PubMed Health⌕ Search

Biomedical subjects

P Bonin

Publications and source records attributed to P Bonin.

At least 19 recordsLinked to original sources
PubMed2007

Impact of nonmyeloablative conditioning regimens on the occurrence of pure red cell aplasia after ABO-incompatible allogeneic haematopoietic stem cell transplantation.

BACKGROUND AND OBJECTIVES: In the setting of major ABO-incompatible allogeneic haematopoietic stem cell transplantation (HSCT), pure red cell aplasia (PRCA) is linked to the persistence of host residual plasma cells secreting antidonor isohaemagglutinins (HA) after transplantation. There are conflicting results regarding the impact of the intensity of conditioning regimen on the occurrence of PRCA after major ABO-mismatched HSCT. MATERIAL AND METHODS: To address this question, we compared two cases occurring after nonmyeloablative (NMA) and myeloablative (MA) HSCT and reviewed previous cases reported in the NMA setting. RESULTS AND CONCLUSIONS: We observed a delayed disappearance of antidonor HAs in the NMA setting, associated to a more prolonged period of red blood cells transfusion dependence than in the MA setting. In our case as in several others, the disappearance of antidonor HAs and resolution of PRCA were observed after reinforcement of the graft-versus-host effect (i.e. immunosuppression removal or donor leukocytes infusion).

ABO Blood-Group System↗
PubMed2001

Metabolic differences between attached and free-living marine bacteria: inadequacy of liquid cultures for describing in situ bacterial activity.

Marinobacter sp. strain CAB was cultivated with or without porous glass beads as solid support. Two substrates were used: the hydrophilic sodium lactate and a hydrophobic C(18)-isoprenoid ketone (6,10,14-trimethylpentadecan-2-one (TMP)). The substrate adsorption onto the beads was measured. Bacterial adhesion was determined by a direct count technique and amounted to 70% of total cells. In the immobilised cell cultures (ICC), generation times were 1.5 and 1.8 times shorter than in the planktonic cultures (FCC) with sodium lactate and with TMP, respectively. In ICC, the growth yields were lower (15.3(FCC) x 10(9) and 0.8(ICC) x 10(9) bacteria mg(-1) of sodium lactate; 50(FCC) x 10(9) and 35(ICC) x 10(9) bacteria mg(-1) of TMP). The mineralisation of substrates was estimated after mass spectrometric determination of the CO2 production rates of both free and immobilised cell cultures. The results indicated a higher specific CO2 production rate in the ICC with sodium lactate (3.1(FCC)+/-0.2 and 3.5(ICC)+/-0.3 nmol CO2 mg(-1) protein min(-1)) but not in the ICC with TMP (1.9(FCC)+/-0.7 and 0.5(ICC)+/-0.3 nmol CO2 mg(-1) protein min(-1)). The affinities for the two substrates were lower in the presence of the solid support (K(m,ICC)=18.2+/-0.2 microM and 37.1+/-2.0 microM, for sodium lactate and TMP, respectively) than without support (K(m,FCC)=8.5+/-1.5 microM and 8.4+/-1.2 microM, for sodium lactate and TMP, respectively). Moreover, the presence of a solid support showed a lower inhibition by the TMP (K(i,FCC)=3.8+/-1.0 microM and K(i,ICC)=12.2+/-2.5 microM) which may explain why the immobilised cell cultures degraded hydrophobic TMP more efficiently than the planktonic cultures.

Bacterial Adhesion↗
PubMed2001

Age of acquisition and word frequency in written picture naming.

This study investigates age of acquisition (AoA) and word frequency effects in both spoken and written picture naming. In the first two experiments, reliable AoA effects on object naming speed, with objective word frequency controlled for, were found in both spoken (Experiment 1) and written picture naming (Experiment 2). In contrast, no reliable objective word frequency effects were observed on naming speed, with AoA controlled for, in either spoken (Experiment 3) or written (Experiment 4) picture naming. The implications of the findings for written picture naming are briefly discussed.

Age Factors↗
PubMed2000

Influence of oxygen supply on heptadecane mineralization by Pseudomonas nautica.

The influence of different states of oxygen supply on heptadecane mineralization has been investigated in resting cell suspensions of Pseudomonas nautica. The rate of heptadecane biodegraded was constant for oxygen concentrations between 21% and 10% (v/v) (about 100% and 50% of air saturation, 230 and 110 microM, respectively). A decline in biodegradation rates occurred for oxygen concentrations below 10% (about 50% of air saturation, 110 microM) and biodegradation stopped with 0.21% oxygen (2.3 microM). In the presence of 1% (11 microM) of oxygen, no CO2 was produced, showing that complete mineralisation of heptadecane was blocked.

Alkanes↗
PubMed2000

Comparison of methods for quantification of cytochrome cd(1)-denitrifying bacteria in environmental marine samples.

Two PCR primer sets were developed for the detection and quantification of cytochrome cd(1)-denitrifying bacteria in environmental marine samples. The specificity and sensitivity of these primers were tested. Both primer sets were suitable for detection, but only one set, cd3F-cd4R, was suitable for the quantification and enumeration of the functional community using most-probable-number PCR and competitive PCR techniques. Quantification of cytochrome cd(1) denitrifiers taken from marine sediment and water samples was achieved using two different molecular techniques which target the nirS gene, and the results were compared to those obtained by using the classical cultivation method. Enumerations using both molecular techniques yielded similar results in seawater and sediment samples. However, both molecular techniques showed 1,000 or 10 times more cytochrome cd(1) denitrifiers in the sediment or water samples, respectively, than were found by use of the conventional cultivation method for counting.

Bacteria↗
PubMed2000

Writing words from pictures: what representations are activated, and when?

In three experiments, the nature of the representations involved in written picture naming and the time course of their activation were investigated. French participants had to produce picture names while hearing distractors. In Experiment 1, distractors semantically related to the picture names yielded a semantic interference effect when a stimulus onset asynchrony (SOA) of--150 msec, but not when a SOA of 0 msec, was used, in both spoken and written picture naming. Experiment 2 showed that the semantic interference effect was not located at the conceptual level. In Experiment 3, participants wrote down picture names while hearing semantically related, phonologically related, both semantically and phonologically related, or unrelated distractors, presented at both SOAs. A semantic interference effect was obtained with phonologically unrelated distractors but was eliminated with phonologically related distractors. Facilitatory effects of phonologically related distractors were found at both SOAs. The implications of the findings for written picture naming are discussed.

Adult↗
PubMed1998

Masked form priming in writing words from pictures: evidence for direct retrieval of orthographic codes.

Three experiments used the masked priming paradigm to investigate the role of orthographic and phonological information in written picture naming. In all the experiments, participants had to write the names of pictures as quickly as possible under three different priming conditions. Nonword primes could be: (1) phonologically and orthographically related to the picture name; (2) orthographically related as in (1) but phonologically related to a lesser degree than in (1); (3) orthographically and phonologically unrelated except for the first consonant (or consonant cluster). Orthographic priming effects were observed with a prime exposure duration of 34 ms (Experiments 1 and 2) and of 51 ms (Experiment 3). In none of the experiments, did homophony between primes and picture names yield an additional advantage. Taken together, these findings support the view of the direct retrieval of orthographic information through lexical access in written picture naming, and thus argue against the traditional view that the retrieval of orthographic codes of obligatorily mediated by phonology.

Adult↗
PubMed1998

In vitro study of a Nd:YAP laser in endodontic retreatment.

Nd:YAP laser is a dental laser with a 1340 nm wavelength. The laser beam is carried by a 200 to 300 microns fiberoptic and is suitable for endodontic therapy. We used the Nd:YAP laser in an in vitro experiment to study its effectiveness in endodontic retreatment. Temperature measurements and irradiation parameters were first defined. Then Nd:YAP laser irradiation was used, alone or in combination with hand instruments, to remove various canal sealers and broken instruments. Clinical parameters were monitored and scanning electron microscopic observations were conducted. When used at 200 mJ--with a pulse duration of 150 ms, an exposure time of 1 s and a frequency of 10 Hz--Nd:YAP laser preserved the dentinal walls of the root canal and enabled root canal retreatment without thermic elevation harming periodontal tissue. It is concluded that, in combination with hand instruments, the Nd:YAP laser is an effective device for root canal preparation in endodontic retreatment.

Dental Pulp Cavity↗
PubMed1998

Apparent reactivation of a red cell alloantibody in a healthy individual after G-CSF administration.

Granulocyte-colony stimulating factor (G-CSF) has been successfully administered to healthy subjects to mobilize peripheral blood stem cells (PBSC) for allogeneic transplantation. Adverse events are moderate. We report the first case of apparent reactivation of an alloantibody to a blood cell antigen (Jk(a)) after G-CSF administration to a healthy subject and its transmission to the PBSC transplant recipient; no concomitant reactivation of other alloantibodies was detected. This case raises questions on the effect of G-CSF on the immune system and its safety in healthy individuals.

Adjuvants, Immunologic↗
PubMed1998

The demographic characteristics of Medicaid-eligible uninsured children.

OBJECTIVES: This study estimated the number of uninsured children in 1993 who were eligible for Medicaid. METHODS: Data from the March 1990 and 1994 Current Population Surveys were analyzed. RESULTS: At least 2.3 million Medicaid-eligible children were uninsured in 1993. These children were more likely to have a working parent than children on Medicaid. Higher proportions of uninsured children less than 6 years of age, children who lived in female-headed single-parent families, and African-American and Hispanic children were eligible for Medicaid. CONCLUSIONS: Many eligible children do not enroll in Medicaid, and they differ in specific ways from enrolled children.

Adolescent↗
PubMed1997

In vitro evaluation of the antibacterial effects of intracanal micro plasma system treatment.

Forty freshly extracted single-rooted teeth were prepared to a size 25 master apical file, autoclaved, and inoculated with a known quantity of Actinomyces naeslundii. The teeth were divided into four groups (n = 10), including an untreated control group. The three treatment groups were exposed to Micro Plasma System (MPS), 0.5% NaOCl and 0.5% NaOCl + MPS respectively. The content of each root canal was absorbed by sterile paper points, diluted in 2 ml Schaedler Broth Medium, and incubated on blood agar. The number of CFU was determined. Data analysis, using an analysis of variance and Scheffe's test at the 1% level (Statview II software), indicated a significant reduction in CFU count for the three treatment groups compared to the control group. For the three treatment groups, no significant intergroup differences were observed.

Actinomyces↗
PubMed1994

High-dose immunoglobulin therapy for severe IgA nephropathy and Henoch-Schönlein purpura.

OBJECTIVE: To determine if polyvalent IgG is promising therapy for severe IgG nephropathy. DESIGN: Open prospective cohort study. SETTING: Referral nephrology unit. PATIENTS: 11 adult patients with severe IgA nephropathy (9 who had idiopathic disease and 2 who had Henoch-Schönlein purpura) and indicators of poor prognosis. INTERVENTION: Patients were given high-dose immunoglobulins (2 g/kg each month) for 3 successive months, followed by intramuscular immunoglobulins (preparation content, 16.5%; 0.35 mL/kg every 15 days) for another 6 months. MEASUREMENTS: Histologic changes were analyzed by comparing pre- and post-therapy renal biopsy specimens blindly, using an activity index (14-point scale), a sclerosis index (10-point scale), and a semiquantitative immunofluorescence test of immune deposits. Proteinuria, hematuria, leukocyturia, enzymuria, and global renal function (creatinine and polyfructosan clearances) were evaluated before and after intervention. RESULTS: Proteinuria (median level before intervention, 5.20 g/d; median level after intervention, 2.25 g/d), hematuria, and leukocyturia decreased substantially. The decrease in glomerular filtration rate was greatly slowed or stopped (median rate of decline in glomerular filtration before, -3.78 mL/min per month; after, 0 mL/min per month). The histologic index of activity (median index before, 5; after, 2) and the staining intensity of glomerular IgA and C3 deposits also decreased. Immunoglobulin therapy was well tolerated. CONCLUSIONS: Immunoglobulin therapy may be effective in treating severe IgA nephropathy and protecting renal function. However, prospective controlled trials must confirm these preliminary results.

Adolescent↗
PubMed1994

[Transfusion and alloimmunization in sickle cell anemia patients].

Transfusion therapy for sickle cell anemia is limited by the development of antibodies to red cell antigens. The aim of this study was to evaluate whether transfusion of blood matched for antigens Rh and Kell would reduce the incidence of alloimmunization. We determined the transfusion history, red cell phenotype and development of alloantibodies in 173 patients with sickle all anemia who received transfusions. Forty nine patients were transfused exclusively with frozen red blood cells (RBL) matched for antigens Rh and Kell; the rate of alloimmunization was 8.2%; antibodies to the Jkb, Jka, Fya and S were developed; 1 patient developed 2 antibodies. In a control group of 124 patients who received standard red blood cells, the rate of alloimmunization was significantly increased to 30.6% (p < 0.05); antibodies against C, E, K, Fya were the most frequently developed and 19 patients (16%) developed antibodies reacting with different antigens. In the 2 groups, alloimmunization occurred after receiving a significantly different number of transfusions: mean 9 in the patients transfused with matched RBC and 32 in the control group. The influence of the kinetics of transfusion was not demonstrated. To assess the effect that racial differences might have on alloimmunization, comparison of the red cell phenotype of patients with that of a panel of unselected blood bank donors was performed: the patients had a significant decrease in the frequency of red cell antigens corresponding to most of the detected alloantibodies JkB, C, S. Fyb, Fya and Kell.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Marinobacter hydrocarbonoclasticus gen. nov., sp. nov., a new, extremely halotolerant, hydrocarbon-degrading marine bacterium.

On the basis of phenotypical characteristics and analysis of 16S rRNA sequence, a new species belonging to a new genus is described, and the name Marinobacter hydrocarbonoclasticus is proposed. This organism, isolated from Mediterranean seawater near a petroleum refinery, is a gram-negative, aerobic, rod-shaped bacterium. It grows at NaCl concentrations of 0.08 to 3.5 M and uses various hydrocarbons as the sole source of carbon and energy. Its DNA has a guanine-plus-cytosine content of 52.7 mol%. The 16S rRNA analysis shows a clear affiliation between M. hydrocarbonoclasticus and the gamma group of the phylum Proteobacteria. A close phylogenetic relationship appears among the species Marinomonas vaga, Oceanospirillum linum, Halomonas elongata, and Pseudomonas aeruginosa. Because of the impossibility of finding a single most closely related species, we suggest that this bacterium be assigned to a new genus, at least temporarily. The possibility of a revision of this status when new data appear is, however, not excluded. The type strain is M. hydrocarbonoclasticus SP.17 (= ATCC 49840).

Bacteriolysis↗
PubMed1991

Dentinal permeability of the dog canine after exposure of a cervical cavity to the beam of a CO2 laser.

The dentinal permeability of the axial wall of a class V cavities in the canine of the dog was analyzed before and after its laser CO2 irradiation at two energy levels: 285 J per cm2 and 570 J per cm2. The sealing of the exposed dentin was verified by means of a pellet of cotton wool placed in contact with the axial wall and on which 20 microliters of a 50 mg per ml solution of noradrenaline was injected with a micrometric syringe. The transdentinal passage of noradrenaline induces a vasoconstriction of the pulp which is attested by a drop in its blood pressure. The absence of any variation in the pulpal pressure is an indication of the sealing to noradrenaline of the dentinal wall irradiated with an energy level of 570 J per cm2. This experimentation illustrates that it is possible to obtain dentinal sealing by means of laser irradiation without affecting the underlying pulp. The quality of this reduction in permeability is dependent upon the different factors which define the energy level.

Animals↗
PubMed1990

[Diffusion of elements of glass ionomer cements placed in a dentin cavity: influence on pulp pressure].

The biocompatibility of glass ionomer cement with silver and titanium ions is studied in vivo on dog's canine. Class V cavities, side by side the pulp, are prepared and Ketak Silver cement is placed inside. Variation of pulp pressure are recorded before and after the cement's applying, after which the crowns are cut and broken at the filling level, the different components part diffusion through the dentin are placed in prominent position by means of a microanalysis and a cartography of the sample is obtained by colorimetric picture. The pulp's haemodynamic responses to Ketak Silver are in harmony with the metallic ions diffusion and specially with silver.

Animals↗
PubMed1990

[Experimental study of the effect of a photopolymerizable glass ionomer cavity liner on pulp pressure and temperature].

The biocompatibility of a light curing glass ionomer cement was studied for its pulpal effect when used as a capping agent in a dentin cavity. Pulpal pressure and temperature were recorded in 14 dog canines after placement of the glass ionomer cement. No increase was observed in 12 specimens on 14 samples. These results indicate that no pulpal effect can be demonstrated when using Vitrabond as a dentin capping agent.

Animals↗