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Regnault A, Levraud JP, Lim A, Six A, Moreau C, Cumano A, Kourilsky P. The expansion and selection of T cell receptor alpha beta intestinal intraepithelial T cell clones. Eur J Immunol 1996; 26:914-21. [PMID: 8625988 DOI: 10.1002/eji.1830260429] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In conventional mice, the T cell receptor (TCR) alpha beta+ CD8 alpha alpha+ and CD8 alpha beta+ subsets of the intestinal intraepithelial lymphocytes (IEL) constitute two subpopulations. Each comprise a few hundred clones expressing apparently random receptor repertoires which are different in individual genetically identical mice (Regnault, A., Cumano, A., Vassalli, P., Guy-Grand, D. and Kourilsky, P., J. Ep. Med. 1994. 180: 1345). We analyzed the repertoire diversity of sorted CD8 alpha alpha and CD8 alpha beta TCR alpha beta+ IEL populations from the small intestine of individual germ-free mice that contain ten times less TCR alpha beta+ T cells than conventional mice. The TCR beta repertoire of the CD8 alpha alpha and the CD8 alpha beta IEL populations of germ-free adult mice shows the same degree of oligoclonality as that of conventional mice. These results show the intestinal microflora is not responsible for the repertoire oligoclonality of TCR alpha beta+ IEL. The presence of the microflora leads to an expansion of clones which arise independently of bacteria. To evaluate the degree of expansion of IEL clones in conventional mice, we went on to measure their clone sizes in vivo by quantitative PCR in the total and in adjacent sections of the small intestine of adult animals. We found that both the CD8 alpha alpha and the CD8 alpha beta TCR alpha beta IEL clones have a heterogeneous size pattern, with clones containing from 3 x 10(3) cells up to 1.2 x 10(6) cells, the clones being qualitatively and quantitatively different in individual mice. Cells from a given IEL clone are not evenly distributed throughout the length of the small intestine. The observation that the TCR alpha beta IEL populations comprise a few hundred clones of very heterogeneous size and distribution suggests that they arise from a limited number of precursors, which may be slowly but continuously renewed, and undergo extensive clonal expansion in the epithelium.
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202
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Cornelis P, Sierra JC, Lim A, Malur A, Tungpradabkul S, Tazka H, Leitão A, Martins CV, di Perna C, Brys L, De Baetseller P, Hamers R. Development of new cloning vectors for the production of immunogenic outer membrane fusion proteins in Escherichia coli. BIO/TECHNOLOGY (NATURE PUBLISHING COMPANY) 1996; 14:203-8. [PMID: 9636324 DOI: 10.1038/nbt0296-203] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The Pseudomonas aeruginosa lipoprotein gene (oprI) was modified by cloning an in-frame polylinker in both orientations at the end of oprI. The resulting plasmids pVUB1 and pVUB2 allow high lipoprotein production in E. coli after IPTG induction. The modified lipoproteins are present in the outer membrane and surface-exposed. Outer membrane-bound fusion proteins of different sizes were produced and used to generate antibodies without use of adjuvant. An 87 bp DNA fragment from the vp72 capsid protein gene of African Swine Fever virus (ASFV) and the entire Leishmania major glycoprotein gp63 gene were expressed in this system. Finally, a fusion lipoprotein containing a 16 amino acid epitope from the pre-S2b region of Hepatitis B virus (HBV) was presented by an antigen-presenting cell line to a T-cell hybridoma while the corresponding cross-linked S2b peptide was not. The results suggest that OprI-based fusion proteins can be used to generate both humoral and cellular immune responses.
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203
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Jacobsen NE, Fairbrother WJ, Kensil CR, Lim A, Wheeler DA, Powell MF. Structure of the saponin adjuvant QS-21 and its base-catalyzed isomerization product by 1H and natural abundance 13C NMR spectroscopy. Carbohydr Res 1996; 280:1-14. [PMID: 8581890 DOI: 10.1016/0008-6215(95)00278-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The saponin QS-21, derived from the bark of the Quillaja saponaria Molina tree, has shown great potential as an adjuvant with a number of vaccines. Kinetic studies carried out to establish the stability of vaccine formulations show that commercially supplied QS-21 (primarily QS-21A) is converted slowly at pH 5.5, and rapidly at higher pH, to an equilibrium mixture of two regioisomers, QS-21A and QS-21B, in a ratio of 20:1. NMR studies show that QS-21A and QS-21B differ only in the point of attachment of the fatty acyl moiety to the fucose sugar ring. The major isomer, QS-21A, has the fatty acyl portion attached at the 4-hydroxyl group whereas the minor isomer, QS-21B, has the fatty acyl portion attached at the 3-hydroxyl group. The isomerization most likely involves ionization of the 3-hydroxy group and intramolecular acyl transfer from the 4-hydroxy group. The relative stereochemistry of the triterpene and the sugar anomeric centers is also established by NMR methods.
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204
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Cleland JL, Kensil CR, Lim A, Jacobsen NE, Basa L, Spellman M, Wheeler DA, Wu JY, Powell MF. Isomerization and formulation stability of the vaccine adjuvant QS-21. J Pharm Sci 1996; 85:22-8. [PMID: 8926578 DOI: 10.1021/js9503136] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The stability of the immunologic adjuvant QS-21 (Cambridge Biotech Corp.) was optimized for use in the MN rgp120 HIV-1 subunit vaccine. QS-21, a saponin purified by reversed phase HPLC from an extract of the bark of the Quillaja saponaria Molina tree, consisted initially of one species (QS-21A), but converted to two species, QS-21A and QS-21B, in aqueous solution. NMR studies indicated that the two species are structural isomers and that isomerization occurs by intramolecular trans-esterification of the fatty acid moiety between the 3- and 4-hydroxyl groups of the fucose ring (Jacobsen et al. Carbohydr. Res., in press). Both isomers were adjuvant active. Storage of QS-21 in aqueous solution resulted in the interconversion between these isomer forms, as well as the slow formation of degradation products due to ester hydrolysis. The critical micellar concentration of QS-21 in succinate buffer was measured by a fluorescent probe method to be 51 +/- 9 micrograms/mL. Studies were performed at different concentrations of QS-21 to assess the influence of micelle formation on stability. These experiments indicated that QS-21 is more stable in the micellar form, presumably because the most labile ester bond linking the fatty acid moiety to fucose is constrained or buried in the hydrophobic micellar environment. The pH of maximum stability was pH 5.5, the pH for minimum degradation of most esters. The final formulation, 500 micrograms/mL QS-21 in 20 mM sodium succinate, 150 mM NaCl, pH 5.5, provided a shelf-life of greater than 2 years.
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205
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Weissburg RP, Berman PW, Cleland JL, Eastman D, Farina F, Frie S, Lim A, Mordenti J, Nguyen TT, Peterson MR. Characterization of the MN gp120 HIV-1 vaccine: antigen binding to alum. Pharm Res 1995; 12:1439-46. [PMID: 8584477 DOI: 10.1023/a:1016266916893] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE The characterization of recombinant MN gp120/alum vaccine requires the study of the gp120-alum interaction for the successful formulation of an alum-based HIV-1 vaccine. METHODS Several observations suggest that the gp120-alum interaction is weak, wherein buffer counterions such as phosphate, sulfate, bicarbonate may cause the desorption of gp120 from alum. Comparison of gp120 with other proteins using particle mobility measurements shows that the weak binding of gp120 to alum is not an anomaly. Serum and plasma also cause desorption of gp120 from alum with a half-life of only a few minutes, wherein this half-life may be faster than the in-vivo recruitment of antigen presenting cells to the site of immunization. RESULTS Immunization of guinea pigs, rabbits and baboons with gp120 formulated in alum or saline demonstrated that alum provides adjuvant activity for gp120, particularly after early immunizations, but the adjuvant effect is attenuated after several boosts. CONCLUSIONS These observations indicate that both the antigen and the adjuvant require optimization together.
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206
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Even J, Lim A, Puisieux I, Ferradini L, Dietrich PY, Toubert A, Hercend T, Triebel F, Pannetier C, Kourilsky P. T-cell repertoires in healthy and diseased human tissues analysed by T-cell receptor beta-chain CDR3 size determination: evidence for oligoclonal expansions in tumours and inflammatory diseases. RESEARCH IN IMMUNOLOGY 1995; 146:65-80. [PMID: 7481075 DOI: 10.1016/0923-2494(96)80240-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Many examples of oligoclonal T-cell expansion in infiltrated diseased tissues have been reported. However, it remains to be established whether such observations can be generalized and to what extent oligoclonal patterns obtained after in vitro culture of T-cell infiltrates reflect in vivo situations. Using new high resolution analysis which requires no in vitro cellular expansion, we detected such oligoclonal T-cell expansions in 7/7 melanoma tumour biopsies, 3/3 biopsies of inflammatory skin during acute graft versus host disease (aGVHD) after allogeneic bone marrow transplantation (alloBMT) and 7/7 synovial membranes from patients with rheumatoid arthritis. Thus, oligoclonal T-cell expansions are readily observed when a sufficiently sensitive detection method is used, suggesting that similar expansions are the rule among T-cell infiltrates in different diseases. This observation and the monitoring of the in vivo evolution of such expansion during the course of the disease and during in vitro culture should have important clinical implications.
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MESH Headings
- Acute Disease
- Adult
- Aged
- Arthritis, Rheumatoid/immunology
- Base Sequence
- Bone Marrow Transplantation
- Clone Cells/immunology
- Cloning, Molecular
- Female
- Graft vs Host Disease/immunology
- Humans
- Immunologic Techniques
- Lymphocytes, Tumor-Infiltrating/immunology
- Male
- Melanoma/immunology
- Molecular Sequence Data
- Receptors, Antigen, T-Cell/analysis
- Receptors, Antigen, T-Cell, alpha-beta/analysis
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Synovial Membrane/immunology
- T-Lymphocytes/classification
- T-Lymphocytes/immunology
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207
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Powell MF, Eastman DJ, Lim A, Lucas C, Peterson M, Vennari J, Weissburg RP, Wrin T, Kensil CR, Newman MJ. Effect of adjuvants on immunogenicity of MN recombinant glycoprotein 120 in guinea pigs. AIDS Res Hum Retroviruses 1995; 11:203-9. [PMID: 7742035 DOI: 10.1089/aid.1995.11.203] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The immunogenicity of recombinant gp120 from the MN strain of HIV-1, a candidate HIV-1 vaccine, was evaluated in guinea pigs using adjuvant formulations with different physical and chemical properties. The adjuvants tested included Freund's adjuvant (FA), alum, and the novel adjuvant QS-21. These studies demonstrated that QS-21 provides a number of advantages compared to the two other adjuvants tested. QS-21 formulations accelerated the production of antibodies to MN rgp120 and elicited complete seroconversion after a single immunization. QS-21 shifted the antigen dose-response curve for antibody production by as much as three orders of magnitude, enabling a more economical use of antigen. Antibody titers to MN rgp120 and to the principal neutralizing determinant in the V3 domain were higher in animals receiving QS-21 formulations than in animals immunized with the other adjuvants, and correlated well with higher virus neutralization titers in an in vitro assay. These results support the testing of QS-21 in future clinical trials of candidate HIV-1 vaccines.
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208
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Braslis KG, Petsch M, Lim A, Civantos F, Soloway MS. Bladder neck preservation following radical prostatectomy: continence and margins. Eur Urol 1995; 28:202-8. [PMID: 8536773 DOI: 10.1159/000475052] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Between December 1991 and January 1994, 134 patients underwent radical retropubic prostatectomy with bladder neck preservation. Forty-nine patients had a positive margin. Number and location of positive margins were analyzed. A tumor was identified at the bladder neck in 10 cases (7.5%). In all 10 patients with bladder neck involvement, a tumor was also identified at multiple other sites. These data suggest that preservation of the bladder neck during radical prostatectomy does not appear to compromise the efficacy of the procedure. Using a self-administered patient questionnaire, we evaluated the effect of bladder neck preservation upon continence in 36 patients. At the initial 3-month follow-up, 24 (67%) patients did not wear any pads. Another 7 (19%) wore pads occasionally, while 5 (14%) patients wore pads daily. To date only 1 of the 134 patients has developed an anastomotic stricture. Bladder neck preservation may aid in an earlier return of continence following radical prostatectomy and reduces anastomotic strictures. It does not appear to compromise the removal of the cancer.
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209
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Dietrich PY, Caignard A, Lim A, Chung V, Pico JL, Pannetier C, Kourilsky P, Hercend T, Even J, Triebel F. In vivo T-cell clonal amplification at time of acute graft-versus-host disease. Blood 1994; 84:2815-20. [PMID: 7919391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In a series of patients transplanted with HLA-matched allogeneic bone marrow grafts (alloBMT), we previously showed that a few T-cell receptor (TCR) V alpha and V beta gene segment transcripts were overexpressed in skin compared with blood at the time of acute graft-versus-host disease (aGVHD). Here, in one selected patient with overexpressed V beta 16 and V alpha 11 transcripts in skin, we analyzed the junctional variability of these transcripts in donor blood, patient blood, and skin collected at aGVHD onset. A unique junctional region sequence accounted for 81% of in frame V beta 16 transcripts (13 of 16) in skin and 59% (13 of 22) in patient blood. Similarly, two recurrent junctional region sequences were found in skin V alpha 11 transcripts, one accounting for 66% (21 of 32) and the other for 16% (5 of 32). These recurrences were also found in patient blood (36% and 15% of V alpha 11 transcripts, respectively). To extend our analysis, a polymerase chain reaction (PCR)-based method was used to precisely determine TCR beta transcript length in run-off reactions using uncloned bulk cDNA samples. All V beta-C beta PCR products analyzed in donor blood, as well as the majority of those analyzed in patient blood, included transcripts with highly diverse junctional region sizes. As expected from the sequence data, most V beta 16-C beta PCR products in skin and patient blood were of the same size (ie, same junctional region). In addition, V beta 3, V beta 5, and V beta 17 transcripts in skin were shown to display highly restricted size variability. The clonality of the V beta 16-C beta and V beta 17-C beta transcripts was further supported by the results of run-off reactions using 13 J beta specific primers. We have identified several recurrent TCR transcripts in skin, some of them also present in patient blood. These data support the view that several T-cell subpopulations are clonally expanded in vivo at the time of aGVHD onset in this case of related HLA-matched alloBMT.
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210
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211
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Liem LK, Lim A, Li BF. Specificities of human, rat and E. coli O6-methylguanine-DNA methyltransferases towards the repair of O6-methyl and O6-ethylguanine in DNA. Nucleic Acids Res 1994; 22:1613-9. [PMID: 8202360 PMCID: PMC308037 DOI: 10.1093/nar/22.9.1613] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The behaviour of highly purified bacterial expressed rat O6-methylguanine-DNA methyltransferase (MGMT) towards the repair of CGCm6GAGCTCGCG and CGCe6GAGCTCGCG (km6G/ke6G = 1.45, where k is the second order repair rate constant determined, m6G and e6G are O6-methyl and O6-ethylguanine) is similar to that of E. coli 39kD Ada protein (km6G/ke6G = 1.6). However, the human MGMT is very different (km6G/ke6G = 163). The preferential repair of O6-ethylguanine lesion by the rat MGMT appears not to be related to the lack of the initiator methionine in the expressed protein since similar results were obtained from N-terminal Glutathione-S-transferase (GST) fused protein (GSTMGMT) which retains the methionine. The possible relationship between these findings and the differences observed in the primary amino acid sequence of these proteins is discussed. In addition the preferential repair of O6-ethylguanine substrate by the 39kD Ada protein as compared to the catalytic C-terminus alone (different by 134 times) suggests that the N-terminus plays a crucial role in the repair of O6-ethylguanine. This is in contrast to the minor effects of the GST domain when fused to the N-terminus of mammalian MGMT.
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212
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Lim A, Saw Y, Wake PN, Croton RS. Use of a eutectic mixture of local anaesthetics in the release of preputial adhesions: is it a worthwhile alternative? BRITISH JOURNAL OF UROLOGY 1994; 73:428-30. [PMID: 8199833 DOI: 10.1111/j.1464-410x.1994.tb07609.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To see if a eutectic mixture of local anaesthetics (EMLA) could be used effectively for the release of preputial adhesions as a day case procedure. PATIENTS AND METHODS A total of 36 consecutive symptomatic children had their preputial adhesions separated under local anaesthetic with EMLA. RESULTS The procedure was successful in 27 children. Of these, 16 remained symptom free at 9 to 12 months follow up although five children had slight recurrence of adhesions. The other 11 children were listed for circumcision at 2 weeks following the procedure because of marked recurrence of adhesions. CONCLUSION EMLA cream is a good alternative to general anaesthetics in the separation of preputial adhesions. The technique is operator-dependent and better results were obtained when one person was using it regularly. Separation of adhesions is a worthwhile procedure in boys with symptomatic non-retractile foreskins.
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213
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Caignard A, Dietrich PY, Morand V, Lim A, Pannetier C, Leridant AM, Hercend T, Even J, Kourilsky P, Triebel F. Evidence for T-cell clonal expansion in a patient with squamous cell carcinoma of the head and neck. Cancer Res 1994; 54:1292-7. [PMID: 8118818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Squamous cell carcinomas of the head and neck (SCCHN) often contain a large mononuclear cell infiltrate, composed mainly of T-lymphocytes which could reflect an in situ immune reaction against the malignant SCCHN cells. We analyzed the molecular structure of the T-cell receptor (TCR) alpha and beta chains expressed by lymphocytes in the tumor, peripheral blood (PBMC), and in the peritumoral tissue in six cases of localized SCCHN. We first determined V alpha and V beta gene segment subfamily usage by polymerase chain reaction using a panel of V subfamily-specific oligonucleotide primers (V alpha 1-w29 and V beta 1-w24). An apparently unrestricted usage of V alpha or V beta gene segment subfamilies was observed for all three samples from the six cases examined. No major difference was observed in T-cell receptor repertoire expression of PBMC between SCCHN and healthy donors, making unlikely the expression of putative tumor-related superantigen(s) in these patients. Intersample comparisons for a given V alpha or V beta T-cell receptor specificity revealed some differences in V gene segment usage in tumor-infiltrating lymphocytes versus PBMC. A detailed analysis of these V segment subfamily specificities (cloning followed by sequencing and CDR3 size distribution analysis) in one patient revealed the presence of recurrent T-cell receptor transcripts (i.e., identical V-N-J sequences) in the tumor (e.g., 40%) and in PBMC (e.g., 75%). These results show that unique T-cell subpopulations are clonally amplified in SCCHN patients, possibly as a consequence of antigen-driven selection.
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MESH Headings
- Adult
- Aged
- Base Sequence
- Carcinoma, Squamous Cell/blood
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/pathology
- Clone Cells
- DNA Primers
- DNA, Neoplasm/genetics
- Gene Expression/genetics
- Head and Neck Neoplasms/blood
- Head and Neck Neoplasms/genetics
- Head and Neck Neoplasms/pathology
- Humans
- Lymphocytes, Tumor-Infiltrating/physiology
- Male
- Middle Aged
- Molecular Sequence Data
- Neutrophils/physiology
- Polymerase Chain Reaction
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Repetitive Sequences, Nucleic Acid
- T-Lymphocytes/physiology
- Transcription, Genetic/genetics
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214
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Lim A, Greenspan DS, Smith BD. Expression of alpha 2 type I collagen in W8 cells increases cell adhesion and decreases colony formation in soft agar. Matrix Biol 1994; 14:21-30. [PMID: 8061917 DOI: 10.1016/0945-053x(94)90026-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A chemically transformed cell line, W8, produces alpha 1(I) homotrimers with no alpha 2(I) chains whereas the parent cell line, K16, produces heterotrimers. When W8 cells were transfected with plasmid constructs containing the full length human alpha 2(I) cDNA driven by viral promoters, the cells expressed alpha 2(I) collagen chains forming varying amounts of heterotrimers. Previously, we have shown that K16 and W8 cells have different growth characteristics (Smith, B.D. et al., Cancer Research 43: 4275-4282, 1983) including population doubling, saturation density, cell adhesion and colony formation in soft agar. These parameters were tested for each transfected cell line in order to determine if the alpha 2(I) expression and heterotrimer formation alters cell characteristics. The cells expressing alpha 2(I) forming heterotrimers needed higher concentrations of trypsin or longer time periods to lift from the plate suggesting a role for alpha 2(I) in cell adhesion. The W8 cells formed colonies in soft agar exhibiting anchorage independent growth. However, W8 cells expressing alpha 2(I) chains formed less colonies in soft agar than W8 cells or W8 cells transfected with a neomycin resistant gene indicating that the alpha 2(I) producing cells were less anchorage independent than W8 cells. Population doubling time, morphology and saturation densities were similar to W8 cells with small alterations towards an epithelial morphology. These results demonstrated that alpha 2(I) within heterotrimer is important for cell adhesion and anchorage independent growth.
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215
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De Vos D, Lim A, De Vos P, Sarniguet A, Kersters K, Cornelis P. Detection of the outer membrane lipoprotein I and its gene in fluorescent and non-fluorescent pseudomonads: implications for taxonomy and diagnosis. JOURNAL OF GENERAL MICROBIOLOGY 1993; 139:2215-23. [PMID: 7902411 DOI: 10.1099/00221287-139-9-2215] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The open reading frame of the OprI lipoprotein gene from Pseudomonas aeruginosa was amplified by polymerase chain reaction (PCR) starting from purified DNA or colony lysates. A fragment of the expected size (249 bp) was detected in all P. aeruginosa strains from various clinical and geographical origins. The gene could only be amplified in pseudomonads of rRNA group I which are considered to be the authentic genus Pseudomonas. Digestions with HaeIII, PvuII and SphI of the amplified fragments demonstrated a sequence variation in the oprI gene. Colony, dot and Western blots with two monoclonal antibodies (mAbs) against the lipoprotein I confirmed our PCR results. These findings open interesting perspectives for the molecular taxonomy of the genus Pseudomonas and the development of diagnostic tools.
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216
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Saw Y, Baltzopoulos V, Lim A, Rostron PK, Bolton-Maggs BG, Calver RF. Early mobilization after operative repair of ruptured Achilles tendon. Injury 1993; 24:479-84. [PMID: 8406770 DOI: 10.1016/0020-1383(93)90155-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The results of 19 patients in a pilot study in which early mobilization after operative repairs of ruptured Achilles tendons are presented. Serial ultrasound scanning of the repaired tendon showed satisfactory healing. Muscle function was analysed isokinetically and gait symmetry was examined using kinetic analysis. Normal strength of plantarflexion and dorsiflexion was achieved with almost normal range of ankle movement. All patients had normal gait kinetic parameters and symmetry. Normal activities were regained rapidly, and 15 out of 19 patients returned to their pre-injury status. There were no reruptures.
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217
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Liem LK, Wong CW, Lim A, Li BF. Factors influencing the repair of the mutagenic lesion O6-methylguanine in DNA by human O6-methylguanine-DNA methyltransferase. J Mol Biol 1993; 231:950-9. [PMID: 8515475 DOI: 10.1006/jmbi.1993.1344] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Oligodeoxynucleotides of various chain lengths (p(Bp)nB, n < or = 9) and the eight possible dinucleotide phosphates (pm6GpB and pBpm6G), each containing a single O6-methylguanine residue (m6G), were used to study the repair kinetics of this lesion by the cloned DNA repair proteins; human 21 kDa O6-methylguanine-DNA methyltransferase (MGMT), human 43 kDa glutathione-S-transferase fused MGMT (GSTMGMT) and the Escherichia coli 39 kDa ada protein. The observed second-order repair rate constants are dependent upon both the chain length of the oligonucleotide substrates for all three proteins and in the case assuming O6-methylguanine is similar to B). The differences observed in the ratios of the rate constants for the substrates with five and four base residues; 125 for the E. coli 39 kDa ada protein, 640 for the human MGMT and 27,800 for the human fusion protein GSTMGMT, suggest that the pentanucleotide phosphate containing this lesion is the "optimal" substrate for the proteins. Surprisingly, the human GSTMGMT is shown to be more effective in the repair of longer substrates with the second-order repair rate constants for TATA-Cm6GTATA being 6.16 x 10(6) for GSTMGMT, 2.00 x 10(6) for MGMT and 0.27 x 10(6) M-1 s-1 for the E. coli 39 kDa ada protein. Thus, the presence of an additional protein domain at the N terminus of human MGMT can alter its selectivity towards certain substrates. Although a number of peptide domains are conserved between the E. coli 39 kDa ada protein and phosphates can also be used to explain the observed sequence specific repair of this lesion within certain DNA sequences.
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218
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Lim A. A leaking tracheal tube connector. Anaesthesia 1992; 47:1106-7. [PMID: 1489064 DOI: 10.1111/j.1365-2044.1992.tb04243.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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219
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Lim A, Goldschlager N. Current and future developments in scintigraphy to assess myocardial perfusion and function. AMERICAN JOURNAL OF CARDIAC IMAGING 1992; 6:83-92. [PMID: 10150085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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220
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Sheward WJ, Lim A, Alder B, Copolov D, Dow RC, Fink G. Hypothalamic release of atrial natriuretic factor and beta-endorphin into rat hypophysial portal plasma: relationship to oestrous cycle and effects of hypophysectomy. J Endocrinol 1991; 131:113-25. [PMID: 1836005 DOI: 10.1677/joe.0.1310113] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The release of beta-endorphin and atrial natriuretic factor (ANF) into hypophysial portal plasma was investigated in male and female Wistar rats. The principal aim of the study was to investigate the possible role of beta-endorphin and ANF in the hypothalamic control of LH and prolactin secretion. In male rats, anaesthetized with urethane, the concentrations of beta-endorphin in portal blood collected immediately after hypophysectomy were within the same range as those in peripheral plasma. Furthermore, electrical stimulation of the median eminence did not increase the portal plasma concentrations of beta-endorphin. In female rats, anaesthetized with alphaxalone, the portal plasma concentrations in long-term (6-8 weeks) or acutely hypophysectomized rats were significantly greater than those in peripheral plasma. In acutely hypophysectomized female rats the concentrations and contents of beta-endorphin in portal plasma collected at 10.00-11.30 h of pro-oestrus were significantly (approximately sixfold) greater than at dioestrus or at 20.00-21.00 h of pro-oestrus, but these changes were not consistently seen in all experiments. In female rats in which the pituitary gland was not removed for portal blood collection, portal plasma contents of ANF remained unchanged throughout the day of pro-oestrus, suggesting that it is unlikely that ANF is involved in the spontaneous LH or prolactin surge. The effects of ovarian steroids on the secretion of hypothalamic ANF and beta-endorphin were determined by measuring the portal plasma concentration of ANF and beta-endorphin on the morning of presumptive pro-oestrus in rats ovariectomized 24 h previously and injected with either oil or oestradial benzoate (OB). Portal plasma contents of ANF were significantly lower in OB- compared with oil-treated rats, suggesting that oestradiol inhibits ANF release into rat hypophysial portal plasma. In contrast, there were no significant between-group differences in the content or concentration of beta-endorphin in portal plasma. Thus, the increased beta-endorphin in the portal plasma of some of the intact animals during the morning of pro-oestrus is not due to the preovulatory surge of oestradiol-17 beta. The output of beta-endorphin into portal blood in long-term hypophysectomized rats was lower than in dioestrous or pro-oestrous rats in which the pituitary gland was removed immediately before portal blood collection.(ABSTRACT TRUNCATED AT 400 WORDS)
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Dighiero G, Hart S, Lim A, Borche L, Levy R, Miller RA. Autoantibody activity of immunoglobulins isolated from B-cell follicular lymphomas. Blood 1991; 78:581-5. [PMID: 1859876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Previous work with monoclonal Igs (MIgs) has demonstrated that a high proportion of paraproteins bind to self-antigens such as the Fc fragment of IgG, Ii blood group antigens, cytoskeleton proteins, DNA, and myelin-associated glycoprotein (MAG). Recent work in CLL indicates that CD5+ B lymphocytes are frequently committed to production of autoantibodies. We have examined the antibody specificity of MIgs derived from the tumor cells of 31 different patients with CD5- B-cell lymphomas. Our results indicate that the tumor cells from 8 of these 31 patients (25.8%) express Igs with autoantibody activity. In two cases antibody activity was multispecific. In four cases, antibody activity was exclusively directed against the Fc fragment of IgG, whereas the two other cases bound to both Fc fragment of IgG and nuclear antigens. Most non-Hodgkin's lymphomas (NHL) are derived from CD5- B cells. These results indicate that like CLL, NHL also express Igs that frequently have autoantibody activity.
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Azhar T, Kamada T, Lopez F, Harun R, Nor IM, Lim A. High dose rate intracavitary radiation therapy of carcinoma of the cervix using a linear source. THE MEDICAL JOURNAL OF MALAYSIA 1991; 46:123-8. [PMID: 1839415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
One hundred patients with carcinoma of the cervix stages 1B to 4A were treated with intracavitary high dose rate radiation using a linear cobalt source. All cases have received external beam pelvic irradiation to 4500cGy mid plane in twenty fractions over four weeks. The results in terms of patient compliance and convenience were good while acute and late morbidities were comparable to standard Manchester technique of low dose rate intracavitary therapy as practised in the Institute of Radiotherapy and Oncology General Hospital Kuala Lumpur. The four year actuarial survival rate is 76% for stage II and 48% for stage III. All three stage IV patients died within 1 year. Four out of seven stage I patients are alive (minimum follow-up 18 months, longest 43 months). One died of systemic spread at 33 months while one is lost to follow up.
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Chenciner N, Delpeyroux F, Israel N, Lambert M, Lim A, Streeck RE, Houssais JF. Enhancement of gene expression by somatic hybridization with primary cells: high-level synthesis of the hepatitis B surface antigen in monkey Vero cells by fusion with primary hepatocytes. Nat Biotechnol 1991; 8:858-62. [PMID: 1370009 DOI: 10.1038/nbt0990-858] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vero cells transfected with the S gene encoding the surface antigen (HBsAg) of the hepatitis B virus (HBV) synthesize HBsAg at low levels. We have obtained a large increase in S gene expression by somatic hybridization of Vero cells with primary hepatocytes, which are the natural target cells for HBV infection. Fusion with cells other than hepatocytes did not enhance expression of the S gene. The Vero/hepatocyte hybrid clones analyzed are stable and have maintained a high level of HBsAg synthesis over prolonged periods. Hybrid cell lines may be of general interest for the high-level synthesis of proteins using cloned genes.
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Kaushik A, Mayer R, Fidanza V, Zaghouani H, Lim A, Bona C, Dighiero G. Ly1 and V-gene expression among hybridomas secreting natural autoantibody. J Autoimmun 1990; 3:687-700. [PMID: 2128453 DOI: 10.1016/s0896-8411(05)80036-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This report presents evidence that multispecific natural autoantibodies (NAAb) arise from both Ly-1+ and Ly-1- B lymphocyte subsets based upon detection of mRNA transcript of Ly1 gene by Northern blotting among hybridomas from several mouse strains. Newborn Xid mice also possess B cells transcribing the Ly-1 gene that secrete multispecific NAAbs. Different VH and VK gene families were expressed at random in both Ly-1+ and Ly-1- hybridoma clones secreting NAAbs. Certain VK gene families VK1, -8, -9, -10 and -19, were preferentially used by NAAbs. No particular VH:VK pairings were observed among NAAbs multispecifically reactive with DNA and cytoskeleton proteins. The NAAbs reactive with BrMRBC exhibited predominant pairing between VH11:VK9 gene families, although, for the first time, we noted the participation of VK1, -10 and -19 gene families in encoding this autoantibody specificity.
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Borche L, Lim A, Binet JL, Dighiero G. Evidence that chronic lymphocytic leukemia B lymphocytes are frequently committed to production of natural autoantibodies. Blood 1990; 76:562-9. [PMID: 2378986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
CD5+ B lymphocytes have been postulated to be primarily involved in autoantibody production. To investigate whether CD5 B lymphocytes from chronic lymphocytic leukemia (CLL) patients display the same function, we fused B lymphocytes from 23 CD5+ B-CLL with nonsecreting murine myeloma X-63 cells. Hybrids were derived from 18 of the 23 patients, but only hybrids from 13 patients were found to secrete immunoglobulin (Ig) (IgM kappa 4, IgM lambda 8, and only kappa light chain 1). Supernatants of these hybrids were tested against an extensive panel of antigens by enzyme-linked immunosorbent assay, indirect immunofluorescence, and hemagglutination. At the same time, peripheral blood mononuclear cells (PBMC) from 15 of these patients, including most patients from whom secreting hybrids had not been obtained, were stimulated with phorbol myristate acetate (PMA). Our results indicated that secreting heterohybrids from CLL B lymphocytes are frequently obtained; however, this is highly dependent on the light chain phenotype, since 8 of 9 lambda-expressing CLL produced hybrids secreting complete Igs, as compared with 4 of 12 kappa-expressing CLL. In addition, B lymphocytes of most patients from whom we failed to derive secreting hybrids also failed to secrete Ig on PMA stimulation. Secondly, CD5+ B-CLL lymphocytes were frequently committed to the production of natural autoantibodies, since in 8 of 15 cases (including hybrids and PMA stimulation) anti-Fc activity was found; three of these also displayed a multispecific binding pattern.
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Menon SD, Yap WH, Lim A, Tan YH. Arachidonic acid regulates the binding of human interferon in human skin fibroblasts. Lipids 1990; 25:321-7. [PMID: 1694948 DOI: 10.1007/bf02544341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The induction of the antiviral state in human fibroblasts by human interferon is inhibited by arachidonic acid, its analogues 5,8,11,14-eicosatetraynoic and 5,8,11-eicosatriynoic acids, as well as by sodium arachidonate. The fatty acids myristic or oleic acid and sodium palmitate do not inhibit the antiviral action of interferon. Experiments were conducted to investigate the mechanism by which arachidonic acid could inhibit the action of interferon. No correlation between cellular lipoxygenase activities and the inhibition of antiviral action of interferon was observed in the fatty acid treated cells. Likewise, the cyclooxygenase inhibitors indomethacin and oxyphenylbutazone do not inhibit the interferon-induced antiviral state. Taken together, the inhibition of interferon action by arachidonates is unlikely to be mediated by cyclooxygenase or lipoxygenase-generated intermediates, even though arachidonates are known to affect the activity of these enzymes in vitro. Measurement of interferon receptors in the fatty acid treated cells showed that arachidonic acid, sodium arachidonate and its analogues decreased the number of human type I interferon receptors available for binding, and inhibited the transcription of the interferon-induced 6-16 gene and the induction of cellular (2'-5')-oligoadenylate synthetase, suggesting the mechanism of inhibition is mediated at the level of the interferon receptor. The significance of the finding that arachidonic acid, a common fatty acid of cells and serum, can affect the antiviral action of interferon is discussed.
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Streeck RE, Chenciner N, Delpeyroux F, Israel N, Lambert M, Lim A, Houssais JF. [A new approach for explaining viral organotropism: fusion of HBV transfected cells with hepatocytes]. ZEITSCHRIFT FUR GASTROENTEROLOGIE. VERHANDLUNGSBAND 1990; 25:89-90. [PMID: 1694375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Smerdely P, Lim A, Boyages SC, Waite K, Wu D, Roberts V, Leslie G, Arnold J, John E, Eastman CJ. Topical iodine-containing antiseptics and neonatal hypothyroidism in very-low-birthweight infants. Lancet 1989; 2:661-4. [PMID: 2570908 DOI: 10.1016/s0140-6736(89)90903-3] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The thyroid function of very-low-birthweight (VLBW; below 1500 g) infants admitted to neonatal intensive-care units was studied at two hospitals; one routinely used topical iodinated antiseptic agents and the other used chlorhexidine-containing antiseptics. Serial monitoring of urinary iodine excretion and serum thyrotropin and thyroxine levels was undertaken from birth for the first 4 weeks of life. Urinary iodine excretion rose dramatically in the 54 iodine-exposed infants and was up to fifty times greater than in the 29 non-exposed infants. Within 14 days, 25% (9 of 36) of the infants exposed to iodine had serum thyrotropin levels above 20 mIU/l, compared with none of the control group. The mean serum thyroxine level in these 9 infants (44.1 nmol/l) was significantly lower than that in exposed infants with normal thyrotropin levels (83.1 nmol/l) and in the non-exposed control group (83.0 nmol/l); thyroxine levels fell before serum thyrotropin rose. These disturbances in thyroid function correlated positively with urinary iodine excretion and hence iodine absorption. Thyroid function had returned to normal by the time of discharge from hospital. It is concluded that iodine absorption, from topical iodine-containing antiseptics, may cause hypothyroidism during a critical period of neurological development in the newborn infant. The routine use of iodine antisepsis in VLBW infants should be avoided because of this effect.
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Abstract
Recent reports in the literature suggest that anxious individuals show an attentional bias to mood-congruent information. Various investigators have hypothesized that such anxiety-based coding biases contribute to the maintenance of mood disorders. The present study sought to determine if attentional biases in anxious subjects extends to the perception of neutral, as opposed to affect-laden, stimuli. A procedure used to determine the locus of attention to foveal and peripheral visual events was used in combination with two inter-stimulus intervals, fixed and variable, to examine anxious and non-anxious subjects' attentional biases. Mood states were established by a well-validated musical induction procedure. The results revealed an attentional bias to foveal visual events in non-anxious subjects and an attenuated or reversed (peripheral) bias in anxious subjects. The clinical implications of these findings are discussed.
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Newton N, Baratham G, Sinniah R, Lim A. Bilateral compressive optic neuropathy secondary to bilateral sphenoethmoidal mucoceles. Ophthalmologica 1989; 198:13-9. [PMID: 2919033 DOI: 10.1159/000309953] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have presented a rare case of bilateral posterior sphenoethmoidal sinus mucoceles with bilateral compressive optic neuropathy. While the duration of compression was variably present over a 10-month period, there were nevertheless significant improvements in visual acuity of the right eye and visual fields bilaterally following extensive optic nerve decompression.
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Dighiero G, Lim A, Lembezat MP, Kaushik A, Andrade L, Freitas A. Comparative study of VH gene family usage by newborn xid and non-xid mice, newborn NZB and adult NZB mice, and by splenic and peritoneal cavity B cell compartments. Eur J Immunol 1988; 18:1979-83. [PMID: 3146510 DOI: 10.1002/eji.1830181217] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
RNA from 170 different Ig-secreting hybridomas was hybridized with VH gene probes 7183, QUPC52, S107, J558, J606, 36-60, V31, X-24 and V-GAM 3.8, with the aim of comparing xid to non-xid mice, neonatal NZB to adult NZB, and the peritoneal cavity with the splenic compartments for VH gene family expression. Our results indicate that (a) defective F1 male xid mice express with high frequency 36-60 and J606 5' proximal VH families, when compared to non-xid F1 females of the same matings. (b) Neonatal NZB mice express 3' proximal 7183 and QUPC52 families with high frequency, when compared to adult mice and to the expected values derived from VH complexity. (c) Natural antibodies against cytoskeleton proteins, DNA, rabbit IgG and 2,4,6-trinitrophenyl did not appear to prefer a particular VH family. The only difference found is related to age; neonatal clones preferentially employ 7183 and QUPC52 while J558 predominates among adult clones. (d) All the 15 antibodies directed against bromelin-treated mouse red blood cells failed to hybridize with any of the nine VH probes employed. These results confirm previous findings indicating the highly homogeneous pattern of these latter antibodies, and suggest that they are encoded by a new VH family (VH11).
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Kaushik A, Lim A, Poncet P, Ge XR, Dighiero G. Comparative analysis of natural antibody specificities among hybridomas originating from spleen and peritoneal cavity of adult NZB and BALB/c mice. Scand J Immunol 1988; 27:461-71. [PMID: 3259008 DOI: 10.1111/j.1365-3083.1988.tb02372.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A preliminary experiment showed that the supernatants of in vitro cultured peritoneal cells (rich in Ly-1 B cell subset shown to secrete most IgM autoantibodies against bromelain-treated mouse red blood cells (BrMRBC) and DNA) from different mouse strains did not contain any significant antibody activity against DNA and cytoskeleton proteins, although the presence of anti-BrMRBC antibodies was clearly evident. Therefore, we investigated comparative natural antibody (NAb) specificities against an antigen panel (DNA, cytoskeleton proteins, IgG, bovine serum albumin (BSA), BrMRBC, trinitrophenyl (TNP), and trimethylammonium (TMA) haptens) among Ig-secreting hybridoma collections from the splenic (158) and peritoneal (230) immune compartments of autoimmune New Zealand black (NZB) and lipopolysaccharide (LPS)-stimulated BALB/c mice. The data showed: (i) isotypic restriction (mu and gamma 3 only), predominance of TMA ion-reactive (including BrMRBC) but negligible anti-DNA-reactive antibody specificities, and lack of simultaneous polyspecific widespread reactivity (i.e. at least four or more antigens) against DNA and cytoskeleton proteins in the peritoneal cavity; (ii) predominance of simultaneous widespread polyspecific reactivity against DNA and cytoskeleton proteins but negligible or no TMA hapten-reactive antibody specificities in the spleen. These observations reflect certain differences in the B cell repertoire of peritoneal cavity (rich in Ly-1 B cells) compared with spleen. The NAb against BrMRBC and those reactive with DNA and cytoskeleton proteins, which have been suggested to be secreted by the Ly-1 B cell subset, are distinguishable on the basis of the presence of separate recurrent idiotypes and preferential localization of B lymphocytes directed against these autoantigens.
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Dighiero G, Lim A, Poncet P, Kaushik A, Ge XR, Mazié JC. Age-related natural antibody specificities among hybridoma clones originating from NZB spleen. Immunol Suppl 1987; 62:341-7. [PMID: 3666786 PMCID: PMC1454123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In the studies presented here, age-related natural antibody specificities have been investigated in the autoimmune NZB mouse strain by cell fusion. The monoclonal immunoglobulins (MIg) secreted by productive hybridoma clones were examined for their antibody activities against a panel of antigens, including single- and double-stranded DNA, actin, tubulin, myosin, bromelain-treated mouse red blood cells (BrMRBC) and TNP-BSA, employing both direct and competitive enzyme immunoassays. The antibody specificities against this panel of antigens were strikingly frequent among hybridoma clones from neonatal NZB (49%) mice, compared to normal BALB/c neonates (8.8%) shown earlier. Among neonatal hybridomas with known antigen reactivities, 73% of the clones exhibited polyspecific binding. In contrast, the majority of hybridomas from 5- and 7-month-old NZB spleen reacted monospecifically (76%) with the antigens tested. Such a characteristic reactivity pattern reflects an age-related evolution of B-cell repertoire expression. Unlike normal BALB/c mice, a high frequency of monospecific TNP-hapten-reactive clones (75%) was noticed among hybridomas of known antigen reactivities from 5- and 7-month-old NZB-strain mice, an age when autoimmune haemolytic anaemia sets in. In conclusion, an elevated frequency of autoreactive clones among neonates (49%) and an aberrant expression of TNP-reactive clones in adults seem to be an outward signal of certain discrepancies at the level of B-cell repertoire expression in autoimmune NZB-strain mice.
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Delpeyroux F, Chenciner N, Lim A, Lambert M, Malpièce Y, Streeck RE. Insertions in the hepatitis B surface antigen. Effect on assembly and secretion of 22-nm particles from mammalian cells. J Mol Biol 1987; 195:343-50. [PMID: 2821275 DOI: 10.1016/0022-2836(87)90655-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The envelope protein of hepatitis B virus carrying the surface antigen, HBsAg, has the unique property of mobilizing cellular lipids into spherical or elongated particles, about 22 nm in diameter, which are secreted from mammalian cells. We have created mutant envelope proteins by insertion of various sequences of different lengths into two regions of the S gene encoding the major envelope protein. S genes carrying inserts in phase with HBsAg were expressed in mouse L cells from the simian virus 40 early promoter. Various single or double inserts in the two major hydrophilic domains of HBsAg were compatible with secretion of 22-nm particles. In all mutant envelope proteins studied, the HBsAg domains required for intracellular aggregation appeared to be intact. However, assembly into particles was not sufficient to assure transport into the extracellular space. The 22-nm HBsAg particle may be a useful vehicle for the export and presentation of foreign peptide sequences.
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Lo GS, Goldberg AP, Lim A, Grundhauser JJ, Anderson C, Schonfeld G. Soy fiber improves lipid and carbohydrate metabolism in primary hyperlipidemic subjects. Atherosclerosis 1986; 62:239-48. [PMID: 3026411 DOI: 10.1016/0021-9150(86)90098-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This study was designed to evaluate the effects of soy fiber, a natural source of dietary fiber that consists of both cellulosic and noncellulosic dietary fiber, on human plasma lipoprotein lipids and glucose tolerance in patients with primary hyperlipidemia. Supplementing 25 g of soy fiber per day provided a significant additional reduction of plasma total-cholesterol by 13 mg/dl (P less than 0.04) and LDL cholesterol by 12 mg/dl (P less than 0.05) beyond that previously achieved by treatment with an NIH Type II-A low-fat, low-cholesterol diet for 12 weeks in Type II-A hypercholesterolemic patients. There were no effects on HDL cholesterol or apoprotein A-I and A-II levels. The hypocholesterolemic effect was greater than in the hyperlipidemic patients with impaired glucose tolerance. Soy fiber supplementation also significantly reduced insulin responses to oral glucose challenge by 20% in Type II-A hypercholesterolemic and by 16.5% in Type IV hypertriglyceridemic patients. Results from this study suggest that supplementing the diet with soy fiber may be beneficial in dietary management of hyperlipidemia in patients with hypercholesterolemia and particularly in hyperlipidemic patients with hyperinsulinemia and impaired glucose tolerance.
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Delpeyroux F, Chenciner N, Lim A, Malpièce Y, Blondel B, Crainic R, van der Werf S, Streeck RE. A poliovirus neutralization epitope expressed on hybrid hepatitis B surface antigen particles. Science 1986; 233:472-5. [PMID: 2425433 DOI: 10.1126/science.2425433] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hepatitis B virus (HBV) envelope protein carrying the surface antigen (HBsAg) is assembled with cellular lipids in mammalian cells into empty viral envelopes. In a study to evaluate the capacity of such particles to present foreign peptide sequences in a biologically active form, in-phase insertions were created in the S gene encoding the major envelope protein. One of the sequences inserted was a synthetic DNA fragment encoding a poliovirus neutralization epitope. Mammalian cells expressing the modified gene secreted hybrid particles closely resembling authentic 22-nanometer HBsAg particles. These particles reacted with a poliovirus-specific monoclonal antibody and induced neutralizing antibodies against poliovirus. The results indicate that empty viral envelopes of HBV may provide a means for the presentation of peptide sequences and for their export from mammalian cells.
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Giam YC, Tham SN, Tan T, Lim A. Drug eruptions from phenylbutazone in Jamu. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1986; 15:118-21. [PMID: 2939787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Drug eruptions from indeginous medicine is often difficult to diagnosis and confirm. It is known that a number of these now supplied by bomohs and Chinese sinsehs contain known drugs and are dispensed as tablets and capsules. We report 3 cases of adverse drug eruption to "Jamu", a Malay herb. A particular brand, "Jamu Indonesia, Toko Air Pancur", from Johor Bahru, Malaysia, is especially recommended for "sakit pinggang" or backache. The cases occurred between January and February 1985, and all had taken brown kidney shaped tablets. The adverse reactions were moderately severe. Two had erythroderma with hepatitis, and one, Steven Johnson Syndrome. Analysis of this jamu for analgesics led to the discovery of adulteration with phenylbutazone and diazepam. Records from local cases from 1974-1984 showed that 8 other patients, all Chinese had adverse cutaneous eruptions from phenylbutazone, oxybutazone and propyphenazone. The skin manifestations were erythroderma (2 cases), vasculitis (2 cases) and toxic epidermal necrolysis (4 cases). Those with toxic epidermal necrolysis had 100% mortality.
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Corcoran MO, Thomas DM, Lim A, Berry RJ, Milroy EJ. Invasive bladder cancer treated by radical external radiotherapy. BRITISH JOURNAL OF UROLOGY 1985; 57:40-2. [PMID: 3971103 DOI: 10.1111/j.1464-410x.1985.tb08981.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Fifty-three consecutive, unselected patients with invasive bladder cancer, Stage T2 to T3, treated by radical radiotherapy have been reviewed. Cystectomy was reserved for patients with significant worsening of disease during treatment, histologically confirmed persistent or recurrent invasive tumour after treatment, or patients with intolerable symptoms due to radiation cystitis. In 64% of our patients a favourable tumour response to radiotherapy was seen, while a further 31% showed disease progression either during or on completion of radiotherapy. Cystectomy was performed on 22% of patients, mainly for radiation cystitis, and was not associated with a significant operative mortality rate. The crude 5-year survival rate was 42%. We conclude that radical radiotherapy is as effective as other forms of treatment for invasive bladder cancer, but that there remains a need to identify those bladder tumours destined to respond poorly to radiotherapy at an earlier stage.
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Kern P, Laurent M, Lim A, Regnault F, Courtois Y. Interaction of bovine epithelial lens (BEL) cells with extracellular matrix (ECM) and eye-derived growth factor (EDGF). II. Partial re-expression of the differentiated collagen distribution and phenotype. Exp Cell Res 1983; 149:85-93. [PMID: 6641803 DOI: 10.1016/0014-4827(83)90382-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The differentiated phenotype of bovine epithelial lens (BEL) cells consists primarily of type IV collagen production with homogeneous cellular form and monolayer organization. We have previously described how, after several subcultures, BEL cells lost this phenotype, which was replaced by a complex collagen mixture consisting predominantly of type I and type III collagens and a minor proportion of type IV collagen. The cells became irregular and formed multilayers. These dedifferentiated cells can re-express their initial morphological properties when subcultured on an extracellular matrix (ECM) in presence of an eye-derived growth factor (EDGF), as described in the first paper of this series [30]. Furthermore, those cells passaged only one time on ECM + EDGF partially re-express the native differentiated collagen phenotype. The cells synthesize a majority of type IV collagen (up to 65%) with minor amounts of interstitial collagens. As in early subcultured cells, the major proportion of total collagen accumulated in the cell layer. Taken together, the morphological and biochemical data emphasize the relationship between cell shape and collagen phenotype expression. They also provide a reversible system for the study of normal gene expression and pathological alterations.
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Goldberg AP, Lim A, Kolar JB, Grundhauser JJ, Steinke FH, Schonfeld G. Soybean protein independently lowers plasma cholesterol levels in primary hypercholesterolemia. Atherosclerosis 1982; 43:355-68. [PMID: 6889432 DOI: 10.1016/0021-9150(82)90035-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Hutchinson JS, Di Nicolantonio R, Lim A, Clements J, Funder JW. Effects of bromocriptine on blood pressure and plasma beta-endorphin in spontaneously hypertensive rats. Clin Sci (Lond) 1981; 61 Suppl 7:343s-345s. [PMID: 6274577 DOI: 10.1042/cs061343s] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
1. Immunoreactive beta-endorphin (IR-beta EP) was two- to three-fold higher in pituitary neuro-intermediate lobes (N-IL) of spontaneously hypertensive rats (SHR) than of normotensive Wistar--Kyoto (NT-WKY) controls. 2. Plasma levels of IR-beta EP were lower in SHR than in NT-WKY rats. 3. Intravenous injections of morphine lowered blood pressure of both SHR and NT-WKY rats to the same level; naloxone restored blood pressure of both groups to pre-morphine values. 4. Infusion of bromocriptine in SHR for 1 week lowered blood pressure and N-IL IR-beta EP concentration. 5. These results confirm and extend postulated dopaminergic defect in this model of hypertension.
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Hutchinson JS, Lim A, DiNicolantonio R, Clements JA, Funder JW. Immunoreactive beta-endorphin levels in plasma and pituitary tissue from genetically hypertensive and normotensive rats. Clin Exp Pharmacol Physiol 1981; 8:455-7. [PMID: 6276059 DOI: 10.1111/j.1440-1681.1981.tb00748.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
1. Levels of immunoreactive beta-endorphin were measured in neurointermediate lobes, anterior lobes and plasma from the Japanese and New Zealand strains of genetically hypertensive rats and their normotensive controls. 2. No significant differences were observed in beta-endorphin between the hypertensive and normotensive rats of the New Zealand strain. 3. The hypertensive rats of the Japanese strain showed significantly higher levels of beta-endorphin in neurointermediate lobe and lower levels in plasma than their normotensive controls. 4. These results suggest that the differences in beta-endorphin levels in the Japanese strain reflect a genetic difference not necessarily related to elevated blood pressure.
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243
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Horowitz J, Whitelaw K, Lim A, Jacobs C. Real-time analysis of hippocampal neural activity in the intervals between interictal spikes. COMPUTER PROGRAMS IN BIOMEDICINE 1981; 13:19-26. [PMID: 7285562 DOI: 10.1016/0010-468x(81)90080-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Previously the electroencephalogram (EEG) was modeled as consisting of faster, smaller waves superimposed on larger, slower waves. The intent of this study is to modify the program to sample neural activity over specific intervals of time following detection of a distinct wave pattern. The use of conditional sampling is illustrated by considering wave detection following epileptic interictal spikes in the rabbit hippocampus. To create an epileptic focus, small pellets of sodium penicillin suspended in agar were placed on the rabbit hippocampus. This produced regularly recurring, spontaneous, large amplitude discharges, or interictal spikes, at the site of application. Following detection of an interictal spike, the program delayed the onset of a sample period for either 1.0 s or 6.0 s. The neural activity was then sampled for 5.1 s, and fast and slow waves were detected over the sample period. The frequency distribution of waves in four of these 5.1 s intervals was calculated. Comparison of the frequency distributions following the 1.0 s and 6.0 s delays showed no discernible differences. The data illustrate that not all types of neural activity are markedly modified by interictal spikes and suggest that hippocampal cellular populations generate similar waves 1.0 s and 6.0 s after such a spike. Moreover, this experiment illustrates adaptation of the program to sample activity over a limited period of time following detection of a specific cortical waveform.
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244
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Reitan JA, Lim A. Automated measurement and frequency analysis of the pneumocardiogram. Anesth Analg 1978; 57:647-52. [PMID: 569988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The flow pneumocardiogram (PnCG), ie, measurement of cardiogenic gas movement in and out of the lung during apnea, was transduced by an in-line, high-gain pneumotachograph. A portion of the differentiated PnCG, the dPn/dt IJ wave, has been shown previously to correlate closely with left ventricular function. A simple analog device was designed and tested to measure the dPn/dt IJ amplitude on a practical beat-to-beat basis. Frequency-power spectral analysis showed the PnCG to be a low frequency phenomenon with the systolic component in the 9-to-10-Hz range. Appropriate band-pass filtering of the PnCG and its applicability as an intraoperative monitoring device are presented.
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Lim A, Khoo TK. Intra-epithelial epithelioma of the cornea. Singapore Med J 1967; 8:72-4. [PMID: 6080368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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