Flow cytometry in clinical oncology: cell cycle and DNA ploidy in assessing tumor behavior

The basic principles of flow cytometry with special emphasis to cell cycle analysis and DNA ploidy measurements are described. The concept of separation of various subcompartments of cell cycle, distinguished by simultaneous determinations of DNA versus RNA and DNA versus protein contents is presented. Based on DNA ploidy patterns, human tumors were divided into two groups designated as diploid range and non-diploid (aneuploid). Since it has been proposed that diploid range tumors have generally better prognoses than non-diploid tumors, the value of DNA ploidy patterns as a prognostic factor is discussed in major groups of human cancers.     

Zur Klinik und Pathologie der Alzheimerschen Krankheit

Ohne Zusammenfassung     

Neuroimaging in Pineal Tumors

BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.     

High-resolution imaging of progressive articular cartilage degeneration.

The objective of this study was to develop and verify a new technique for monitoring the progression of osteoarthritis (OA) by combining a rat model with the imaging modality optical coherence tomography (OCT). Time-sequential, in vivo, OCT imaging was performed on the left femoral condyles of 12 Wistar rats following sodium-iodoacetic acid-induced OA progression. The right femoral condyles (untreated) were also imaged and served as controls. Imaging was performed on days 0, 10, 20, 30, and 60 with an OCT system capable of acquiring images at four frames per second and an axial resolution of 5 microm. Progressive changes were analyzed using an OA scoring system. OCT successfully identified progressive cartilage degeneration as well as alteration of the cartilage/bone interface. Significant changes to both of these structures were observed in the sodium-iodoacetic acid-injected condyles. Structural changes detected with OCT were confirmed histologically. OCT in combination with a well-known model used in arthritis research represents a powerful tool for following degenerative joint disease progression in a given animal by detecting changes to the cartilage/bone interface and articular cartilage.     

Humalog Mix25 improves 24-hour plasma glucose profiles compared with the human insulin mixture 30/70 in patients with type 2 diabetes mellitus.

OBJECTIVE: To compare the effects of Humalog Mix25 (Humalog Mix75/25 in the USA) (Mix25) and human insulin 30/70 (30/70) on the 24-hour inpatient plasma glucose (PG) profile in patients with type 2 diabetes mellitus (T2DM). DESIGN: A randomised, open-label, 8-week crossover study. Study insulins were injected twice daily, 5 minutes before breakfast and dinner. SETTING: Four-week outpatient (dose-adjustment) treatment phase, and 3-day inpatient (test) phase. PATIENTS: Twenty-five insulin-treated patients with T2DM (ages 40-66 years), mean (+/- standard error of the mean) (SEM) HbA1c 7.7% +/- 0.23%, and body mass index (BMI) 29.3 +/- 0.83 kg/m2. OUTCOME MEASURES: 24-hour PG profiles, PG excursions after meals, PG area under the curve (AUC), and 30-day hypoglycaemia rate. RESULTS: The 2-hour PG excursions following breakfast (5.5 +/- 0.34 v. 7.2 +/- 0.34 mmol/l, p = 0.002) and dinner (2.4 +/- 0.27 v. 3.4 +/- 0.27 mmol/l, p = 0.018) were smaller with Mix25 than with 30/70. PG AUC between breakfast and lunch was smaller with Mix25 than with 30/70 (77.6 +/- 3.8 v. 89.5 +/- 4.3 mmol/h/ml, p = 0.001). PG AUC between lunch and dinner, dinner and bedtime, and bedtime and breakfast did not differ between treatments. Pre-meal and nocturnal PG were comparable. The postprandial insulin requirement for lunch meals was supplied equally by the two insulin treatments. The thirty-day hypoglycaemia rate was low (Mix25 0.049 +/- 0.018 v. 30/70 0.100 +/- 0.018 episodes/patient/30 days, p = 0.586) for both treatments. CONCLUSION: In patients with T2DM, Mix25 improved the 24-hour PG profile with lower postprandial PG excursions than with human insulin 30/70.     

Opioid modulation of LHRH release in vitro depends upon levels of testosterone in vivo

The in vitro release of LHRH from hypothalami of adult male rats (intact, 5-day castrates, 5-day castrates replaced with various doses of testosterone) was measured under basal conditions and after the addition of KCl, the opiate antagonist naloxone or the opiate agonist DAGO to the perifusion medium. Hypothalami from all treatment groups responded to 56 mM KCl with an increased output of LHRH. LHRH release was also induced by naloxone (10(-6)M), but only from tissues derived from intacts and castrates given physiological doses of testosterone. The opiate agonist DAGO (10(-6)M) did not alter the basal release of LHRH; it, however, caused a significant decrease in the K+-induced release of LHRH from hypothalami derived from intact rats and rats replaced with physiological levels of testosterone but not from those derived from castrate rats or castrate rats replaced with small amounts of testosterone. The specificity of this latter response was shown by its reversibility with naloxone. The lack of DAGO effects upon tissues from rats with low levels of steroid implied steroid dependency of the response to opioidergic influences and indeed, the response to DAGO was restored when testosterone was replaced at physiological doses. Measurement of hypothalamic LHRH content showed no significant differences between tissues obtained from intact, castrate and testosterone-replaced castrate rats. These in vitro data support the view that the inhibitory influence of opioids upon LHRH release depends on the presence of gonadal steroids in vivo.     

Modification of Ha-ras oncogene p21 expression and cell cycle progression in the human colonic cancer cell line HT-29

Multiparameter flow cytometric measurements of the Ha-ras oncogene product, Ha-p21, versus DNA content were used to study the effect of prednisolone, sodium butyrate, and hyperosmolality on the expression of this gene during the cell cycle of HT-29, a human colonic carcinoma cell line. In control cells the expression of Ha-p21 was cell cycle dependent; it increased during G1 and remained approximately constant as cells traversed the S- and G2 + M phases. Two compartments of G1 cells, one expressing low (G1A) and the other (G1B) high levels of Ha-p21 could be identified. Cells grown with prednisolone (1.4-2.1 microM) expressed higher Ha-p21 levels than controls. Cell cycle analysis revealed that this effect was accompanied by a change in the distribution of cells in G1 phase: whereas the proportion of cells in G1A was reduced, that of cells in G1B was increased. The steroid had no detectable effect on cells in S and G2 + M. By contrast, sodium butyrate and hyperosmolality caused a marked decrease in Ha-p21 content. This reduction was not accompanied by any modification of the proportion of cells in the cell cycle compartments. These results would suggest that Ha-p21 is not likely to be a primary regulator of cell cycle progression in HT-29 cells.