanner mutants and mutants that carry small internal deletions within the essential 80-bp region. Insertion of a synthetic oligonucleotide that includes the downstream G-box is demonstrated to rescue a low level of cAMP-inducible expression following insertion into cassette mutants. The effect of introducing a change in the relative spacing between regulatory elements has also been investigated. We have analyzed nuclear extracts for the presence of DNA-binding proteins that interact specifically with the pst-cath (CP2) regulatory region and identified two such putative trans-acting factors: 1) the AT-factor that is observed within a few hours following the onset of starvation and that binds tightly to stretches of alternating adenine-thymine residues (poly(dA-dT]; and 2) the AG-factor that is present in nuclear extracts of aggregated cells. Competition studies have demonstrated significant differences in the affinity that characterizes the binding of the two factors to G-box-containing sequences. The binding specificities of these DNA-binding proteins have been analyzed using gel mobility-shift and DNaseI footprinting assays.
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559
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Bader AM, Hunt CO, Datta S, Naulty JS, Ostheimer GW. Anesthesia for the obstetric patient with multiple sclerosis. J Clin Anesth 1988; 1:21-4. [PMID: 3272740 DOI: 10.1016/0952-8180(88)90006-2] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Data on all obstetric patients delivering at the Brigham and Women's Hospital during the years 1982 through 1987 were collected. The anesthetic techniques used, the type and amount of anesthetic agents administered, and the postpartum relapse rate of multiple sclerosis patients were compared. Women who received epidural anesthesia for vaginal delivery did not have a significantly higher incidence of relapse than those who received local infiltration. However, all of the women who experienced postpartum relapses had received concentrations of bupivacaine greater than 0.25%. This finding may suggest that a higher concentration of drug over a longer period of time may adversely influence the relapse rate.
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560
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Gissen AJ, Gugino LD, Datta S, Miller J, Covino BG. Effects of fentanyl and sufentanil on peripheral mammalian nerves. Anesth Analg 1987; 66:1272-6. [PMID: 2961289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of fentanyl and sufentanil on peripheral nerves were evaluated in isolated sheathed and desheathed rabbit vagus nerves. The action potential amplitudes of A and C fibers were recorded before and after a 30-min exposure to 50 and 100 micrograms/ml of fentanyl and sufentanil. A reversible decrease in the action potential amplitude of A fibers in desheathed nerves was observed after exposure to 100 micrograms/ml of each drug. The action potential amplitude of C fibers was also decreased but not to the same degree as was the A fiber action potential. Pretreatment with naloxone failed to block the reduction in action potential amplitude produced by the two opiates. No evidence of irreversible conduction blockade indicative of local neural toxicity was seen in these studies. The results suggest that high concentrations of fentanyl and sufentanil may exert a weak local anesthetic-type action on peripheral nerves.
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561
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Shankar N, Radhakrishnan V, Datta S, Sharma KN. Chemically induced cardiorespiratory reflexes arising from the gut serosa of dogs. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1987; 25:848-52. [PMID: 3453813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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562
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Datta S, Kumar R, Chaudhuri DK, Pal SC. Epidemiological aspects of plasmid profiles in Shigella dysenteriae type 1 strains isolated from Burma & India. Indian J Med Res 1987; 86:568-70. [PMID: 2967798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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563
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Monestier M, Bonin B, Migliorini P, Dang H, Datta S, Kuppers R, Rose N, Maurer P, Talal N, Bona C. Autoantibodies of various specificities encoded by genes from the VH J558 family bind to foreign antigens and share idiotopes of antibodies specific for self and foreign antigens. J Exp Med 1987; 166:1109-24. [PMID: 2443598 PMCID: PMC2188723 DOI: 10.1084/jem.166.4.1109] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We examined the binding to foreign antigens and the expression of crossreactive idiotypes by a panel of 20 murine monoclonal autoantibodies encoded by V genes from the VH J558 family. 9 of 20 antibodies bound to foreign antigens such as bacterial polysaccharides, poly(Glu50, Tyr50), poly(Glu54,Lys37,Phe9), arsonate, and lysozyme, known to interact with antibodies encoded by genes from the VH J558 family. A high proportion of our panel of autoantibodies expressed crossreactive idiotypes originally borne by monoclonal rheumatoid factors, anti-Sm, and anti-DNA antibodies, all encoded by V genes from the VH J558 family. Some of these VH J558+ autoantibodies shared crossreactive idiotypes with VH J558+ antibodies directed against foreign antigens such as influenza virus hemagglutinin, poly(Glu60,Ala30,Tyr10), arsonate, and dextran. The implications of these findings are discussed with respect to the process of activation of self-reactive clones.
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564
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Datta S, Kumar VM, Chhina GS, Singh B. Effect of application of serotonin in medial preoptic area on body temperature and sleep-wakefulness. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1987; 25:681-5. [PMID: 3450590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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565
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Datta S, Cahay M, McLennan M. Scatter-matrix approach to quantum transport. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 36:5655-5658. [PMID: 9942225 DOI: 10.1103/physrevb.36.5655] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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566
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Saha GC, Datta S, Mukherjee SC. Charge transfer in collisions of atomic hydrogen with N7+ ions in the high-energy region. PHYSICAL REVIEW. A, GENERAL PHYSICS 1987; 36:1656-1662. [PMID: 9899046 DOI: 10.1103/physreva.36.1656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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567
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Datta S, Li WH, Ghosh I, Luo CC, Chan L. Structure and expression of dog apolipoprotein C-II and C-III mRNAs. Implications for the evolution and functional constraints of apolipoprotein structure. J Biol Chem 1987; 262:10588-93. [PMID: 2956259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The complete cDNAs for canine apolipoprotein (apo) C-II and C-III have been cloned in the plasmid vector, pUC-18, and the phage vector, lambda gt11. With 32P-labeled nick-translated cDNAs as hybridization probes, apoC-II and apoC-III mRNAs were found to be expressed in canine liver, jejunum, ileum, colon, pancreas, spleen, ovary, and bladder at the following relative concentrations: 100, 35, 30, 10, 15, 5, 30, and 2% for apoC-II, and 100, 35, 15, 2, 20, 5, 30, and 5% for apoC-III. Neither mRNA was detected in canine brain, kidney, lung, muscle, oviduct, uterus, or testis. Both mRNAs are approximately 700 nucleotides in length. Complete sequence analysis revealed that apoC-II mRNA codes for a protein of 101 amino acid residues including 22 residues in the signal peptide and 79 residues in the mature peptide region. ApoC-III mRNA codes for a protein of 100 amino acid residues, including 20 in the signal peptide and 80 residues in the mature peptide region. It contains a single cysteine residue in position 54. Secondary structural analysis shows the presence of two regions each of amphipathic helix for apoC-II (residues 14-33 and 44-63) and apoC-III (residues 16-33 and 50-69). Computer analysis of the amphipathic helical regions demonstrates the importance of variation in the dihedral angles of the side chains in the charge microenvironment of the helices. Statistical analysis of sequence similarities between human apoC-II, apoC-III, apoA-II, apoA-I, apoE, and apoA-IV, and dog apoC-II and apoC-III, and rat apoC-III, apoA-II, apoA-I, apoE, and apoA-IV indicates that all these proteins have evolved rapidly, especially in the rat in which apoC-III has evolved at three times the rate in man and dog. Further, the shorter apolipoproteins, apoA-II, apoC-II, and a-poC-III, have evolved more rapidly than the longer ones, apoA-I, apoE, and apoA-IV. Some regions in the individual apolipoproteins are better conserved than others. The rate of evolution of individual regions seems to be related to the stringency of their functional requirements.
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568
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Ampil F, Datta R, Datta S. Elective postoperative external radiotherapy after hysterectomy in early-stage carcinoma of the cervix. Is additional vaginal cuff irradiation necessary? Cancer 1987; 60:280-8. [PMID: 3594365 DOI: 10.1002/1097-0142(19870801)60:3<280::aid-cncr2820600303>3.0.co;2-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This retrospective study of 44 patients who received postoperative radiotherapy soon after hysterectomy for early Stage IB to IIA carcinoma of the cervix was undertaken to determine the need for additional vaginal cuff irradiation (AVCI) following external pelvic irradiation (EPI). The reasons for adjuvant radiotherapy administration were mostly the nonradical type of performed hysterectomy or the presence of adverse prognostic histopathologic features. The overall survival and local control rates were 80% (35/44) and 89% (39/44) at 2 years and 63% (26/41) and 80% (33/41) at 5 years, respectively. Although the 2-year results seemed to indicate that AVCI was necessary, this was not supported by the obtained longer term data. Moreover, it appeared that AVCI could perhaps be safely done after EPI, when occult early-stage cervical carcinoma was found after total abdominal hysterectomy. Data from this study and the literature concerning AVCI's appropriate role in this particular disease condition are discussed.
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569
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Datta S, Li WH, Ghosh I, Luo CC, Chan L. Structure and expression of dog apolipoprotein C-II and C-III mRNAs. Implications for the evolution and functional constraints of apolipoprotein structure. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61003-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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570
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Malinow AM, Naulty JS, Hunt CO, Datta S, Ostheimer GW. Precordial ultrasonic monitoring during cesarean delivery. Anesthesiology 1987; 66:816-9. [PMID: 3296857 DOI: 10.1097/00000542-198706000-00018] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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571
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Datta S, Datta SC. Purification and characterization of fish surface mucin. THE ITALIAN JOURNAL OF BIOCHEMISTRY 1987; 36:143-52. [PMID: 3610597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Fish surface mucin from Pampus argenteus was extracted with different organic solvents and the residue passed through Sephadex G-200. The major peak was purified by DEAE-Cellulose chromatography and five fractions were obtained. Carbohydrate and protein contents showed that major peak is a glycoprotein. Rechromatography of this component on the Sephadex G-200 column gave a single peak, with an estimated minimal molecular weight of 6.9 X 10(5). Analysis of individual sugar components revealed the presence of galactose, glucose, mannose, arabinose, N-acetyl glucosamine, N-acetyl galactosamine and sialic acid. The most represented amino acids are threonine, serine, proline, glutamic acid and glycine. The N-terminal amino acid end was blocked. Nearly 47% of sulphate was acid labile. Sialic acid and fucose were released rapidly by mild acid hydrolysis. The presence of blood group-A activity suggests that some kind of terminal alpha-Gal-NAC may be present.
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572
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Datta S, Bandyopadhyay S. Aharonov-Bohm effect in semiconductor microstructures. PHYSICAL REVIEW LETTERS 1987; 58:717-720. [PMID: 10035017 DOI: 10.1103/physrevlett.58.717] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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573
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Flanagan HL, Datta S, Lambert DH, Gissen AJ, Covino BG. Effect of pregnancy on bupivacaine-induced conduction blockade in the isolated rabbit vagus nerve. Anesth Analg 1987; 66:123-6. [PMID: 3813055] [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]
Abstract
Bupivacaine-induced conduction blockade of A, B, and C fibers of the isolated vagus nerve was compared in fourteen pregnant and fourteen nonpregnant rabbits. After a control period in HEPES-Liley solution, the isolated nerves were exposed to bupivacaine concentrations of 0.1 mM to 1.0 mM. After 30 min exposure, the nerves were stimulated supramaximally and the percent reduction in amplitude of A, B, and C fiber compound action potentials was recorded. Linear regressions were fitted by the least squares method. The A fiber conduction blockade was consistently greater in the nerves from pregnant rabbits (P less than 0.001). The slope of the C fiber dose-response curves was also significantly greater in nerves from pregnant rabbits (P less than 0.01). The results indicate that the response of isolated nerves from pregnant animals to local anesthetic-induced conduction blockade differs from that of nerves from nonpregnant animals. However, it is not certain whether the difference is related simply to a more rapid diffusion and shorter onset of block or an enhanced sensitivity of the nerve membrane during pregnancy.
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574
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Nellen W, Datta S, Reymond C, Sivertsen A, Mann S, Crowley T, Firtel RA. Molecular biology in Dictyostelium: tools and applications. Methods Cell Biol 1987; 28:67-100. [PMID: 3600419 DOI: 10.1016/s0091-679x(08)61637-4] [Citation(s) in RCA: 195] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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575
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Datta S, Firtel RA. Identification of the sequences controlling cyclic AMP regulation and cell-type-specific expression of a prestalk-specific gene in Dictyostelium discoideum. Mol Cell Biol 1987; 7:149-59. [PMID: 3031453 PMCID: PMC365051 DOI: 10.1128/mcb.7.1.149-159.1987] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We have cloned and analyzed a developmentally and spatially regulated prestalk cell-specific gene from Dictyostelium discoideum. The gene encodes a protein highly homologous to the lysosomal cysteine proteinases cathepsin H and cathepsin B. Amino acid comparisons between these enzymes showed that the active-site amino acids were conserved, as were amino acids known to be important for catalysis and residues which form the intramolecular cysteine bridges. We have constructed a series of internal deletions, duplications, and linker scanner mutations within the region 300 base pairs 5' to the cap site. Analysis of expression of the mutations in transformants identified a approximately 35-base pair GC-rich region containing a dAdC/dGdT palindromic repeat and a G-rich box which is homologous to the 3' GT half of the palindromic repeat. Deletion or disruption of the G box resulted in a approximately 50-fold drop in the level of expression of the gene fusion in transformants in response to cyclic AMP in single-cell culture but did not affect the temporal pattern of regulation or control by cyclic AMP. The expression of such constructs during normal multicellular differentiation paralleled that of the endogenous gene; however, the level of RNA from the constructs was only approximately 10-fold lower than that of constructs containing the G box. Deletion of the 3' half of the palindromic sequence and the G box region resulted in a dramatic decrease in the level of transcription, although the constructs still showed proper temporal expression. These results suggest that this 35-base-pair region acts as an important part of the regulatory region for cell type and cyclic AMP regulation.
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