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Large crystal growth and characterization of the optical and terahertz (THz) properties of organic nonlinear optical (NLO) crystal NMBA (4‐Nitro‐4′‐methylbenzylidene aniline) is presented. The reported method of crystal growth consistently produces high‐quality single crystals. The THz generation efficiency and optical properties of NMBA to other THz generation crystals including BNA and MNA are compared. The low THz absorptions that make NMBA an ideal source for THz time‐domain spectroscopy are highlighted. [ABSTRACT FROM AUTHOR]

Following lymphadenectomy, popliteal peripheral leucocytes present in afferent lymphatics draining the skin can be obtained relatively free of contaminating cells derived from blood and central lymph in contrast to prescapular and hepatic peripheral lymph which contain contaminating cells. Popliteal peripheral lymphocytes comprise a population of long-lived dividing cells that are deficient responders in mixed lymphocyte cultures (MLC) but elicit strong responses following stimulation with phorbol myristate acetate plus ionomycin or concanavalin A. Deficient responsiveness persisted when popliteal peripheral lymphocytes were cultured for 3 weeks prior to setting up MLC. The in vitro results correlate with in vivo results from normal lymphocyte transfer reactions and indicate that peripheral lymphocytes may comprise a population deficient in T-cell receptors mediating allogeneic stimulation. [ABSTRACT FROM AUTHOR]

A possible role for the major histocompatibility complex (MHC) in the localization of lymphocytes in different lymphoid organs was investigated using inbred mouse strains. Lymphocytes labelled with the intracellular fluorochrome Hoechst 33342 (H33342) were transfused intravenously (IV) into unimmunized mice and the distribution of these labelled lymphocytes examined. In some combinations (e.g. C57BL/6 - CBA) 2 h after injection allogeneic lymphocytes accumulated in the region between the marginal zones and outer aspects of the while pulp of the spleen. In contrast, in syngeneic controls (e.g. CBA - CBA) the lymphocytes migrated normally into the white pulp. Similar results were obtained in Peyer's patches. Mapping studies in the spleen indicated that the failure to migrate normally is predominantly controlled by the MHC complex, although some non-MHC genes may play a role. In the case of the MHC the most definitive combination was BALB/c-H-2dm2 (H-2L deletion mutant) lymphocytes transfused into BALB/c recipients, the mutant lymphocytes failing to migrate normally and, therefore, implicating the H-2L region in the phenomenon. No differences in the viability of labelled lymphocytes as 6 and 24 h after injection into either syngeneic or allogeneic recipients suggests that the inability of cells to passage through lymphoid organs may represent inappropriate receptors rather than elimination of the allogeneic lymphocytes by natural killer cells (NK) as previously proposed. [ABSTRACT FROM AUTHOR]

Telomere-specific clones are a valuable resource for the characterization of chromosomal rearrangements. We previously reported a first-generation set of human telomere probes consisting of 34 genomic clones, which were a known distance from the end of the chromosome ( approximately 300 kb), and 7 clones corresponding to the most distal markers on the integrated genetic/physical map (1p, 5p, 6p, 9p, 12p, 15q, and 20q). Subsequently, this resource has been optimized and completed: the size of the genomic clones has been expanded to a target size of 100-200 kb, which is optimal for use in genome-scanning methodologies, and additional probes for the remaining seven telomeres have been identified. For each clone we give an associated mapped sequence-tagged site and provide distances from the telomere estimated using a combination of fiberFISH, interphase FISH, sequence analysis, and radiation-hybrid mapping. This updated set of telomeric clones is an invaluable resource for clinical diagnosis and represents an important contribution to genetic and physical mapping efforts aimed at telomeric regions.

The integrin alphaOX-62 subunit is defined by the OX-62 monoclonal antibody that was raised against rat dendritic cells in lymph (veiled cells) and shows properties similar to those of human alphaE that is predominantly expressed on intraepithelial lymphocytes. To clone alphaOX-62, rat probes generated using primers specific for the human alphaE sequence were used to screen rat T cell cDNA libraries. cDNA clones encoding two similar but not identical alpha subunits that are closely related but distinct from human alphaE were isolated. alphaE1 is predicted to be the rat homolog of mouse alphaM290 and alphaE2 corresponds to rat alphaOX-62. Immunofluorescence analysis revealed that mouse alphaE1 and rat alphaE2 are expressed in dendritic epidermal T cells in the skin, intraepithelial lymphocytes in the small intestine and in cells with a dendritic morphology present at sites where gammadelta T cells occur in lymphoid organs. Unexpectedly, in veiled cells alphaE2 is co-expressed with intracellular CD3-delta and a 33-kDa CD3 chain but not the T cell receptor. These findings suggest that veiled cells may be derived from a lymphoid precursor. Furthermore, veiled cells show phenotypic similarities to intraepithelial lymphocytes.

Cytogenetically undetectable deletions are suspected to be an important cause of mental retardation and developmental delay, as suggested by the observation that about 7% of children with undiagnosed mental retardation have rearrangements affecting the chromosome ends. Screening the whole genome for regions of aneuploidy smaller than 5 Mb is not feasible, but the availability of a high resolution map of the X chromosome means that it is possible to look for deletions in males by PCR. We have screened 96 affected males and their 96 unaffected fathers with 110 markers distributed across the X chromosome. No deletions were found in either group. Our results show that the prevalence of deletions greater than 1 Mb in children with mental retardation is less than 3.9% (95% confidence interval). We conclude that X chromosome deletions in the size range 1-5 Mb are a rare cause of mental retardation in males.

The integrin alpha OX-62 subunit is defined by the OX-62 monoclonal antibody that was raised against rat dendritic cells in lymph (veiled cells) and shows properties similar to those of human alpha E2 that is predominantly expressed on intraepithelial lymphocytes. To clone alpha OX-62, rat probes generated using primers specific for the human alpha E sequence were used to screen rat T cell cDNA libraries. cDNA clones encoding two similar but not identical alpha subunits that are closely related to but distinct from human alpha E were isolated. alpha E1 is predicted to be the rat homolog of mouse alpha M290 and alpha E2 corresponds to rat alpha OX-62. Immunofluorescence analysis revealed that mouse alpha E1 and rat alpha E2 are expressed in dendritic epidermal T cells in the skin, intraepithelial lymphocytes in the small intestine and in cells with a dendritic morphology present at sites where gamma delta T cells occur in lymphoid organs. Unexpectedly, alpha E2 is co-expressed with intracellular CD3-delta and a 33-kDa CD3 chain but not the T cell receptor in veiled cells. These findings suggest that veiled cells may be derived from a lymphoid precursor. Furthermore, veiled cells show phenotypic similarities to intraepithelial lymphocytes.

A random-bred strain (Q) was established and divided into six replicates. Each replicate was divergently selected for 6-week weight (for over 30 generations) and each had an unselected control. We have investigated the H-2 haplotype of individual mice of the 18 selected Q strains to determine whether selection for size had also selected for H-2 or H-2-linked genes. From the results it appeared that only the H2b and H-2q haplotypes were present in the foundation stock. A large number of individuals of the six small sublines were of H-2b haplotype, while the majority of those of the six large sublines were of the H-2q haplotype. Individuals in the six control strains were H-2b, H-2q or both (i.e., H-2 heterozygotes and/or H-2 recombinants). These results suggest that control of body size is associated with H-2 or an H-2-linked gene(s).

The mechanisms determining which parental haplotype is selected in (CBA X B10) (k X b)F1 female mice for major histocompatibility complex (H-2) restricted, male-specific (H-Y), immune, cytotoxic T-cell (Tc-cell) responses, was investigated. The data show that haplotype preference is variable, and may be directed towards one, both, or neither of the parental haplotypes. This preference is reflected in the precursor or frequency of memory Tc cells as measured by limiting dilution assays. It was further shown that maternal influence, antigen dose, route of immunization, and a feedback mechanism on the stimulator cells in vivo could not influence haplotype preference or its observed variability. Evidence for cross-reactive killing by H-2k and H-2b H-Y immune Tc cells on H-2b and H-2k allogeneic targets, respectively,, (i.e., the independent haplotype of the other parent of the F1 mice), provide evidence for natural tolerance as a possible mechanism to explain haplotype preference.

The role of sulfated polysaccharides in lymphocyte migration has been analyzed in vivo using lymphocytes labeled with an intracellular DNA-binding fluorochrome Hoechst 33342. The influence of a panel of sulfated polysaccharides on entry (by injecting the sulfated polysaccharide prior to the labeled cells) and displacement from lymphoid organs (by injecting the sulfated polysaccharide after the labeled cells have localized) indicated that different sulfated polysaccharides have selective effects on entry and displacement, and furthermore positioning of subpopulations within organs. Additional experiments suggested that receptors for sulfated polysaccharides on high endothelial venules may interact with complementary structures on lymphocytes. The data supporting this conclusion were: (a) the normal localization behavior of lymphocytes preincubated with sulfated polysaccharides; (b) an inverse relationship between the expression of lymphocyte surface receptors for sulfated polysaccharides and the ability of the lymphocytes to enter lymphoid organs and (c) the selective binding of sulfated polysaccharide-coupled fluoresceinated beads to high endothelial venules. In this case only the beads coupled with the sulfated polysaccharides that inhibited entry bound to the high endothelial venules. These findings are discussed in terms of a fundamental cellular recognition system utilizing sulfated polysaccharides.

Murine cytotoxic T-cell (Tc cell) responses to various antigens are controlled by immune response genes (Ir) mapping in the major histocompatibility complex (H-2). Both helper T cells, controlled by I region-coded genes, and Tc cells, controlled by K/D antigens, are necessary for a positive response. An H-2-restricted Tc-cell response to the male specific minor transplantation antigen (H-Y) can be elicited in B10 (H-2b) female mice primed with syngeneic male spleen cells intraperitoneally (i.p.) or intravenously (i.v.), or by skin grafting followed by restimulation in vitro in mixed lymphocyte culture (MLR) with male cells. CBA (H-2k) mice do not respond by these routes of in vivo priming, and this was thought to be due to a lack of permissible Ir genes for helper function. However, we now report that subcutaneous hind-footpad (fp) immunisation of 'non-responder' CBA mice with syngeneic male cells changes them to responders, a result which argues against a generalised Ir gene-controlled helper defect.

The immunoregulation of cytotoxic T-cell responses to the male-specific antigen H-Y in mice has been found to be genetically controlled by genes of the major histocompatibility complex (H-2). Responsiveness was mainly confined to H-2b strains, but it has also been found in recombinant strains, F1 hybrids, and chimeras that carry at least part of the H-2b haplotype. By using a different immunization procedure it has been shown recently that an H-2k mouse strain (CBA) is also able to mount an equivalent H-Y-specific response. We investigate here, by applying this immunization technique, the responsiveness of other H-2k strains and of strains of other independent H-2 haplotypes. Both responders and nonresponders are found in three haplotypes: k, s, and d. The strain distribution pattern of responsiveness shows a combined influence of non-H-2 and H-2 genes. In certain strains there is a high variability in responsiveness between genetically identical individual animals. We discuss a model of immune response (Ir) gene function which could account for these observations.