The cortisol awakening response predicts subclinical depressive symptomatology in Mexican American adults

While childhood trauma appears to be a risk factor for the onset of depression and subclinical depressive symptomatology in Mexican Americans, the specific physiological mechanisms contributing to this relationship remain to be clarified. Stress-induced dysregulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis is associated with depressive symptomatology in non-Hispanics. The current study assessed the extent to which the cortisol awakening response (CAR) predicts subclinical depressive symptomatology beyond the influence of childhood trauma in a sample of 55 Mexican American males and females ages 18-38 years, without a diagnosis of clinical depression. Participants were assessed for exposure to early trauma and current depressive symptomatology. Salivary cortisol samples were collected on two consecutive days at awakening, 30, 45, and 60 min thereafter, and again at 3 p.m., 6 p.m. and 9 p.m. Data were analyzed using general linear models with repeated measures at four morning time points, and again, at three afternoon and evening time points. Results indicated a significant Symptoms×Time interaction for the CAR(p<0.05). The Symptom×Time interaction was not significant for afternoon and evening cortisol concentrations. Moreover, subclinical symptomatology was associated with attenuation of the initial rise in CAR, after controlling for the total frequency of exposure to childhood traumas. Hierarchical analyses show attenuation of the initial rise in the CAR was the best predictor of greater subclinical depressive symptomatology beyond the influence of trauma, and independent of a current diagnosis of major depression in a sample of adult Mexican Americans.

Plasma adrenocorticotropin responses to opioid blockade with naloxone: generating a dose-response curve in a single session

We examined two methods of generating a dose-response curve to the opioid receptor antagonist naloxone. In 15 healthy male subjects (18-25 years) plasma adrenocorticotropin (ACTH) responses to five doses of naloxone studied over 5 separate days were compared to plasma ACTH responses to five incremental doses of naloxone studied within a single session. There was a statistically significant positive correlation in ACTH responses (area under the curve and peak) between dosing methods. Furthermore, the doses of naloxone that produced half-maximal and maximal ACTH response were similar. The comparability of ACTH responses between the two naloxone dosing techniques, combined with the safety and ease associated with the single-session methodology, underscores the usefulness of the single-session technique for future investigations.

Quantitative bedside assay for cardiac troponin T: a complementary method to centralized laboratory testing

BACKGROUND

In the evaluation of chest pain patients, whole blood bedside assays of highly specific cardiac molecules may be an attractive alternative to centralized clinical chemistry testing. We now report on an optimized test strip device for cardiac troponin T (cTnT) that can be analyzed by a cardiac reader for quantitative assessment of the test result.

METHODS AND RESULTS

The cTnT test strip reader measures, via a CCD camera, the reflectance of the signal line. For quantitative analysis, a calibration curve was constructed from 1030 samples of 252 consecutive patients with acute coronary syndromes. In a method comparison of 140 samples, the quantitative results of the cTnT test strip reader correlated closely with the results of the cTnT ELISA (r = 0.98; y = 0.85x + 0. 002). Within-run and day-to-day (n = 10) mean CVs were between 11% and 16%, respectively. The cross-reactivity with skeletal troponin T was <0.02%. In patients with myocardial infarction, 45% and 91% of all samples were positive on admission and at 4-8 h after the onset of symptoms, respectively. ROC curve analysis demonstrated a comparable efficiency of the cTnT test strip reader and the laboratory-based cTnT ELISA in patients with suspected myocardial infarction.

CONCLUSIONS

It is now possible to quantitatively determine cTnT at the patient's bedside with a rapid and convenient test device. This will facilitate the diagnostic work up of patients with suspected myocardial cell necrosis.

Adrenocortical responses and family history of alcoholism

BACKGROUND

This study was designed to assess whether nonalcoholic offspring from families with a high density of alcohol-dependent individuals have altered hypothalamic-pituitary-adrenal (HPA) axis dynamics compared with nonalcoholic subjects without a family history of alcohol dependence.

METHODS

Seventy-eight nonalcoholic subjects aged 18 to 25 were enrolled in the protocol. Thirty-nine subjects were offspring from families with a high density of alcohol dependence and were designated as family history-positive (FHP) subjects. Thirty-nine subjects were biological offspring of nonalcohol-dependent parents and were designated as family history-negative (FHN) subjects. Subjects received naloxone hydrochloride (0 and 125 microg/kg) and cosyntropin (0, 0.25 microg, and 250 microg) in double-blind, randomized order and cortisol was monitored. A subset of subjects (11 FHP, 11 FHN) was admitted to the General Clinical Research Center to measure serum cortisol levels every 30 min for 24 hr.

RESULTS

FHP subjects had an increased cortisol response to opioid receptor blockade induced by naloxone. However, no group differences in cortisol were uncovered during administration of cosyntropin or during monitoring of the cortisol circadian profile.

CONCLUSION

These observations suggest that differences in the cortisol dynamics between FHP and FHN subjects are unmasked by opioid receptor blockade directed at the hypothalamus, but not when cortisol levels are directly provoked at the level of the adrenal gland. In addition, unprovoked cortisol secretion monitored over a 24-hr interval cannot distinguish FHP from FHN subjects.

Adrenocorticotropin responses to naloxone in sons of alcohol-dependent men

The endogenous opioid system is part of a neural circuitry functionally related to alcohol-seeking behaviors. A family history of alcoholism is the strongest predictor of future development of alcohol dependence. This study was designed to evaluate ACTH responses to opioid receptor blockade as a function of family history for alcohol dependence. The nonselective opioid antagonist naloxone stimulates ACTH secretion by blocking opioidergic input on paraventricular corticotropin-releasing factor neurons, thereby providing a methodology for comparing hypothalamic opioid tone between study groups. Sixty nonalcoholic subjects, aged 18-25 yr, were enrolled in a protocol to measure the ACTH response to naloxone. Thirty-two subjects were offspring from families with a high density of alcohol dependence and were designated as family history-positive subjects. Twenty-eight subjects were offspring of nonalcohol-dependent parents and were designated family history-negative subjects. Subjects received naloxone (125 microg/kg) or placebo (0.9% saline) in double blind, randomized order. Plasma ACTH was monitored. Family history-positive men had increased ACTH response to naloxone compared to 1) family history-positive women, 2) family history-negative men, and 3) family history-negative women. Despite differences in plasma ACTH levels after naloxone administration, plasma naloxone concentrations did not differ between study groups. This finding suggests that nonalcoholic male offspring of alcohol-dependent men have altered endogenous opioid activity directed at hypothalamic corticotropin-releasing factor neurons.

Family history of alcoholism and hypothalamic opioidergic activity

BACKGROUND

This study was designed to assess whether nonalcoholic offspring from families with a high density of alcohol-dependent individuals have altered endogenous central nervous system opioid activity. Naloxone hydrochloride stimulates plasma cortisol by blocking opioidergic input on the corticotropin-releasing factor neuron, thereby providing a noninvasive method for measuring hypothalamic opioid tone.

METHODS

Forty-eight nonalcoholic subjects aged 18 to 25 years were enrolled in a protocol to measure endogenous opioid activity by inducing opioid receptor blockade with the receptor antagonist, naloxone. Twenty-six subjects were offspring from families with a high density of alcohol dependence and were designated as family history-positive subjects. Twenty-two subjects were biological offspring of nonalcohol-dependent parents and designated as family history-negative subjects. Subjects received naloxone hydrochloride (0, 125, and 375 microg/kg) in double-blind, randomized order. Serum cortisol levels were monitored.

RESULTS

Family history-negative subjects had a graded cortisol response to each dose of naloxone. In contrast, family history-positive subjects achieved a maximal cortisol response to the 125-microg/kg dose of naloxone hydrochloride with no further increase in cortisol levels observed following the 375-microg/kg dose. Family history-negative subjects had a diminished cortisol response to the 125-microg/kg dose compared with the family history-positive subjects. Plasma naloxone concentrations did not differ between family history groups.

CONCLUSIONS

Individuals from families with a high density of alcohol dependence are more sensitive to naloxone compared with offspring of nonalcohol-dependent parents. This implies that individuals with a family history of alcohol dependence have diminished endogenous hypothalamic opioid activity.

Multicentre evaluation of an immunological rapid test for the detection of troponin T in whole blood samples

In a multicentre study we assessed the analytical and diagnostic performance of a rapid test (TROPT rapid test, Boehringer Mannheim; in the USA: CARDIACT) for cardiac troponin T compared to quantitative troponin T ELISA and creatine kinase-MB mass determinations. The rapid test requires 150 microliters of heparinized or EDTA whole blood; serum is not suitable. Interference testing with biotin, haemoglobin and 27 standard drugs yielded no significant influence in the physiological range. Skeletal muscle troponin T concentrations > or = 40 micrograms/l gave positive results with the rapid test. We used the rapid test for 369 samples from 203 patients with suspected acute coronary syndromes and compared the results to troponin T ELISA and creatine kinase-MB mass. 90 patients (44%) were primarily classified as having myocardial infarction by the WHO criteria. Twenty-two (20%) of the 113 non-myocardial infarction patients were unstable angina pectoris cases showing increased troponin T ELISA but not increased creatine kinase-MB mass values. Consequently, these were classified as minor myocardial damage cases. The rapid test was positive in 99% of all samples with a troponin T ELISA value > or = 0.30 micrograms/l and negative in 95 to 96% of all samples below this value. Diagnostic sensitivities for the detection of acute myocardial infarction within the first 12 hours after onset of pain were the same, 90%, for the rapid test, troponin T ELISA and creatine kinase-MB mass. After 48 hours, diagnostic sensitivity of creatine kinase-MB mass sharply decreased whereas that of the troponin T assays remained close to 100% beyond 72 hours after onset of symptoms. Diagnostic specificities for acute myocardial infarction (WHO) of all markers remained between 80 and 100% over this time. The diagnostic sensitivity of the rapid test for the detection of high risk unstable angina pectoris patients with minor myocardial damage was nearly the same as for troponin T ELISA. A major advantage of the rapid test is the ease of use and 20 minute turn around time. This facilitates the detection of increased troponin T at alternate sites.

Intestinal obstruction due to phytobezoars. Observations in two patients with hypothyroidism and previous gastric surgery

Two patients had small-bowel obstruction due to phytobezoars. Both patients were hypothyroid. One patient had undergone a previous pyloroplasty for pyloric stenosis and the other a truncal vagotomy and a pyloroplasty for a duodenal ulcer. Similarities and differences between the two cases and the possible predisposing factors in the formation of the phytobezoars are discussed. The recognition of high-risk patients, and their education to prevent phytobezoars are emphasized.