Primitive erythropoiesis in early chick embryogenesis. II. Correlation between hemoglobin synthesis and the mitotic history.

Primitive erythroblasts in the circulating blood of the chick embryo continue to divide while synthesizing hemoglobin (Hb). Hb measurements on successive generations of erythroblasts show that there is a progressive increase in the Hb content of both interphase and metaphase cells. Furthermore, for any given embryo the Hb content of metaphase cells is always significantly greater than that of interphase cells. The distribution of Hb values for metaphase cells suggests that there are six Hb classes corresponding to the number of cell cycles in the proliferative phase. The location of erythroblasts in the cell cycle was determined by combining Feulgen cytophotometry with thymidine radioautography on the same cells. Measurements of the Hb content for erythroblasts in different compartments of the cell cycle (G1, S, G2, and M) show a progressive increase through the cycle. Thus, the amount of Hb per cell is a function of the number of cell divisions since the initiation of Hb synthesis and, to a lesser degree, the stage of the cell cycle. Earlier generations of erythroblasts synthesize Hb at a faster rate than the terminal generation. Several models have been proposed to explain these findings

Early responses to chemotherapy detected by pulse cytophotometry.

DNA/cell distributions were recorded by automated cytofluorometry (=pulse cytophotometry) in bone-marrow aspirates of leukaemia and lymphosarcoma patients subjected to chemotherapy. In most cases, early perturbations in DNA/cell histographs were observed, characteristically reflecting the known mode of action of the drugs. These changes in general preceded the clinical observation of drug response. In a series of 23 measurements in 19 patients, a positive correlation between early cytophotometric changes and clinical effects of chemotherapy was observed in 17 patients. Five patients were negative for both cytophotometric and clinical reactions and one patient was probably false-positive. The validity of the assay for early detection of drug resistance in acute leukaemia and related diseases is discussed

DNA Cytophotometric Findings in Pheochromocytoma

Fifty adrenalectomy specimens containing normal (n = 3), hyperplastic (n =4), or neoplastic (n = 43) medullary tissue were subjected lo quantitative measurements of DNA content. Of the 43 pheochromocytomas, 16 were neoplasms inherited in the setting of multiple endocrine neoplasia type 2A. Five of 27 sporadic pheochromocytomas followed a malignant clinical course. Follow-up data were available in 25 patients. In normal medulla and adrenomedullary hyperplasia, either diploid or euploid DNA distributions were found. In contrast, 87% (33 of 38) of the benign and all five malignant pheochromocytomas exhibited nondiploid or aneuploid DNA histograms. No differences in DNA content existed between sporadic and hereditary tumors. In contrast to earlier reports, in this study DNA cytophotometry was not suitable to discriminate benign from malignant adrenomedullary tumors. In addition, DNA measurements appeared not to be a useful tool to assess the prognosis of an individual malignant pheochromocytoma

The Effect of Adrenocorticotropin on the Nucleic Acids and Histochemistry of the Guinea-Pig Adrenal Cortex

The effect of adrenocorticotropin (Armour ACTHar gel) on the mean amount of deoxyribonucleic acid (DNA) per nucleus, and the scatter about this mean, in adrenal nuclei from mature guinea-pigs was studied, using cytophotometry of Feulgen stained nuclear smears. The results were compared with those from chemical analysis of the same material. The mean adrenal nuclear DM content was similar to that in a control specimen mounted on the same slide in each instance, except after administration of adrenocorticotropin for 5 and 7 days. Cytophotometric analyses showed a highly statistically significant increase (P<0.01) in mean adrenal nuclear DNA content after treatment of the animals with ACTH for 5 and 7 days, Chemical analyses gave values for adrenal nuclear DNA which were slightly higher than those for pooled kidney nuclei. The significance of these findings is discussed. Statistical analysis of the results indicates that only specimens on the same slide are to be compared when using cyto-photometry of the Feulgen reaction. If specimens on different slides are used for comparison a large error is introduced. The effect of ACTH was also studied on adrenocortical ribonucleic acid (RNA), plasmalogens, alkaline and acid phosphatase, ascorbic acid and glycogen in mature guinea-pigs after treatment with ACTH for similar periods of time (1, 3, 5, 7, 10, 14 and 21 days) and also for 3, 6, 12 and 18hr and for 28 days. A gradual increase in adrenocortical ribonucleic acid occurred with ACTH treatment. This increase was found in all zones of the adrenal cortex. Depletion of lipid and of plasmalogens was evident in the zona fasciculata and zona reticularis after ACTH administration for 3, 6, 12 and 18 hr. In the other experimental groups of animals an increase in lipid and plasmalogens occurred with continued ACTH administration. At 28 days, however, some depletion of these substances was found in the zona reticularis. ACTH administration caused an increased concentration of alkaline and acid phosphatase in all adrenocortical zones. The increase was most evident after treatment with ACTH for 5 and 7 days, when hyperplasia was maximal. Ascorbic acid depletion was observed after ACTH treatment for 3, 6, 12 and 18 hr and for 1 day. The adrenocortical content and distribution of ascorbic acid was normal in adrenals of guinea-pigs receiving ACTH for longer periods. Glycogen depletion occurred at 12 and 18 hr only. The findings are discussed and compared with results of other authors who studied the pituitary-adrenal relationship. It is evident that ribonucleic acid, alkaline and acid phosphatase and ascorbic acid have important roles in adrenocortical Physiology. The results suggest that ribonucleic acid and phosphatases are probably concerned with adrenocortical hyperplasia. It seems more likely, however, that ascorbic acid and glycogen are concerned with secretion of adrenocortical hormones, as depletion of these substances occurred when secretion of ketosteroids was probably at a maximum

Cell cycle and DNA content of mitotic cells in brain ganglia of drosophila larvae

The programmes of replication of hetero- and euchromatin regions, mitotic cell cycle and the DNA content in metaphases in brain ganglia from late third instar larvae of Drosophila melanogaster (wild type and a tumour bearing mutant, 1(2)gl, strain) and of Drosophila nasuta were examined by autoradiography of [3H]thymidine labelled (continuous or pulse) cells and by cytophotometry, respectively. Brain ganglia labelled continuously with [3H]thymidine for 24 h in vitro showed a significantly high proportion of cells with incorporation of radioactivity restricted to heterochromatin only. Pulse labelling of brain ganglia from larvae of Drosophila melanogaster and Drosophila nasuta followed by chase for different time intervals showed that (i) the frequency of labelled metaphases was more than 50% within 15 to 30 min of chase and remained higher than 50% in nearly all the chase samples till 24 h, (ii) euchromatin labelled metaphases appeared with a low frequency within 1 to 4 h chase period but the heterochromatin labelled metaphases continued to be more common in the later chase samples also, (iii) single chromatid labelled second cycle metaphases were seen within 1 to 4 h after the pulse, but their frequency did not increase in the later samples. Cytophotometry of feulgen-DNA and Hoechst 33258 stained metaphases in late third instar larval brain ganglia revealed a greater variation in the DNA content of individual metaphases, although the means were close to the expected 4 C content. It appears that in relation to the known asymmetric cell divisions of neuroblast and other neural cells, the mitotically active cells in brain ganglia comprise a heterogenous population with widely varying lengths of the different phases of cell cycle; some of them may not cycle regularly and may possibly have a discontinuous S-phase

Significance of proliferative activity and DNA ploidy in pancreatic cancer and chronic pancreatitis

Summary: Background: Precise preoperative assessment of diagnosis and prognosis in patients with pancreatic tumors would facilitate improvement of treatment strategies. In this context, we evaluated the significance of the proliferative index and of static DNA cytophotometry in the diagnosis and prognosis of pancreatic tumors. Methods: Consecutive surgical specimens from 26 patients with ductal pancreatic cancers and eight patients with chronic pancreatitis were investigated by: 1. Staging; 2. Conventional histological and cytological grading; 3. MIB-1 (Ki-67 labeling) proliferating index; and 4. Static DNA cytophotometry. Results: All patients with chronic pancreatitis had a normal MIB-1 labeling index and a euploid DNA content. In contrast, patients with pancreatic cancers rarely had a normal labeling index (1 of 26 patients) or a euploid DNA content (6 of 26 patients). Staging significantly correlated with survival time. However, it did not correlate with cytological criteria. Cytological criteria, such as conventional grading, MIB-1 proliferating index, and DNA ploidy, were not significantly correlated with survival time. Conventional grading was significantly correlated (p<0.02) with proliferating index, but not with DNA ploidy. Conclusion: Proliferating index and DNA ploidy are relevant cytological markers that can help to discriminate between chronic pancreatitis and pancreatic cancer. The prognostic significance of these markers in pancreatic cancer patients, however, seems to be less relevant than tumor stage and of limited relevance for the individual cancer patien

A DNA cytophotometric study of salt adaptation in Allium cepa and Nicotiana bigelovii

Abstract Nuclear DNA was measured by Feulgen cytophotometry in NaCl-exposed Allium cepa roots and Nico-tiana bigelovii calli cultured in vitro. Analysis of the differentiation zone of A. cepa roots grown in water showed that only 2.8% of the nuclei had DNA contents higher than 4 C, where 2 C nuclei were predominant. In roots grown in salt water, 2 C nuclei were less numerous than 4 C nuclei and the DNA content was greater than 4 C in 19.2% of the cells, with 1.4% of the cells having a DNA content of 16 C. Two C, 4 C, 8 C, and a few 16 C nuclei, together with many nuclei with intermediate DNA content values, occurred in both the control and salt-treated calli of N. bigelovii. About 49.1% of the nuclei had DNA values around 2 C in the controls, while the percentage of cells with nuclei with higher DNA content values increased in calli as the NaCl concentration in the medium increased. Fifteen per cent of the nuclei had DNA values around 16 C in calli grown on media with 10 gr l−1 NaCl added, compared to 2.8..