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Chromosomal translocation t(X;14)(q28;q11) has been observed in patients with pro-lymphocytic T-cell leukaemia (T-PLL). In two cases of T-PLL, one of which was associated with Ataxia telangiectasia (AT), the chromosomal break occurred in two different introns of a gene c6.1A, located at the Xq28 locus. Fusion transcripts, consisting of 5' sequences of c6.1A and the TCR alpha constant (C) region, were expressed at high levels in the leukaemic cells from both patients, but in only one case did this fusion generate an in-frame c6.1A-C alpha mRNA. However, the breaks within c6.1A seem to affect another gene, c6.1B, which is transcribed from the same CpG rich island as c6.1A but in the opposite transcriptional orientation. The c6.1B gene is not damaged by the translocation but is transcribed in both T-PLL cases. Furthermore, c6.1B may lack protein coding capacity and thus this translocation might result in a novel mechanism in tumorigenesis. In any event, this is the first cloned gene which is implicated in pathogenesis of chronic/pro-lymphocytic leukaemia of the T-cell lineage.

A new human T-cell non-Hodgkin lymphoma cell line of the T-cell receptor (TCR) gamma/delta lineage has been derived from the peripheral blood of a patient with a subcutaneous T-cell lymphoma in leukemic phase. The cell line (Karpas 384) initially had the same characteristics as malignant cells from the patient. Both the original tumor and the cell line failed to express any T-cell differentiation antigens other than very weak cell-surface expression of CD3 and cytoplasmic CD7; with continued growth in vitro, surface CD3 became undetectable in the presence of maintained strong cytoplasmic expression. The cell line has a complex karyotype with six abnormal chromosomes exhibiting not only t(7;14) (p13;q11.2) but also inv7(p13;q22.1), t(1;2)(q11;q35), t(2;1;14) (q35;q11-q32.1;q22.1), interstitial deletion 12(q24.1q24.3), and an unidentified marker chromosome. DNA blot analysis showed that TCR C beta and TCR J alpha-C alpha DNA sequences were in germline configuration in all restriction endonuclease digests. TCR gamma sequences showed biallelic V gamma 9-J gamma P-C gamma 1 rearrangements, the TCR gamma rearrangement detected in the majority of normal TCR gamma/delta bearing cells. Use of a range of TCR delta probes showed biallelic deletion of both J delta 1 and J delta 2, but three rearranged fragments when probed with a 3' C delta genomic probe. Similar breakpoints at 7p13 have been reported in a wide range of hematologic malignancies. Molecular cloning of the t(7;14)(p13;q11.2) translocation breakpoint in this cell line may define new DNA sequences of oncogenic potential at the 7p13 locus.

Acute leukemias (ALs) with phenotypic and genotypic features of several hematopoietic lineages are difficult to classify and may represent the transformation of multipotent stem cells. We have studied immunological features of 200 cases of acute leukemia (109 acute myelogenous leukemia, AML, and 91 acute lymphoblastic leukemia, ALL, according to FAB criteria), including 17 (8.5%) classified as biphenotypic by a scoring system based on the number and specificity of unexpected lineage antigens and which gives more weight to cytoplasmic markers such as myeloperoxidase, CD3, and CD22, and less to other membrane markers. Sixty-eight AML and 42 ALL cases were also examined for rearrangements of the immunoglobulin (Ig) and T-cell receptor (TCR) beta, gamma, and delta genes, and these included 12 biphenotypic AL. The expression of myeloid antigens in ALL was seen in 25% of the cases. All B-lineage ALL had rearrangements and/or deletions of the Ig genes whereas TCR beta, gamma, and delta genes were rearranged in 21%, 52%, and 71%, respectively. TCR delta, gamma and/or beta were rearranged in T-ALL and four out of 13 cases had Ig gene rearrangement. Lymphoid-associated antigens were expressed in 40% of AML cases; those most frequent expressed were CD7 (17%), CD2 (15%), CD19 (10%), and CD10 (7.5%). Evidence of Ig and/or TCR gene rearrangements was detected in 12% of AML cases. There was no correlation between the isolated expression of terminal deoxynucleotidyl transferase (TdT), B, and T-cell antigens with Ig and TCR gene rearrangements. However, in cases of AML defined as biphenotypic because they expressed two or more lymphoid antigens there was a statistically significant correlation between gene rearrangements and lymphoid score (p < 0.001). Our findings support the concept of biphenotypic leukemia as a distinct entity in which there is frequent correspondence between phenotypic and genotypic changes.

High VUV powers, up to 2.5 kW at 133 nm, are obtained from two-photon-resonant, difference-frequency generation in hydrogen by using an ArF excimer laser and a frequency-doubled Nd:YAG-pumped dye laser. This radiation is used to perform two-photon excitation of neon at greater than 150000 cm(-1) , the shortest two-photon transition yet accessed to our knowledge.

Previous cell subfractionation studies have indicated that bcl-2 is an inner mitochondrial membrane protein. We have sought to determine the ultrastructural localization of bcl-2 protein in lymphoma and breast carcinoma cell lines and biopsy material known to overexpress bcl-2 using immunoelectron microscopy. To avoid the possibility of processing artifacts, samples were prepared by three different methods: progressive lowering of temperature, cryosectioning, and freeze-substitution. In all instances the labeling of bcl-2 protein was relatively weak but the distribution the same. In both lymphoma and breast carcinoma tissues, bcl-2 protein was detected on the periphery of mitochondria: little labeling of either the mitochondrial matrix or cristae could be detected. Labeling was also detected on the perinuclear membrane and throughout the cytoplasm, as also indicated by confocal microscopy. These data therefore indicate that bcl-2 protein can be detected at several intracellular sites and that at the likely functional destination, the mitochondria, there appears to be, contrary to expectations, a preferential association with the outer membrane.

We present a detailed comparison of theory and experiment for transient stimulated Brillouin scattering for a pump pulse with Gaussian temporal profile. A new approach for measuring Brillouin linewidths is demon-strated, and an unexplained asymmetry is observed.

We examined 150 cases of acute myeloid leukemia (AML) and 8 cases of acute undifferentiated leukemi (AUL) of adults for both phenotypic and genotypic evidence of commitment to the lymphoid lineages. There was no correlation between expression of lymphoid differentiation antigens and rearrangement of T-cell receptor (TCR) and immunoglobulin (Ig) DNA sequences. In particular 8 cases of CD7(+) AML were germline for all TCR α, β,μ, and δ Also none of the 11 cases with IgJH rearrangement expressed CD19 either on the cell surface or within the cytoplasm. Ten out of 13 cases with TCR/Ig gene rearrangement were either cytologically undifferentiated AML of FAB type M1 or AUL. None had clear immunophenotypic evidence for commitment to lymphoid lineages but 9 expressed only very small amounts of CD45 'framework' antigens and 7 expressed small amounts of CDw52 (CAMPATH-1). This phenotypic combination is otherwise seen only in precursor B cell ALL. TCR/Ig gene rearrangement in AML and AUL of adults appears to have become dissociated from the rest of the lymphoid differentiation 'program'. Recognition of these cases may be facilitated by the weak expression of both CD45 and CDw52 antigens.

We report what is to our knowledge the first high-resolution Brillouin gain spectrum in a solid. Resonances corresponding to longitudinal (compressional) and transverse (shear) acoustic waves in fused silica are observed with good resolution and a high signal-to-noise ratio. Absolute gain coefficients, linewidths, and Brillouin frequency shifts are measured. The agreement with previously measured values is good.

CAMPATH-1 (CDw52) antigen is a heavily glycosylated, non-modulating glycoprotein expressed abundantly on the cell surface of nearly all normal and malignant lymphocytes but not on hemopoietic stem cells. A series of rat monoclonal antibodies (MAbs) with CDw52 specificity but of varying immunoglobulin isotype has been produced, and assessed for ability to deplete lymphoid cells in patients with lymphoproliferative disorders. Although all IgM, IgG2a and IgG2b rat MAbs were able to elicit lysis with human complement in vitro, only the IgG2b MAb (CAMPATH-1G) could elicit substantial lymphoid depletion in vivo. The efficacy of CAMPATH-1 G probably results from its ability to bind human Fc receptors and activate cell-mediated lysis of antibody-coated cells. Twenty-nine patients with lymphoid malignancies have received between 250 mg and 680 mg of CAMPATH-1G; nine of these attained complete remission A human MAb with CDw52 specificity has been produced by "grafting" the complementarity-determining regions (CDRs) of the rat MAb into human IgG1 heavy- and kappa light-chain genes. These constructs were transfected into a rat myeloma cell line. Sufficient human MAb (CAMPATH-1H) has been purified to treat two patients with non-Hodgkin's lymphoma in leukemic phase. Although each patient only received approximately 100 mg of MAb, remission was induced in both patients with recovery of normal hemopoiesis during the course of therapy CDw52 MAbs are the first MAbs to demonstrate consistent anti-tumor effects in vivo and may have roles in the therapy of a wide range of lymphoid malignancies and as powerful immunosuppressive agents.

Two-photon laser-induced fluorescence has been used to detect oxygen atoms in the gas phase above a heated, catalytically stabilized combustor. Excitation was at 226 nm and detection at 777 nm. Special care using the collection optics was necessary to avoid detector saturation from intense thermal emission background from the heated plate. The experimental configuration together with considerations of quenching collisions and photochemical production of oxygen atoms are described.

Doppler-free laser-induced fluorescence of oxygen atoms has been measured in the burnt gases of an atmospheric-pressure flame, where the Doppler and collisional widths are similar. The 3p(3)P level was excited using counterpropagating beams at 226 nm. Upper-state fine-structure splitting could be partially resolved, and a collisionally broadened Lorentzian width of 0.42 cm(-1) was measured. This corresponds to a broadening cross section of 10(-13) cm(2), which is larger than that expected for collisional quenching alone.

The existence of stem cells committed to the T lymphoid lineage was deduced from studying how rat T and B stem cells differ in their expression of membrane W3/13 antigen and in their susceptibility in vivo to gamma irradiation. Stem cell activity of rat bone marrow and fetal liver was measured in long-term radiation chimeras using B and T cell alloantigenic surface markers to identify the progeny of donor cells. Monoclonal mouse anti-rat thymocyte antibody W3/13 labeled approximately 40% of fetal liver cells and 60-70% of young rat bone marrow cells (40% brightly, 25% dimly). Bright, dim, and negative cells were separated on a fluorescence-activated cell sorter. All B and T lymphoid stem cells in fetal liver were W3/13 bright, as were B lymphoid stem cells in bone marrow. W3/13 dim bone marrow had over half the T cell repopulating activity of unseparated marrow but gave virtually no B cell repopulation. In further experiments, the radiosensitivity of endogenous B and T lymphoid stem cells was determined by exposing host rats to between 4.5 and 10 Gy of gamma irradiation before repopulation with genetically marked marrow. The results depended on whether chimerism was assayed before day 50 or after day 100. At early times, a radioresistant T stem cell was indicated, whose activity waned later. Thus committed T stem cells of rats carry moderate amounts of W3/13 antigen and are more radioresistant but less permanently chimeragenic than the stem cells that regenerate B lymphocytes.

A Nd:YAG laser was Q switched twice during one flashlamp pulse and pumped a dye laser, whose frequency-doubled output, tuned to an OH absorption line, illuminated a planar region through a flame. The OH laser-induced fluorescence was focused onto an oscillating mirror, which directed the successive two-dimensional images onto different halves of a vidicon tube. Usable pair separation times of 40 to 180 microsec were obtained. The method has promise for studying changes in small-scale structure in turbulent reactive flows and for instantaneous measurement of the spatial distribution of two observables.

Total collisional removal rate constants for the CH A(2)Delta and B(2)Sigma(-) electronic states are obtained in low pressure (<20-Torr) hydrocarbon flames. The B state is consistently removed ~70% faster than the A state. Variations of +/-50% are observed for different rotational levels and positions in the flame. For these flames, A-state emission following excitation of the B state indicates a rapid electronic-to-electronic energy transfer pathway that is insensitive to collision environment. Upper limits to the collider specific cross sections are obtained for H(2)O, N(2), and CO(2). The CH concentration and temperature profiles are measured and parametrized using a unique method.

A genetically reshaped human IgG1 monoclonal antibody (CAMPATH-1H) was used to treat two patients with non-Hodgkin lymphoma. Doses of 1-20 mg daily were given intravenously for up to 43 days. In both patients lymphoma cells were cleared from the blood and bone marrow and splenomegaly resolved. One patient had lymphadenopathy which also resolved. These effects were achieved without myelosuppression, and normal haemopoeisis was restored during the course of treatment, partially in one patient and completely in the other. No antiglobulin response was detected in either patient. CAMPATH-1H is a potent lympholytic antibody which might have an important use in the treatment of lymphoproliferative disorders and additionally as an immunosuppressive agent.

We report what is to our knowledge the first two-photon-excited fluorescence spectroscopy of atomic fluorine. A doubled dye laser at 286 nm is Raman shifted in H(2) to 170 nm (sixth anti-Stokes order) to excite ground-state (2)P degrees (J) fluorine atoms to the (2)D degrees (J) level. The fluorine atoms are detected by one of two methods: observing the fluorescence decay to the (2)P(J) level or observing F(+) production through the absorption of an additional photo by the excited atoms. We have measured relative two-photon absorption cross sections to and the radiative lifetimes of the (2)D degrees (J) states.

A method for obtaining a two-dimensional image of laser-induced fluorescence of a naturally occurring flame radical is described. A tunable laser beam is focused by a cylindrical lens into a sheet that passes through the flame, exciting OH lying within the plane defined by the laser. The fluorescence at right angles is imaged onto an intensified vidicon tube, forming a map of the ground-state OH concentration within the flame. For a sheet 0.5 mm thick, up to 2800 counts/mm(2) of flame area are obtained on a single laser pulse for an OH concentration of 700 parts in 10(6). The method holds considerable promise for imaging in time-varying systems, such as reactive turbulent combustion.

The temperature, wavelength, and J dependence of the rotational Raman gain coefficient has been determined for the S-branch transitions in N(2). First, the temperature dependence (80-300 K) of the density-broadening coefficients was measured using stimulated Raman spectroscopy. Second, the wavelength dependence (250-600 nm) of the polarizability anisotropy was empirically determined by fitting to the most recent experimental data. These two results were then used to calculate the rotational Raman gain coefficients with accuracies estimated at 5%. At room temperature, the high-density limit of the steady-state gain coefficient of the strongest line, S(10), is 4.8 x 10(-12) cm/W for a Stokes wavelength of 568 nm.