26
|
Hwang SM, Kang YC, Lee YB, Yoon KB, Ahn SK, Choi EH. The effects of epidural blockade on the acute pain in herpes zoster. ARCHIVES OF DERMATOLOGY 1999; 135:1359-64. [PMID: 10566834 DOI: 10.1001/archderm.135.11.1359] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To evaluate the relief of acute pain and possible preventive effects on postherpetic neuralgia through the use of an epidural blockade in the acute stage of herpes zoster. DESIGN Prospective, nonrandomized, comparative clinical trial. SETTING A dermatologic clinic in a university hospital. PATIENTS Sixty-five consecutive patients with pain due to acute herpes zoster were treated for a 7-day hospitalization period from July 1, 1996, through June 30, 1997. INTERVENTION The consecutive patients were divided into 2 groups. Group A consisted of 30 patients who were seen from July 1, 1996, through December 31, 1996, and who were treated with intravenous acyclovir (5 mg/kg) for 7 days. Group B consisted of 35 patients who were seen from January 1, 1997, through June 30, 1997, and who were treated with intravenous acyclovir (5 mg/kg) and an epidural blockade for 7 days. The changes in the intensity of pain and the total duration of pain in both groups were assessed for 12 to 18 months. MAIN OUTCOME MEASURES The number of days required for relief of pain and the total duration of pain. RESULTS The mean +/- SD number of days required for relief of pain, which was rated on a scale of 100 (worst pain) to 0 (no pain), was significantly fewer in group B than in group A: it took 2.6 +/- 1.1 days to go from 100 to 50 on the relief-of-pain scale in group B, but 3.8 +/- 1.1 days in group A (P = .03), and 12.5 +/- 6.4 days to go from 100 to 10 in group B, but 20.1 +/- 14.6 days in group A (P = .04). The duration of late residual pain was significantly shorter in group B (5.9 +/- 5.8 days) than in group A (11.9 +/- 7.5 days) (P = .03). The total duration of pain was also significantly shorter in group B (18.5 +/- 9.3 days) than in group A (31.6 +/- 17.6 days) (P = .04). CONCLUSIONS We believe that an epidural blockade combined with an antiviral agent is a very effective treatment modality for the pain of acute herpes zoster, and we recommend its use for the prevention of postherpetic neuralgia, with a view to shortening the total duration of pain, especially late residual pain.
Collapse
|
27
|
Lark MW, Stroup GB, Hwang SM, James IE, Rieman DJ, Drake FH, Bradbeer JN, Mathur A, Erhard KF, Newlander KA, Ross ST, Salyers KL, Smith BR, Miller WH, Huffman WF, Gowen M. Design and characterization of orally active Arg-Gly-Asp peptidomimetic vitronectin receptor antagonist SB 265123 for prevention of bone loss in osteoporosis. J Pharmacol Exp Ther 1999; 291:612-7. [PMID: 10525079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
The Arg-Gly-Asp (RGD)-binding integrin alpha(V)beta(3) is highly expressed on osteoclasts and has been proposed to mediate cell-matrix adhesion required for osteoclast-mediated bone resorption. Antagonism of this receptor should prevent stable osteoclast adhesion and thereby inhibit bone resorption. We have generated an orally bioavailable, nonpeptide RGD mimetic alpha(v)beta(3) antagonist, SB 265123, which prevents bone loss in vivo when dosed by oral administration. SB 265123 binds alpha(v)beta(3) and the closely related integrin alpha(v)beta(5) with high affinity (K(i) = 3.5 and 1.3 nM, respectively), but binds only weakly to the related RGD-binding integrins alpha(IIb)beta(3) (K(i) >1 microM) and alpha(5)beta(1) (K(i) >1 microM). The compound inhibits alpha(v)beta(3)-mediated cell adhesion with an IC(50) = 60 nM and more importantly, inhibits human osteoclast-mediated bone resorption in vitro with an IC(50) = 48 nM. In vivo, SB 265123 completely blocks bone resorption in a thyroparathyroidectomized rat model of acute bone resorption when dosed at 2.5 mg/kg/h by continuous i.v. infusion. When dosed orally with 3 to 30 mg/kg b.i.d. , in the ovariectomy-induced rat model of osteoporosis, SB 265123 prevents bone resorption in a dose-dependent fashion. This is the first report of an orally active alpha(v)beta(3) antagonist that is effective at inhibiting bone resorption when dosed in a pharmaceutically acceptable fashion. Such a molecule may provide a novel therapeutic agent for the treatment of postmenopausal osteoporosis.
Collapse
|
28
|
Deckert J, Khalaf RA, Hwang SM, Zitomer RS. Characterization of the DNA binding and bending HMG domain of the yeast hypoxic repressor Rox1. Nucleic Acids Res 1999; 27:3518-26. [PMID: 10446242 PMCID: PMC148596 DOI: 10.1093/nar/27.17.3518] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The yeast Rox1 hypoxic transcriptional repressor protein binds to and bends a specific DNA sequence through an HMG domain located at the N-terminus. To better understand the structure of Rox1 and how it interacts with DNA, 38 missense mutations in the HMG domain were isolated through a combination of random and site-directed mutageneses, the latter directed to two Ile residues that play an important role in DNA recognition and bending by HMG domains. The mutants were characterized in terms of their ability to repress the hypoxic gene ANB1 and the auto-repressed ROX1 gene in vivo. The mutant HMG domains were fused to maltose binding protein and expressed in and purified from Escherichia coli and their relative affinities for DNA and ability to bend DNA were determined. A model of the structure of the Rox1 HMG domain was derived using sequence similarities between Rox1 and the human protein SRY, the structure of which has been determined. The results of the mutational analysis are interpreted in terms of the model structure of Rox1.
Collapse
|
29
|
James IE, Lark MW, Zembryki D, Lee-Rykaczewski EV, Hwang SM, Tomaszek TA, Belfiore P, Gowen M. Development and characterization of a human in vitro resorption assay: demonstration of utility using novel antiresorptive agents. J Bone Miner Res 1999; 14:1562-9. [PMID: 10469285 DOI: 10.1359/jbmr.1999.14.9.1562] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A human in vitro resorption assay has been developed using osteoclastoma-derived osteoclasts and used to evaluate novel antiresorptive agents including antagonists of the alphavbeta3 integrin, and inhibitors of cathepsin K and the osteoclast ATPase. The potency of novel compounds in the in vitro resorption assay correlates with functional assays for each class of inhibitor: the human alphavbeta3-mediated cell adhesion assay for the vitronectin receptor antagonists (r2 = 0.82), the chick osteoclast vacuolar ATPase enzyme assay for the H+-ATPase inhibitors (r2 = 0.77) and the recombinant human cathepsin K enzyme assay for the cathepsin K inhibitors (r2 = 0.80). Cell suspensions, rich in osteoclasts, are prepared by collagenase digestion of the tumor tissue. These cells can be stored long-term in liquid nitrogen and upon thawing maintain their bone-resorbing phenotype. The cryopreserved cells can be cultured on bovine cortical bone for 24-48 h and resorption can be measured by either confocal microscopy or biochemical assays. The resorptive activity of osteoclasts derived from a number of tumors can be inhibited reproducibly using a number of mechanistically unique antiresorptive compounds. In addition, the measurement of resorption pits by laser confocal microscopy correlates with the release of type I collagen C-telopeptides or N-telopeptides, as measured by enzyme-linked immunosorbent assay. Resorption can be measured reproducibly using a 48-h incubation of osteoclasts on bone slices, or a 24-h incubation with bone particles. This in vitro human osteoclast resorption assay provides a robust system for the evaluation of inhibitors of osteoclastic function that may be developed for the treatment of metabolic bone diseases such as osteoporosis.
Collapse
|
30
|
Ahn SK, Hwang SM, Jiang SJ, Choi EH, Lee SH. The changes of epidermal calcium gradient and transitional cells after prolonged occlusion following tape stripping in the murine epidermis. J Invest Dermatol 1999; 113:189-95. [PMID: 10469302 DOI: 10.1046/j.1523-1747.1999.00650.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Disruption of the epidermal permeability barrier causes an immediate loss of the calcium gradient, and barrier recovery is parallel with the restoration of the calcium gradient in the epidermis. Artificial restoration of the barrier function by occlusion with a water vapor-impermeable membrane abrogate the expected increase in lipid synthesis and retard the barrier recovery, as well as block the normalization of the epidermal calcium gradient. To clarify the long-term effects of occlusion after acute barrier perturbation, we studied the calcium distribution and epidermal keratinocytes response after occlusion with a water vapor-impermeable membrane immediately following tape stripping in the murine epidermis. Acute barrier disruption caused an immediate depletion of most calcium ions in the upper epidermis, obliterating the normal calcium gradient. When the skin barrier function was artificially corrected by occlusion, the return of calcium ions to the epidermis was blocked. After 2 h of air exposure or occlusion, the density of epidermal calcium precipitates remained negligible. The transitional cell layers appeared with occlusion, but not or negligibly with air exposure. By 6 h though, calcium precipitates could be seen, the density of the calcium precipitates with occlusion was more sparse than with air exposure. With the air exposure, the thickness of the stratum corneum had normalized and the calcium gradient nearly recovered to normal after 24 h. The longer the occlusion period, the greater was the increase of transitional cells. By 60 h of occlusion, the thickness of the stratum corneum had increased and the transitional cell layers had disappeared, in parallel with the calcium gradient which was almost normalized. These results show that prolonged occlusion of tape-stripped epidermis induced transitional cells and delayed the restoration of the epidermal calcium gradient, the stratum corneum was then restored, transitional cells having disappeared, in parallel with normalization of the epidermal calcium gradient.
Collapse
|
31
|
Kang YC, Choi EH, Hwang SM, Lee WS, Lee SH, Ahn SK. Acne mechanica due to an orthopedic crutch. Cutis 1999; 64:97-8. [PMID: 10467500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Acne mechanica describes local irritation due to the skin being pressured, occluded, rubbed, squeezed, stretched, or heated. Examples of various physical traumas that provoke lesions in acne patients are given. Users of orthopedic crutches are at particular risk for such conditions. A crutch is another extrinsic factor to be added to the list of causes of acne mechanica.
Collapse
|
32
|
Miller WH, Bondinell WE, Cousins RD, Erhard KF, Jakas DR, Keenan RM, Ku TW, Newlander KA, Ross ST, Haltiwanger RC, Bradbeer J, Drake FH, Gowen M, Hoffman SJ, Hwang SM, James IE, Lark MW, Lechowska B, Rieman DJ, Stroup GB, Vasko-Moser JA, Zembryki DL, Azzarano LM, Adams PC, Huffman WF. Orally bioavailable nonpeptide vitronectin receptor antagonists with efficacy in an osteoporosis model. Bioorg Med Chem Lett 1999; 9:1807-12. [PMID: 10406646 DOI: 10.1016/s0960-894x(99)00283-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A new series of potent nonpeptide vitronectin receptor antagonists, based on a novel carbocyclic Gly-Asp mimetic, has been discovered. A representative of this series, SB 265123 (4), has 100% oral bioavailability in rats, and is orally active in vivo in the ovariectomized rat model of osteoporosis.
Collapse
|
33
|
Keenan RM, Miller WH, Barton LS, Bondinell WE, Cousins RD, Eppley DF, Hwang SM, Kwon C, Lago MA, Nguyen TT, Smith BR, Uzinskas IN, Yuan CC. Orally bioavailable nonpeptide vitronectin receptor antagonists containing 2-aminopyridine arginine mimetics. Bioorg Med Chem Lett 1999; 9:1801-6. [PMID: 10406645 DOI: 10.1016/s0960-894x(99)00282-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A peptide RGD analog containing a novel 2-aminopyridine arginine mimetic was discovered to have good affinity and selectivity for the vitronectin receptor. Incorporation of the 2-aminopyridine arginine mimetic into the 3-oxo-1,4-benzodiazepine-2-acetic acid integrin antagonist series led to novel and potent nonpeptide vitronectin receptor antagonists with promising levels of oral bioavailability.
Collapse
|
34
|
Kumar S, Hand AT, Connor JR, Dodds RA, Ryan PJ, Trill JJ, Fisher SM, Nuttall ME, Lipshutz DB, Zou C, Hwang SM, Votta BJ, James IE, Rieman DJ, Gowen M, Lee JC. Identification and cloning of a connective tissue growth factor-like cDNA from human osteoblasts encoding a novel regulator of osteoblast functions. J Biol Chem 1999; 274:17123-31. [PMID: 10358067 DOI: 10.1074/jbc.274.24.17123] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We have identified and cloned a novel connective tissue growth factor-like (CTGF-L) cDNA from primary human osteoblast cells encoding a 250-amino acid single chain polypeptide. Murine CTGF-L cDNA, encoding a polypeptide of 251 amino acids, was obtained from a murine lung cDNA library. CTGF-L protein bears significant identity ( approximately 60%) to the CCN (CTGF, Cef10/Cyr61, Nov) family of proteins. CTGF-L is composed of three distinct domains, an insulin-like growth factor binding domain, a von Willebrand Factor type C motif, and a thrombospondin type I repeat. However, unlike CTGF, CTGF-L lacks the C-terminal domain implicated in dimerization and heparin binding. CTGF-L mRNA ( approximately 1.3 kilobases) is expressed in primary human osteoblasts, fibroblasts, ovary, testes, and heart, and a approximately 26-kDa protein is secreted from primary human osteoblasts and fibroblasts. In situ hybridization indicates high expression in osteoblasts forming bone, discrete alkaline phosphatase positive bone marrow cells, and chondrocytes. Specific binding of 125I-labeled insulin-like growth factors to CTGF-L was demonstrated by ligand Western blotting and cross-linking experiments. Recombinant human CTGF-L promotes the adhesion of osteoblast cells and inhibits the binding of fibrinogen to integrin receptors. In addition, recombinant human CTGF-L inhibits osteocalcin production in rat osteoblast-like Ros 17/2.8 cells. Taken together, these results suggest that CTGF-L may play an important role in modulating bone turnover.
Collapse
|
35
|
Abstract
We report a 54-year-old male patient who developed an unusual form of generalized drug eruption. He had pain and breathlessness on the left chest wall. He had history of taking several drugs at private clinics under a diagnosis of herpes zoster. Two weeks later he had a generalized skin eruption. Examination showed multiple variable sized, mild pruritic, erythematous macules and papules on the face and upper extremities. Skin lesions take the form of a clinically consistent with disseminated superficial actinic porokeratosis (DSAP). Methylprednisolone 16 mg, astemisole 10 mg, oxatomide 60 mg was prescribed. Topical corticosteroid cream was applied. Within two months, his eruption had cleared almost completely. The pathogenetic mechanisms of this case are unclear, but drug and UV light have been considered.
Collapse
|
36
|
Abstract
BACKGROUND Traction alopecia associated with the nurse's cap is a relatively common form of occupational hair loss. METHODS We examined 199 healthy South Korean nurses to assess the clinical and pathologic characteristics of traction alopecia caused by prolonged traction exerted at the point of attachment of the nurse's cap. RESULTS Seven nurses (3.5% of 199) had hair loss at the pin site used to secure the nurse's cap. The lesions were exclusively localized on the parieto-occipital scalp. Histopathologic findings revealed characteristic cicatricial changes which showed a marked decrease in the number of hair follicles without inflammation. CONCLUSIONS Nurse's cap alopecia is not an uncommon occupational alopecia, and appears to be a distinct clinical entity which should be distinguished from other forms of patchy alopecia.
Collapse
|
37
|
Keenan RM, Callahan JF, Samanen JM, Bondinell WE, Calvo RR, Chen L, DeBrosse C, Eggleston DS, Haltiwanger RC, Hwang SM, Jakas DR, Ku TW, Miller WH, Newlander KA, Nichols A, Parker MF, Southhall LS, Uzinskas I, Vasko-Moser JA, Venslavsky JW, Wong AS, Huffman WF. Conformational preferences in a benzodiazepine series of potent nonpeptide fibrinogen receptor antagonists. J Med Chem 1999; 42:545-59. [PMID: 10052962 DOI: 10.1021/jm980166z] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previously, we reported the direct design of highly potent nonpeptide 3-oxo-1,4-benzodiazepine fibrinogen receptor antagonists from a constrained, RGD-containing cyclic semipeptide. The critical features incorporated into the design of these nonpeptides were the exocyclic amide at the 8-position which overlaid the Arg carbonyl, the phenyl ring which maintained an extended Gly conformation, and the diazepine ring which mimicked the gamma-turn at Asp. In this paper, we investigate conformational preferences of the 8-substituted benzodiazepine analogues by examining structural modifications to both the exocyclic amide and the seven-membered diazepine ring and by studying the conformation of the benzodiazepine ring using molecular modeling, X-ray crystallography, and NMR. We found that the directionality of the amide at the 8-position had little effect on activity and the (E)-olefin analogue retained significant potency, indicating that the trans orientation of the amide, and not the carbonyl or NH groups, made the largest contribution to the observed activity. For the diazepine ring, with the exception of the closely analogous 3-oxo-2-benzazepine ring system described previously, all of the modifications led to a significant reduction in activity compared to the potent 3-oxo-1, 4-benzodiazepine parent ring system, implicating this particular type of ring system as a desirable structural feature for high potency. Energy minimizations of a number of the modified analogues revealed that none could adopt the same low-energy conformation as the one shared by the active (S)-isomer of the 3-oxo-1, 4-benzodiazepines and 3-oxo-2-benzazepines. The overall data suggest that the features contributing to the observed high potency in this series are the orientation of the 3-4 amide and the conformational constraint imposed by the seven-membered ring, both of which position the key acidic and basic groups in the proper spatial relationship.
Collapse
|
38
|
Deckert J, Torres AM, Hwang SM, Kastaniotis AJ, Zitomer RS. The anatomy of a hypoxic operator in Saccharomyces cerevisiae. Genetics 1998; 150:1429-41. [PMID: 9832521 PMCID: PMC1460422 DOI: 10.1093/genetics/150.4.1429] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aerobic repression of the hypoxic genes of Saccharomyces cerevisiae is mediated by the DNA-binding protein Rox1 and the Tup1/Ssn6 general repression complex. To determine the DNA sequence requirements for repression, we carried out a mutational analysis of the consensus Rox1-binding site and an analysis of the arrangement of the Rox1 sites into operators in the hypoxic ANB1 gene. We found that single base pair substitutions in the consensus sequence resulted in lower affinities for Rox1, and the decreased affinity of Rox1 for mutant sites correlated with the ability of these sites to repress expression of the hypoxic ANB1 gene. In addition, there was a general but not complete correlation between the strength of repression of a given hypoxic gene and the compliance of the Rox1 sites in that gene to the consensus sequence. An analysis of the ANB1 operators revealed that the two Rox1 sites within an operator acted synergistically in vivo, but that Rox1 did not bind cooperatively in vitro, suggesting the presence of a higher order repression complex in the cell. In addition, the spacing or helical phasing of the Rox1 sites was not important in repression. The differential repression by the two operators of the ANB1 gene was found to be due partly to the location of the operators and partly to the sequences between the two Rox1-binding sites in each. Finally, while Rox1 repression requires the Tup1/Ssn6 general repression complex and this complex has been proposed to require the aminoterminal regions of histones H3 and H4 for full repression of a number of genes, we found that these regions were dispensable for ANB1 repression and the repression of two other hypoxic genes.
Collapse
|
39
|
Keenan RM, Miller WH, Lago MA, Ali FE, Bondinell WE, Callahan JF, Calvo RR, Cousins RD, Hwang SM, Jakas DR, Ku TW, Kwon C, Nguyen TT, Reader VA, Rieman DJ, Ross ST, Takata DT, Uzinskas IN, Yuan CC, Smith BR. Benzimidazole derivatives as arginine mimetics in 1,4-benzodiazepine nonpeptide vitronectin receptor (alpha v beta 3) antagonists. Bioorg Med Chem Lett 1998; 8:3165-70. [PMID: 9873696 DOI: 10.1016/s0960-894x(98)00555-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In a 3-oxo-1,4-benzodiazepine-2-acetic acid series of vitronectin receptor (alpha v beta 3) antagonists containing a benzimidazole as a novel arginine mimetic, we examined the effects of benzimidazole modifications and amide substitutions on both activity and pharmacokinetics.
Collapse
|
40
|
Keenan RM, Lago MA, Miller WH, Ali FE, Cousins RD, Hall LB, Hwang SM, Jakas DR, Kwon C, Louden C, Nguyen TT, Ohlstein EH, Rieman DJ, Ross ST, Samanen JM, Smith BR, Stadel J, Takata DT, Vickery L, Yuan CC, Yue TL. Discovery of an imidazopyridine-containing 1,4-benzodiazepine nonpeptide vitronectin receptor (alpha v beta 3) antagonist with efficacy in a restenosis model. Bioorg Med Chem Lett 1998; 8:3171-6. [PMID: 9873697 DOI: 10.1016/s0960-894x(98)00556-3] [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: 10/27/2022]
Abstract
In the 3-oxo-1,4-benzodiazepine-2-acetic acid series of vitronectin receptor (alpha v beta 3) antagonists, a compound containing an imidazopyridine arginine mimetic was discovered which had sufficient potency and i.v. pharmacokinetics for demonstration of efficacy in a rat restenosis model.
Collapse
|
41
|
|
42
|
Wong A, Hwang SM, Johanson K, Samanen J, Bennett D, Landvatter SW, Chen W, Heys JR, Ali FE, Ku TW, Bondinell W, Nichols AJ, Powers DA, Stadel JM. Binding of [3H]-SK&F 107260 and [3H]-SB 214857 to purified integrin alphaIIbbeta3: evidence for a common binding site for cyclic arginyl-glycinyl-aspartic acid peptides and nonpeptides. J Pharmacol Exp Ther 1998; 285:228-35. [PMID: 9536015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The aggregation of activated platelets is mediated by the binding of fibrinogen to its cell surface receptor, the integrin alphaIIbbeta3. The recognition of fibrinogen by alphaIIbbeta3 depends, in part, on the tripeptide sequence Arg-Gly-Asp (RGD) in the adhesive protein. The interactions of a cyclic RGD-containing pentapeptide, [3H]-SK&F-107260, and a 1,4-benzodiazepine-based nonpeptide [3H]-SB-214857, with purified alphaIIbbeta3 have been investigated. Both compounds potently inhibit platelet aggregation at submicromolar concentrations. Binding of both [3H]-SK&F-107260 (Kd = 1.19 nM) and [3H]-SB-214857 (Kd = 1.85 nM) to alphaIIbbeta3 is of high affinity and fully reversible. The binding is monophasic, indicating a single class of noncooperative binding sites. The two radioligands exhibited similar values in binding to alphaIIbbeta3 purified on an RGD-affinity column (Bmax = 0.2 mol/mol alphaIIbbeta3) or to alphaIIbbeta3 purified over a lentil lectin column (Bmax = 0.03 mol/mol alphaIIbbeta3), suggesting that SK&F-107260 and SB-214857 interact with the same population of receptors. Binding of [3H]-SK&F-107260 and [3H]-SB-214857 to alphaIIbbeta3 require divalent cations, Mg++, Ca++ and Mn++ are able to support binding, with Mn++ being the most effective. Thirteen alphaIIbbeta3 antagonists, including four linear and three cyclic RGD peptides, five peptidomimetics, the fibrinogen gamma-chain dodecapeptide (HHLGGAKQAGDV) and the snake venom protein, echistatin, complete for [3H]-SK&F-107260 or [3H]-SB-214857 binding to alphaIIbbeta3. The affinity constants (Ki) of these compounds, determined by the two radioligand binding assays, are similar. Furthermore, these compounds exhibit the same rank order of potency in inhibiting biotinylated-fibrinogen binding to alphaIIbbeta3. Scatchard plot analyses of the [3H]-SK&F-107260 binding isotherms in the presence of unlabeled SB-214857 and gamma-chain dodecapeptide reveal competitive-type antagonism, indicating that SB-214857, gamma-chain dodecapeptide and SK&F-107260 interact with mutually exclusive binding sites on alphaIIbbeta3.
Collapse
|
43
|
|
44
|
|
45
|
Lee WS, Hwang SM, Ahn SK. Frontal fibrosing alopecia in a postmenopausal woman. Cutis 1997; 60:299-300. [PMID: 9426971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A case is presented of a 52-year-old woman in whom clinical and histopathologic findings suggested cicatricial alopecia. Our patient had an uncommon, but distinctive, clinical presentation. It was characterized by bandlike frontal hair loss. This was recently described as patterned cicatricial alopecia, presented in a recent study as postmenopausal frontal hairline recession with scarring. Our patient's case should be differentiated from recognized forms of scarring alopecia.
Collapse
|
46
|
Keenan RM, Miller WH, Kwon C, Ali FE, Callahan JF, Calvo RR, Hwang SM, Kopple KD, Peishoff CE, Samanen JM, Wong AS, Yuan CK, Huffman WF. Discovery of potent nonpeptide vitronectin receptor (alpha v beta 3) antagonists. J Med Chem 1997; 40:2289-92. [PMID: 9240343 DOI: 10.1021/jm970205r] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
47
|
Kumar CS, James IE, Wong A, Mwangi V, Feild JA, Nuthulaganti P, Connor JR, Eichman C, Ali F, Hwang SM, Rieman DJ, Drake FH, Gowen M. Cloning and characterization of a novel integrin beta3 subunit. J Biol Chem 1997; 272:16390-7. [PMID: 9195946 DOI: 10.1074/jbc.272.26.16390] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We have identified a novel integrin beta3 subunit, termed beta3C, from a human osteoclast cDNA library. The COOH-terminal sequence and 3'-untranslated region of the beta3C subunit differs from the previously reported beta3A (platelet) and beta3B (placenta) sequences, while the regions coding for the transmembrane and extracellular domains are identical. The beta3C cytoplasmic domain contains 37 amino acids, the last 17 of which are encoded by a novel exon located about 6 kilobase pairs downstream of exon 14 of the beta3A gene. HEK 293 cells were stably co-transfected with alphaV and either beta3C (HEKbeta3C) or beta3A (HEKbeta3A). The viability of HEKbeta3C cells was lower than that of HEKbeta3A cells, and HEKbeta3C cells in culture grew as clusters rather than as a monolayer. The novel cytoplasmic domain did not affect receptor binding affinity; both alphaVbeta3A and alphaVbeta3C isoforms exhibited high affinity binding to 125I-echistatin and cyclic and linear RGD peptides. However, in contrast to HEKbeta3A, HEKbeta3C cells failed to adhere to osteopontin, an alphaVbeta3 matrix protein. The data provide further support for the key role of the cytoplasmic domain of the beta3 integrin in cell adhesion and suggest a potential role for the beta3C integrin subunit in modulating cell-matrix interactions.
Collapse
|
48
|
Hwang SM, Choi EH, Lee WS, Choi SI, Ahn SK. Nevus spilus (speckled lentiginous nevus) associated with a nodular neurotized nevus. Am J Dermatopathol 1997; 19:308-11. [PMID: 9185922 DOI: 10.1097/00000372-199706000-00020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report a case of nevus spilus with neurotized nevus studied by immunohistochemical methods using S-100, leu-6, glial fibrillary acid protein (GFAP), and myelin basic protein (MBP). Histologic findings of the speckled lesion showed irregular rete ridge elongation, increased epidermal melanocytes and melanin in the epidermis, and scattered nevus cell nests in the upper dermis, but showed neurotized nevus in the deep dermis, which has many features of neurofibroma. Diffuse expression of S-100 protein and MBP, focal staining with GFAP, and lack of staining with leu-7 were observed, Leu-7, positive only in neurofibromas and not in neurotized nevus, appears to be the more pertinent method for distinguishing neurotized nevus from neurofibroma.
Collapse
|
49
|
|
50
|
Ahn SK, Kim KT, Lee SH, Hwang SM, Choi EH, Choi S. The efficacy of treatment with triamcinolone acetonide in calcinosis cutis following extravasation of calcium gluconate: a preliminary study. Pediatr Dermatol 1997; 14:103-9. [PMID: 9144694 DOI: 10.1111/j.1525-1470.1997.tb00214.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Neonatal hypocalcemia is not an uncommon condition, especially in the premature neonate. It is effectively treated by intravenous administration of calcium gluconate. Complications of extravasation during intravenous infusion include localized calcification and occasionally necrosis. When this occurs, however, there is no specific mode of treatment except supportive management and skin graft. This experiment was designed to evaluate the efficacy and safety of treatment with triamcinolone acetonide in calcinosis cutis following extravasation of calcium gluconate. Initially, 2 cc of 10% calcium gluconate was injected subcutaneously into two rabbits at seven sites on the shaved skin of the back. Another two rabbits were injected at the same sites with 0.5 cc of triamcinolone acetonide (10 mg/dl) after injection of 2 cc of 10% calcium gluconate. As a control, 2 cc of normal saline was injected into another rabbit in the same manner. These five rabbits were observed over the next 7 weeks and underwent pathologic examination at various intervals (on days 1, 3, 8, 15, 30, 37, 45). In the 10% calcium gluconate injected rabbits, nodules and large ulcerated lesions developed after 15 days. Multiple, linear, ulcerative and indurated masses were noted on day 37. The lesions healed progressively with a decrease in ulceration, and after 2 months, the masses disappeared gradually. Histologically, on day 15 calcium deposits were seen in the walls of the arteries, veins, dermis, and muscle fibers and epidermal necrosis was seen at the injection sites. From day 37 discharge of calcium deposits began to take place by means of transepidermal elimination. After 2 months, the calcium and mucin deposition was observed focally in the dermis. In the rabbits injected with 10% calcium gluconate and triamcinolone acetonide, mild erythema and induration were seen after day 15 at the injection sites; this gradually disappeared. After 30 days the injection sites were normal in appearance. Histologically, at day 15 calcium deposition was seen in the upper dermis, but after 1 month the injection sites were histologically normal. We suggest that intralesional injection of triamcinolone acetonide for the treatment of calcinosis cutis following extravasation of calcium gluconate is effective, probably due to its antiinflammatory effect and its role in facilitating the resorption of calcium in the tissue.
Collapse
|