Isolation and characterization of three forms of joining peptide from adult human pituitaries: lack of adrenal androgen-stimulating activity.

Three structural variants of the joining peptide (JP) fragment of POMC have been purified from human pituitaries. Ion exchange and reverse phase tissue extraction procedures were combined with reverse phase HPLC to achieve complete purification of each form of JP. Fragments resulting from tryptic hydrolysis of each form were characterized by amino acid analysis and fast atom bombardment mass spectrometry. The predominant form of human JP, accounting for about 50% of the total purified, was found to be conjugated to glutathione through the lone cysteine residue at position 9. The other two variants were identified as human JP with a free cysteine residue and human JP dimer and accounted for 35% and 15%, respectively, of the total purified. Recently, human JP-(1-18) has been suggested as having adrenal androgen-stimulating activity. None of the three JP variants or their respective 1-20 amino-terminal fragments resulting from tryptic hydrolysis showed any ability to promote the secretion of dehydroepiandrosterone sulfate by cultured human fetal adrenal cells. Similarly, no potentiation of the stimulatory effects of ACTH-(1-39) was observed. The three variants of human JP as well as JP purified from rat, porcine, and bovine pituitaries were tested for their ability to stimulate androgenic steroids from dispersed fetal rabbit adrenal cells. None showed any significant biological activity either in stimulating steroid secretion or in potentiating the action of ACTH-(1-39).     

Age, clinical presentation, and outcome of acute coronary syndromes in the Euroheart acute coronary syndrome survey.

AIMS: Age is one of the most powerful determinants of prognosis in myocardial infarction, but there is comparatively little recent data across the whole spectrum of acute coronary syndromes (ACS). We examined the impact of increasing age on clinical presentation and hospital outcome in a large sample of patients with ACS. METHODS AND RESULTS: Patients (n = 10 253) from the Euroheart ACS survey in 103 hospitals in 25 countries were investigated. There was a significant inverse association between the age and the likelihood of presenting with ST-elevation. For each decade of life, the odds of presenting with ST-elevation decreased by 0.82 [95% confidence interval (CI) 0.79-0.84]; P < 0.0001. Elderly patients were considerably less often treated by cardiologists, less extensively investigated, and, when presenting with ST-elevation ACS, less likely to be treated with reperfusion. Compared with patients <55 years, the odds ratios of hospital mortality were 1.87 (1.21-2.88) at age 55-64, 3.70 (2.51-5.44) at age 65-74, 6.23 (4.25-9.14) at age 75-84, and 14.5 (9.47-22.1) among patients > or =85 years, with no major differences across different types of admission or discharge diagnoses. CONCLUSION: Elderly ACS patients were less likely to present with ST-elevation but had substantial in-hospital mortality, yet they were markedly less intensively treated and investigated.     

Exposures of older adults with chronic respiratory illness to nitrogen dioxide. A combined laboratory and field study.

We combined field and laboratory experimentation to evaluate the effects of nitrogen dioxide in a panel of Los Angeles area residents with chronic respiratory illness, 15 men and 11 women aged 47 to 69. All had heavy smoking history, chronic symptoms, and low FEV1; some also had low FVC. During the fall-winter high-NO2 season, they monitored themselves for 2-wk periods using spirometers in the home, passive NO2 sampling badges, and diaries to record time and activity patterns and clinical status. In the middle of each self-monitoring week they were exposed in a chamber, once to clean air and once to 0.3 ppm NO2. Chamber exposures were double blind, lasted 4 h, and included four 7-min exercise sessions with average ventilation rates near 25 L/min. Symptom reports and hourly forced expiratory function tests showed no statistically significant differences between clean air and NO2 chamber exposures, although peak flow showed a approximately 3% loss with NO2 relative to clean air during the first 2 h of exposure only (p = 0.056). No significant overall differences were found between field self-measurements and measurements of lung function in the chamber or between field measurements in clean air and NO2 exposure weeks. Field data showed that group average lung function and symptom levels were worse in the morning than later in the day (p < 0.005) but otherwise were stable over 2 wk. Even though most subjects smoked and stayed indoors 80 to 90% of the time, personal NO2 exposures correlated significantly with outdoor NO2 concentrations as reported by local monitoring stations.(ABSTRACT TRUNCATED AT 250 WORDS)     

The acute effects of cigarette smoking on treadmill exercise distances in patients with stable intermittent claudication

The hypothesis that smoking has an acute effect on treadmill exercise performance in patients with peripheral vascular disease was investigated in a crossover trial. Twelve patients with stable intermittent claudication who were regular smokers attended on two occasions within one week and treadmill tests were performed after 1/2, 1, 1 1/2, and 2 hours. Immediately before the second exercise test, two standard cigarettes were smoked or an unlit cigarette was "sham-smoked." Because participants could not be blinded, an attempt to control for patient bias was made. Half were told that we expected smoking to make no difference or possibly cause some improvement, and half were told that we expected it to make no difference or possibly cause some deterioration. These explanations and the order of study days were determined by balanced randomization. Suggestion had a significant influence on claudication distance immediately after smoking (p less than 0.01) but no significant effect on walking distance. Combining data from both groups assumes that no overall bias was introduced by the explanations given. Immediately after smoking, small, nonsignificant increases in claudication distance (+10%, 95% CI-7%, +27%) and walking distance (+9%, 95% CI-2%, +19%) were observed. Smoking caused a mean increase in heart rate of 9 beats per minute, which persisted for one hour, but no consistent change in blood pressure. The results show that suggestion may have a significant influence on treadmill exercise distances. Smoking is unlikely to have an important acute effect on exercise performance in claudicants.