Biochemical response of lymphoma cells to mitogenic stimulation by prolactin

A previous study showed that cultured Nb 2 node rat lymphoma cells stopped replicating when transferred to medium supplemented with horse serum instead of fetal calf serum; resumption of growth could be induced by the addition of prolactin or other lactogens. The present study shows that in the absence of prolactin cells accumulated early in the G1 phase from which, on stimulation by the hormone, they proceeded through the cell cycle in a synchronized fashion. Ornithine decarboxylase and S-adenosyl methionine decarboxylase activities were closely related to the proliferative status of the cells. In stationary cultures the enzyme activity was barely detectable; following the addition of prolactin, the levels increased over 100-fold and displayed well-defined changes as the cells proceeded through the cell cycle. The results suggest the lymphoma cells are very useful for studying biochemical events resulting from the interaction of a mitogenic polypeptide hormone and its target cell.

Somatic hybridization in Nicotiana: Segregation of organellar traits among hybrid and cybrid plants

Protoplasts from a nitrate reductase-deficient mutant of Nicotiana tabacum L. were fused with protoplasts from a stamen-less, cytoplasmically malesterile cultivar of tobacco containing the cytoplasm from N. suaveolens Lehm. Plants were regenerated from the fused protoplasts and characterized with respect to stamen development, chromosome number, and chloroplast composition. Of 29 regenerated plants, stamen production was restored in 26 plants and pollen production in 22. One plant was male sterile and two plants have never flowered. Analysis of the electrophoretic mobility of ribulose-1,5-bisphosphate carboxylase (RuBPcase) showed that 19 of the plants contained RuBPcase of the N. suaveolens type, six plants contained enzyme of the N. tabacum type, and four plants contained both types. Analysis of resistance to tentoxin in seedlings from 20 of the plants demonstrated that 14 had N. suaveolens-type chloroplasts, three had N. tabacum type, and three contained both types. Many of the plants which produced stamens and pollen still contained chloroplasts of the N. suaveolens type. Thus, the trait of cytoplasmic male sterility in tobacco is not an expression of the type of chloroplast genetic material.

Amyotrophic lateral sclerosis and parkinsonism-dementia among Filipino migrants to Guam

Amyotrophic lateral sclerosis (ALS) has occurred in 9 Filipino migrants to Guam 1 to 29 years after their arrival and parkinsonism-dementia (PD) in 2 migrants 13 and 26 years after arrival. Seven additional Filipino patients developed more classic Parkinson disease (P) 5 to 24 years after their migration to Guam. Furthermore, 10 part-Filipino patients who were born on Guam of Filipino and Chamorro parentage developed ALS, while 6 such part-Filipino patients developed PD. An estimate of the average annual crude mortality rate for ALS among Filipino migrants was approximately six times that of the continental United States, yet half that currently observed among Chamorros living on Guam. A majority of all migrant patients were born in northwestern Luzon in the Philippine Islands, indicating the desirability of an intensive field epidemiological investigation in that area.

Amyotrophic lateral sclerosis among Chamorro migrants from Guam

Amyotrophic lateral sclerosis (ALS), which occurs in unusually high incidence among the Chamorro people on the island of Guam, has developed in 28 Chamorro migrants--24 of whom had onset in the United States, Japan, Germany, or Korea--after periods of absence from Guam of 1 to 34 years. Thus, the latency period for the disease, if caused by environmental factors on Guam, may be over three decades. Four further patients developed ALS within 1 to 14 years of their return to Guam after long-term residence in the continental United States. The minimum exposure time to environmental variables on Guam, based on age at migration, was 18 years, and all patients had spent their childhood and adolescence on Guam. Estimates of crude mortality rates for ALS from these data are considerably higher than for the United States population, and lower than the ALS mortality rates for nonmigrant Chamorros on Guam.

Inheritance behavior of information coding for small subunit polypeptides of fraction 1 protein

In various genera of plants, the small subunit of fraction 1 protein is often composed of more than one kind of polypeptide; these differ in isoelectric points and amino acid composition. Previous analysis of numerous individual progeny of Nicotiana tabacum (two kinds of polypeptides), N. glauca + N. langsdorffii parasexual hybrids (three kinds) and other examples showed no change in F-1 protein composition as a consequence of alternation of generations. Experiments reported here show that absence of one number of each of the 24 different pairs of chromosomes in an N. tabacum monosomic series and also absence of the "S" pair in a nullisome did not affect F-1 protein composition. Absence of the "E" pair caused reduction in the amount of the least acidic of the two kinds of N. tabacum small subunit polypeptides. The question of how many individual progeny of self-fertile hybrids would have to be analyzed to detect segregation of genes coding for F-1 protein small subunit polypeptides, if segregation occurs, was answered by analysis of F1 hybrids between N. otophora and N. tomentosiformis, and two subspecies of N. suaveolens, together with their F2 progeny. In both cases, analysis of 16 progeny was sufficient to demonstrate a segregation pattern of two F1 hybrid type to one each of the two parental types. Therefore, in the absence of segregation, it is likely that coding information for different kinds of F-1 protein small subunit polypeptides is sequestered on heterologous chromosomes, as postulated in previous reports.

Studies on amyotrophic lateral sclerosis by neutron activation analysis--2. Comparative study of analytical results on Guam PD, Japanese ALS and Alzheimer disease cases

Metal analysis of calcium, manganese, aluminum and copper in CNS tissue samples of degenerative CNS disease cases (six Japanese ALS, three Japanese Alzheimer disease, four Guam PD, one Guam ALS) using neutron activation analysis, was conducted with following results: Five of six Japanese ALS cases, two of three Japanese Alzheimer disease cases and all of four Guam PD cases showed a high content of calcium and aluminum in CNS tissue with a significant positive correlation between calcium and aluminum and/or between calcium and manganese. These findings suggest a possible process of metal-induced soft tissue calcification with interaction of other di- and/or trivalent cations such as aluminum, manganese in CNS tissue of these degenerative CNS diseases.

Nicotiana Chromosome Coding for a Specific Polypeptide of the Small Subunit of Fraction 1 Protein

Fraction 1 protein has been isolated from leaves of a male sterile Nicotiana tabacum plant containing an extra N. debneyichromosome. The extra chromosome induces appearance of a third polypeptide composing the small subunit of fraction 1 protein, which otherwise contains two polypeptides as is shown by analysis of numerous different cultivars of N. tabacum.