301
|
Juo SH, Han Z, Smith JD, Colangelo L, Liu K. Common polymorphism in promoter of microsomal triglyceride transfer protein gene influences cholesterol, ApoB, and triglyceride levels in young african american men: results from the coronary artery risk development in young adults (CARDIA) study. Arterioscler Thromb Vasc Biol 2000; 20:1316-22. [PMID: 10807748 DOI: 10.1161/01.atv.20.5.1316] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/1999] [Accepted: 12/29/1999] [Indexed: 11/16/2022]
Abstract
The microsomal triglyceride transfer protein (MTP) plays a key role in the assembly of apolipoprotein B (apoB)-containing lipoproteins. We investigated the relation between lipid profiles and a common functional polymorphism (-493G/T) of the MTP gene in a large sample of young black men in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. We performed serial cross-sectional analyses on lipids of 586 black men in 5 exams over 10 years of follow-up. Total cholesterol, LDL cholesterol, and apoB levels were very similar between the GT and GG genotypes; therefore, the GT and GG genotypes were combined as 1 group when the 3 phenotypes were analyzed. The results from ANCOVA showed that the TT group (prevalence 7%) had higher levels of apoB-related lipids than did the GT+GG group: the difference in total cholesterol ranged from 2 (P=0.79) to 19 (P=0.002) mg/dL in exams 1 to 5; the difference in LDL cholesterol ranged from 10 (P=0.14) to 17 (P=0.003) mg/dL in exams 1 to 4, but in examination 5, the difference became negligible. The TT group had higher levels of apoB, measured in only 2 exams, by 6 (P=0.12) and 9 (P=0.03) mg/dL. The TT group had higher levels of triglycerides than did the TG or GG group by 3 to 34 (P=0.02 to approximately 0.003) mg/dL in all 5 exams. HDL cholesterol and apolipoprotein A-I levels were similar among the 3 genotypes. Our serial cross-sectional analyses indicated that the TT genotype was associated with higher levels of total cholesterol, LDL cholesterol, triglycerides, and apoB in young black men. The broad effect of this polymorphism on several atherogenic traits suggests that the MTP gene could be influential in atherosclerosis.
Collapse
|
302
|
Hancock GE, Smith JD, Heers KM. Serum neutralizing antibody titers of seropositive chimpanzees immunized with vaccines coformulated with natural fusion and attachment proteins of respiratory syncytial virus. J Infect Dis 2000; 181:1768-71. [PMID: 10823781 DOI: 10.1086/315475] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/1999] [Revised: 01/18/2000] [Indexed: 11/03/2022] Open
Abstract
Subunit vaccines formulated with purified fusion proteins from the A2 (PFP-2) or attenuated 248/404 (PFP-3) strains of respiratory syncytial virus (RSV) were evaluated, either alone or in combination with native attachment (G) protein, for their ability to augment serum neutralizing antibody titers in seropositive chimpanzees. The results suggested that combination vaccines enhanced serum neutralizing antibody titers against both laboratory strains and clinical isolates of RSV. When compared with PFP-2 alone, the resultant neutralizing antibody titers after vaccination with PFP-2+Ga protein were significantly elevated against 71% of A strains tested. In a confirmatory experiment, immunization with PFP-3+Ga+Gb proteins resulted in elevated serum neutralizing antibody titers against 86% of A and 50% of B strains tested versus injection with PFP-3 alone. The results suggest that subunit vaccines composed of both PFP and G proteins have more potential than PFP alone to augment neutralizing antibody titers in seropositive recipients.
Collapse
|
303
|
Vincent B, Smith JD. Effect of estradiol on neuronal Swedish-mutated beta-amyloid precursor protein metabolism: reversal by astrocytic cells. Biochem Biophys Res Commun 2000; 271:82-5. [PMID: 10777685 DOI: 10.1006/bbrc.2000.2581] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease is the most frequent neurodegenerative disorder in the aged population and is characterized by the deposition of the 40/42-residue amyloid beta protein (Abeta), a proteolytic fragment of the beta-amyloid precursor protein (APP). Recently, it has been shown that physiological doses of estradiol reduce the generation of endogenous Abeta in primary cortical neurons. Here we investigate the influence of estrogen in amyloidogenesis and sAPPalpha secretion in the CNS. By means of primary cortical neurons overexpressing humanized APP(695) bearing the Swedish mutation (hAPP(695sw)), we analyzed APP maturation in the absence or in the presence of estrogen. We show that estrogen at a 2 microM concentration increases the release of the neuroprotective sAPPalpha fragment but does not reduce the release of Abeta in primary neurons overexpressing the Swedish-mutated form of APP. Furthermore, neurons cocultured with astrocytic cells or grown with astrocytes conditioned media do not exhibit the estrogen-induced increase in sAPPalpha secretion. Altogether, our data indicate that astrocytes interfere with estrogen in the regulation of sAPPalpha secretion, probably via secreted factor(s).
Collapse
|
304
|
Febbraio M, Podrez EA, Smith JD, Hajjar DP, Hazen SL, Hoff HF, Sharma K, Silverstein RL. Targeted disruption of the class B scavenger receptor CD36 protects against atherosclerotic lesion development in mice. J Clin Invest 2000; 105:1049-56. [PMID: 10772649 PMCID: PMC300837 DOI: 10.1172/jci9259] [Citation(s) in RCA: 755] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Macrophage scavenger receptors have been implicated as key players in the pathogenesis of atherosclerosis. To assess the role of the class B scavenger receptor CD36 in atherogenesis, we crossed a CD36-null strain with the atherogenic apo E-null strain and quantified lesion development. There was a 76.5% decrease in aortic tree lesion area (Western diet) and a 45% decrease in aortic sinus lesion area (normal chow) in the CD36-apo E double-null mice when compared with controls, despite alterations in lipoprotein profiles that often correlate with increased atherogenicity. Macrophages derived from CD36-apo E double-null mice bound and internalized more than 60% less copper-oxidized LDL and LDL modified by monocyte-generated reactive nitrogen species. A similar inhibition of in vitro lipid accumulation and foam cell formation after exposure to these ligands was seen. These results support a major role for CD36 in atherosclerotic lesion development in vivo and suggest that blockade of CD36 can be protective even in more extreme proatherogenic circumstances.
Collapse
|
305
|
Smith JD, Lawson C, Yacoub MH, Rose ML. Activation of NF-kappa B in human endothelial cells induced by monoclonal and allospecific HLA antibodies. Int Immunol 2000; 12:563-71. [PMID: 10744658 DOI: 10.1093/intimm/12.4.563] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Chronic graft rejection, characterized by a gradual occlusion of grafted vessels, is the most serious complication following heart and kidney transplantation. Although often associated with chronic production of anti-HLA and anti-endothelial antibodies, the precise role of antibodies in chronic rejection remains uncertain. Here we have investigated whether HLA-specific antibodies, either monoclonal or derived from patients, cause endothelial cell activation. Thus we investigated tyrosine phosphorlyation, NF-kappaB activation and cell proliferation in human umbilical vein endothelial cells (HUVEC) or microvascular endothelial cells from adult human heart (CMEC). Ligation of monomorphic determinants of MHC class I molecules (using the mAb W6/32) on the surface of HUVEC caused an increase in tyrosine phosphorylation of proteins of mol. wt approximately 75-80 kDa. Similarly, ligation of monomorphic determinants on both CMEC and HUVEC resulted in increased NF-kappaB binding compared to controls (by 74.4 and 52.5%, P = 0.001) and this was enhanced by addition of secondary antibody. Two HLA-specific mAb resulted in a 277 and 170% increase in NF-kappaB-binding activity compared to controls. Four patient samples containing HLA antibodies were used against HLA-specific HUVEC and four samples were incubated with HUVEC bearing irrelevant antigens. Patient sera alone enhanced NF-kappaB binding by 27-186%, but only when added to HUVEC bearing relevant antigens. W6/32 and allospecific antibodies from patients significantly enhanced HUVEC proliferation, measured by uptake of [(3)H]thymidine. In conclusion, activation of NF-kappaB by human anti-HLA antibodies demonstrates their potential role in pathogenesis of chronic vascular occlusive disease following transplantation.
Collapse
|
306
|
Sim RS, Smith JD, Chan AS. Comparison of the aesthetic facial proportions of southern Chinese and white women. ARCHIVES OF FACIAL PLASTIC SURGERY 2000; 2:113-20. [PMID: 10925436 DOI: 10.1001/archfaci.2.2.113] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To compare the aesthetic facial proportions of southern Chinese women with published average and ideal values for white women. DESIGN One hundred Chinese women between the ages of 18 and 40 years who had not undergone previous facial surgery were chosen at random, and their aesthetic facial proportions were measured from 5 x 7-in photographs. Comparisons were made with similar reported measurements for the white face, and the surgical relevance of the differences observed is discussed. RESULTS The major facial differences observed in the Chinese face were the wider intercanthal distance, the wider nasal base, a different profile of the lower face, and differences in the eyelids. The Chinese nose was less prominent, the alae were more flared, the nostrils were more horizontally oriented, the alar-columellar relationships were different, and the nasal tip was less defined. CONCLUSIONS Although the general principles of facial plastic surgery apply to both white and Chinese faces, the aesthetic goals are different. The aim is to retain the ethnicity and natural appearance of the face.
Collapse
|
307
|
Smith JD, Minda JP. Thirty categorization results in search of a model. J Exp Psychol Learn Mem Cogn 2000. [PMID: 10682288 DOI: 10.1037//0278-7393.26.1.3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
One category structure dominated in the shift toward exemplar-based theories of categorization. Given the theoretical burden on this category structure, the authors reanalyzed 30 of its uses over 20 years in 8 articles. The authors suggest 4 conclusions. (a) This category structure may encourage exemplar-memorization processes because of its poor structure, the learning difficulties it causes, and its small, memorizable exemplar sets. Its results may only generalize narrowly. (b) Exemplar models have an advantage in fitting these 30 data sets only because they reproduce a performance advantage for training items. Other models fit equally well if granted this capacity. (c) A simpler exemplar process than assumed by exemplar models suffices to explain these data sets. (d) An important qualitative result predicted by exemplar theory is not found overall and possibly should not even be expected. The authors conclude that the data produced by this category structure do not clearly support exemplar theory.
Collapse
|
308
|
Pribaz JJ, Meara JG, Wright S, Smith JD, Stephens W, Breuing KH. Lip and vermilion reconstruction with the facial artery musculomucosal flap. Plast Reconstr Surg 2000; 105:864-72. [PMID: 10724244 DOI: 10.1097/00006534-200003000-00007] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The lips are a complex laminated structure. When lost through injury or disease, they present a complex reconstructive challenge. The facial artery musculomucosal (FAMM) flap is a composite flap with features similar to those of lip tissue. In this article, the anatomy, dissection, and clinical applications for the use of the FAMM flap in lip and vermilion reconstruction are discussed. A series of 16 FAMM flaps in 13 patients is presented. Seven patients had upper-lip reconstruction and six had lower-lip reconstruction. Superiorly based FAMM flaps were used in eight patients, and eight inferiorly based flaps were performed in five patients. Three patients had bilateral, inferiorly based flaps. In summary, the FAMM flap is a local flap that can be used for lip and vermilion reconstruction. Although not identical to the lip, it has many similar features, which make it an excellent option for lip reconstruction.
Collapse
|
309
|
Abstract
Apolipoprotein E (apoE) was discovered as a plasma protein involved in lipoprotein metabolism. ApoE is synthesized by the liver and is also made locally in the brain. There are three common variants of apoE, resulting from common genetic variation, called E2, E3 and E4. The E3 allele is the most prevalent form, and the proportion of the three alleles differs between populations. Epidemiological studies have found that the E4 allele is associated with decreased longevity, increased plasma cholesterol levels and increased prevalence for cardiovascular disease and particularly for Alzheimer's disease. The apoE polymorphism also affects response to head trauma, cognitive decline upon ageing and several other disorders. Thus, common genetic variation in the apoE gene may be associated with successful ageing.
Collapse
|
310
|
Saadeh E, Szatkowski M, Vary CP, Smith JD, Himmelfarb J, Mahoney RJ. HLA-DMA allele polymorphism: no impact on kidney allograft outcome. Hum Immunol 2000; 61:345-7. [PMID: 10689127 DOI: 10.1016/s0198-8859(99)00178-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to analyze the association of HLA-DMA alleles with rejection episodes and early graft loss (EGL) in renal transplant recipients. One hundred and eighty four HLA-DMA alleles were retrospectively analyzed by DNA sequence analysis in 92 kidney transplant recipients. The gene frequencies of HLA-DMA *0101, *0102, *0103 and *0104 were found to be similar in all recipients, regardless of rejection vs non rejection episodes and EGL incidence. In conclusion, HLA-DMA allele polymorphism did not impact renal allograft outcome.
Collapse
|
311
|
Smith JD, Craig AG, Kriek N, Hudson-Taylor D, Kyes S, Fagan T, Fagen T, Pinches R, Baruch DI, Newbold CI, Miller LH. Identification of a Plasmodium falciparum intercellular adhesion molecule-1 binding domain: a parasite adhesion trait implicated in cerebral malaria. Proc Natl Acad Sci U S A 2000; 97:1766-71. [PMID: 10677532 PMCID: PMC26510 DOI: 10.1073/pnas.040545897] [Citation(s) in RCA: 172] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Binding of infected erythrocytes to brain venules is a central pathogenic event in the lethal malaria disease complication, cerebral malaria. The only parasite adhesion trait linked to cerebral sequestration is binding to intercellular adhesion molecule-1 (ICAM-1). In this report, we show that Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) binds ICAM-1. We have cloned and expressed PfEMP1 recombinant proteins from the A4tres parasite. Using heterologous expression in mammalian cells, the minimal ICAM-1 binding domain was a complex domain consisting of the second Duffy binding-like (DBL) domain and the C2 domain. Constructs that contained either domain alone did not bind ICAM-1. Based on phylogenetic criteria, there are five distinct PfEMP1 DBL types designated alpha, beta, gamma, delta, and epsilon. The DBL domain from the A4tres that binds ICAM-1 is DBLbeta type. A PfEMP1 cloned from a distinct ICAM-1 binding variant, the A4 parasite, contains a DBLbeta domain and a C2 domain in tandem arrangement similar to the A4tres PfEMP1. Anti-PfEMP1 antisera implicate the DBLbeta domain from A4var PfEMP1 in ICAM-1 adhesion. The identification of a P. falciparum ICAM-1 binding domain may clarify mechanisms responsible for the pathogenesis of cerebral malaria and lead to interventions or vaccines that reduce malarial disease.
Collapse
|
312
|
Smith JD. The power of mental retardation: reflections on the value of people with disabilities. MENTAL RETARDATION 2000; 38:70-2. [PMID: 10703220 DOI: 10.1352/0047-6765(2000)038<0070:tpomrr>2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
313
|
Milczuk HA, Smith JD, Everts EC. Congenital laryngeal webs: surgical management and clinical embryology. Int J Pediatr Otorhinolaryngol 2000; 52:1-9. [PMID: 10699233 DOI: 10.1016/s0165-5876(99)00284-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Laryngeal webs are uncommon congenital anomalies. The formation of a laryngeal web represents anomalous embryologic development of the larynx. The extent of airway involvement varies which ultimately affects surgical management. A series of five congenital laryngeal webs each with subglottic involvement is reported. One patient also had a ventral laryngeal cleft. All patients ultimately required open laryngeal reconstruction, either laryngotracheal reconstruction (LTR) or thyrotomy (laryngofissure) and silastic keel, to correct the defect and all were decannulated. Findings at surgery correlate with recent descriptions of embryonic laryngeal development though the actual mechanism by which webs develop remains unknown. The findings suggest that congenital glottic webs require accurate endoscopic diagnosis and open airway reconstruction for definitive treatment.
Collapse
|
314
|
Farrar JD, Smith JD, Murphy TL, Murphy KM. Recruitment of Stat4 to the human interferon-alpha/beta receptor requires activated Stat2. J Biol Chem 2000; 275:2693-7. [PMID: 10644731 DOI: 10.1074/jbc.275.4.2693] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Stat4 activation is involved in differentiation of type 1 helper (Th1) T cells. Although Stat4 is activated by interleukin (IL)-12 in both human and murine T cells, Stat4 is activated by interferon (IFN)-alpha only in human, but not murine, CD4(+) T cells. This species-specific difference in cytokine activation of Stat4 underlies critical differences in Th1 development in response to cytokines and is important to the interpretation of murine models of immunopathogenesis. Here, we sought to determine the mechanism of Stat4 recruitment and activation by the human IFN-alpha receptor. Analysis of phosphopeptide binding analysis suggests that Stat4 does not interact directly with tyrosine-phosphorylated amino acid residues within the cytoplasmic domains of either of the subunits of the IFN-alpha receptor complex. Expression of murine Stat4 in the Stat1-deficient U3A and the Stat2-deficient U6A cell lines shows that IFN-alpha-induced Stat4 phosphorylation requires the presence of activated Stat2 but not Stat1. Thus, in contrast to the direct recruitment of Stat4 by the IL-12 receptor, Stat4 activation by the human IFN-alpha receptor occurs through indirect recruitment by intermediates involving Stat2.
Collapse
|
315
|
Abstract
One category structure dominated in the shift toward exemplar-based theories of categorization. Given the theoretical burden on this category structure, the authors reanalyzed 30 of its uses over 20 years in 8 articles. The authors suggest 4 conclusions. (a) This category structure may encourage exemplar-memorization processes because of its poor structure, the learning difficulties it causes, and its small, memorizable exemplar sets. Its results may only generalize narrowly. (b) Exemplar models have an advantage in fitting these 30 data sets only because they reproduce a performance advantage for training items. Other models fit equally well if granted this capacity. (c) A simpler exemplar process than assumed by exemplar models suffices to explain these data sets. (d) An important qualitative result predicted by exemplar theory is not found overall and possibly should not even be expected. The authors conclude that the data produced by this category structure do not clearly support exemplar theory.
Collapse
|
316
|
Brody EN, Willis MC, Smith JD, Jayasena S, Zichi D, Gold L. The use of aptamers in large arrays for molecular diagnostics. MOLECULAR DIAGNOSIS : A JOURNAL DEVOTED TO THE UNDERSTANDING OF HUMAN DISEASE THROUGH THE CLINICAL APPLICATION OF MOLECULAR BIOLOGY 1999; 4:381-8. [PMID: 10671648 DOI: 10.1016/s1084-8592(99)80014-9] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Aptamers are single-stranded oligonucleotides derived from an in vitro evolution protocol called systematic evolution of ligands by exponential enrichment (SELEX). They bind tightly and specifically to target molecules; most aptamers to proteins bind with Kds (equilibrium dissociation constant) in the range of 1 pM to 1 nM. METHODS AND RESULTS The SELEX protocol has been automated; therefore, hundreds to thousands of aptamers can be made in an economically feasible fashion. Blood and urine can be analyzed on chips that capture and quantitate proteins. SELEX has been adapted to the use of 5-bromo (5-Br) and 5-iodo (5-I) deoxyuridine residues. These halogenated bases can be specifically cross-linked to proteins. Selection pressure during in vitro evolution can be applied for both binding specificity and specific photo-cross-linkability. These are sufficiently independent parameters to allow one reagent, a photo-cross-linkable aptamer, to substitute for two reagents, the capture antibody and the detection antibody, in a typical sandwich array. After a cycle of binding, washing, cross-linking, and detergent washing, proteins will be specifically and covalently linked to their cognate aptamers. CONCLUSIONS Because no other proteins are present on the chips, protein-specific stain will now show a meaningful array of pixels on the chip. Learning algorithms and retrospective studies should lead to a robust, simple, diagnostic chip.
Collapse
|
317
|
Smith JD. Darwin's last child: mental retardation and the need for a romantic science. MENTAL RETARDATION 1999; 37:504-6. [PMID: 10635673 DOI: 10.1352/0047-6765(1999)037<0504:dlcmra>2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
318
|
Perlyn C, Meara JG, Smith JD, Breuing KH, Bartlett R. Secondary reconstruction of a giant congenital lentiginous dermal nevus with serial, large-volume tissue expansion. Ann Plast Surg 1999; 43:546-50. [PMID: 10560874 DOI: 10.1097/00000637-199911000-00015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Giant congenital pigmented nevi pose a substantial reconstructive challenge for the treating physician. Due to the increased risk of malignant transformation in such lesions, complete excision with tissue expansion or skin grafting is the generally accepted treatment. These modalities can, however, leave the patient with secondary deformities that also require complex reconstructive procedures. The following case details a patient requiring secondary reconstruction with large-volume tissue expansion 12 years after excision of a giant nevus, and split-thickness skin grafting. This patient illustrates a severe secondary deformity and the usefulness of large-volume serial expansion in such patients.
Collapse
|
319
|
Buffet PA, Gamain B, Scheidig C, Baruch D, Smith JD, Hernandez-Rivas R, Pouvelle B, Oishi S, Fujii N, Fusai T, Parzy D, Miller LH, Gysin J, Scherf A. Plasmodium falciparum domain mediating adhesion to chondroitin sulfate A: a receptor for human placental infection. Proc Natl Acad Sci U S A 1999; 96:12743-8. [PMID: 10535993 PMCID: PMC23079 DOI: 10.1073/pnas.96.22.12743] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Malaria during the first pregnancy causes a high rate of fetal and neonatal death. The decreasing susceptibility during subsequent pregnancies correlates with acquisition of antibodies that block binding of infected red cells to chondroitin sulfate A (CSA), a receptor for parasites in the placenta. Here we identify a domain within a particular Plasmodium falciparum erythrocyte membrane protein 1 that binds CSA. We cloned a var gene expressed in CSA-binding parasitized red blood cells (PRBCs). The gene had eight receptor-like domains, each of which was expressed on the surface of Chinese hamster ovary cells and was tested for CSA binding. CSA linked to biotin used as a probe demonstrated that two Duffy-binding-like (DBL) domains (DBL3 and DBL7) bound CSA. DBL7, but not DBL3, also bound chondroitin sulfate C (CSC) linked to biotin, a negatively charged sugar that does not support PRBC adhesion. Furthermore, CSA, but not CSC, blocked the interaction with DBL3; both CSA and CSC blocked binding to DBL7. Thus, only the DBL3 domain displays the same binding specificity as PRBCs. Because protective antibodies present after pregnancy block binding to CSA of parasites from different parts of the world, DBL-3, although variant, may induce cross-reactive immunity that will protect pregnant women and their fetuses.
Collapse
|
320
|
Smith JD, Staehelin LA, Todd P. Early root cap development and graviresponse in white clover (Trifolium repens) grown in space and on a two-axis clinostat. JOURNAL OF PLANT PHYSIOLOGY 1999; 155:543-550. [PMID: 11543182 DOI: 10.1016/s0176-1617(99)80052-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
White clover (Trifolium repens) was germinated and grown in microgravity aboard the Space Shuttle (STS-60, 1994; STS-63, 1995), on Earth in stationary racks and in a slow-rotating two-axis clinostat. The objective of this study was to determine if normal root cap development and early plant gravity responses were dependent on gravitational cues. Seedlings were germinated in space and chemically fixed in orbit after 21, 40, and 72 h. Seedlings 96 h old were returned viable to earth. Germination and total seedling length were not dependent on gravity treatment. In space-flown seedlings, the number of cell stories in the root cap and the geometry of central columella cells did not differ from those of the Earth-grown seedlings. The root cap structure of clinorotated plants appeared similar to that of seedlings from microgravity, with the exception of three-day rotated plants, which displayed significant cellular damage in the columella region. Nuclear polarity did not depend on gravity; however, the positions of amyloplasts in the central columella cells were dependent on both the gravity treatment and the age of the seedlings. Seedlings from space, returned viable to earth, responded to horizontal stimulation as did 1 g controls, but seedlings rotated on the clinostat for the same duration had a reduced curvature response. This study demonstrates that initial root cap development is insensitive to either chronic clinorotation or microgravity. Soon after differentiation, however, clinorotation leads to loss of normal root cap structure and plant graviresponse while microgravity does not.
Collapse
|
321
|
Takahashi Y, Smith JD. Cholesterol efflux to apolipoprotein AI involves endocytosis and resecretion in a calcium-dependent pathway. Proc Natl Acad Sci U S A 1999; 96:11358-63. [PMID: 10500181 PMCID: PMC18038 DOI: 10.1073/pnas.96.20.11358] [Citation(s) in RCA: 190] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We previously have described the cAMP-mediated induction of cholesterol and phospholipid efflux from the murine macrophage RAW264 cell line to lipid-free apolipoprotein acceptors. This induction of cholesterol efflux is associated with increased binding and association of apolipoprotein to the cells. In the present study, using primarily apolipoprotein AI (apoAI) as the acceptor, cAMP-dependent cholesterol efflux to apolipoprotein acceptors was associated with apoAI binding to coated pits, cellular uptake, and resecretion. After cell association and washing, 58% of the apoAI was resecreted during a 90-min chase period. In addition, after apoAI uptake and washing, cholesterol efflux was observed during a chase period without additional acceptors. Cholesterol efflux was partially blocked by chlorpromazine and hypertonic media, two inhibitors of coated pit endocytosis. Cholesterol efflux to apoAI was found to depend on extracellular calcium. By temporally separating the cAMP induction phase from the apoAI chase phase, calcium was found to be required during the apoAI chase phase rather than during the cAMP induction period. In the absence of calcium the 8-Br-cAMP-mediated induction of apoAI binding was maintained, but the specific apoAI cellular association was inhibited. The data are consistent with a model for cholesterol efflux to apolipoproteins that involves a calcium-dependent endocytic pathway, followed by recycling and the subsequent release of the nascent lipoprotein particle from the cell.
Collapse
|
322
|
Dansky HM, Charlton SA, Sikes JL, Heath SC, Simantov R, Levin LF, Shu P, Moore KJ, Breslow JL, Smith JD. Genetic background determines the extent of atherosclerosis in ApoE-deficient mice. Arterioscler Thromb Vasc Biol 1999; 19:1960-8. [PMID: 10446078 DOI: 10.1161/01.atv.19.8.1960] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Two strains of ApoE-deficient mice were found to have markedly different plasma lipoprotein profiles and susceptibility to atherosclerosis when fed either a low-fat chow or a high-fat Western-type diet. FVB/NJ ApoE-deficient (FVB E0) mice had higher total cholesterol, HDL cholesterol, ApoA1, and ApoA2 levels when compared with C57BL/6J ApoE-deficient (C57 E0) mice. At 16 weeks of age, mean aortic root atherosclerotic lesion area was 7- to 9-fold higher in chow diet-fed C57 E0 mice and 3.5-fold higher in Western diet-fed C57 E0 mice compared with FVB E0 mice fed similar diets. Lesion area in chow diet-fed first-generation mice from a strain intercross was intermediate in size compared with parental values. The distribution of the lesion area in 150 chow diet-fed second-generation progeny spanned the range of the lesion area in both parental strains. There were no correlations between total cholesterol, non-HDL cholesterol, HDL cholesterol, ApoA1, ApoA2, ApoJ, or anti-cardiolipin antibodies and lesion area in the second-generation progeny. Thus, a genomic approach may succeed in identifying the genes responsible for the variation in atherosclerosis susceptibility in these 2 strains of ApoE-deficient mice, which could not be explained by measured plasma parameters.
Collapse
|
323
|
De Oliveira e Silva ER, Kong M, Han Z, Starr C, Kass EM, Juo SH, Foster D, Dansky HM, Merkel M, Cundey K, Brinton EA, Breslow JL, Smith JD. Metabolic and genetic determinants of HDL metabolism and hepatic lipase activity in normolipidemic females. J Lipid Res 1999; 40:1211-21. [PMID: 10393206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Abstract
The metabolic and genetic determinants of HDL cholesterol (HDL-C) levels and HDL turnover were studied in 36 normolipidemic female subjects on a whole-food low-fat metabolic diet. Lipid, lipoprotein, and apolipoprotein levels, lipoprotein size, and apolipoprotein turnover parameters were determined, as were genetic variation at one site in the hepatic lipase promoter and six sites in the apolipoprotein AI/CIII/AIV gene cluster. Menopause had no significant effect on HDL-C or turnover. Stepwise multiple regression analysis revealed that HDL-C was most strongly correlated with HDL size, apolipoprotein A-II (apoA-II), and apolipoprotein A-I (apoA-I) levels, which together could account for 90% of the variation in HDL-C. HDL size was inversely correlated with triglycerides, body mass index, and hepatic lipase activity, which together accounted for 82% of the variation in HDL size. The hepatic lipase promoter genotype had a strong effect on hepatic lipase activity and could account for 38% of the variation in hepatic lipase activity. The apoA-I transport rate (AI-TR) was the major determinant of apoA-I levels, but AI-TR was not associated with six common genetic polymorphism in the apoAI/CIII/AIV gene cluster.A simplified model of HDL metabolism is proposed, in which A-I and apoA-II levels combined with triglycerides, and hepatic lipase activity could account for 80% of the variation in HDL-C.
Collapse
|
324
|
Dansky HM, Charlton SA, Barlow CB, Tamminen M, Smith JD, Frank JS, Breslow JL. Apo A-I inhibits foam cell formation in Apo E-deficient mice after monocyte adherence to endothelium. J Clin Invest 1999; 104:31-9. [PMID: 10393696 PMCID: PMC408406 DOI: 10.1172/jci6577] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We have previously shown that expression of the human apo A-I transgene on the apo E-deficient background increases HDL cholesterol and greatly diminishes fatty streak lesion formation. To examine the mechanism, prelesional events in atherosclerotic plaque development were examined in 6- to 8-week-old apo E-deficient and apo E-deficient/human apo A-I transgenic mice. A quantitative assessment of subendothelial lipid deposition by freeze-fracture and deep-etch electron microscopy indicated that elevated apo A-I did not affect the distribution or amount of aortic arch subendothelial lipid deposits. Immunohistochemical staining for VCAM-1 demonstrated similar expression on endothelial cells at prelesional aortic branch sites from both apo E-deficient and apo E-deficient/human apo A-I transgenic mice. Transmission electron microscopy revealed monocytes bound to the aortic arch in mice of both genotypes, and immunohistochemical staining demonstrated that the area occupied by bound mononuclear cells was unchanged. Serum paraoxonase and aryl esterase activity did not differ between apo E-deficient and apo E-deficient/human apo A-I transgenic mice. These data suggest that increases in apo A-I and HDL cholesterol inhibit foam cell formation in apo E-deficient/human apo A-I transgenic mice at a stage following lipid deposition, endothelial activation, and monocyte adherence, without increases in HDL-associated paraoxonase.
Collapse
|
325
|
Abstract
Malformations of the tongue are rare. There are < 50 cases of tongue hypoplasia reported in the literature since the first case described by de Jussieu in 1718. These are usually associated with the hypoglossia-hypodactaly syndrome. We describe a newborn with a hypoplastic anterior tongue unfused to the posterior tongue and airway obstruction. Its embryology, theories of pathogenesis, treatment and clinical course are discussed.
Collapse
|