MORPHOLOGY OF SACCHARUM-SORGHUM HYBRID DERIVATIVES

The intergeneric hybrid between sugarcane (Saccharum sp.) and sorghum (Sorghum bicolor (L.) Moench.) was produced by pollinating sugarcane inflorescences of clone F 36-819 (2n = ca. 112) with diploid (2n = 20) ‘Rex’ sorghum pollen. The backcross four (BC₄) population, produced by back-crossing twice with diploid and then twice more with tetraploid (2n = 40) ‘Rio’ sorghum, combined 40 Sorghum and 4-10 Saccharum chromosomes. Different BC₄ individuals were morphologically distinct within and between chromosome complexes, indicating that their genomes must comprise different combinations of Sorghum and Saccharum chromosomes. Selfing for one or more generations results in almost complete elimination of Saccharum chromosomes and morphologically modified sorghums are recovered. Modified sorghums have various combinations of Saccharum characteristics superimposed on a basic Sorghum morphology. The presence of Saccharum characters in some of the recovered sorghums with 2n = 40 chromosomes indicates the potential for a gene transfer from sugarcane to sorghum.     

A comparative cytopathologic study of noninvasive and invasive squamous cell carcinoma of the lung

Atypical cells and tissue fragments from the sputum of patients with early and advanced stages of squamous cell carcinoma of the bronchus are objectively characterized and quantitatively compared in this paper. Four classes of single-cell features of cytoplasm, nucleus, nucleolus and nuclear-cytoplasmic ratio are analyzed as a function of cell size and tumor development stage. Distinct differences in the cellular patterns are observed which may enhance cytologic discrimination between noninvasive and invasive stages of squamous cell carcinoma of the bronchus. Initial results justify the application of more sensitive measurement techniques (i.e., automated cytology) to an enlarged data base.     

Interaction of DNA with a porphyrin ligand: evidence for intercalation.

The porphyrin photosensitizer, meso-Tetra (4-N-methylpyridyl) porphine tetraperchlorate binds to calf thymus DNA by intercalation and by external electrostatic association. This was concluded from the results of measruements involving Scatchard analysis, viscometry, thermal denaturation, and circular dichroism.     

Circulating immune complexes as possible cause for anticomplementary activity in humans with malignant melanoma

Summary Sera from 98 melanoma patients, 20 noncancer patients with immune complex-associated diseases, and 90 normal donors were analyzed for anticomplementary (AC) activity by the complement consumption method. Some of these sera were also tested for immune complex-like materials by the Raji cell radioimmune assay. In addition, serum samples from ten melanoma patients were analyzed serially to correlate the AC activity with clinical course. Significant levels of Ac activity were found in 45% of melanoma sera, 75% of nonmalignant immune complex-associated disease sera, and 10% of normal donors' sera. In some patients, AC activity decreased and became undetectable as their disease progressed. AC-negative serum samples taken from melanoma patients late in the course of disease when the tumor burden was large became anticomplementary when mixed with autologous or allogeneic serum samples taken earlier at the time of little or no tumor burden. The early serum samples contained antibodies against autologous tumor extracts, as shown by a complement fixation test. Absorption of early serum samples with cultured allogeneic melanoma cells reduced their ability to consume complement when mixed with autologous late serum samples, suggesting the presence of free antigen in the latter. The mixed samples of early and late sera and the sera positive in the complement consumption test contained heavy nonmonomeric IgG. Therefore, the AC activity of melanoma sera could be due to tumor-associated antigen-antibody complexes.     

Interferon Treatment of Ehrlich Ascites Tumor Cells: Effects on Exogenous mRNA Translation and tRNA Inactivation in the Cell Extract

We reported earlier that in cell extracts that were prepared from interferon-treated Ehrlich ascites tumor cells and preincubated and passed through Sephadex G-25 (S30_INT), the translation of exogenous mRNA (viral and host) was impaired and the impairment could be overcome to a large extent by adding a crude tRNA preparation from Ehrlich ascites tumor cells but not from Escherichia coli. We find now that the rate of inactivation of some tRNA's (especially those specific for leucine, lysine, and serine) but not those of many others is faster in S30_INT than in corresponding extracts from control cells. This increased rate of tRNA inactivation may perhaps account for the need for added RNA to overcome at least partially the impairment of translation in S30_INT. The relationship of the increased rate of tRNA inactivation to the antiviral effect of interferon is unclear. So far no significant difference has been detected in the amount of tRNA needed to overcome the impairment of encephalomyocarditis virus RNA translation in S30_INT between tRNA from interferon-treated cells and tRNA from control cells. Furthermore, no difference was found in the rate of inactivation in S30_INT between leucine-specific tRNA's from interferon-treated and from control cells. tRNA's specific for leucine and lysine were not inactivated (unless very slowly) during incubation under our conditions in an extract from interferon-treated (or from control) cells unless the extract had been passed through Sephadex G-25 or dialyzed. The translation of exogenous mRNA was, however, impaired in an extract from interferon-treated cells that had not been passed through Sephadex G-25. This impairment was apparently not overcome by added tRNA.     

Synthesis and degradation of proteins during wheat endosperm development

Synthesis of proteins rich in lysine declines progressively with endosperm development and these proteins appear to be degraded preferentially at later stages. The proteolytic enzymes in extracts of endosperms at a late stage of development release considerably more lysine radioactivity from labelled endosperm proteins as compared with the enzymes in endosperms at an early stage.     

An interactive nonrandom-mating two-sex model whose intrinsic growth rate lies between one-sex rates.

In a recent paper, the author has presented an interactive two-sex model and applied it to the U.S. population, 1940–1971. While the model has removed many inconsistencies in the one-sex models for males and females, it has two major limitations. First, the model assumes random mating of men and women within their reproductive ages. Second, it gives an intrinsic growth rate that is not necessarily intermediate between the male and the female intrinsic growth rates, as obtained from the one-sex models. A new two-sex model is provided in this paper that removes both these limitations. The new model is applied to the U.S. population for the years 1940–1974.