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1.
Phys Rev Lett ; 116(4): 041801, 2016 Jan 29.
Article in English | MEDLINE | ID: mdl-26871322

ABSTRACT

We report on measurements of the decays of B¯ mesons into the semileptonic final states B¯â†’D^(*)π^(+)π^(-)ℓ^(-)ν¯, where D^(*) represents a D or D^(*) meson and ℓ^(-) is an electron or a muon. These measurements are based on 471×10^(6) BB ¯ pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R_{π^{+}π^{-}}^{(*)}=B(B[over ¯]→D^{(*)}π^{+}π^{-}ℓ^{-}ν[over ¯])/B(B[over ¯]→D^{(*)}ℓ^{-}ν[over ¯]) using events in which the second B meson is fully reconstructed. We find R_{π^{+}π^{-}}=0.067±0.010±0.008 and R_{π^{+}π^{-}}^{*}=0.019±0.005±0.004, where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that B[over ¯]→D^{(*)}ππℓ^{-}ν[over ¯] decays, where π denotes either a π^{±} and π^{0} meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.

2.
Phys Rev Lett ; 114(17): 171801, 2015 May 01.
Article in English | MEDLINE | ID: mdl-25978225

ABSTRACT

We present a search for a neutral, long-lived particle L that is produced in e+ e- collisions and decays at a significant distance from the e+ e- interaction point into various flavor combinations of two oppositely charged tracks. The analysis uses an e+ e- data sample with a luminosity of 489.1 fb(-1) collected by the BABAR detector at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and just below the ϒ(4S). Fitting the two-track mass distribution in search of a signal peak, we do not observe a significant signal, and set 90% confidence level upper limits on the product of the L production cross section, branching fraction, and reconstruction efficiency for six possible two-body L decay modes as a function of the L mass. The efficiency is given for each final state as a function of the mass, lifetime, and transverse momentum of the candidate, allowing application of the upper limits to any production model. In addition, upper limits are provided on the branching fraction B(B→XsL), where Xs is a strange hadronic system.

3.
Phys Rev Lett ; 114(8): 081801, 2015 Feb 27.
Article in English | MEDLINE | ID: mdl-25768754

ABSTRACT

We present a measurement of the asymmetry A_{CP} between same-sign inclusive dilepton samples ℓ^{+}ℓ^{+} and ℓ^{-}ℓ^{-} (ℓ=e, µ) from semileptonic B decays in ϒ(4S)→BB[over ¯] events, using the complete data set recorded by the BABAR experiment near the ϒ(4S) resonance, corresponding to 471×10^{6} BB[over ¯] pairs. The asymmetry A_{CP} allows comparison between the mixing probabilities P(B[over ¯]^{0}→B^{0}) and P(B^{0}→B[over ¯]^{0}), and therefore probes CP and T violation. The result, A_{CP}=[-3.9±3.5(stat)±1.9(syst)]×10^{-3}, is consistent with the standard model expectation.

4.
Phys Rev Lett ; 113(20): 201801, 2014 Nov 14.
Article in English | MEDLINE | ID: mdl-25432035

ABSTRACT

Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, µ^{+}µ^{-} using 514 fb^{-1} of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model predictions, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10^{-4}-10^{-3} for dark photon masses in the range 0.02-10.2 GeV. We further constrain the range of the parameter space favored by interpretations of the discrepancy between the calculated and measured anomalous magnetic moment of the muon.

5.
J Plast Reconstr Aesthet Surg ; 67(12): 1711-8, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25219338

ABSTRACT

30-44% of patients with clinical groin node melanoma have involved pelvic nodes. Clinical guidelines selectively target pelvic lymph node dissection (PLND) to those meeting radiological and clinico-pathological criteria, but we lack satisfactory diagnostic tools to preoperatively identify patients with pelvic node disease. We evaluate routine PLND for all patients undergoing superficial node dissection (SLND), performed as a combined single-stage ilioinguinal lymph node dissection (ILND). Retrospective analysis of 67 ILNDs in consecutive patients presenting with palpable, cytologically melanocytic groin nodes. We examine predictors of pelvic node status and determine efficacy of 2010 UK guidelines in patient selection for PLND. 28 patients (42%) had histologically positive pelvic nodes; half had just one involved node (53.6%). 43% of pelvic metastases were radiologically occult. Significant predictors of pelvic melanoma were stage N3 groin nodes (p = 0.049), one third of groin nodes involved (p = 0.0009), positive Cloquet's node (p = 0.005), previous in transit disease (p = 0.001), and staging CT (p = 0.007). UK guidelines, primarily reliant upon staging CT, were effective selection criteria (p = 0.04), identifying 57% of pelvic metastases. CT and in-transit disease status in combination was the strongest predictor of pelvic disease (p = 0.006, RR 4.5, PPV 0.75, NPV 0.83). A combined CT and in-transit disease status provides a potentially clinically useful preoperative selection tool for ILND. With a high prevalence of occult pelvic node involvement, potential to avoid the morbidity of untreated pelvic nodes, and 5 year survival figures of 24-35% following surgery, we advocate ILND in all patients with clinically evident melanoma in a single groin node.


Subject(s)
Lymph Node Excision , Lymph Nodes/surgery , Melanoma/secondary , Melanoma/surgery , Patient Selection , Adult , Aged , Female , Humans , Inguinal Canal , Lymph Nodes/diagnostic imaging , Lymph Nodes/pathology , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Staging , Pelvis , Practice Guidelines as Topic , Retrospective Studies , Survival Rate , Tomography, X-Ray Computed
6.
Phys Rev Lett ; 111(11): 111801, 2013 Sep 13.
Article in English | MEDLINE | ID: mdl-24074072

ABSTRACT

We measure the mass difference Δm0 between the D*(2010)+ and the D0 and the natural linewidth Γ of the transition D*(2010)+ → D0π+. The data were recorded with the BABAR detector at center-of-mass energies at and near the Υ(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb(-1). The D0 is reconstructed in the decay modes D0 → K- π+ and D0 → K- π+ π- π+. For the decay mode D0 → K- π+ we obtain Γ = (83.4±1.7±1.5) keV and Δm0 = (145425.6±0.6±1.7) keV, [corrected] where the quoted errors are statistical and systematic, respectively. For the D0 → K- π+ π- π+ mode we obtain Γ = (83.2±1.5±2.6) keV and Δm0 = (145426.6±0.5±1.9) keV. [corrected] The combined measurements yield Γ = (83.3±1.2±1.4) keV and Δm0 = (145425.9±0.4±1.7) keV; the width is a factor of approximately 12 times more precise than the previous value, while the mass difference is a factor of approximately 6 times more precise.

7.
Phys Rev Lett ; 111(10): 101802, 2013 Sep 06.
Article in English | MEDLINE | ID: mdl-25166652

ABSTRACT

We present results of a search for CP violation in B0- B0 mixing with the BABAR detector. We select a sample of B0→D*- Xℓ+ ν decays with a partial reconstruction method and use kaon tagging to assess the flavor of the other B meson in the event. We determine the CP violating asymmetry ACP≡[N(B0B0)-N(B0B0)]/[N(B0B0)+N(B0B0)]=(0.06±0.17(-0.32)(+0.38))%, corresponding to ΔCP=1-|q/p|=(0.29±0.84(-1.61)(+1.88))×10(-3).

8.
Phys Rev Lett ; 109(19): 191801, 2012 Nov 09.
Article in English | MEDLINE | ID: mdl-23215373

ABSTRACT

The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B → X(s)γ plus B → X(d)γ, is studied using a data sample of (382.8 ± 4.2) × 10(6)Υ(4S) → BB decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B → X(s)γ) = (3.21 ± 0.33) × 10(-4) for E(γ) >1.8 GeV and the direct CP asymmetry A(CP) (B → X(s+d)γ) = 0.057 ± 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.


Subject(s)
Models, Theoretical , Nuclear Physics/methods , Photons , Mesons , Nuclear Energy
9.
Phys Rev Lett ; 109(21): 211801, 2012 Nov 21.
Article in English | MEDLINE | ID: mdl-23215586

ABSTRACT

Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B(0) or B(0)), and J/ψK(L)(0) or ccK(S)(0) final states (referred to as B(+) or B(-)), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B(0) → B(-) and B(-) → B(0), as a function of the time difference between the two B decays. Using 468 × 10(6) BB pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS(T)(+) = -1.37 ± 0.14(stat) ± 0.06(syst) and ΔS(T)(-) = 1.17 ± 0.18(stat) ± 0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.

10.
Phys Rev Lett ; 108(21): 211801, 2012 May 25.
Article in English | MEDLINE | ID: mdl-23003239

ABSTRACT

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb(-1) of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the standard model-dark-sector mixing angle and the dark-sector coupling constant.

11.
Phys Rev Lett ; 109(10): 101802, 2012 Sep 07.
Article in English | MEDLINE | ID: mdl-23005279

ABSTRACT

Based on the full BABAR data sample, we report improved measurements of the ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or µ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D(*))=0.332±0.024±0.018, which exceed the standard model expectations by 2.0σ and 2.7σ, respectively. Taken together, our results disagree with these expectations at the 3.4σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

12.
Phys Rev Lett ; 107(22): 221803, 2011 Nov 25.
Article in English | MEDLINE | ID: mdl-22182022

ABSTRACT

We search for hadronic decays of a light Higgs boson (A(0)) produced in radiative decays of an Υ(2S) or Υ(3S) meson, Υ→γA(0). The data have been recorded by the BABAR experiment at the Υ(3S) and Υ(2S) center-of-mass energies and include (121.3±1.2)×10(6) Υ(3S) and (98.3±0.9)×10(6) Υ(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions B(Υ(nS)→γA(0))B(A(0)→hadrons) (n=2 or 3) that range from 1×10(-6) for an A(0) mass of 0.3 GeV/c(2) to 8×10(-5) at 7 GeV/c(2).

13.
Klin Padiatr ; 221(4): 241-6, 2009.
Article in English | MEDLINE | ID: mdl-19629902

ABSTRACT

BACKGROUND: Parents of chronically ill children face numerous burdens in daily life, which can impair their quality of life (QoL) significantly. Therefore in family-oriented rehabilitation, not only the children themselves, but also their parents receive interventions. These aim at stabilizing parents both mentally and physically to enable them to support their children in the best possible way. This study investigates the effects of an inpatient family-oriented rehabilitation program on the QoL of parents of chronically ill children. PATIENTS: A consecutive sample of 231 mothers and 155 fathers of children suffering from cancer, cardiac diseases or cystic fibrosis participated in the study. METHOD: In a prospective longitudinal study, parental QoL was repeatedly assessed using the Ulm Quality of Life Inventory for Parents (ULQIE) at three different time points: admission to the rehabilitation clinic, discharge after four weeks of inpatient treatment, and at a six-month follow-up. RESULTS: Parental QoL increased markedly during rehabilitation treatment (mothers eta (2)=.326, fathers eta (2)=.249). Moreover, six months after the intervention, parental quality of life was still markedly improved compared to baseline assessment (mothers eta (2)=.259, fathers eta (2)=.069). The child's diagnosis had no effect on the level and course of parental QoL. CONCLUSIONS: Taking part in family-oriented rehabilitation can improve the QoL of parents of children suffering from cancer, cardiac diseases or cystic fibrosis. Such programs could be expected to affect the way chronically ill children cope with their condition and this should be examined in future studies.


Subject(s)
Chronic Disease/psychology , Chronic Disease/rehabilitation , Family Therapy/methods , Parents/psychology , Quality of Life/psychology , Adult , Child , Cystic Fibrosis/psychology , Cystic Fibrosis/rehabilitation , Education , Female , Follow-Up Studies , Germany , Heart Diseases/psychology , Heart Diseases/rehabilitation , Humans , Male , Middle Aged , Neoplasms/psychology , Neoplasms/rehabilitation , Patient Admission , Patient Satisfaction , Rehabilitation Centers , Surveys and Questionnaires , Young Adult
14.
J Plast Reconstr Aesthet Surg ; 62(10): e368-72, 2009 Oct.
Article in English | MEDLINE | ID: mdl-18572004

ABSTRACT

Treatment of giant basal cell carcinomas (GBCC) can pose several challenges. In such instances, use of routine and recommended treatments for sporadic, average size basal cell carcinomas (BCC) is suboptimal, impractical and often leads to treatment failure. Surgical excision of such large lesions results in marked intra and postoperative morbidity. While individually, photodynamic therapy, topical imiquimod and surgical excision are all established treatments for BCC, their combined use in the treatment of GBCC has not been explored. Three patients with histologically proven GBCC were sequentially treated with three cycles of metvix photodynamic therapy followed by a 6-week course of topical imiquimod. This led to a reduction in the size of these lesions which were subsequently excised.


Subject(s)
Aminoquinolines/administration & dosage , Antineoplastic Agents/administration & dosage , Carcinoma, Basal Cell/drug therapy , Photochemotherapy/methods , Skin Neoplasms/drug therapy , Administration, Topical , Aged , Aminolevulinic Acid/administration & dosage , Aminolevulinic Acid/analogs & derivatives , Carcinoma, Basal Cell/pathology , Carcinoma, Basal Cell/surgery , Female , Humans , Imiquimod , Male , Middle Aged , Photosensitizing Agents/administration & dosage , Skin Neoplasms/pathology , Skin Neoplasms/surgery
15.
Acta Neurochir Suppl ; 100: 29-31, 2007.
Article in English | MEDLINE | ID: mdl-17985540

ABSTRACT

BACKGROUND: N-Acetylcysteine (NAC) is a safe pharmaceutical agent known to protect cells from oxidative damage. Following peripheral nerve transection, NAC has been found to eliminate sensory neuronal loss. This study examines the dose-response relationship of NAC in preventing neuronal death. METHODS AND FINDINGS: The rat sciatic nerve transection model was used, and stereological quantification of sensory neuron survival carried out at two weeks post-axotomy. NAC was administered systemically as an intraperitoneal injection to five groups of rats at a range of doses (1-300 mg/kg/day). Significant neuronal loss was observed in the 1 mg/kg/day dosage group (18.5% loss, p = 0.067 vs. sham treatment). A degree of neuroprotection occurred with 10 mg/kg/day (9.1% loss, p < 0.005 vs. control), whilst there was no significant loss with either 150 or 300 mg/kg/day. CONCLUSIONS: The prevention of sensory neuronal loss with NAC is dose dependent and effective over a wide therapeutic range. This analysis confirms the efficacy of systemic administration and provides a dose framework with which NAC has clinical potential to improve outcome after peripheral nerve trauma.


Subject(s)
Acetylcysteine/administration & dosage , Neurons, Afferent/drug effects , Neurons, Afferent/pathology , Sciatic Nerve/injuries , Sciatic Nerve/pathology , Acetylcysteine/pharmacology , Animals , Cell Count , Dose-Response Relationship, Drug , Ganglia, Spinal/drug effects , Ganglia, Spinal/pathology , Rats , Sciatic Nerve/drug effects , Wounds and Injuries/pathology
16.
J Plast Reconstr Aesthet Surg ; 59(6): 631-5, 2006.
Article in English | MEDLINE | ID: mdl-16716956

ABSTRACT

The goal of reconstruction of the skull base is to repair dural defects with a watertight seal and separate it from the nasopharynx and the exterior environment with well vascularised tissue. This prevents cerebro-spinal fluid leakage and secondary contamination leading to the potentially life threatening complications of meningitis or extradural abscess. Following large composite resections, traditional techniques to repair the dura involve the use of an autologous fascial graft or a pericranial flap, whilst a regional pedicled or free muscle flap is used to close the dead space defect. We describe a technique performed in two cases, whereby a single flap, the rectus abdominis muscle free flap, can be used to provide vascularised reconstruction both of the dura and the skull base. The anterior rectus sheath, islanded on a single perforator vessel, is used as a vascularised layer to reconstruct dura, whilst the supporting rectus abdominis muscle provides bulk to obliterate dead space. We show that this flap is suitable for reconstruction even in the presence of chronic infection. Advantages of a vascularised reconstruction are the rapid healing of the wound, even after radiotherapy, the delivery of systemic antibiotics to the site of the operation, and that it may allow early postoperative radiotherapy to be planned.


Subject(s)
Dura Mater/surgery , Rectus Abdominis/transplantation , Skull Base/surgery , Surgical Flaps , Adult , Brain Abscess/surgery , Carcinoma, Adenoid Cystic/surgery , Chronic Disease , Humans , Male , Middle Aged , Nose Neoplasms/surgery , Otitis Media/complications , Otitis Media/surgery , Plastic Surgery Procedures/methods , Surgical Flaps/blood supply , Temporal Lobe/surgery , Treatment Outcome
17.
Inflamm Res ; 51(12): 572-8, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12558190

ABSTRACT

INTRODUCTION: In cutaneous lymphocytic inflammation, enhanced regional blood flow is suggested by persistent erythema and warmth. Direct assessment of the microcirculation, however, has been limited by tissue edema and skin thickness. METHODS: To assess the microcirculatory adaptations to the epicutaneous antigen oxazolone, we studied the first pass kinetics and microvascular topography of the inflammatory skin microcirculation using a specially adapted epi-illumination intravital microscopy system. The fluorescence intravital videomicroscopy and streaming image acquisition of fluorescein-labeled dextran (approximately 500,000 MW) injections were used to assess changes in plasma flow. RESULTS: Direct plasma tracer injections of both the oxazolone-stimulated and control microcirculation demonstrated comparable transit times (leading edge and intensity-weighted peak times) from the carotid artery to the superficial vascular plexus (p > 0.05). In contrast to transit times, continuous infusion of the plasma tracer demonstrated a significant increase in the delivery of the fluorescein-labeled dextran to the oxazolone-stimulated microcirculation. Quantitative morphometry of intravital microscopic images demonstrated a 2.2-fold increase in the mean diameter of vessels in the superficial vascular plexus (p < 0.01). Further, fluorescence intensity mapping indicated that the increase was associated with increased perfusion of focal regions of the superficial vascular plexus (p < 0.001). CONCLUSIONS: These results indicate that the oxazolone-stimulated adaptations of the inflammatory microcirculation include both microvascular dilatation and the redistribution of plasma flow.


Subject(s)
Oxazoles/pharmacology , Skin/blood supply , Animals , Capillaries/anatomy & histology , Capillaries/drug effects , Coloring Agents , Eosine Yellowish-(YS) , Erythema/pathology , Fluorescent Dyes , Hematoxylin , Lymphocytes/drug effects , Microcirculation/drug effects , Microscopy, Fluorescence , Regional Blood Flow/drug effects , Sheep , Skin/drug effects , Stimulation, Chemical
18.
In Vitro Cell Dev Biol Anim ; 37(9): 599-605, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11710437

ABSTRACT

L.ymphocyte interactions with endothelial cells in microcirculation are an important regulatory step in the delivery of lymphocytes to peripheral sites of inflammation. In normal circumstances, the predicted wall shear stress in small venules range from 10 to 100 dyn/cm2. Attempts to measure the adhesion of lymphocytes under physiologic conditions have produced variable results, suggesting the importance of studying biologically relevant migratory lymphocytes. To quantify the effect of shear stress on these migratory lymphocytes, we used lymphocytes obtained from sheep efferent lymph ducts, defined as migratory cells, to perfuse sheep endothelial monolayers under conditions of flow. Quantitative cytomorphometry was used to distinguish cells in contact with the endothelial monolayers from cells in the flow stream. As expected, migratory cells in contact with the normal endothelial monolayer demonstrated flow velocities less than the velocity of cells in the adjacent flow stream. The flow velocities of these efferent lymphocytes were independent of cell size. To model the inflammatory microcirculation, lymphocytes were perfused over sequential endothelial monolayers to directly compare the velocity of cells in contact with cytokine-activated and unactivated control monolayers. The tumor necrosis factor and interleukin-1-activated endothelial monolayers marginally decreased cell velocities at 1.2 dyn/cm2 (3.6%), but significantly reduced cell velocities 0.3 dyn/cm2 (27.4%; P < 0.05). Similarly, the fraction of statically adherent lymphocytes decreased as shear stress increased to 1.2 dyn/cm2. These results suggest that typical wall shear stress in small venules. of the order of 20 dyn/cm2, are too high to permit adhesion and transmigration of migratory lymphocytes. Additional mechanisnis must be present in vivo to facilitate lymphocyte transmigration in the inflammatory microcircu-


Subject(s)
Endothelium, Vascular/physiology , Lymphocytes/physiology , Animals , Endothelium, Vascular/cytology , In Vitro Techniques , Inflammation/physiopathology , Jugular Veins , Lymphocytes/cytology , Microscopy, Video , Sheep , Stress, Mechanical
19.
Am J Physiol Heart Circ Physiol ; 281(4): H1742-50, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11557566

ABSTRACT

Microcirculation is the primary mechanism for delivering lymphocytes to inflammatory tissues. Blood flow within microvessels ensures a supply of lymphocytes at the blood-endothelial interface. Whether the structure of the inflammatory microcirculation facilitates lymphocyte transmigration is less clear. To illuminate the microcirculatory changes associated with lymphocyte transmigration, we used intravital videomicroscopy to examine the dermal microcirculation after application of the epicutaneous antigen oxazolone. Intravascular injection of fluorescein-labeled dextran demonstrated focal topographic changes in the microcirculation. These focal changes had the appearance of loops or hairpin turns in the oxazolone-stimulated skin. Changes were maximal at 96 h and coincided with peak lymphocyte recruitment. To determine whether these changes were associated with lymphocyte transmigration, lymphocytes obtained from efferent lymph of draining lymph nodes at 96 h were fluorescently labeled and reinjected into inflammatory microcirculation. Epifuorescence intravital video microscopy demonstrated focal areas were associated with lymphocyte slowing and occasional transmigration. In contrast, focal loops and lymphocyte slowing were rarely observed in the contralateral control microcirculation. Results suggest that structural adaptations in inflammatory microcirculation represented by focal topographic changes may contribute to regulation of tissue entry by recirculating lymphocytes.


Subject(s)
Dermatitis, Contact/physiopathology , Lymphocytes/physiology , Skin/blood supply , Adjuvants, Immunologic , Animals , Cell Movement/physiology , Dermatitis, Contact/immunology , Ear , Microcirculation , Oxazolone/immunology , Sheep , Time Factors
20.
Transplantation ; 72(3): 516-22, 2001 Aug 15.
Article in English | MEDLINE | ID: mdl-11502985

ABSTRACT

BACKGROUND: Initially developed for histocompatibility testing, the normal lymphocyte transfer (NLT) reaction involves the intradermal injection of allogeneic lymphocytes from one individual to another. Because of the unique kinetics of the immunological response to allogeneic lymphocytes, the NLT reaction has been considered an informative system for the analysis of transplant immunity. METHODS: In this study, we used bilateral efferent lymph duct cannulations in sheep to examine the regional lymphatic response to the NLT reaction. Our studies used monoclonal antibodies to define lymphocyte population dynamics and DNA flow cytometry to reflect lymphocyte proliferative responses. RESULTS: The results confirmed a biphasic NLT reaction. An unexpected finding was the marked differences between the early and late NLT responses. The early response was characterized by T-lymphocyte proliferation, as reflected by S-phase DNA, which was comparable in both the NLT-stimulated and contralateral control efferent lymphocytes. This bilateral proliferative response was observed in both CD4+ and CD8+ lymphocytes. In contrast, the late response was restricted to the efferent lymph from the NLT-stimulated lymph node. Dual-parameter flow cytometry demonstrated that the dominant component of this unilateral NLT response was CD8+ lymphocytes. CONCLUSIONS: These results suggest important functional distinctions between systemic and regional lymphatic responses to intradermal alloantigens.


Subject(s)
Histocompatibility Testing/methods , Lymphatic System/physiology , Lymphocyte Transfusion , Animals , B-Lymphocytes/physiology , CD4-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/cytology , Cell Cycle , Cell Division/physiology , Erythema/immunology , Injections, Intradermal , Lymph/cytology , Lymph/physiology , Lymph Nodes/cytology , Phenotype , Sheep , T-Lymphocytes/physiology , Transplantation Immunology
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