SEARCH · PubMed Health

Results for “RAP”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources

PubMed2003

Cell cycle arrest by Kaposi's sarcoma-associated herpesvirus replication-associated protein is mediated at both the transcriptional and posttranslational levels by binding to CCAAT/enhancer-binding protein alpha and p21(CIP-1).

Lytic-cycle replication of Kaposi's sarcoma-associated herpesvirus (KSHV) in PEL cells causes G(1) cell cycle arrest mediated by the virus-encoded replication-associated protein (RAP) (or K8 protein), which induces high-level expression of the cellular C/EBPalpha and p21 proteins. Here we have examined the mechanism of this induction at both the transcriptional and posttranslational levels. RAP proved to bind very efficiently to both C/EBPalpha and p21 and stabilized them by up to 10-fold from proteasome-mediated degradation in vitro. Cross-linking revealed that RAP itself forms stable dimers and tetramers in solution and forms higher-order complexes but not heterodimers with C/EBPalpha. Cotransfection of RAP with C/EBPalpha cooperatively stimulated both the C/EBPalpha and p21 promoters in luciferase reporter gene assays. Only the basic/leucine zipper region of RAP was needed for interaction with and stabilization of C/EBPalpha, but both the N-terminal and C-terminal domains were required for transcriptional augmentation. In vitro-translated RAP interfered with DNA binding by C/EBPalpha in electrophonetic mobility shift assay (EMSA) experiments but did not itself bind to the target C/EBPalpha sites or form supershifted bands. However, in endogenous chromatin immunoprecipitation (ChIP) assays with tetradecanoyl phorbol acetate-induced PEL cells, RAP proved to specifically associate with the C/EBPalpha promoter in vivo, but only in a C/EBPalpha-dependent manner, implying an in vivo piggyback interaction with DNA-bound C/EBPalpha. Expression of exogenous RAP (Ad-RAP) caused G(1)/S cell cycle arrest in human dermal microvascular endothelial cells and also induced both the C/EBPalpha and p21 proteins, which formed punctate nuclear patterns that colocalized with RAP in PML nuclear bodies. In the presence of RAP, C/EBPalpha was also efficiently recruited into viral DNA replication compartments in both infected and cotransfected cells. In support of a direct role for this interaction in viral DNA replication, three C/EBPalpha binding sites were identified by in vitro EMSA experiments within a 220-bp core segment of the duplicated KSHV Ori-Lyt region, and although RAP did not bind to Ori-Lyt DNA directly in vitro, both endogenous RAP and C/EBPalpha were found to be associated with the Ori-Lyt region by ChIP assays in lytically induced PEL cells. Finally, we found that the KSHV lytic cycle could not be triggered by either synchronizing KSHV latently infected PEL cells in G(1) phase or inducing p21 in a C/EBPalpha-independent process.

Base Sequence↗

PubMed1994

Expression of gp330 and gp330/alpha 2-macroglobulin receptor-associated protein in renal tubular differentiation.

The gp330/alpha 2-macroglobulin receptor-associated protein (RAP) is a 39- to 45-kd protein that binds to the low-density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor and to gp330, a major glycoprotein of the brush border of proximal tubule cells. Despite evidence that gp330 functions as a receptor for several ligands and that soluble RAP inhibits ligand binding to gp330 in vitro, the physiologic function of RAP is unknown. Given the predominant location of RAP within the rough endoplasmic reticulum (RER), RAP might be involved in the intracellular processing and/or transport of gp330. The developing rat kidney was used as a dynamic model to study in detail the relationship between gp330 and RAP in vivo by immunohistochemical techniques. RAP was expressed in the renal vesicle and continued to be present, with a vesicular and perinuclear pattern of staining, in both proximal tubule cells and glomerular cells at subsequent stages. Immunoperoxidase electron microscopy demonstrated RAP in cisternae of the RER and in large subapical vesicles. gp330 was initially expressed in early proximal tubule cells in S-shaped bodies and was located in the perinuclear envelope and cytoplasmic vesicles as well as at the apical surface. Cytoplasmic gp330 staining was more evident at a stage subsequent to the S-shaped body, possibly related to more active biosynthesis. By comparative analysis of the patterns of immunofluorescence and immunoperoxidase staining, gp330 and RAP colocalized in the RER and in some large subapical vacuoles, but no definite RAP staining could be detected at the surface of proximal tubule cells at any stage, despite the presence of abundant gp330 in this location. The expression of gp330 at the apical surface of immature tubular cells was associated with the onset of fluid-phase endocytosis of fluoroscein isothiocyanate-dextran and, therefore, of reabsorption of material from the tubular lumen, in the absence of concomitant changes in RAP expression in the same cells. These findings indicate that the role of endogenous RAP may not be directly related to ligand binding of gp330 at the surface of proximal tubule cells, although RAP may be involved in the processing and the intracellular trafficking of newly synthesized gp330, in particular in the delivery of gp330 to the plasma membrane.

Animals↗

PubMed1990

The immunosuppressive macrolides FK-506 and rapamycin act as reciprocal antagonists in murine T cells.

The structurally related immunosuppressive macrolides FK-506 and rapamycin (RAP) were previously shown to inhibit T cell stimulation through different mechanisms. FK-506 acts similarly to cyclosporin A (CsA) and prevents IL-2 production and IL-2R expression. RAP has little or no effect on these events but markedly impedes the response to IL-2. The present study was initiated to examine the possibility of a complementation between the immunosuppressive actions of RAP and FK-506 or CsA on various murine T cell responses. RAP potentiated the effect of CsA on proliferation and IL-2R expression in T cells stimulated with ionomycin + PMA. However, in the same system, RAP acted as a potent antagonist of FK-506 suppression. RAP also blocked FK-506- but not CsA-mediated inhibition of IL-2 mRNA induction. By using model systems sensitive to inhibition by RAP but not FK-506 we further demonstrated that FK-506 reciprocally behaves as an antagonist of RAP. In one such model, the stimulation of splenic T cells with IL-2 + PMA, FK-506, but not CsA, reversed the suppressive effect of RAP on proliferation. FK-506 also antagonized RAP-mediated inhibition with respect to the induction of Ly-6E Ag expression by IFN in YAC cells. To explore further the competition between the two macrolides at the cellular level, we performed binding experiments with a radiolabeled derivative of FK-506. Both FK-506 and RAP, but not CsA, inhibited the binding of this probe in YAC cells. Taken together, these data demonstrate that FK-506 and RAP antagonize each other's biologic activity and physically interact with a common receptor site(s) in T cells. Moreover, CsA acts at a site distinct from the cellular target(s) of FK-506 or RAP.

Animals↗

PubMed1994

Pre-discharge atrial pacing test in evaluation of risk stratification after uncomplicated myocardial infarction.

Right atrial pacing (RAP) using three pacing stages (I: 100 BPM/5 min; II: 120 BPM/5 min; III: 140 BPM/5 min) was performed for residual myocardial ischemia, hypotensive response and related prognostic significance in 55 uncomplicated acute myocardial infarction (AMI) patients. We aimed to clarify whether early risk stratification and jeopardized myocardium score, calculated using pacing results, could predict disease severity and future major cardiac events during long-term follow-up. During RAP testing, 24 patients displayed negative and 31 patients positive RAP. The positive RAP group had a significantly higher incidence of multivessel disease, higher jeopardized myocardium scores and left ventricular end-diastolic pressure than the negative RAP group. As expected, according to pacing response the disease severity score also showed a significant difference. During the one-year follow-up, there were three recurrent angina attacks, reinfarction and two congestive heart failures in the negative RAP group. In the positive RAP group, four died, six had new or recurrent myocardial infarctions and six developed congestive heart failure. Only six patients in the positive RAP group carried the critical risk, four suffered from recurrent angina, two developed reinfarction, three developed congestive heart failure, and two died. Total major cardiac events in the positive RAP group appeared to significantly increase compared to those in the negative RAP group. Our results show that early RAP with three pacing stages is useful in predicting subsequent major cardiac events after uncomplicated myocardial infarction. We also observed that hypotensive response during positive RAP represents the best predictor of critical risk requiring further invasive studies. We believe that RAP is justified for risk strategy.

Aged↗

PubMed1997

Inhibition of CTL induction by rapamycin: IL-2 rescues granzyme B and perforin expression but only partially restores cytotoxic activity.

Rapamycin (RAP) is a potent inhibitor of CTL induction. Since RAP is known to block IL-2 signaling through the IL-2R, we hypothesized that RAP may interfere with CTL generation by inhibiting IL-2-induced expression of granzyme (Gzm) B, perforin, and/or Fas ligand (FasL). MHC-unrestricted mouse CTL induced in vitro with anti-CD3 mAb in the presence of RAP (1 ng/ml) exhibited dramatically reduced cellular proliferation and cytotoxicity against P815 tumor target cells. Gzm B mRNA expression and enzymatic activity in RAP-treated CTL were greatly reduced compared with those in control CTL. Perforin mRNA expression was also reduced by RAP. In contrast, RAP failed to inhibit FasL mRNA expression. RAP, therefore, inhibits induction of the perforin/Gzm B cytolytic pathway but spares Fas/FasL-mediated cytotoxicity. To determine whether RAP exerts a total blockade of the IL-2R signaling pathway, we induced CTL in the presence of both RAP and exogenous rIL-2 (100 U/ml). Under these conditions, Gzm B and perforin mRNA and protein expression as well as cellular proliferation were restored to at least control levels. Surprisingly, inhibition of cytotoxicity was only partially alleviated when CTL were induced in the presence of RAP plus rIL-2, even though CTL conjugated normally with target cells and had an intact granule secretory pathway. We conclude that 1) the inhibitory effect of RAP at the level of the IL-2R is incomplete; and 2) the suppressive effect of RAP on CTL induction is only partly due to inhibition of Gzm B and perforin gene expression.

Animals↗

PubMed2000

Ribosomal stalk protein phosphorylating activities in Saccharomyces cerevisiae.

With ribosomal P protein as a substrate, five peaks of protein kinase activity are eluted after chromatography of a Saccharomyces cerevisiae cellular extract on DEAE-cellulose. Two of them correspond to CK-II and the other three have been called RAP-1, RAP-II, and RAP-III. RAP-I was previously characterized. RAP-III is present in a very small amount, which hindered its purification. RAP-II was further purified on phosphocellulose, heparin-Sepharose, and P protein-Sepharose, studied in detail, and compared with other acidic protein kinases, including RAP-I, CK-II, and PK60. RAP-II is shown by SDS-PAGE and centrifugation on glycerol linear density gradients to have a molecular mass of around 62 kDa and it is immunologically different from RAP-I and PK60. RAP-II phosphorylates the P proteins in the last serine residue at the highly conserved carboxyl terminal domain as other P-protein kinases. The ribosome-bound stalk P proteins are not equally phosphorylated by the different kinases. Thus, RAP-II and PK60 mainly phosphorylate P1beta and P2alpha whereas RAP-I and CK-II modify all of them. A comparative study of the K(m) and V(max) of the phosphorylation reaction by the different kinases using individual purified acidic proteins suggests changes in the substrate susceptibility upon binding to the ribosome. All the data available reveal clear differences in the characteristics of the various P protein kinases and suggest that the cell may use them to differentially modify the stalk depending, perhaps, on metabolic requirements.

Amino Acid Sequence↗

PubMed2002

Prospective comparison of radical retropubic prostatectomy and robot-assisted anatomic prostatectomy: the Vattikuti Urology Institute experience.

OBJECTIVES: Robotic assistance may enhance the precision of anatomic dissection and increase the feasibility of performing laparoscopic radical prostatectomy for most surgeons. We performed a prospective comparison of 30 consecutive patients undergoing conventional radical retropubic prostatectomy (RRP) and 30 initial patients undergoing robot-assisted anatomic prostatectomy (RAP) at our institution. METHODS: The study design was a prospective nonrandomized comparison of anatomic RRP performed using the technique of Walsh and RAP performed with the da Vinci surgical system. We evaluated the baseline patient and tumor characteristics (age, body mass index, serum prostate-specific antigen, Gleason score, and clinical stage), intraoperative parameters (operative time, blood loss, and need for transfusion), postoperative parameters (pain score, hospitalization duration, catheter duration), histopathologic parameters, and complications in the two groups. RESULTS: The preoperative parameters were comparable for both groups of patients. The mean setup time for RAP was 0.95 hours. The mean operating time was 2.3 hours for RRP and 4.8 hours for RAP (P <0.001). One patient required conversion from RAP to RRP because of a lack of progress. The mean blood loss was 970 mL for RRP and 329 mL for RAP (P <0.001). The drop in hemoglobin was greater in the RRP group (4.4 versus 1.2 g in RAP; P <0.05). The mean pain score on postoperative day 1 was 7 in the RRP group and 4 in RAP group (P = 0.05). The mean hospital stay was 56 hours in the RRP group and 36 hours in the RAP group (P value not significant). Sixty-three percent of the RAP and 0% of the RRP groups were discharged within 23 hours (P <0.001). The mean duration of postoperative catheterization was 14 days for the RRP and 11 days for the RAP groups (difference not significant). The pathologic stage, margin status, and prostate-specific antigen values were not different between the two groups. The setup time, operative time, blood loss amount, and catheterization duration were significantly reduced after the first 20 patients. CONCLUSIONS: Currently, RAP is a longer procedure than RRP. However, the blood loss is minimal and patients feel less pain and are discharged earlier from the hospital. In our hands, the margin status and complication rates were comparable for both techniques.

Aged↗

PubMed1996

Rapamycin inhibits protein kinase C activity and stimulates Na+ transport in A6 cells.

Rapamycin and FK506 have unique cellular effects despite the fact that they bind to the same set of immunophilins, the FK506 binding proteins (FKBP). We have previously reported that rapamycin (RAP) stimulates sodium transport in A6 cells. FK506 did not stimulate sodium transport but did inhibit the stimulation seen in RAP-treated cells. Since FKBP12 has been shown to have sequence homology with an endogenous inhibitor of protein kinase C (PKC) and PKC inhibition has been shown to increase Na+ channel activity in A6 cells, studies to determine the effect of RAP on PKC activity and its relationship to sodium transport were performed. Here we report that RAP stimulates sodium transport, and the effect is not additive to that seen with a cell-permeant inhibitor of PKCalpha and -beta subtypes. RAP significantly inhibits endogenous PKC activity in A6 cells both in membrane and cytosolic preparations. There is a strong correlation between the degree of inhibition of PKC activity and the stimulation of sodium transport by RAP. RAP has no effect on Na+/K+-ATPase activity over this time course. Purified recombinant FKBP12 with or without FK506 has no effect on PKC activity when incubated with a rat brain-derived PKC preparation of known activity. By contrast, RAP plus FKBP12 significantly inhibits PKC activity. RAP plus FKBP12 inhibits the PKCalpha and not the -beta subtype. The results demonstrate inhibition of PKC activity by RAP and not FK506 through its binding to FKBP12. The inhibition of PKC activity by RAP stimulates sodium transport in A6. The results therefore imply the existence of an endogenous RAP-like ligand which when bound to FKBP12 could regulate Na+ channel activity through this mechanism.

Animals↗

PubMed2001

High affinity binding of receptor-associated protein to heparin and low density lipoprotein receptor-related protein requires similar basic amino acid sequence motifs.

The 39-kDa receptor-associated protein (RAP) is a specialized chaperone for members of the low density lipoprotein receptor gene family, which also binds heparin. Previous studies have identified a triplicate repeat sequence within RAP that appears to exhibit differential functions. Here we generated a series of truncated and site-directed RAP mutants in order to define the sites within RAP that are important for interacting with heparin and low density lipoprotein receptor-related protein (LRP). We found that high affinity binding of RAP to heparin is mediated by the carboxyl-terminal repeat of RAP, whereas both the carboxyl-terminal repeat and a combination of amino and central repeats exhibit high affinity binding to LRP. Several motifs were found to mediate the binding of RAP to heparin, and each contained a cluster of basic amino acids; among them, an intact R(282)VSR(285)SR(287)EK(289) motif is required for high affinity binding of RAP to heparin, whereas two other motifs, R(203)LR(205)R(206) and R(314)ISR(317)AR(319), also contribute to this interaction. We also found that intact motifs of both R(203)LR(205)R(206) and R(282)VSR(285)SR(287)EK(289) are required for high affinity binding of RAP to LRP, with the third motif, R(314)ISR(317)AR(319), contributing little to RAP-LRP interaction. We conclude that electrostatic interactions likely contribute significantly in the binding of RAP to both heparin and LRP and that high affinity interaction with both heparin and LRP appears to require mostly overlapping sequence motifs within RAP.

Amino Acid Sequence↗

PubMed2006

Interaction of lipoprotein lipase and receptor-associated protein.

Receptor-associated protein (RAP) is a recognized chaperone/escort protein for members of the low density lipoprotein receptor family. In this report, we show that RAP binds to lipoprotein lipase (LPL) and may play a role in the maturation of LPL. Binding of highly purified RAP to LPL was demonstrated in vitro by solid phase assays, surface plasmon resonance, and rate zonal centrifugation. The dissociation constant for this interaction measured by the first two techniques ranged between 2.4 and 13 nM, values similar to those reported for the binding of RAP to LRP or gp330. The specificity of the interaction was demonstrated by competition with a panel of LPL monoclonal antibodies. Rate zonal centrifugation demonstrated the presence of a stable complex with an apparent Mr consistent with the formation of a complex between monomeric LPL and RAP. RAP x LPL complexes were co-immunoprecipitated in adipocyte lysates or from solutions of purified LPL and RAP. The interaction was also demonstrated in whole cells by cross-linking experiments. RAP-deficient adipocytes secreted LPL with a specific activity 2.5-fold lower than the lipase secreted by control cells. Heparin addition to cultured RAP-deficient adipocytes failed to stimulate LPL secretion in the medium, suggesting defective binding of the lipase to the plasma membrane. These studies demonstrate that RAP binds to LPL with high affinity both in purified systems and cell extracts and that RAP-deficient adipocytes secrete poorly assembled LPL. A function of RAP may be to prevent premature interaction of LPL with binding partners in the secretory pathway, namely LRP and heparan sulfate proteoglycan.

Adipocytes↗

PubMed2001

Analysis of cartilage-derived retinoic acid-sensitive protein in cerebrospinal fluid From patients With spinal diseases.

STUDY DESIGN: The expression of cartilage-derived retinoic acid-sensitive protein (CD-RAP) was measured in cerebrospinal fluid from patients with spinal diseases. OBJECTIVES: To quantify the levels of CD-RAP in human cerebrospinal fluid and to clarify its character. SUMMARY OF BACKGROUND DATA: Cartilage-derived retinoic acid-sensitive protein is a newly discovered, secreted molecule that is expressed during the chondrogenesis phase of endochondral bone formation and in articular cartilage. In recent studies CD-RAP has been detected in the serum of patients with melanoma and breast cancer, and it has been used to monitor tumor activity. However, the function of CD-RAP is unknown, and the expression of CD-RAP in human cerebrospinal fluid has never been reported. METHODS: The concentration of CD-RAP in human cerebrospinal fluid was measured by enzyme-linked immunosorbent assay with antihuman CD-RAP antibodies. Cerebrospinal fluid samples were collected from two groups of patients. Group 1, the control group, consisted of 40 patients: 22 with trauma and 18 with gynecologic diseases. Group 2 consisted of 172 patients with spinal diseases: 5 with meningioma, 5 with neurinoma, 5 with arachnoid cyst, 30 with cervical spondylotic myelopathy, 35 with lumbar disc herniation, 56 with lumbar canal stenosis, and 36 with scoliosis. RESULTS: The concentration of CD-RAP in the control group was 16.5 +/- 8.3 ng/mL. The concentrations of CD-RAP in Group 2 were: 35.3 +/- 14.7 ng/mL in meningioma, 23.5 +/- 7.41 ng/mL in neurinoma, 26.0 +/- 22.2 ng/mL in arachnoid cyst, 41.7 +/- 22.3 ng/mL in cervical myelopathy, 27.8 +/- 14.7 ng/mL in lumbar disc herniation, 36.5 +/- 18.4 ng/mL in lumbar canal stenosis, and 13.4 +/- 7.48 ng/mL in scoliosis. The concentrations of CD-RAP in cervical myelopathy, lumbar canal stenosis, and lumbar disc herniation were significantly higher than in the control group (P < 0.001). CONCLUSIONS: The CD-RAP concentration was low in the control group, whereas it was significantly higher in spinal diseases that cause spinal stenosis. CD-RAP is expressed in cerebrospinal fluid as a result of damage to or stressing of neural structures and could be a marker for spinal diseases.

Adolescent↗

PubMed2006

Critical review of resident assessment protocols.

OBJECTIVES: To evaluate the quality of all 18 federally mandated Resident Assessment Protocols (RAPs) by measuring their adherence to established criteria for clinical practice guidelines (CPGs). DESIGN: Analytical evaluation. SETTING: United States nursing homes. PARTICIPANTS: Eighteen federally mandated RAPs. MEASUREMENTS: Each RAP was evaluated using review criteria based on the 1992 Institute of Medicine criteria for measuring the quality of clinical practice guidelines. Criteria included measurements of RAP validity, reliability/reproducibility, clinical applicability, clinical flexibility, clarity/format, scheduled review, expertise needed to complete, multidisciplinary process, and resources needed to complete. Two reviewers, each a geriatrician with expertise in nursing home medicine, evaluated each RAP on the degree of compliance with each criterion using a 2-point scale for each criterion. RESULTS: Overall, no individual RAP met all of the review criteria. The Urinary Incontinence RAP best approximated all the review criteria. The Pressure Ulcer RAP received the lowest score. Notable deficiencies in most of the RAPs included poor validity, documentation, reliability, clinical flexibility, and clinical applicability. CONCLUSION: The RAPs synthesize large amounts of information into key points and recommendations. Nevertheless, RAPs perform poorly when held to formal standards expected for CPGs. Based on these findings, the authors and a technical expert panel convened by the Agency for Health Care Research and Quality generated recommendations that might improve the use and quality of future RAPs.

Documentation↗

PubMed1996

Babesia bovis rhoptry-associated protein 1 is immunodominant for T helper cells of immune cattle and contains T-cell epitopes conserved among geographically distant B. bovis strains.

The ability of rhoptry-associated protein 1 (RAP-1) of Babesia bovis and Babesia bigemina to confer partial protective immunity in cattle has stimulated interest in characterizing both B-cell and T-cell epitopes of these proteins. It was previously shown that B. bovis RAP-1 associates with the merozoite surface as well as rhoptries and expresses B-cell epitopes conserved among otherwise antigenically different B. bovis strains. An amino-terminal 307-amino-acid domain of the molecule that is highly conserved in the B. bigemina RAP-1 homolog did not contain cross-reactive B-cell epitopes. The studies reported here demonstrate that B. bovis RAP-1 is strongly immunogenic for T helper (Th) cells from B. bovis-immune cattle and that like B-cell epitopes, Th-cell epitopes are conserved in different B. bovis strains but not in B. bigemina RAP-1. Lymphocytes from cattle immune to challenge with the Mexico strain of B. bovis proliferated against recombinant B. bovis RAP-1 protein derived from the Mexico strain. T-cell lines established by stimulating lymphocytes with recombinant RAP-1 protein responded against B. bovis, but not B. bigemina, merozoites. T-cell lines established by repeated stimulation of lymphocytes with B. bovis membrane antigen proliferated strongly against RAP-1, demonstrating the immunodominant nature of this protein. RAP-1-specific CD4+ T cell clones recognized Mexico, Texas, Australia, and Israel strains of B. bovis but neither B. bigemina merozoites nor recombinant B. bigemina RAP- 1. Analysis of cytokine mRNA in RAP-1-specific Th cell clones revealed strong expression of gamma interferon but little or no expression of interleukin-2 (IL-2), IL-4, or IL-10. Gamma interferon production was confirmed by enzyme-linked imunosorbent assay. These results indicate the potential to use selected B. bovis RAP-1 peptides as immunogens to prime for strong, anamnestic, strain-cross-reactive type 1 immune responses upon exposure to B. bovis.

Animals↗

PubMed1999

Cartilage-derived retinoic acid-sensitive protein and type II collagen expression during fracture healing are potential targets for Sox9 regulation.

Cartilage-derived retinoic acid-sensitive protein (CD-RAP) and mRNA were examined in the mouse fracture model by immunohistochemistry and Northern blot analysis and compared with the expression of type II collagen. We also studied the expression of the transcription factor Sox9, reported to enhance type II collagen and CD-RAP gene expression in vitro. CD-RAP was first detected in immature chondrocytes on day 5. Intense signals for CD-RAP were found in fracture cartilage on days 7 and 9. CD-RAP decreased at the phase of endochondral ossification. Throughout fracture healing, CD-RAP was detected in cartilage and not in bone or fibrous tissue, thus CD-RAP may be a molecular marker of cartilage formation during fracture healing. Northern blot analysis revealed similar changes in CD-RAP and type II collagen mRNA levels. However, with respect to protein levels, CD-RAP decreased faster than type II collagen implying the stability is lower than type II collagen. Increased levels of Sox9 mRNA and protein were detected on day 5 and coincided with the initial increase of CD-RAP and type II collagen mRNAs. Sox9 mRNA levels declined with the progress of chondrocyte hypertrophy, followed by a concomitant decrease in CD-RAP and type II collagen mRNA levels. These changes in Sox9 expression compared with the cartilage-specific genes (CD-RAP and type II collagen) suggest that cell differentiation during fracture healing may be controlled by specific transcriptional factors which regulate phenotypic changes of the cells.

Animals↗

PubMed2004

Effect of diet composition on postweaning colibacillosis in piglets.

The weaning of piglets is often associated with digestive disorders, particularly diarrhea--postweaning colibacillosis (PWC)--which is caused by infection with enterotoxigenic strains of Escherichia coli. It has been shown previously that a diet for newly weaned pigs based on cooked white rice and animal protein decreases the occurrence of PWC, whereas the addition of carboxymethylcellulose (CMC) to this diet enhances PWC. The aims of the current work were to 1) determine whether substitution of animal protein with plant proteins in the cooked-white-rice diet influenced its protective effects on PWC and 2) confirm that an increase in viscosity of the digesta by adding CMC to the diet favors the development of PWC--with (Exp. 1) or without (Exp. 2) experimental infection of piglets with E. coli. The diets were 1) cooked white rice and animal protein sources (RAP), 2) RAP + CMC added at 40 g of CMC/kg (air-dry basis) of diet, 3) cooked white rice and plant protein sources (RPP), and 4) wheat and plant protein sources (WPP). Experiments 1 and 2 were conducted using 32 and 24 piglets (eight and six per treatment), respectively. Piglets were weaned at 21 d (d 1), and fed ad libitum until slaughter on d 9. In Exp. 1, piglets were orally infected with enterotoxigenic E. coli on d 4, 5, 6, and 7. On d 8 of Exp. 1, the E. coli scores in feces of pigs fed RAP + CMC were higher than with RAP (P < 0.01). On d 9 after weaning, feces from pigs fed diet RAP were normal or moist, whereas feces from pigs fed RAP + CMC were wet to diarrheic. On d 7 of Exp. 2, pigs fed diets RAP + CMC and WPP had wetter feces than pigs fed diets RAP or RPP (P < 0.05). On d 8, the E. coli scores in feces were higher (P < 0.01) with pigs fed RAP + CMC than with all other diets. The E. coli scores in the digesta were also higher with pigs fed RAP + CMC, and to a lesser extent with diet WPP, than with pigs fed RAP or RPP (P < 0.01). The large intestine was heavier in pigs fed diets RPP and WPP, and the digesta were more acidic (P < 0.05). This study confirmed that diet RAP was protective against PWC, and that substitution of animal proteins with plant protein in a rice-based diet did not diminish its protective effects. The addition of CMC to cooked white rice increased digesta viscosity and enhanced PWC. Consequently, this diet represents a useful model for studying this condition.

Animal Feed↗

PubMed2000

Non-invasive estimation of right atrial pressure by combined Doppler echocardiographic measurements of the inferior vena cava in patients with congestive heart failure.

BACKGROUND: In patients with congestive heart failure, evaluation of right atrial pressure (RAP) provides useful therapeutic, functional and prognostic information. The aim of this study was to investigate whether a combination of inferior vena cava variables measured by Doppler echocardiography could provide a reliable non-invasive estimate of RAP. METHODS: One hundred consecutive patients with severe congestive heart failure (ejection fraction 24 +/- 6%) due to dilated cardiomyopathy were evaluated by simultaneous Doppler echocardiography and hemodynamic studies. RAP, end-expiratory (IVCDmax) and end-inspiratory (IVCDmin) diameters of the inferior vena cava, its collapse index [CIIVC = (IVCDmax - IVCDmin/IVCDmax)*100] and systolic fraction of forward inferior vena cava flow were measured and correlated by both single and multilinear regression analysis. The accuracy of generated equations was tested in a separate testing group of 61 patients at baseline and a subgroup of 20 patients after loading manipulations, prospectively studied in the same methodological setting. RESULTS: All Doppler echocardiographic variables were correlated with RAP. The IVCDmin showed the strongest correlation (r = 0.84, p < 0.0001). Stepwise regression analysis identified two equations for predicting RAP: 1) RAP = (6.4*IVCDmin + 0.04*CIIVC - 2) (r = 0.82, p < 0.0001, SEE 1.7 mmHg) in all patients, and 2) RAP = (4.9*IVCDmin + 0.01*CIIVC - 0.2) (r = 0.92, p < 0.0001, SEE 1.2 mmHg) in patients without tricuspid regurgitation. In the testing group estimated and measured RAP was strongly correlated at baseline (r = 0.95, SEE 1.3 mmHg, p < 0.00001) and after loading manipulations (r = 0.96, SEE 1.2 mmHg, p < 0.00001). The agreement between invasive and non-invasive measurements of RAP in identifying patients with normal (< or = 5 mmHg), moderately increased (< 5 RAP < 10 mmHg) and markedly increased (> or = 10 mmHg) RAP was 81 or 93% using equation 1 or 2, respectively. CONCLUSIONS: Our results provide evidence that in patients with congestive heart failure indices derived from Doppler measurements of the inferior vena cava can be used to produce an accurate, strong and non-invasive estimate of RAP. This is another example of the usefulness of Doppler echocardiography in evaluating hemodynamic profile and its changes in patients with congestive heart failure. Echocardiographic assessment of the inferior vena cava should be included in the evaluation of patients with congestive heart failure.

Analysis of Variance↗

PubMed2002

Recurrent abdominal pain among a sample of Egyptian children in relation to family and school related problems.

Recurrent Abdominal pain (RAP) is a common feature of growing children especially above the age of five. It may be experienced for either organic or non-organic (psychogenic) reasons. The main objective of the present study is to investigate the possible relation between the occurrence of RAP and some family and school related problems. It is a descriptive cross sectional study designed to assess children aged 7-12 years, of both sexes, attending El-Salam health insurance clinic (Eastern Cairo) for their RAP. Seven hundred children (400 boys and 300 girls) suffering from RAP were investigated. They were subjected to routine investigations (urine and stool analysis, complete blood picture, x-ray abdomen) to exclude the possible organic cause for their RAP. A specially designed questionnaire for the purpose of the present study was applied after testing its validity (it was judged by 10 professors of Psychology, Psychiatry and community medicine before its use). It was applied individually on each child (or his/her caregiver). Data were collected from each subject as regard: His/her personal history, socio-demographic characteristics, characters of RAP (its type, severity, onset, duration, frequency, site and its relation to other symptoms), some organic and psychological symptoms and history of family troubles and school related problems. Data were collected, tabulated and analyzed using Chi- square test to compare children of organic and non-organic RAP. Results revealed that RAP was mostly non-organic in origin (65.7%). It was commonly associated with family troubles (59.7%) and school related problems (40.3%). Children with non-organic RAP expressed many psychological symptoms especially; tantrums (41.1%), phobias related to school (17.4%) as well as continuous crying (13%) and appetite loss (14%). There was significant female predominance (p = 0.0000) in expressing RAP in direct relation to family troubles and school related problems compared to boys. Non-organic RAP was described as mild (68.2%), gradual (64.3%), poorly localized (79.6%) pain, that was experienced more or less on daily basis (79%), and lasts for shorter duration (68.5%) [less than 15 minutes]. It was commonly associated with headaches (46.9%), diarrhea (36.9%), and other pains all over the body (13.4%). It was related neither to meals or to sleep (71.1%). On the other hand, RAP (both organic and non-organic) was not significantly related to child's socio-demographic background. Results were discussed and interpreted with results of other researchers. Many recommendations were introduced for proper assessment and management of such children.

Abdominal Pain↗

PubMed1994

The 39-kDa receptor-associated protein regulates ligand binding by the very low density lipoprotein receptor.

A 39-kDa receptor associated protein (RAP) binds and inhibits ligand binding by two members of the low density lipoprotein (LDL) receptor family, gp330 and low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor. To determine if additional members of the LDL receptor family may interact with RAP, Chinese hamster ovary cells were transfected with plasmids directing expression of the very low density lipoprotein (VLDL) receptor cDNA or the LDL receptor cDNA. Detergent-soluble extracts from these and normal Chinese hamster ovary cells were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, after which the proteins were transferred to nitrocellulose membranes and incubated with RAP. When detergent extracts from normal cells were incubated with RAP, several polypeptides, including a 130-kDa protein, were observed to bind RAP. In cells transfected with the VLDL receptor cDNA, a substantial increase in RAP binding to the 130-kDa polypeptide was noted. This protein was identified as the VLDL receptor by immunoblotting. The VLDL receptor present in detergent extracts from transfected cells bound to RAP-Sepharose, and a KD of 0.7 nM for the interaction between RAP and the purified VLDL receptor was determined using enzyme-linked immunosorbent assay. The purified VLDL receptor bound 125I-labeled VLDL, but not 125I-labeled LDL, and the binding of 125I-labeled VLDL was completely inhibited by RAP. Further, RAP inhibited the uptake and degradation of 125I-VLDL by cells overexpressing the VLDL receptor. Thus the VLDL receptor represents the third member of the LDL receptor family whose ligand binding properties are antagonized by RAP. This suggests a common functional role for RAP in modulating ligand binding by members of the LDL receptor family.

Amino Acid Sequence↗