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Regulatory role of collagen V in establishing mechanical properties of tendons and ligaments is tissue dependent. J Orthop Res 2015; 33:882-8. [PMID: 25876927 PMCID: PMC4417070 DOI: 10.1002/jor.22893] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/10/2015] [Indexed: 02/04/2023]
Abstract
Patients with classic (type I) Ehlers-Danlos syndrome (EDS), characterized by heterozygous mutations in the Col5a1 and Col5a2 genes, exhibit connective tissue hyperelasticity and recurrent joint dislocations, indicating a potential regulatory role for collagen V in joint stabilizing soft tissues. This study asked whether the contribution of collagen V to the establishment of mechanical properties is tissue dependent. We mechanically tested four different tissues from wild type and targeted collagen V-null mice: the flexor digitorum longus (FDL) tendon, Achilles tendon (ACH), the anterior cruciate ligament (ACL), and the supraspinatus tendon (SST). Area was significantly reduced in the Col5a1(ΔTen/ΔTen) group in the FDL, ACH, and SST. Maximum load and stiffness were reduced in the Col5a1(ΔTen/ΔTen) group for all tissues. However, insertion site and midsubstance modulus were reduced only for the ACL and SST. This study provides evidence that the regulatory role of collagen V in extracellular matrix assembly is tissue dependent and that joint instability in classic EDS may be caused in part by insufficient mechanical properties of the tendons and ligaments surrounding each joint.
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Type, duration, and incidence of pathologic findings after retroorbital bleeding of mice by experienced and novice personnel. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2015; 54:317-327. [PMID: 26045459 PMCID: PMC4460946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/01/2014] [Accepted: 09/16/2014] [Indexed: 06/04/2023]
Abstract
Retroorbital blood collection is a common technique in laboratory rodents due to the ease with which it can be performed and the sample volumes obtained for subsequent blood analyses. However, its use has been discouraged recently due to aesthetic discomfort and anecdotal reports of potential for ocular injury during blood collection. We hypothesized that a single standardized session of in-person training would be sufficient to learn the appropriate technique and minimize the likelihood for adverse outcomes. Experienced instructors (n = 2) conducted hands-on training classes to teach novice personnel (n = 40) to perform this procedure. Blood was collected from anesthetized mice (n = 40) via a capillary tube first placed at the medial canthus of the right eye and then advanced into the retroorbital space; the left retroorbital spaces served as unmanipulated controls. For comparison, the experienced instructors similarly collected blood from 40 additional mice. The tube could be inserted only once in each mouse, with the goal of obtaining 50 to 100 μL blood. Overall, 79 of 80 mice (98.8%) showed normal body condition, posture, and behavior throughout the 14-d study. Thus, any clinical observation scores pertained specifically to ocular lesions, which occurred at least once after sampling in 43 (53.8%) of the mice. Clinical and histopathologic scores of mice after bleeding did not differ between experienced and novice personnel. We conclude that a coordinated hands-on training program can provide consistent and sufficient instruction for research personnel to conduct retroorbital blood collection with competence in anesthetized laboratory mice.
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Abstract
RATIONALE Fetuses that develop in diabetic mothers have a higher incidence of birth defects that include cardiovascular defects, but the signaling pathways that mediate these developmental effects are poorly understood. It is reasonable to hypothesize that diabetic maternal effects are mediated by 1 or more pathways activated downstream of aberrant glucose metabolism, because poorly controlled maternal glucose levels correlate with the frequency and severity of the defects. OBJECTIVE We investigated whether RasGRP3 (Ras guanyl-releasing protein 3), a Ras activator expressed in developing blood vessels, mediates diabetes-induced vascular developmental defects. RasGRP3 is activated by diacylglycerol, and diacylglycerol is overproduced by aberrant glucose metabolism in diabetic individuals. We also investigated the effects of overactivation and loss of function for RasGRP3 in primary endothelial cells and developing vessels. METHODS AND RESULTS Analysis of mouse embryos from diabetic mothers showed that diabetes-induced developmental defects were dramatically attenuated in embryos that lacked Rasgrp3 function. Endothelial cells that expressed activated RasGRP3 had elevated Ras-ERK signaling and perturbed migration, whereas endothelial cells that lacked Rasgrp3 function had attenuated Ras-ERK signaling and did not migrate in response to endothelin-1. Developing blood vessels exhibited endothelin-stimulated vessel dysmorphogenesis that required Rasgrp3 function. CONCLUSIONS These findings provide the first evidence that RasGRP3 contributes to developmental defects found in embryos that develop in a diabetic environment. The results also elucidate RasGRP3-mediated signaling in endothelial cells and identify endothelin-1 as an upstream input and Ras/MEK/ERK as a downstream effector pathway. RasGRP3 may be a novel therapeutic target for the fetal complications of diabetes.
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Signaling pathways that regulate blood vessel morphogenesis. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a22-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Habitat corridors function as both drift fences and movement conduits for dispersing flies. Oecologia 2005; 143:645-51. [PMID: 15800750 DOI: 10.1007/s00442-005-0023-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2004] [Accepted: 01/19/2005] [Indexed: 10/25/2022]
Abstract
Corridors connect otherwise isolated habitat patches and can direct movement of animals among such patches. In eight experimental landscapes, we tested two hypotheses of how corridors might affect dispersal behavior. The Traditional Corridor hypothesis posits that animals preferentially leave patches via corridors, following them into adjacent patches. The Drift Fence hypothesis posits that animals dispersing through matrix habitat are diverted into patches with corridors because they follow corridors when encountered. House flies (Musca domestica L.), a species that prefers the habitat of our patches and corridors, were released in a central patch (100x100 m) and recaptured in peripheral patches that were or were not connected by a corridor. Flies were captured more frequently in connected than unconnected patches, thereby supporting the Traditional Corridor hypothesis. The Drift Fence hypothesis was also supported, as flies were captured more frequently in unconnected patches with blind (dead end) corridors than in unconnected patches of equal area without blind corridors. A second experiment tested whether these results might be dependent on the type of patch-matrix boundary encountered by dispersing flies and whether edge-following behavior might be the mechanism underlying the observed corridor effect in the first experiment. We recorded dispersal patterns of flies released along forest edges with dense undergrowth in the forest ("closed" edges) and along edges with little forest understory ("open" edges). Flies were less likely to cross and more likely to follow closed edges than open edges, indicating that when patch and corridor edges are pronounced, edge-following behavior of flies may direct them along corridors into connected patches. Because edges in the first experiment were open, these results also suggest that corridor effects for flies in that experiment would have been even stronger if the edges around the source patches and corridors had been more closed. Taken together, our results suggest that corridors can affect dispersal of organisms in unappreciated ways (i.e., as drift fences) and that edge type can alter dispersal behavior.
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Inhibitors of cyclic AMP phosphodiesterase. 4. Synthesis and evaluation of potential prodrugs of lixazinone (N-cyclohexyl-N-methyl-4-[(1,2,3,5-tetrahydro-2- oxoimidazo[2,1-b]quinazolin-7-yl)-oxy]butyramide, RS-82856). J Med Chem 1988; 31:2145-52. [PMID: 2846840 DOI: 10.1021/jm00119a015] [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 cyclic AMP phosphodiesterase (cAMP PDE) inhibitor and cardiotonic agent lixazinone (N-cyclohexyl-N-methyl-4-[(1,2,3,5-tetrahydro-2- oxoimidazo[2,1-b]quinazolin-7-yl)oxy]butyramide, RS-82856, 1) and its acid and base addition salts were found to be insufficiently soluble in formulations suitable for intravenous administration. These results prompted an investigation into potential prodrugs with enhanced aqueous solubility designed to deliver 1 by three distinct mechanisms: (1) decarboxylation of alpha-carboxamides; (2) hydrolytic loss of a solubilizing N-1-(acyloxy)methyl or (N,N-dialkylamino)methyl moiety; or (3) intramolecular closure of a guanidino ester or amide. The target compounds were evaluated as delivery systems for 1 by three criteria: (1) chemical conversion rate to 1 under physiological conditions; (2) inhibition of type IV cAMP PDE at a fixed time point; and (3) in vivo inotropic activity in anesthetized dogs by both intravenous and oral administration. Release of 1 from 4a (series 1) was found to be too slow to be of value as a prodrug of 1, since decarboxylation could be induced only by strong acid, conditions under which hydrolytic ring opening was found to severely compete. Conversely, 1 was released too readily on exposure of (N,N-dialkylamino)methyl derivatives such as 8d (series 2) to physiological conditions, although no large increase in aqueous solubility was realized. Finally, both the physicochemical and in vitro studies indicated that ring closure of the guanidinium esters and amides 17a-k (series 3) to 1 was quantitative and pH- and time-dependent, suggesting the possibility of delivery of the open, water-soluble prodrug form, followed by closure to 1 in plasma. Detailed examination of these agents in vivo, however, demonstrated that only those compounds that rapidly cyclized to 1, as measured by plasma levels of 1, exhibited inotropic activity, indicating that the open prodrug form was not efficiently absorbed upon oral administration.
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Synthesis and gastric antisecretory properties of allenic 16-phenoxy-omega-tetranor prostaglandin E analogs. PROSTAGLANDINS 1987; 33:169-80. [PMID: 3588969 DOI: 10.1016/0090-6980(87)90004-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In order to improve the modest oral activity of PGE2 as an inhibitor of gastric acid secretion, analogs were prepared and tested orally in histamine-challenged rats. Insertion of a double bond at C-4, resulting in the 4,5-allene analog of PGE1, gave a small increase in activity. Introduction of the omega-tetranor-16-phenoxy lower sidechain, a modification known to enhance activity in the PGF series, gave an eight-fold increase in activity. The analog having both modifications (enprostil, 2) showed a six hundred-fold increase in oral antisecretory activity over PGE2, which may reflect a potentiation effect. Modification of enprostil at C-1 (various esters) and at C-11 (11-methyl, 11-deoxy) generally resulted in compounds of high activity while modifications at other sites generally resulted in significant reductions in activity.
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Synthesis and antiallergic activity of some mono- and disubstituted xanthone-2-carboxylic acids. J Med Chem 1978; 21:669-72. [PMID: 671465 DOI: 10.1021/jm00205a014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A series of xanthone-2-carboxylic acids, substituted mainly with electron-withdrawing groups, has been synthesized and assayed for antiallergic activity, using the passive cutaneous anaphylaxis (PCA) reaction in the rat. The effect of substituent type and substitution pattern on PCA neutralizing capacity is presented.
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Abstract
1. Human hepatic "acid" beta-galactosidase preparations, which had been purified approximately 250-fold, were examined for activities toward 4-methylumbelliferyl beta-galactosylceramide, lactosylceramide, galactosyl-N-acetylgalactosaminyl-[N-acetylneuraminyl]-galactosyl-glucosylceramide(GM1-ganglioside) and galactosyl-N-acetylgalactosaminyl-galactosyl-glucosylceramide (asialo GM1-ganglioside). 2. The enzyme was active toward the synthetic substrate, GM1-ganglioside and asialo GM1-ganglioside but was inactive toward galactosylceramide. Under our assay conditions, optimized for lactosylceramidase II, the preparations were as active toward lactosylceramide as toward GM1-ganglioside or its asialo derivative. The apparent Km values for the three natural substrates were similar. When determined by the assay system of Wehger, D.A., Sattler, M., Clark, C. and McKelvey, H. (1974) Clin. Chim Acta 56, 199-206, lactosylceramide-cleaving activity was 0.2% of that determined by our assay system. This confirmed our previous suggestion that the Wenger assay system determines exclusively the activity of lactosylceramidase I, which is probably identical with galactosylceramide beta-galactosidase. 3. Crude sodium taurocholate was far more effective than pure taurocholate in stimulating hydrolysis of the three glycosphingolipids by the beta-galactosidase. However, crude taurocholate could largely be replaced by smaller amounts of sodium taurodeoxycholate, suggesting that the unique activating capacity of the crude taurocholate might be due to taurodeoxycholate present as the major impurity. 4. Cl- was generally stimulatory for hydrolysis of the natural glycosphingolipids by our enzyme preparation. Effects of additional oleic acid and Triton X-100 were generally minor in either direction. 5. When the enzyme preparation was diluted with water, activity toward the synthetic substrate declined rapidly while those toward the natural substrates were essentially stable. Activity toward the synthetic substrate remained much more stable when the enzyme was diluted with 0.1 M sodium citrate/phosphate buffer, pH 5.0. 6. These observations provide insight into the complex relationship among the human hepatic beta-galactosidases.
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Abstract
Some new approaches to the 1,6-methano[10]annulene system are described. The routes were used to prepare 1,6-methano[10]annulene-3-acetic acid and the alpha-methyl analog. The compounds showed antinflammatory and analgesic activity, though less than that of corresponding naphthalene compounds; the possible effect of the chirality of the annulene on the observed biological activity is discussed.
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Synthesis of B-seco doisynolic acids. JOURNAL OF STEROID BIOCHEMISTRY 1975; 6:193-4. [PMID: 1186226 DOI: 10.1016/0022-4731(75)90131-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Synthesis of prostaglandins by conjugate addition and alkylation of a directed enolate ion. 11-deoxyprostaglandins. J Org Chem 1974; 39:2506-9. [PMID: 4416029 DOI: 10.1021/jo00931a008] [Citation(s) in RCA: 81] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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1-Alkylamino-3-(2-thiazolyloxy)-2-propanols. A novel class of mixed myocardial beta-stimulants-beta-blockers. J Med Chem 1974; 17:200-3. [PMID: 4148933 DOI: 10.1021/jm00248a012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Structure activity relationship among 6-substituted-2-naphthylacetic acids. A new series of nonsteroidal anti-inflammatory agents. Scand J Rheumatol 1973; 2:7-11. [PMID: 4773965 DOI: 10.3109/03009747309097090] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Synthesis of 2',2'-difluoro-6,7-dihydro-16-methylenecyclopropa(6,7)progesterone analogues. JOURNAL OF THE CHEMICAL SOCIETY. PERKIN TRANSACTIONS 1 1973; 3:227-30. [PMID: 4736245 DOI: 10.1039/p19730000227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Synthesis of 13-cis-prostaglandins via a highly stereoselective conjugate addition with a functionalized organocopper reagent. J Am Chem Soc 1972; 94:9256-8. [PMID: 4642372 DOI: 10.1021/ja00781a062] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Synthesis of prostaglandin models and prostaglandins by conjugate addition of a functionalized organocopper reagent. J Am Chem Soc 1972; 94:7827-32. [PMID: 5076755 DOI: 10.1021/ja00777a027] [Citation(s) in RCA: 148] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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17-Alpha-propadienyl-19-nortestosterone and related compounds. A new series of potent orally active progestogens. J Med Chem 1971; 14:1190-2. [PMID: 5116232 DOI: 10.1021/jm00294a012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Photochemical cycloadducts. V. Photochemical addition of olefins to the steroidal 1-en-3-one system. J Org Chem 1970; 35:2560-4. [PMID: 5449217 DOI: 10.1021/jo00833a020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Synthetic studies on insect hormones. 8. A new stereospecific synthesis of trisubstituted olefins from organocopper reagents and acetylenes. J Am Chem Soc 1969; 91:1853-4. [PMID: 5779834 DOI: 10.1021/ja01035a046] [Citation(s) in RCA: 97] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Syntheses of some sterically pure N-protected peptides by stepwise addition of amino acids to the carboxyl end of the peptide chain. Aust J Chem 1967. [DOI: 10.1071/ch9670797] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Steroids. CCXCII. Synthetic studies on insect hormones. II. The synthesis of ecdysone. J Am Chem Soc 1966; 88:862-3. [PMID: 5902567 DOI: 10.1021/ja00956a060] [Citation(s) in RCA: 50] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Synthetic studies on insect hormones. I. Synthesis of the tetracyclic nucleus of ecdysone. J Am Chem Soc 1966; 88:379-80. [PMID: 5900550 DOI: 10.1021/ja00954a048] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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17-Chloroethynylated steroids. 3. The synthesis of 17-alpha-chloroethynyl-5, 7, 9-estratrien-17-beta-ol-3-one. J Med Chem 1965; 8:536-7. [PMID: 5883722 DOI: 10.1021/jm00328a030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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