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P Bailly

Publications and source records attributed to P Bailly.

At least 55 records · Page 3Linked to original sources
PubMed1996

Molecular characterization of a new urea transporter in the human kidney.

A cDNA clone (HUT2) sharing 61.1% and 89.9% sequence identity with the human erythroid (HUT11) and the rabbit (UT2) urea transporters, respectively, was isolated by homology cloning from a human kidney library. HUT2 transcripts were restricted to the kidney and the HUT2 polypeptide was not immunoprecipitated with blood group Kidd-related antibodies (anti-Jk3) in coupled transcription-translation assays. Functional expression studies in Xenopus oocytes demonstrated that HUT2-mediated urea transport was not inhibited by p-chloromercuribenzene sulfonate (pCMBS) which, however, inhibited the urea flux mediated by HUT11. These findings demonstrate that at least two distinct urea transporters are present in human tissues. By in situ hybridization, the gene encoding HUT2 has been assigned to chromosome 18q12.1-q21-1, as found previously for the Kidd/urea transporter HUT11, suggesting that both genes evolved from duplication of a common ancestor.

Adult↗
PubMed1996

Characterization of the gene encoding the human LW blood group protein in LW+ and LW- phenotypes.

The LW blood group is carried by a 42-kD glycoprotein that belongs to the family of intercellular adhesion molecules. The LW gene is organized into three exons spanning an HindIII fragment of approximately 2.65 kb. The exon/intron architecture correlates to the structural domains of the protein and resembles that of other Ig superfamily members except that the signal peptide and the first Ig-like domain are encoded by the first exon. The 5'UT region (nucleotides -289 to +9) includes potential binding sites for various transcription factors (Ets, CACC, SP1, GATA-1, AP2) and exhibited a significant transcriptional activity after transfection in the erythroleukemic K562 cells. No obvious abnormality of the LW gene, including the 5'UT region, has been detected by sequencing polymerase chain reaction-amplified genomic DNA from RhD+ or RhD- donors and from an Rhnull variant that lacks the Rh and LW proteins on red blood cells. However, a deletion of 10 bp in exon 1 of the LW gene was identified in the genome of an LW (a- b-) individual (Big) deficient for LW antigens but carrying a normal Rh phenotype. The 10-bp deletion generates a premature stop codon and encodes a truncated protein without transmembrane and cytoplasmic domain. No detectable abnormality of the LW gene or transcript could be detected in another LW(a- b-) individual (Nic), suggesting the heterogeneity of these phenotypes.

Amino Acid Sequence↗
PubMed1996

Candidate gene acting as a suppressor of the RH locus in most cases of Rh-deficiency.

The Rh antigen is a multi-subunit complex composed of Rh polypeptides and associated glycoproteins (Rh50, CD47, LW and glycophorin B); these interact in the red cell membrane and are lacking or severely reduced in Rhnull cells. As a result, individuals with Rhnull suffer chronic haemolytic anaemia known as the Rh-deficiency syndrome. Most frequently, Rhnull phenotypes are caused by homozygosity of an autosomal suppressor gene unlinked to the RH locus (Rhnull regulator or Rhmod types). We have analysed the genes and transcripts encoding Rh, CD47 and Rh50 proteins in five such unrelated Rhnull cases. In all patients, we identified alteration of Rh50--frameshift, nucleotide mutations, or failure of amplification--which correlated with Rhnull phenotype. We propose that mutant alleles of Rh50, which map to chromosome 6p11-21.1, are likely candidates for suppressors of the RH locus accounting for most cases of Rh-deficiency.

Amino Acid Sequence↗
PubMed1996

Functional differentiation of the human red blood cell and kidney urea transporters.

The recent cloning of two urea transporters will allow to better understand their role in the urinary concentrating mechanism. This physiological approach needs to be sustained by a knowledge of their functional characteristics. We compared the pharmacological properties of the human red blood cell and kidney urea transporters (HUT11 and HUT2) in the Xenopus oocyte expression system. Both proteins allow the rapid transfer of urea but not of water. Both are inhibited by phloretin, although with different half-maximal inhibitory concentrations (IC50; 75 microM, for HUT11 and 230 microM for HUT2). Whereas para-chloromercuribenzene sulfonate inhibits HUT11 with an IC50 of 150 microM, it does not inhibit HUT2, whatever the concentration used. We demonstrate that thiourea diffuses through HUT11 with a Michaelis constant (Km) of 40 mM, but not through HUT2. In contrast, it inhibits urea transport through both proteins. This identification of a substrate binding site independent from the transport activity is the first step in the understanding of the molecular events underlying urea transport.

4-Chloromercuribenzenesulfonate↗
PubMed1996

Evidence for distinct vascular and tubular urea transporters in the rat kidney.

Facilitated urea transport has been demonstrated in several mammalian tissues, including those of the collecting ducts and red blood cells. Two urea transporters have been recently cloned: UT2, expressed in rabbit inner medullary collecting ducts, and HUT11, expressed in human erythrocytes. Because of significant identity (63%) between these two transporters, and because HUT11 is also expressed in the human kidney, they could represent the same transporter with species-related differences in their-sequences. In the study presented here, two different cDNA fragments, corresponding to the rat equivalents (rUT2 and rUT11) of the two previously cloned urea transporters, were isolated by reverse transcription-polymerase chain reaction. These rat probes were used for Northern analysis of RNA extracted from rat tissues. From the following findings, the results show that rUT2 and rUT11 are two distinct urea transporters: (1) The two cDNA fragments isolated in the rat exhibit different sequences; (2) The mRNA for rUT2 is found exclusively in the kidney, with two transcripts (3.2- and 4.4-kilobase (kb)), whereas rUT11 (only one transcript, 4.2 kb) is present in the brain, spleen, kidney, and testis; (3) in the kidney, the inner stripe of the outer medulla expresses rUT11 mRNA and the short transcript of rUT2, whereas the inner medulla expresses rUT11 and the two rUT2 transcripts; (4) In hydronephrotic kidneys that have completely lost their tubular epithelium but have intact vasculature, rUT2 transcripts are no longer expressed, whereas expression of rUT11 is intensified; (5) Experimental chronic alterations in urine concentrating activity induced different changes in the expression of rUT2 and rUT11.

Amino Acid Sequence↗
PubMed1995

Molecular basis and expression of the LWa/LWb blood group polymorphism.

The Landsteiner-Wiener (LW) blood group antigens reside on a 42-kD erythrocyte membrane glycoprotein that has recently been cloned. Here, we found that the molecular basis for the LWa/LWb polymorphism is determined by a single base pair mutation (A308G) that correlates with a Pvu II restriction site and results in a Gln70Arg amino acid substitution. COS-7 cells transfected with LWa or LWb cDNAs reacted with human anti-LWa and anti-LWb sera, respectively, as well as with a murine monoclonal anti-LWab antibody, as shown by flow cytometry analysis. Moreover, a 42-kD protein was immunoprecipitated from the transfected cells with the monoclonal anti-LWab antibody. These findings indicate that LWa and LWb are alleles of the LW blood group locus as defined also by a monoclonal anti-LWab of nonhuman origin. In addition, the LW locus has been assigned to chromosome 19p13.3 by in situ hybridization. Study by Southern blot analysis indicated also that the LW locus is composed of a single gene that was not grossly rearranged in rare LW(a-b-) and Rhnull individuals deficient for LW antigens. In addition, Pvu II restriction fragment-length polymorphism analysis indicated that these variants were all homozygous for a phenotypically silent LWa allele.

Alleles↗
PubMed1995

Kidd blood group and urea transport function of human erythrocytes are carried by the same protein.

The gene encoding the urea transporter of human erythrocytes (HUT11 clone) has been cloned recently (Olives, B., Neau, P., Bailly, P., Hediger, M. A., Rousselet, G., Cartron, J. P., and Ripoche, P. (1994) J. Biol. Chem. 269, 31649-31652). Now, this gene has been assigned to chromosome 18q12-q21 by in situ hybridization, as also found for the Kidd (Jk) blood group locus. In coupled transcription-translation assays, the HUT11 cDNA directed the synthesis of a 36-kDa protein which was immunoprecipitated by a human anti-Jk3 antibody produced by immunized Jk(a-b-) donors whose red cells lack Kidd antigens. The anti-Jk3 antibody also immunoprecipitated a protein material of 46-60 kDa from all red cell membranes, except those from Jk(a-b-) cells. After N-glycanase digestion the 46-60-kDa component was reduced to 36 kDa. A rabbit antibody raised against the predicted NH2-terminal amino-acids of the HUT11 protein reacted on immunoblots with a 46-60-kDa component present in all human erythrocytes except those from Jk(a-b-) individuals. Jk(a-b-) red cells lack the Kidd/urea transport protein and have a selective defect of the urea transport capacity, but a normal water permeability and aquaporin-associated Colton blood group antigens. These findings indicate that the erythrocyte urea transporter is encoded by the Kidd locus and may have implications for the biology of urea transporters and their tissue-specific regulation.

Animals↗
PubMed1995

Purification and partial characterization of the erythrocyte Kx protein deficient in McLeod patients.

A 37-kDa protein was immunopurified from human erythrocytes as a complex with a monoclonal antibody directed against the Kell blood group protein of 93 kDa. A rabbit antibody raised against the purified complex reacted on a Western blot with the 93-kDa and 37-kDa proteins and was able to immunoprecipitate the 37-kDa component from K0 erythrocytes which express large amount of the Kx antigen, but not from erythrocytes of patients suffering from McLeod syndrome, a X-linked disorder in which the Kx antigen is lacking. Additional studies have shown that the 37-kDa protein is not glycosylated, and permitted the sequence of the 22 first N-terminal amino acids to be established. This sequence was identical to the predicted protein product of the XK gene cloned recently, which is deleted or mutated in McLeod patients [Ho, M., Chelly, J., Carter, N., Danek, A., Crocker, P. & Monaco, A. P. (1994) Cell 77, 869-880]. Our findings provide strong evidence that the 37-kDa red cell membrane protein is identical to the Kx protein produced by the XK structural gene and demonstrate that Kx and Kell proteins are two subunits expressed as a complex hold by disulfide bond(s) at the red cell surface.

Amino Acid Sequence↗
PubMed1995

The red cell LW blood group protein is an intercellular adhesion molecule which binds to CD11/CD18 leukocyte integrins.

Leukocyte adhesion involves the leukocyte-specific integrins CD11a/CD18, CD11b/CD18 and CD11c/CD18, which bind to intercellular adhesion molecules (ICAM). Three ICAM have been described, and are expressed on leukocytes and various other cells, but are absent from red cells. Here, we show that the red cell Landsteiner-Wiener (LW) blood group glycoprotein is an ICAM which binds to the leukocyte-specific integrins. This finding has important implications in red cell physiology.

Blood Group Antigens↗
PubMed1995

Structural analysis of the RH-like blood group gene products in nonhuman primates.

Rh-related transcripts present in bone marrow samples from several species of nonhuman primates (chimpanzee, gorilla, gibbon, crab-eating macaque) have been amplified by RT-polymerase chain reaction using primers deduced from the sequence of human RH genes. Nucleotide sequence analysis of the nonhuman transcripts revealed a high degree of similarity to human blood group Rh sequences, suggesting a great conservation of the RH genes throughout evolution. Full-length transcripts, potentially encoding 417 amino acid long proteins homologous to Rh polypeptides, were characterized, as well as mRNA isoforms which harbored nucleotide deletions or insertions and potentially encode truncated proteins. Proteins of 30-40,000 M(r), immunologically related to human Rh proteins, were detected by western blot analysis with antipeptide antibodies, indicating that Rh-like transcripts are translated into membrane proteins. Comparison of human and nonhuman protein sequences was pivotal in clarifying the molecular basis of the blood group C/c polymorphism, showing that only the Pro103Ser substitution was correlated with C/c polymorphism. In addition, it was shown that a proline residue at position 102 was critical in the expression of C and c epitopes, most likely by providing an appropriate conformation of Rh polypeptides. From these data a phylogenetic reconstruction of the RH locus evolution has been calculated from which an unrooted phylogenetic tree could be proposed, indicating that African ape Rh-like genes would be closer to the human RhD gene than to the human RhCE gene.

Amino Acid Sequence↗
PubMed1995

Use of pulsed-field gel electrophoresis for investigation of an outbreak of Clostridium difficile infection among geriatric patients.

A six-month outbreak of Clostridium difficile infection among elderly residents of a middle-term-care facility was investigated. Pulsed-field gel electrophoresis was used to genotype 22 outbreak strains and 30 epidemiologically unrelated strains. A prospective case-control study was conducted to identify risk factors for epidemic Clostridium difficile-associated diarrhea. All epidemiologically unrelated Clostridium difficile strains of the same serogroup could be differentiated by their DNA patterns with two restriction enzymes (SmaI and KspI). Among clustered strains, two epidemic serogroups (C and K) were identified. Two different DNA patterns were identified among serogroup C strains and three among serogroup K strains. Multivariate analysis showed that the risk of Clostridium difficile infection increased with antimicrobial chemotherapy (beta-lactam agents and pristinamycin) and the presence of a feeding tube. This study confirms the high discriminative power of restriction fragment length polymorphism analysis by pulsed-field gel electrophoresis to describe Clostridium difficile epidemiology. The typing results confirm that infection was principally exogenous in this outbreak. Furthermore, they indicate the need to improve all measures limiting transmission of infection.

Aged↗
PubMed1995

Rest technetium 99m-sestamibi tomoscintigraphy in hibernating myocardium.

The myocardial uptake of rest-injected technetium 99m sestamibi on single-photon-emission computed tomographic images was assessed in 25 patients. All had an area of myocardial dysfunction that could be related to a coronary artery stenosis. None of the patients had clinical evidence of a myocardial infarction. Three months after revascularization, viability was demonstrated by contrast angiography and center-line analysis in 21 (78%) of the 27 formerly hibernating territories. Among these, none had a transmural defect, and 38% had a normal technetium 99m-sestamibi uptake. The four transmural preoperative defects were located in territories without viability. Eight of the 9 territories that were normal at scintigraphy proved to be viable postoperatively. It is concluded that as long as some residual technetium 99m-sestamibi uptake is present, viable myocardium is also present.

Aged↗
PubMed1995

Systemic-pulmonary shunt with a right retroesophageal subclavian artery.

A 19-day-old child suffering from cyanosis due to tetralogy of Fallot was palliated by using his right retroesophageal subclavian artery. It was anastomosed side-to-side onto the ascending aorta and end-to-side onto the right pulmonary artery. The palliation obtained with this systemic-pulmonary shunt was satisfying. The right brachial vascular flow was normal.

Aorta↗
PubMed1995

Nasal carriage of Staphylococcus aureus and cross-contamination in a surgical intensive care unit: efficacy of mupirocin ointment.

A six month prospective study was carried out in a surgical intensive care unit (SICU) of a university hospital to assess the incidence and routes of exogenous colonization by Staphylococcus aureus. A total of 157 patients were included in the study. One thousand one hundred and eleven specimens (nasal, surgical wound swabs, tracheal secretions obtained on admission and once a week thereafter, and all clinical specimens) were collected over a four month period from patients without nasal decontamination (A). They were compared with 729 specimens collected over a two month period from patients treated with nasal mupirocin ointment (B). All S. aureus strains were typed by restriction fragment length polymorphism (RFLP) pulsed-field gel electrophoresis after SmaI macrorestriction. The nasal colonization rates on admission were 25.5 and 32.7% in groups A and B, respectively. Thirty-one untreated patients (31.3%) and three patients (5.1%) treated with nasal ointment, acquired the nasal S. aureus in the SICU (P = 0.00027). Nasal carriers were more frequently colonized in the bronchopulmonary tract (Bp) and surgical wound (Sw) (62%) than patients who were not nasal carriers (14%) (P < 0.00001). The patterns were identical for nasal, Bp and Sw strains from the same patient. RFLP analysis characterized seven epidemic strains of methicillin-resistant S. aureus (MRSA) which colonized 60% of group A and 9% of group B patients (P < 0.00001). The bronchopulmonary tract infection rate was reduced in group B (P = 0.032). In conclusion, in an SICU, nasal carriage of S. aureus appeared to be the source of endogenous and cross-colonization. The use of nasal mupirocin ointment reduced the incidence of Bp and Sw colonization, as well as the MRSA infection rate.

Administration, Intranasal↗
PubMed1995

Mitral annuloplasty with a flexible linear reducer.

Although the ideal technique is still controversial, mitral valve reconstruction for mitral insufficiency usually includes an annuloplasty. From August 1985 to June 1993, 126 cases of pure, acquired mitral insufficiency were repaired by means of a posterior annuloplasty. Whatever the etiology, all types of mitral insufficiency allowing a mitral reconstruction were included. The annuloplasty, performed with a flexible linear reducer, was associated with valvular (62%) and subvalvular (11%) repairs. An associated surgical procedure was necessary in 62% of the patients. Operative mortality was 2.4%, and follow-up (mean 29 months) was complete for all survivors. Five-year survival was 90%. Five-year complication-free rate for emboli was 91%. Only one patient at 12 months underwent reoperation to treat recurrent mitral insufficiency. Ninety-seven patients were in New York Heart Association Class I or II. Follow-up echocardiographic studies on 75% of eligible patients showed a free rate for significant regurgitation of 99%. Mean valve area was estimated at 2.88 +/- 0.85 cm2. These findings suggest that the flexible linear reducer seems to be a reliable device and a valid alternative for annuloplasty.

Adult↗
PubMed1995

[Congenital pulmonary arteriovenous fistula. Apropos of 2 cases].

The authors discuss echocardiographic diagnosis and endovascular treatment of two different anatomical types of pulmonary arteriovenous fistula. Transoesophageal echocardiography in a cyanotic 3 year old boy revealed a direct right pulmonary artery left atrial fistula, treated by surgical ligation of the anomalous feeding artery. A cerebral abscess in a 22 year old man with hereditary haemorrhagic telangiectasia revealed pulmonary and cerebral arteriovenous malformations, which were both treated successfully by embolization. The value of echography is the demonstration of the right to left shunt at pulmonary level and, in some cases, the direct visualization of the arteriovenous malformation. Embolization should be considered as the therapeutic method of choice in all pulmonary arteriovenous fistula, except for direct pulmonary artery left atrial fistula.

Adult↗
PubMed1994

Cloning and functional expression of a urea transporter from human bone marrow cells.

A rapid passive urea transport has been previously described in the mammalian renal inner medullary collecting duct epithelial cells and in mammalian erythrocytes. Recently, a vasopressin-regulated urea transporter (UT2) has been cloned from a rabbit kidney medullary cDNA library (You, G., Smith, C. P., Kanai, Y., Lee, W. S., Stelzner, M., and Hediger, M. A. (1993) Nature 365, 844-847). We now report the cloning and characterization of a complementary DNA (HUT11) encoding an urea transporter isolated from a human bone marrow library. It encodes a 43,000-Da polypeptide of 391 amino acids that exhibited 63% sequence identity with the rabbit urea transporter and a similar membrane topology. HUT11 carries 2 putative glycosylation sites and 10 cysteines, of which only 7 are conserved at an equivalent position in UT2. HUT11 transcripts have been identified in human erythroid and renal tissues. Expression studies in Xenopus oocytes demonstrated that HUT11 mediates a facilitated urea transport that was inhibited, as described in mammalian erythrocytes, by very low concentrations of phloretin, p-chloromercuribenzene sulfonate, and urea analogues. No unidirectional movements of charged molecules, glycerol, or water were associated with HUT11 expression in oocytes. These findings suggest that HUT11 is most likely responsible for the facilitated urea transport in human red blood cells.

4-Chloromercuribenzenesulfonate↗