Ultrastructural demonstration of hormone-induced movement of carotenoid droplets and endoplasmic reticulum in xanthophores of the goldfish,Carassius auratus L.

Summary The hormone-induced pigment dispersion in primary cultures of xanthophores of goldfish (Carassius auratus L.) has been shown to involve the dispersion of not only carotenoid droplets but also of smooth endoplasmic reticulum. The dispersion of these organelles is inhibited by cytochalasin B and is accompanied by thinning of the cell body, thickening of the processes, and also overall changes in cellular morphology (process extension) under certain conditions. Electron microscopic examination of heavy meromyosin treated glycerinated xanthophores in scales revealed the presence of actin filaments in these cells.This work was supported, in part, by grants AM-5384 and AM-13724 from U.S.P.H.S.     

Intermediate filaments with novel protein composition from certain goldfish cells

Using the conditions for vimentin filament recycling, intermediate filaments (approximately 10 nm) were prepared from the cytoskeleton of a goldfish tumor cell line (erythrophoroma or xanthophoroma). 2-D analysis showed unusual protein composition, with four proteins of molecular weights of 60, 45, 56 and 51 kilodaltons in ratios of approximately 4:4:1:1. These correspond to four of the major cytoskeletal proteins of both the tumor cells and normal xanthophores.     

Is there a PGM1 4 allele specific to Amerindian populations?

Summary Rare PGM₁ variants in Macushi and Wayampi Amerindian populations have been compared electrophoretically and by means of electrofocusing. They appear to be identical. The findings are discussed.     

Development and characterization of highly polymorphic long TC repeat microsatellite markers for genetic analysis of peanut

Background

The immune system has paradoxical roles during cancer development and the prognostic significance of immune modulating factors is controversial. The aim of this study was to determine the expression of cyclooxygenase 2 (COX-2), transforming growth factor-beta (TGF- beta), interleukin-10 (IL-10) and their prognostic significance in breast cancers. Ki67 was included as a measure of growth fraction of tumor cells.

Methods

On immunohistochemical stained slides from 38 breast cancer patients, we performed digital video analysis of tumor cell areas and adjacent tumor stromal areas from the primary tumors and their corresponding lymph node metastases. COX-2 was recorded as graded staining intensity.

Results

The expression of TGF-beta, IL-10 and Ki67 were recorded in tumor cell areas and adjacent tumor stromal areas. In both primary tumors and metastases, the expression of COX-2 was higher in the tumor stromal areas than in the tumor cell areas (both P < 0.001). High stromal staining intensity in the primary tumors was associated with a 3.9 (95% CI 1.1-14.2) times higher risk of death compared to the low staining group (P = 0.036). The expression of TGF-beta was highest in the tumor cell areas of both primary tumors and metastases (both P < 0.001). High stromal expression of TGF-beta was associated with increased mortality. For IL-10, the stromal expression was highest in the primary tumors (P < 0.001), whereas in the metastases the expression was highest in tumor cell areas (P < 0.001). High IL-10 expression in tumor- and stromal cell areas of primary tumors predicted mortality. Ki67 was higher expressed in tumor stromal areas of the metastases, and in tumor cell areas of the primary tumors (P < 0.001). Ki67 expression in tumor cell areas and stromal areas of the metastases was independently associated with breast cancer mortality.

Conclusions

Stromal expression of COX-2, TGF-beta and Ki67 may facilitate tumor progression in breast cancer.     

Insulin resistance in adolescents with Down syndrome: a cross-sectional study

Background

The prevalence of diabetes mellitus is higher in individuals with Down syndrome (DS) than in the general population; it may be due to the high prevalence of obesity presented by many of them. The aim of this study was to evaluate the insulin resistance (IR) using the HOMA (Homeostasis Model Assessment) method, in DS adolescents, describing it according to the sex, body mass index (BMI) and pubertal development.

Methods

15 adolescents with DS (8 males and 7 females) were studied, aged 10 to 18 years, without history of disease or use of medication that could change the suggested laboratory evaluation. On physical examination, the pubertal signs, acanthosis nigricans (AN), weight and height were evaluated. Fasting plasma glucose and insulin were analysed by the colorimetric method and RIA-kit LINCO, respectively. IR was calculated using the HOMA method. The patients were grouped into obese, overweight and normal, according to their BMI percentiles. The EPIINFO 2004 software was used to calculate the BMI, its percentile and Z score.

Results

Five patients were adults (Tanner V or presence of menarche), 9 pubertal (Tanner II – IV) and 1 prepubertal (Tanner I). No one had AN. Two were obese, 4 overweight and 9 normal. Considering the total number of patients, HOMA was 1.7 ± 1.0, insulin 9.3 ± 4.8 μU/ml and glucose 74.4 ± 14.8 mg/dl. The HOMA values were 2.0 ± 1.0 in females and 1.5 ± 1.0 in males. Considering the nutritional classification, the values of HOMA and insulin were: HOMA: 3.3 ± 0.6, 2.0 ± 1.1 and 1.3 ± 0.6, and insulin: 18.15 ± 1.6 μU/ml, 10.3 ± 3.5 μU/ml and 6.8 ± 2.8 μU/ml, in the obese, overweight and normal groups respectively. Considering puberty, the values of HOMA and insulin were: HOMA: 2.5 ± 1.3, 1.4 ± 0.6 and 0.8 ± 0.0, and insulin: 13.0 ± 5.8 μU/ml, 7.8 ± 2.9 μU/ml and 4.0 ± 0.0 μU/ml, in the adult, pubertal and prepubertal groups respectively.

Conclusion

The obese and overweight, female and adult patients showed the highest values of HOMA and insulin.     

Proteomics of ischemia and reperfusion injuries in rabbit myocardium with and without intervention by an oxygen-free radical scavenger

A brief period of ischemia followed by timely reperfusion may lead to prolonged, yet reversible, contractile dysfunction (myocardial stunning). Damage to the myocardium occurs not only during ischemia, but also during reperfusion, where a massive release of oxygen-free radicals (OFR) occurs. We have previously utilized 2-DE and MS to define 57 protein spot changes during brief ischemia/reperfusion (15 min ischemia, 60 min reperfusion; 15I/60R) injury in a rabbit model (White, M. Y., Cordwell, S. J., McCarron, H. C. K., Prasan, A. M. et al., Proteomics 2005, 5, 1395-1410) and shown that the majority of these occur because of physical and/or chemical PTMs. In this study, we subjected rabbit myocardium to 15I/60R in the presence of the OFR scavenger N-(2-mercaptopropionyl) glycine (MPG). Thirty-seven of 57 protein spots altered during 15I/60R remained at control levels in the presence of MPG (15I/60R + MPG). Changes to contractile proteins, including myosin light chain 2 (MLC-2) and troponin C (TnC), were prevented by the addition of MPG. To further investigate the individual effects of ischemia and reperfusion, we generated 2-DE gels from rabbit myocardium subjected to brief ischemia alone (15I/0R), and observed alterations of 33 protein spots, including 18/20 seen in both 15I/60R-treated and 15I/60R + MPG-treated tissue. The tissue was also subjected to ischemia in the presence of MPG (15I/0R + MPG), and 21 spot changes, representing 14 protein variants, remained altered despite the presence of the OFR scavenger. These ischemia-specific proteins comprised those involved in energy metabolism (lactate dehydrogenase and ATP synthase alpha), redox regulation (NADH ubiquinone oxidoreductase 51 kDa and GST Mu), and stress response (Hsp27 and 70, and deamidated alpha B-crystallin). We conclude that contractile dysfunction associated with myocardial stunning is predominantly caused by OFR damage at the onset of reperfusion, but that OFR-independent damage also occurs during ischemia. These ischemia-specific protein modifications may be indicative of early myocardial injury.     

Hormone-induced dispersion or aggregation of carotenoid-containing smooth endoplasmic reticulum in cultured xanthophores from the goldfish, Carrassius auratus L.

A novel organelle movement is described in goldfish xanthophores. Smooth endoplasmic reticulum, containing carotenoids pigments, undergo MSH or c-AMP-induced dispersion. This dispersion is independent of RNA and protein synthesis, not modulated by c-GMP and inhibited by cytochalasin B but only at the relatively high concentration of 10 mug/ml. Epinephrine induces aggregation, a process that is inhibited by colchicine. These results suggest, but do not prove, the involvement of microfilaments in dispersion and microtubules in the aggregation of carotenoid-containing endoplasmic reticulum.     

Adenosine 3',5'-monophosphate, morphogenetic movements and embryonic neural differentiation in Pleurodeles waltlii.

Evidence is presented for the following hypothesis dealing with dibutyryl-c-AMP induction of neural differentiation in Pleurodeles waltlii embryos: (1) Dibutyryl-c-AMP induces the determination for neural differentiation. (2) Additional dibutyryl-c-AMP is not needed for cytodifferentiation. (3) Cytodifferentiation of induced cells can only take place after morphogenetic movements (in vivo) or extensive cell migrations (in vitro). It is suggested that cell migrations, both in vivo and in vitro, lead to the separation of the induced cells from one another or from unidentified inhibitory cells.