Dopaminergic agents selectively alter the post-translational processing of beta-endorphin in the intermediate pituitary of the rat

The present study examines whether sustained changes in the biosynthetic activity of the intermediate pituitary, induced pharmacologically by treating rats with dopamine receptor ligands, alters the post-translational processing of beta-endorphin (beta-END). Separation of the individual molecular forms of beta-END using ion exchange chromatography revealed that beta-END is processed to alpha-N-acetylated and nonacetylated forms of beta-END-(1-31), beta-END-(1-27) and beta-END-(1-26) in the neurointermediate lobe (NIL). Chronic treatment with D-2, but not D-1, dopamine receptor antagonists elevated total beta-END immunoreactivity (i beta-END) in the NIL but this increase was predominantly attributable to elevations in the concentrations of N-acetyl-beta-END-(1-31) and N-acetyl-beta-END-(1-27). In contrast, N-acetyl-beta-END-(1-26) was not significantly affected. The dopaminergic agonist, bromocriptine, had the opposite effect; it lowered total i beta-END levels, depleting N-acetyl-beta-END-(1-31) and N-acetyl-beta-END-(1-27) to a greater extent than N-acetyl-beta-END-(1-26). beta-END peptides were released in vitro in the same relative proportion as they were contained in the NIL suggesting that individual molecular forms of beta-END are not released preferentially. i gamma-END levels also were modulated by dopaminergic agents but the processing of gamma-END and alpha-END was not altered. Acute haloperidol treatment depleted i gamma-END levels but did not affect the pattern of beta-END peptides in the NIL. These results indicate that dopaminergic agents influence not only the secretion but also the post-translational processing of pituitary beta-END.     

Plasma adenosine changes during cardiac surgery.

Changes in plasma adenosine and inosine were measured during high-dose narcotic anesthesia and surgery for coronary artery bypass grafting (CABG), and mitral or aortic valve replacement (V). Arterial and mixed venous blood samples were obtained for measurement of adenosine and inosine at eight sampling intervals ranging from preanesthesia induction to discontinuation of cardiopulmonary bypass (CPB). Arterial but not mixed venous adenosine was markedly elevated in blood samples 10 minutes after intubation, but the fourfold elevation was significant only in the CABG patient group. Mixed venous inosine and adenosine were most consistently elevated in post-CPB samples. In a separate study of arterial adenosine changes during induction, a uniform drug administration protocol was used, and again adenosine was significantly increased immediately after intubation. It is possible that adenosine and perhaps inosine may contribute to cardiovascular responses following induction-intubation and also after discontinuing CPB.     

Magnetic resonance tomographic diagnosis of a myelolipoma of the adrenal glands

Myelolipoma is an uncommon, benign, adrenal lesion composed of fatty tissue and bone marrow elements. The presence of fat within this tumor is the key factor in identification and noninvasive diagnosis with imaging methods. Since fat has a characteristic behavior reflected by the MR signal intensity, a specific diagnosis can be made by MRI.     

Ethanol and breast cancer: An association that may be both confounded and causal

We have examined the association of alcohol intake during various life periods, by beverage category, with breast cancer risk in Greece. A hospital-based case-control study was performed in Athens, Involving 820 women with breast cancer as well as 795 orthopedic patients and 753 healthy visitor controls-Relative risk patterns were very similar with either control series, which were therefore combined to increase precision of the estimates. Drinkers of beer were at significantly elevated risk for breast cancer [odds ratio (OR), 1.34 (95% confidence interval, 1.05-1.71)]. However, drinkers of other alcoholic beverages were not at increased risk. Among beer drinkers there was no dose-response, and drinkers of both beer and other beverages had a lower OR compared to drinkers of beer only. By contrast, drinkers of 3 or more glasses of alcohol per day, mostly of spirits, were at elevated risk for breast cancer [OR for 3 - < 4 glasses per day, 3.01 (1.14-7.95); OR for 4 or more glasses per day, 3.79 (1.05-13.71)]. Reported frequency of consumption was a stronger predictor of breast cancer risk than either duration-weighted total consumption or consumption before the age of 30 years. There were no coherent patterns for interaction with menopausal status, obesity or use of menopausal estrogens. The association of very low levels of alcohol intake with breast cancer risk may be due to confounding, whereas drinking 3 or more glasses of alcoholic beverages daily appears to genuinely increase breast cancer risk, perhaps by acting as a late-stage growth enhancing factor. However, the data also are compatible with a linear relationship that has no threshold.     

Comparison of CD44 expression in early colorectal carcinomas of the de novo and ex adenoma types

Small colorectal carcinomas without morphological evidence of origin from an adenoma have been called ”de novo” carcinomas. As changes in the expression of the adhesion molecule CD44 and its variants have been described along the adenoma-carcinoma sequence in colorectal carcinoma, we compared patterns of CD44 expression in early de novo and ex-adenoma colorectal carcinomas by staining specimens from a group of early (pT1) colorectal carcinomas by immunohistochemistry for CD44 (standard and variant forms v3, v5, v6, v7, v7/8, v10). We evaluated carcinoma, adenoma (ex-adenoma cases), transitional mucosal areas and apparently nonneoplastic mucosa peripheral to the lesions (when present). A marked increase was seen in numbers and intensity of standard and variant forms of CD44 in carcinomatous areas compared with nonneoplastic mucosa in both groups, with no significant difference between the groups. However, adenoma areas of the ex-adenoma cases and the transitional mucosa of the de novo carcinomas had nearly identical staining patterns. Together with data from other molecular studies, this may be interpreted as evidence for an adenoma-type precursor lesion in so-called de novo colorectal carcinomas.     

Health effects associated with sulfuryl fluoride and methyl bromide exposure among structural fumigation workers.

OBJECTIVES: This study assessed the health effects associated with occupational exposure to methyl bromide and sulfuryl fluoride among structural fumigation workers. METHODS: A cross-sectional study of 123 structural fumigation workers and 120 referents in south Florida was conducted. Nerve conduction, vibration, neurobehavioral, visual, olfactory, and renal function testing was included. RESULTS: The median lifetime duration of methyl bromide and sulfuryl fluoride exposure among workers was 1.20 years and 2.85 years, respectively. Sulfuryl fluoride exposure over the year preceding examination was associated with significantly reduced performance on the Pattern Memory Test and on olfactory testing. In addition, fumigation workers had significantly reduced performance on the Santa Ana Dexterity Test of the dominant hand and a nonsignificantly higher prevalence of carpal tunnel syndrome than did the referents. CONCLUSIONS: Occupational sulfuryl fluoride exposures may be associated with subclinical effects on the central nervous system, including effects on olfactory and some cognitive functions. However, no widespread pattern of cognitive deficits was observed. The peripheral nerve effects were likely caused by ergonomic stresses experienced by the fumigation workers.     

Electrochemical characterization of cobalt-based alloys using the mini-cell system.

OBJECTIVES: The aim of this work was to investigate the electrochemical behavior of cobalt-based alloys of different compositions using the mini-cell system (MCS) and to test the sensitivity of this technique in the detection of variations in the electrochemical behavior caused by the different compositions of cobalt-based alloys. METHODS: The electrochemical measurements were performed on two cobalt-based alloys, having a small content of gold (B?rlight and Gold Core); one cobalt-platinum-ruthenium alloy (Porta Smart) and one classical Co-based alloy (Wironit), in two different electrolytes, 1% NaCl and phosphate buffered solution (PBS). RESULTS: Based on I versus E curves, enhanced pitting corrosion capability was observed for the cobalt-based alloys, especially for those with lower chromium content and with the addition of a small amount of gold. The alloying of Co with Pt and Ru (Porta Smart), and the standard Co-based alloy do not show any critical instability; in contrast, a small addition of Au enhanced the pitting corrosion activity and reduced the corrosion stability. For higher alloy stability, a minimum 30% atomic ratio of chromium in the alloy composition is necessary. Furthermore, it was shown that MCS has sensitivity for the qualitative comparison of the alloys as well as in the electrochemical characterization of each alloy. SIGNIFICANCE: Electrochemical measurements are essential to assess the quality of an alloy. MCS might help in understanding the role the elements play in the electrochemical behavior of the alloys and at the same time contribute to the selection of the alloys in terms of their quality, even before more complex tests in vitro or in vivo are applied, and might reduce the costs for materials research.