Integration of Diamond-Based Quantum Emitters with Nanophotonic Circuits.

Nanophotonics provides a promising approach to advance quantum technology by replicating fundamental building blocks of nanoscale quantum optic systems in large numbers with high reproducibility on monolithic chips. While photonic integrated circuit components and single-photon detectors offer attractive performance on silicon chips, the large-scale integration of individually accessible quantum emitters has remained a challenge. Here, we demonstrate simultaneous optical access to several integrated solid-state spin systems with Purcell-enhanced coupling of single photons with high modal purity from lithographically positioned nitrogen vacancy centers into photonic integrated circuits. Photonic crystal cavities embedded in networks of tantalum pentoxide-on-insulator waveguides provide efficient interfaces to quantum emitters that allow us to optically detect magnetic resonances (ODMR) as desired in quantum sensing. Nanophotonic networks that provide configurable optical interfaces to nanoscale quantum emitters via many independent channels will allow for novel functionality in photonic quantum information processors and quantum sensing schemes.

Randomized controlled trial on the effective dose of anti-snake venom in cases of snake bite with systemic envenomation.

Snake bite is the common cause of morbidity and mortality in India. Snake antivenom, although very effective, is expensive, scarce, and associated with side effects. The conventional dose may not be required in all cases and a smaller dose may be as effective. A randomized double blind controlled trial was conducted to compare the effect of lower versus the conventional (high) dose. Patients presenting within 24 hours of snake bite with hematological or neurological evidence of systemic envenomation were included in the study. Patients were randomized either to receive high dose (2 vials over 1 hour, followed by 2 vials over 4 hours and repeated 4 hourly until clotting parameters normalized and then 2 vials as infusion over 24 hours) or low dose (2 vials over 1 hour, followed by 1 vial over four hours, repeated 4 hourly until clotting parameters were normalized and then 1 vial as an infusion over 24 hours). Thirty one patients received high dose and 29 a low dose. The mean dose of antivenom used was significantly different in the two groups (8.9 and 4.7, respectively). There was no mortality. The duration of stay was 4.94 and 3.48 days, respectively. There was no difference in the transfusion, dialysis or ventilation requirement of the two groups. Low dose regimen is more effective and required 5 vials less than the conventional dose. Each vial costs Rs. 200, so the estimated savings is Rs. 1000 per patient.

Immunophenotyping of human dendriform cells from the conjunctival epithelium.

PURPOSE: Conjunctival Langerhans cells are bone marrow-derived, antigen-presenting cells that play a major role in the immune response of the ocular surface, but they have as yet been little investigated, either functionally or phenotypically. This study was undertaken in impression cytology to provide an extended immunophenotype of human conjunctival dendriform cells. METHODS: Immunostaining procedures were used to seek for the expression of the following 30 membrane antigens related to the immune system, using dendriform cells obtained in conjunctival specimens from 80 normal subjects and 105 with chronic conjunctivitis: class II antigens HLADR and DQ, CD1a (T6) and CD5, which usually mark Langerhans cells, macrophage markers CD14, CD36 and CD63, various lymphocyte antigens (CD2, CD4 and CD8), receptor to interleukin 2 (CD25), adhesion molecules and integrins (CD11a, CD11b, CD11c, CD18, CD29, CD41, CD61), the selectin CD62, ICAM-1 (CD54), ICAM-3 (CD50) and ELAM-1, CD45RO, related to activation of immune cells, and its ligand CD22, receptors to immunoglobulins (CD23 and CD32) and complement (CD21), transferrin receptor CD71, tryptase and vimentin, were thus investigated. RESULTS: Conjunctival dendriform cells reliably expressed several antigens: class II antigens HLA DR and HLA DQ, CD1a, vimentin, CD11a and CD18 (LFA-1), CD14, CD22, CD36, CD45RO, ICAM-3 and CD63. Other markers were only occasionally found (CD4, CD11b, CD29, CD32 and CD54), and the remaining above antigens were not expressed. No relevant difference was found between normal and inflammatory specimens in the immunophenotype of dendriform cells. CONCLUSIONS: This study sheds light on the main antigen-presenting cells of the ocular surface. The conjunctival cells share common immunophenotypic features with those from skin or mucosae, but our results showed some discrepancies, probably related to the specific immune status of the ocular structures.

PMA induces platelet activation of specific antigens (CD62/CD63) in GpIIb-IIIa deficient platelets from Glanzmann's thrombasthenia.

Glanzmann's thrombasthenia (GT) is a hereditary platelet disorder resulting from a quantitative or qualitative deficiency of the major platelet membrane complex GPIIb-IIIa (CD41) required for platelet aggregation. We investigated by flow cytometry, the expression of CD41, fibrinogen, and of two platelet activation-related antigens, CD62 and CD63, (i) before and after activation of platelets by PMA, and (ii) on the surface and within the cytoplasm of resting platelets, after permeabilization by saponin. Platelets from a series of normal subjects and from nine members of two GT families, were reacted with FITC-conjugated antibodies and analyzed on a flow cytometer. Fluorescence intensities measured on normal and GT platelets were quantified by using calibrated beads. Results showed lack of both GPIIb-IIIa and fibrinogen, on the platelet surface and also within the cytoplasm in five of these GT patients, whereas GPIIb-IIIa and fibrinogen remained normal in the four other cases. However, CD62 and CD63 antigenic levels were found within normal range for all members of these families, after PMA stimulation and also after platelet permeabilization. This work therefore showed that the lack of CD41 in GT, which causes strong disturbance of platelet aggregation, may not be associated with the deficiency of activation pathways.

Positive CD17 myeloid antigen in acute leukemia expressing lymphoid antigens: abnormal genomic processes in multiphenotypic leukemia or new subtypes within lymphoid leukemia?

Specific morphological and histochemical changes serve to define stages of differentiation during terminal myeloid maturation. The development of the hybridoma technology has allowed generation of monoclonal antibodies selectively reactive with antigenic determinants expressed in the hematopoietic system by myeloid cells at specific stages of differentiation. Here, the characterization by one of these antibodies i.e. GO35 (CD17) which shows myeloid specificity, was reported on blastic cells from 30% of acute lymphoid leukemia cases investigated (8/25). This monoclonal antibody may prove useful in the subclassification of atypical lymphoproliferative disorders including "hybrid leukemias" and serve as a possible prognostic factor for a therapy.

Multiphenotypic acute leukemias: clinicopathologic correlations and response to therapy.

Multiphenotypic acute leukemias (MAL), defined by the coexpression on most blast cells of antigens classically attributed to different lineages, remain a rare event. We isolated a series of 26 such cases from a cohort of 1565 leukemic patients whose cells were immunophenotyped at diagnosis. Markers of B and myeloid lineage (BM) were associated in 16 cases (62%), 3 coexpressed B and T markers (BT), and T-cell and myeloid antigens (TM) were found in 7 (27%). A tumoral syndrome was observed in 69% of the patients, without significant differences between the immunophenotypic subgroups. Median event free survivals in the three immunophenotypic subgroups as defined were respectively 24 months for BM-MAL, 4 months for TM-MAL and 7 months for BT-MAL respectively. The poorer prognosis of TM-MAL was significantly different from that of BM-MAL (p < 0.001). This concurred with the poorer prognosis associated with CD7 expression or absence or CD10, both characteristic features of TM-MAL.

Fluorescent staining of the actin cytoskeleton in human lymphocytes, monocytes and polymorphonuclear cells using a DNAse 1/anti-DNAse 1 immunoglobulin fluorescein conjugated system.

The actin associated with membrane-enriched extracts of leukocytes can be quantitated by DNAse 1 inhibition. Using this assay, we previously demonstrated that the actin level in monocytes was significantly higher than that in polymorphonuclear, T and B cells respectively. However, the extracellular location of the actin fraction detected by DNAse 1 inhibition (monomeric "G") remained unclear. This study using the DNAse 1/anti DNAse 1 immunoglobulin fluorescein conjugated system demonstrated that G-actin is present primarily in the cortical cell cytoplasm of leukocytes, in confirmation of our previous biochemical findings. Since the solubilized G-actin activities of membrane-rich lymphoid cell fractions, measured by DNAse 1 inhibition, are a reflection of the migratory potential, this immunofluorescent system may permit identification of the leukocytic cell subpopulations that have a potential for active circulation.

[Value of monoclonal antibody study of lymphocyte subpopulations in newborn infants of HIV1 seropositive mothers]. / Intérêt de l'étude par anticorps monoclonaux des sous-populations lymphocytaires chez le nouveau-né de mère VIH1 séro-positive.

The outcome of infants born to HIV1 seropositive (HIV1+) mothers is still uncertain is spite of current progress in techniques for viral detection. Using the almost elective tropism of HIV1 virus for CD4 lymphocytes and the central role of these cells in the immune regulation, we studied blood lymphocyte populations with 7 monoclonal antibodies during the first month of life in 28 newborns of HIV1 seropositive mothers. Our data are compared to an age-matched population of 35 control infants. According to our results, the coexistence of a low CD8 lymphocyte percentage together with a high CD4/CD8 ratio seems to be correlated with an unfavourable outcome.

[Multi-phenotype leukemia in children. Apropos of 18 cases]. / Leucémies multiphénotypiques chez l'enfant. A propos de 18 observations.

Eighteen cases of pediatric acute multi-phenotypic leukemia from 24 French centers investigated during 5 years are reported. The multi-phenotypic character of these cases was shown by the paradoxical presence of 2 or 3 associated membrane antigens which are normally lineage restricted. The following bi-phenotypic combinations were found: B/T lymphoid (n = 6), B/myeloid (n = 7) or T/myeloid (n = 2). Three cases of tri-phenotypic association were also observed [B/T/myeloid (n = 2), B/myeloid/megakaryoblastic (n = 1)]. Our findings suggest that combinations with a myeloid composant and the presence of cALLA (common acute lymphoid leukemia antigen) on less than 45% of cells seem to be related to a shorter survival.

Polymerized actin in lymphoid cells: functional interpretation.

Nitrobenzoxadiazol (NBD) phallacidin, an active fluorescent derivative of the actin-binding mushroom toxin phallacidin provides a convenient actin-specific fluorescent label for cellular cytoskeleton structures. Topographical fluorescent microscopy images of lymphoid cells obtained with NBD-phallacidin staining reveal that the major feature of the cellular cytoskeleton characterized by actin are mainly associated with cell membrane, a pattern that correlates strikingly with their DNAse 1 inhibition. Such actin pools may thus be involved in a membrane-associated protein network controlling membrane viscoplastic deformation and cell motility.

Neutral maltase: the first human B-cell enzymatic marker reflecting terminal differentiation of mature B cells into plasma cells.

Neutral maltase activity (alpha-D-glucoside glucohydrolase; EC: 3.2.1.20) was measured in B and T lymphocytes from peripheral blood of normal subjects and patients suffering from chronic or acute lymphoid leukemias. Neutral maltase activity is undetectable in T cells from normal subjects as well as in patients with chronic or acute T-lymphoid leukemias. Conversely, whereas this enzyme activity is always undetectable in chronic or acute B-lymphoid leukemia, neutral maltase activity is expressed in mature B cells from normal subjects. The detection of higher neutral maltase activity in plasma cells from myelomas than in normal B cells supports the concept that the expression of neutral maltase activity is related to the stages of differentiation and maturation reached by lymphocytes of the B-cell lineage. Neutral maltase therefore appears as the first B-cell enzymatic marker described that is expressed in the course of terminal differentiation of mature B cells into plasma cells.