High-dose cytosine arabinoside: response to therapy in acute leukaemia and non-Hodgkin's lymphoma

Twenty-six patients with acute leukaemia and 14 with high-grade lymphoma received cytosine arabinoside (ara-C) at a twice daily dose of 2 g/m2 administered as a 3-h infusion. Thirty-four patients received 12 doses and six electively received four doses only. Complete remission was achieved in six of seven patients with acute myelogenous leukaemia (AML), one of two evaluable patients with blast crisis of chronic myeloid leukaemia and three of eight patients with acute lymphoblastic leukaemia (ALL). Three further patients with ALL had only minimal bone marrow infiltration after one cycle, toxicity precluding administration of a second. Three patients with AML who received four doses only showed no evidence of response. Four of 14 patients with lymphoma who received 12 doses, entered complete remission. Five additional patients died with minimal residual disease whilst severely neutropenic. A complete and a partial response were seen in two patients with immunoblastic and centrocytic lymphoma respectively who received four doses. These results confirm the activity of high-dose ara-C in patients with AML and suggest that it may also be a potentially useful agent in ALL and high-grade lymphoma, especially as the incidence of CNS toxicity is lower than that reported at higher doses.

Centrocytic lymphoma: a distinct clinicopathologic and immunologic entity. A multiparameter study of 18 cases at diagnosis and relapse

The clinical, pathologic, and immunologic aspects of malignant lymphoma of centrocytic type (ML,cc) were studied at diagnosis and often at relapse in 18 patients. The typical patient was a middle-aged or older man with adenopathy, often massive splenomegaly, hepatomegaly, marrow involvement, and, not infrequently, peripheral blood involvement. Histopathologically, ML,cc had a diffuse or vaguely nodular growth pattern with, predominantly, cells resembling centrocytes (cleaved follicular center cells) sometimes with admixed small round lymphocytes but with virtually no transformed cells. In 2 cases the neoplastic cells formed a mantle zone around reactive-appearing follicles. Cell suspensions and frozen sections revealed the monoclonal B-cell nature of all but 1 nonmarking case, and the polyclonality of the follicles in the 1 mantle zone case tested. The B cells had some, but not all, characteristics of both normal mantle and follicular center cells when eight nodes were studied with the use of a panel of monoclonal antibodies, peanut lectin, and endogenous alkaline phosphatase activity. Of 13 patients who underwent repeat biopsies, 1 developed a high grade unclassifiable B-cell lymphoma, and 6 had less marked changes. None of 7 patients tested had a change in light chain class. In conclusion, ML,cc is a distinct entity separable from other B-cell lymphomas in which either centrocytes or small round lymphocytes predominate.

Diploidization and chromosomal pairing affinities in the tetraploid wheats and their putative amphiploid progenitor

The genomes of the diploid wheats Triticum boeoticum and T. urartu are closely related, giving 7II in the f1 hybrid (T(b)T(u)) and 8.4 (0-14) II + 2.5 (0-7) IV in the derived amphiploid (T(b)T(b)T(u)T(u)). The genomes of the tetraploid wheats are also closely related, giving up to 7II at the polyhaploid level (AB) in the absence of the gene Ph but 14II at the tetraploid level (AABB) in the normal presence of Ph. If the amphiploid is the progenitor of the tetraploids, one or the other homoeologue (T(b) or T(u)) in each of the 7 homoeologous groups (the 7 potential IV) must have differentiated with respect to pairing affinity in order to account for 14II in the tetraploid. Consequently, in tetraploid X amphiploid hybrids (T(b)T(u)AB) carrying the Ph gene from the tetraploid, the seven differentiated chromosomes (B) would be expected to give 7I while, on the basis of their observed chiasma frequency, T(b), T(u) and the less differentiated A would be expected to give 4.17I + 3.57II + 3.23III), assuming homoeologous pairing. The expected chromosomal configuration freqencies at MI (11.17I + 3.57II + 3.23III) closely fit the observed values (11.22I + 3.45II + 3.19III + 0.071IV) for such hybrids (X(2) = 0.0046; P>0.99). Thus diploidization of the boeoticum-urartu amphiploid clearly could account for the origin of the tetraploid wheats. Furthermore, T. aestivum X amphiploid hybrids (T(b)T(u)ABD) with and without Ph indicated that B as well as A chomosomes tended to pair with their presumed T(b)T(u) homologues in the absence of Ph. Other tests showed that the tetraploid wheats could not plausibly have originated from any postulated Triticum-Sitopsis (TTSS) parental combinations with or without such chromosomal differentiation.

Short-term treatment for acute myelogenous leukaemia

Short-term treatment with doxorubicin, cytarabine, and 6-thioguanine was given to 91 consecutive adults with acute myelogenous leukaemia. Fifty patients received high doses (regimen I) and 41 very high doses (regimen II). Where possible, six treatment cycles were given (total dose of doxorubicin 450 mg/m2) regardless of the number of cycles required to achieve complete remission. No additional treatment was given. The remission rate was significantly higher with regimen I than with regimen II (34/50 compared with 15/41, p less than 0.01), the latter, more intensive regimen being associated with a greater incidence of fatal infection (13/41 compared with 5/50, p less than 0.01). Duration of remission was, however, significantly longer with regimen II (p less than 0.05); the median has not yet been reached after a minimum follow-up of two years. Intensive short-term treatment is a feasible strategy for the treatment of acute myelogenous leukaemia.

A comparison of two schedules of cytosine arabinoside used in combination with adriamycin and 6-thioguanine in the treatment of acute myelogenous leukemia

The most effective schedule of cytosine arabinoside (Ara-C) administration remains controversial and is further confused by the use of combination chemotherapy. Two remission induction regimens comprising adriamycin, Ara-C, and 6-thioguanine have been compared in patients with acute myelogenous leukemia. Administration of Ara-C by continuous intravenous infusion resulted in faster clearing of leukemic blasts from the peripheral blood and bone marrow than after administration of the same dose by twice daily intravenous injection. Myelosuppression and gastrointestinal toxicity were, however, more pronounced when Ara-C was given by infusion. The complete remission rate was higher in the patients treated with intravenous infusions. It is too early to assess the duration of remission in the infusion study; however, despite the relatively low remission rate, 80% of patients under the age of 60 in the intravenous bolus study remain in remission with a minimum follow-up of two years.

Biochemical selection of immature, haploid embryos of Zea mays L

A method was devised for the biochemical selection of immature, haploid Zea mays embryos using Adh1 (-) and either the Stock 6 or indeterminate gametophyte (ig in W23) high haploid-inducing systems. Haploid (Adh1 (-)) embryos survived exposure to levels of allyl alcohol which killed diploid (Adh1 (+)/Adh1 (-)) embryos. Of the total surviving embryos which were examined cytologically 15% (using ig) and 22% (using Stock 6) were haploid. In two experiments with Stock 6, 100% of the surviving embryos were haploid. To obtain maximum effectiveness of Stock 6 and ig, Adh1 (-) was transferred to stock 6 and W23 backgrounds. Immature, haploid embryos are being used to develop haploid, morphogenic tissue cultures of Zea mays.

Ingestion of dyed-opsonised yeasts as a simple way of detecting phagocytes in lymphocyte preparations. Cytophilic binding of immunoglobulins by ingesting cells

Procion-dyed yeasts which have been incubated in fresh serum and washed are readily ingested by human blood monocytes and tumour macrophages during a 30 min incubation period. Uptake is enhanced by centrifugation. Intracellular yeasts can be readily distinquished from extracellular by their much slower uptake of toluidine blue. Yeast ingestion is a much more reliable test for blood monocytes than the latex bead test and it is easier to read. The ingestion test may be combined with a rosette test for surface immunoglobulins (SmIg). Since the yeasts take up immunoglobulins from human serum during the complement-coating stage it is necessary, in a combined ingestion-SmIg test, to use fresh serum from another species (sheep) for opsonisation of the yeasts. A technique is described for reducing the number of immunoglobulin-bearing monocytes to a low level with a combined ingestion-SmIg rosette technique to detect residual immunoglobulin-bearing phagocytes.

Expression of immunoglobin G on blood lymphocytes in chronic lymphocytic leukaemia

A sensitive rosette test utilizing antibody-coated red cells has been applied to the study of the immunoglobulins on the surface of blood lymphocytes in chronic lymphocytic leukaemia (CLL). Contrary to other reports, IgG has been found to be a common surface membrane immunoglobulin (SmIg) on CLL cells. The reasons for this variation are discussed. Evidence is presented to show that (a) the anti-IgG-coated erythrocytes really are detecting IgG and not a cross-reacting substance, (b) the IgG is intrinsic to the cell and not cytophilically bound and (c) Fc-binding and other artefacts have been excluded. Expression of Ig by individual cells was studied by using mixtures of fluorescein- and rhodamine-labelled red cells coated with various anti-Ig. Fifty-one cases of untreated CLL were tested and the lymphocytes of thirty-eight of these cases bore Ig of a single light chain type. These cases could be classified on the basis of their lymphocyte SmIg as follows: eighteen expressing M and D and G, eleven expressing D and G but not M, six expressing M and D but not G, and three expressing G alone.

Basis of difference between reciprocal crosses involving Triticum boeoticum and T. urartu

The boeoticum (♀) X urartu (♂) F1 hybrids gave small, plump and viable seeds while the reciprocal crosses with T. urartu as the female parent had long, shrivelled and non-viable seeds. Reciprocal nuclear-substitution lines comprising the nucleus of one species into the cytoplasm of the other were developed through repeated backcrossing and were crossed as female parents with respective non-recurrent parents (the cytoplasm donors). The difference between the reciprocal crosses was presumably attributable to different boeoticum urartu genomic ratios in the triploid endosperm rather than to the cytoplasmic difference between the diploid wheats. The endosperm with two doses of the boeoticum and one of the urartu genome resulted in small, plump and viable seed while the endosperm of the reciprocal crosses with two doses of the urartu and one of the boeoticum genome led to large but shrivelled and non-viable seeds irrespective of the cytoplasmic type. One dose of the paternal genome in the triploid endosperm is probably not expressed in the presence of two doses of the maternal genome thereby leading to the difference between the reciprocal crosses. The results reported here indicate that difference between reciprocal crosses may not always be attributed to cytoplasmic difference between the parental species.

Genetic control of seed proteins in wheat

Electrophoretic profiles of crude protein extracts from seed of F1 hybrids and reciprocal crosses among diploid, tetraploid and hexaploid wheats were compared with those of their respective parental species. The electrophoretic patterns within each of three pairs of reciprocal crosses, T.boeoticum X T.urartu, T.monococcun X T. urartu and T.dicoccum X T. araraticum, were different from one another but were identical with those of their respective maternal parents. Protein bands characteristic of the paternal parents were missing in F1 hybrid seed suggesting that the major seed proteins in wheat were presumably regulated by genotype of the maternal parent rather than by the seed genotype. However, in another three pairs of reciprocal crosses, T.boeoticum X T. durum, T.dicoccum X T.aestivum and T. zhukovskyi x T. aestivum, protein bands attributable to the paternal parents were present in the F1 hybrid seeds indicating that the seed proteins were not always exclusively regulated by the maternal genotype. The expression of paternal genomes is presumably determined by dosage and genetic affinity of the maternal and paternal genomes in the hybrid endosperm. The maternal regulation of seed protein content is probably accomplished through the maternal control over seed size. The seed protein quality may, however, depend upon the extent of expression of the paternal genome.

Genetic variability and improvement of seed proteins in wheat

Albumins, globulins, gliadins and glutenins presumably comprising 100 percent of the wheat seed proteins were sequentially extracted and electrophoresed on SDS-polyacrylamide gels. The SDS-electrophoretic patterns within each of the four fractions from T. boeotiaum, T. urartu, T. turgidum, T. timopheevii, T. aestivum, Ae. speltoides and Ae. squawosa were similar. They differed from one species to another only in a few minor components or density of certain components. Similarity in MW's of components, as indicated by the SDS-electrophoretic patterns, suggests that the wheats and Aegilops exhibit no variability for structural genes coding seed proteins. A minimum of 60 to 70 and a maximum of 360 to 420 structural genes with major or minor effects control the total seed protein in T. aestivum. Presumably, only one or the other homoeoallele was expressed in the polyploids. Different components of albumins and globulins presumably had distinct MW's and amino acid composition, while the components of gliadins and glutenins could be classified into a few groups each containing one or more components with the same MW and nearly identical amino acid composition. The genes for components with similar MW's and amino acid composition arose through multiplication of a single original gene and perhaps share the same regulatory mechanism. Seed protein content and quality in wheat might be improved through the incorporation of structural genes, coding for polypeptides with distinct MW's, from distantly related species, rather than by manipulation of the structural genes within the Triticum-Aegilops group. Regulatory mutants similar to opaque-2 of corn could be used to alter the proportion of gliadins in relation to albumins and globulins, to improve amino acid composition of wheat proteins.

Studies of heterosis, combining ability and inheritance of yield and yield components in a diallel cross of bengal gram (Cicer arietinum L.)

A 5 X 5 diallel cross among well-adapted varieties of gram from different agroclimatic regions was studied for heterosis, combining ability and inheritance of days-to-flowering, primary branches, pods per plant, 100-seed weight and grain yield. A high degree of heterosis over mid-parent and better parent was observed for primary branches, no. of pods and grain yield, whereas very little heterosis was exhibited for days-to-flower and 100-seed weight. Crosses among lines of diverse origin generally gave higher heterosis and over-dominance than lines from the same region. Primary branch number, pod number, and grain yield exhibited positive over-dominance; days-to-flower showed negative over-dominance while 100-seed weight had no dominance. Both general and specific combining ability effects were significant for all the characters studied but g.c.a. effects appeared to be more important for days-to-flower, 100-seed weight and grain yield. Graphical analysis indicated additive effects for all the characters, with complete dominance for days-to-flower, no dominance for 100-seed weight and over-dominance for the other three characters. Dominant genes conditioned earliness, primary branch number and 100-seed weight. The role of various parents and crosses in planning a hybridization programme has been discussed.

Combining ability and inheritance of pod and cluster number inPhaseolus mungo L

A set of sixPhaseolus mungo lines was studied in a diallel cross over two generations to investigate general and specific combining ability and mode of inheritance for cluster and pod number. General combining ability effects were more important for both characters.Per se performance appeared to be a good index to rank the parental lines for general combining ability. Additive gene effects with partial dominance to overdominance for these traits were noted. High cluster and pod number seem to be governed by recessive genes.