Clinical and biomarker profiling of prodromal Alzheimer's disease in workpackage 5 of the Innovative Medicines Initiative PharmaCog project: a 'European ADNI study'

BACKGROUND

In the field of Alzheimer's disease (AD), the validation of biomarkers for early AD diagnosis and for use as a surrogate outcome in AD clinical trials is of considerable research interest.

OBJECTIVE

To characterize the clinical profile and genetic, neuroimaging and neurophysiological biomarkers of prodromal AD in amnestic mild cognitive impairment (aMCI) patients enrolled in the IMI WP5 PharmaCog (also referred to as the European ADNI study).

METHODS

A total of 147 aMCI patients were enrolled in 13 European memory clinics. Patients underwent clinical and neuropsychological evaluation, magnetic resonance imaging (MRI), electroencephalography (EEG) and lumbar puncture to assess the levels of amyloid β peptide 1-42 (Aβ42), tau and p-tau, and blood samples were collected. Genetic (APOE), neuroimaging (3T morphometry and diffusion MRI) and EEG (with resting-state and auditory oddball event-related potential (AO-ERP) paradigm) biomarkers were evaluated.

RESULTS

Prodromal AD was found in 55 aMCI patients defined by low Aβ42 in the cerebrospinal fluid (Aβ positive). Compared to the aMCI group with high Aβ42 levels (Aβ negative), Aβ positive patients showed poorer visual (P = 0.001), spatial recognition (P < 0.0005) and working (P = 0.024) memory, as well as a higher frequency of APOE4 (P < 0.0005), lower hippocampal volume (P = 0.04), reduced thickness of the parietal cortex (P < 0.009) and structural connectivity of the corpus callosum (P < 0.05), higher amplitude of delta rhythms at rest (P = 0.03) and lower amplitude of posterior cingulate sources of AO-ERP (P = 0.03).

CONCLUSION

These results suggest that, in aMCI patients, prodromal AD is characterized by a distinctive cognitive profile and genetic, neuroimaging and neurophysiological biomarkers. Longitudinal assessment will help to identify the role of these biomarkers in AD progression.

Twenty-four-hour endothelin-1 secretory pattern in stroke patients

Endothelin-1 (ET-1) is a potent and long-acting vasoconstrictor peptide, which may play a role in the pathophysiology of a number of diseases. Controversial data exist on its role in human ischemic stroke. In order to ascertain whether changes in ET-1 plasma levels occur in ischemic stroke, plasma ET-1 levels and mean arterial pressure were determined in 15 patients at their first ischemic cerebral infarction and in 15 control subjects, over a 24-hour period. In stroke patients, mean 24-hour plasma ET-1 levels (4.9+/-0.5 ng/L) were higher (P< 0.05) than in control subjects (3.2+/-0.3 ng/L), and correlated with the mean size of the lesion, but not with the severity score of the neurological deficit. These results support the hypothesis that ET-1 levels reflect an indicator function for the amount of damaged cerebral tissue rather than a pathophysiological role.

Evaluation of the secretory pattern of plasma arginine vasopressin in stroke patients

Arginine vasopressin (AVP) may play a role in the development of ischemic brain edema and/or cerebral vasospasm. Data available on AVP plasma levels in ischemic stroke are few and discordant. In order to ascertain whether changes in AVP plasma levels occur in ischemic stroke, plasma AVP levels, plasma osmolality and mean arterial pressure were determined in 24 patients with unprecedented ischemic cerebral infarction and in 15 controls over a 24-hour period. In stroke patients, mean 24-hour plasma AVP levels (7.2 +/- 0.8 ng/l) were higher (p < 0.05) than in control subjects (2.4 +/- 0.3 ng/l), and correlated with the severity score of the neurologic deficit and the mean size of the lesion. In patients with a more severe neurologic deficit, the mean 24-hour plasma AVP levels (8.7 +/- 1.0 ng/l) were higher than in patients with a less severe neurologic deficit (5.2 +/- 0.8 ng/l). Data indicate that in ischemic stroke an increased AVP secretion occurs independently of osmotic or baroreceptorial mechanisms. The possibility that AVP may play a role in neuronal cell damage following cerebral ischemia warrants further attention.

Serum leptin levels in patients with viral chronic hepatitis or liver cirrhosis

BACKGROUND/AIM

Serum levels of leptin, the adipocyte-derived hormone regulating food intake and energy expenditure in mammals, have been found to be increased in cirrhotic patients. The aim of the present study was to investigate leptin serum level in relation to anthropometric features and liver function in patients with viral chronic hepatitis or liver cirrhosis.

METHODS

Serum leptin levels were determined by radioimmunoassay in 30 male and 10 female patients with chronic hepatitis, in 42 male and 10 female patients with liver cirrhosis, and in four respective control groups. Liver function was evaluated by the monoethylglycinexylidide formation test. Body mass index and body fat mass were estimated by weight, height and skinfold thickness measurements.

RESULTS

Compared with controls, absolute serum leptin levels were significantly (p<0.01) lower in chronic hepatitis patients and similar in cirrhotic patients. Leptin serum levels were significantly (p<0.05) higher in cirrhotic than in chronic hepatitis patients. When expressed in relation to body fat mass, the above differences persisted; however, cirrhotic females showed significantly (p<0.05) higher serum leptin values than controls. Serum leptin values correlated negatively (p<0.01) with monoethylglycinexylidide serum values in all groups of patients.

CONCLUSIONS

In patients with chronic viral liver disease, serum leptin levels tend to increase as liver function worsens. This may reflect a decline in the ability to downregulate energy expenditure as an adaptation to anorexia and/or to defective substrate utilisation due to liver disease and may negatively influence body weight homeostasis in these patients.

Twenty-four-hour variation in serum leptin in the elderly

To investigate the possibility that the aging process may affect the diurnal variation in serum leptin in humans, serum leptin levels were measured by a sensitive radioimmunoassay method in 12 elderly (aged 72 to 87 years) and 10 middle-aged (35 to 50 years) lean male subjects. Fasting blood samples (4 mL) were drawn at 8:00 AM, and then every 4 hours until 10:00 PM and every 2 hours from 12:00 midnight to 8:00 AM of the next morning. Circadian rhythmicity analysis was performed using the cosinor method. In elderly subjects, serum leptin levels showed a significant diurnal rhythm, which was similar to that observed in controls. Single cosinor analysis showed a significant rhythm in eight of 12 elderly subjects and in all middle-aged subjects but one. Compared with middle-aged subjects, similar mesor mean values (7.8 +/- 1.0 v 8.1 +/- 0.8 ng/mL) but a decreased amplitude (1.4 +/- 0.3 v 2.3 +/- 0.2 ng/mL) and an earlier acrophase (11:56 PM v 2:04 AM) were observed in the elderly. The data demonstrate that the diurnal variation in serum leptin is generally preserved in the elderly. However, the amplitude of leptin diurnal excursion undergoes a reduction with advancing age. It can be speculated that the blunted diurnal variation in serum leptin observed in the elderly may result in an alteration of the afferent signal in the adipose tissue-central nervous system homeostatic loop.

Somatostatin release in response to glucose is impaired in chronic renal failure

In order to evaluate somatostatin (SRIH) secretion in uremia, plasma SRIH concentrations were determined in basal conditions and after an oral glucose tolerance test (OGTT) in 14 non-dialysed patients with chronic renal failure (CRF), seven of whom had normal glucose tolerance (NGT) and seven impaired glucose tolerance (IGT). Plasma insulin, C-peptide and glucagon and blood glucose concentrations were also evaluated. The results were compared with those obtained in a group of age- and sex-matched normal subjects. In CRF patients, plasma SRIH fasting values (8.6 +/- 0.6 and 7.8 +/- 0.6 pmol/L in NGT and IGT patients, respectively) were comparable to those recorded in controls (7.7 +/- 0.5 pmol/L). SRIH response to OGTT, evaluated as area under curves (AUC) above basal, was similar in both groups of CRF patients (412.9 +/- 84.5 and 415.6 +/- 51.9 pmol/L per min), and significantly lower than in controls (660.1 +/- 58.5 pmol/L per min). Data indicate that chronic uremia induces a loss of SRIH secretory cell responsiveness to glucose. A possible effect of impaired SRIH secretion on glucose metabolism in CRF is discussed.

Oxidative stress in subjects affected by celiac disease

In order to study the role of oxidative stress in celiac disease, protein carbonyl groups, thiobarbituric acid-reactive substance and pentosidine were evaluated in the plasma of nine patients with asymptomatic celiac disease and in a control group (n = 25). Plasma alpha-tocopherol, retinol and lipids were determined in the same samples. The levels of markers of oxidative stress derived from both protein (carbonyl groups) and lipids (thiobarbituric acid-reactive substances) were significantly higher in celiac disease patients, whereas lipoproteins and alpha-tocopherol were significantly lower. These data indicate that in celiac disease, even when asymptomatic, a redox imbalance persists; this is probably caused by an absorption deficiency, even if slight. Dietary supplementation with antioxidant molecules may offer some benefit and deserves further investigation.

Inter-organ leptin exchange in humans

To assess the individual role of splanchnic organs, kidney, and peripheral tissues on leptin metabolism, leptin exchange across the splanchnic bed, kidney, and leg has been evaluated by the arterio-venous technique in post-absorptive non-obese subjects. Leptin levels in the hepatic and renal veins were significantly lower (p < 0.001), while femoral vein levels were consistently greater (p < 0.05) than in the artery. The fractional extraction of leptin, namely the percentage of arterial leptin extracted, was greater in splanchnic organs (16%) than in the kidney (9.5%). Urinary excretion of leptin was undetectable in most subjects, indicating that leptin is degraded within the kidney. There was no correlation between fractional extraction of leptin and glomerular filtration rate, whereas leptin fractional extraction was directly related to renal plasma flow (p = 0.017). Renal leptin clearance was about 50% of the glomerular filtration rate. Our data demonstrate that both splanchnic organs and the kidney cooperate in the disposal of leptin, while peripheral tissues add significant amounts of leptin to the circulation. In non-obese subjects the contribution of the kidney to whole body clearance is no more than 50%. The removal of leptin by the kidney depends on renal plasma flow but not on glomerular filtration rate or filtered leptin.

Plasma somatostatin response to an oral test meal in liver transplant patients

Ten liver transplant patients were studied in basal conditions and after ingestion of a standard mixed test meal. Control groups included 10 normal subjects, 10 patients with nonalcoholic liver cirrhosis, and seven kidney transplant patients. Plasma somatostatin, blood glucose, and plasma insulin, C-peptide, and glucagon were determined before and 15, 30, 45, 60, 90, 120, and 180 minutes after the start of the meal. In liver transplant patients, basal somatostatin and insulin levels were significantly lower than in cirrhotics and were comparable to those recorded in controls and in kidney transplant patients. The time course of the somatostatin secretory response after the meal was similar in any group, but the increase, evaluated as the incremental area above baseline, was significantly higher in liver transplant patients than in controls and cirrhotics and comparable to that recorded in kidney transplant patients. Insulin incremental areas were also lower than in cirrhotics and comparable to those recorded in controls and kidney transplant patients. The data suggest that in liver transplant patients an increased somatostatin response to a meal may be related to a relative beta-cell secretory defect, which in turn seems consequent to immunosuppressive treatment.

Evaluation of beta-endorphin secretion in patients suffering from episodic cluster headache

In order to obtain data regarding peripheral levels of beta-endorphin in head pain syndromes, we evaluated the plasma beta-endorphin secretory pattern in 12 adult male patients suffering from cluster headache. Blood samples were drawn every 2 hours for a 24-hour period, and in addition at 30-minute intervals for 120 minutes during cluster attacks. The same sampling was repeated during an asymptomatic period. Cluster headache patients showed no significant beta-endorphin circadian rhythm and a delayed acrophase during cluster periods compared with that recorded in the remission period and in normal subjects. Eighteen cluster headache attacks were recorded during the study day, 13 (72%) of which were followed by a significant increase in beta-endorphin levels. No correlation was found between beta-endorphin maximum net increase and intensity and/or duration of pain. These data suggest the hypothesis of a temporary alteration of beta-endorphin circadian secretion, probably related to involvement of neural structures controlling biorhythm pacemakers.

Effect of the 5-HT3 receptor antagonist ondansetron on plasma AVP secretion: a study in cancer patients

The aim of the present study was to investigate the effects of a serotonin subtype 3 receptor antagonist, ondansetron, on arginine vasopressin secretion in humans. Plasma vasopressin concentrations were determined in 24 breast cancer patients undergoing adjuvant chemotherapy, before and after ondansetron intravenous (i.v.) administration. Ondansetron (8 mg i.v. at time 0 and 8 mg po at time 240 min) was administered alone in 12 patients and afterwards in combination with chemotherapy in all patients. No changes in hormone levels were found after ondansetron alone and in 17 patients who did not claim nausea and/or emesis after chemotherapy. In seven patients who experienced nausea and /or emesis, vasopressin levels significantly (P < 0.01) increased (from 6.3 +/- 0.9 ng/L in basal conditions to 15.1 +/- 3.3 ng/L at 10 h; P < 0.05 vs baseline). The results suggest the possibility that in humans, serotoninergic mechanisms, which modulate vasopressin secretion, may involve the activation of the serotonin receptors recognised by ondansetron.

Raised plasma arginine vasopressin concentrations during cluster headache attacks

To obtain data about peripheral concentrations of arginine vasopressin in head pain syndromes, the plasma arginine vasopressin secretory pattern in 12 adult male patients with cluster headache was evaluated. Blood samples for plasma arginine vasopressin and osmolality determinations were collected before, and at 15, 30, 45, 60, 90, and 120 minutes during a cluster attack. Blood pressure was also monitored. The same sampling was repeated during an asymptomatic period. During cluster attacks, the mean values of plasma arginine vasopressin before an attack (2.3 (0.1) ng/l) significantly increased, reaching their peak at 45 minutes (4.8 (0.5) ng/l; P < 0.01 v baseline). No significant variations were found in mean arterial pressure and plasma osmolality. These data suggested involvement of neurotransmitter mechanisms regulating arginine vasopressin secretion and a possible role of arginine vasopressin in vasomotor phenomena accompanying cluster attacks.

Lichen planus induced by interferon-alpha-2a therapy for chronic active hepatitis C

OBJECTIVE

To report the development of hepatitis C virus (HCV)-positive chronic active hepatitis with lichen planus in a patient during interferon treatment.

DESIGN

Case report and literature review.

PATIENT

A 64-year-old anti-HCV and HCV-RNA-positive woman.

INTERVENTIONS

The patient received interferon-alpha-2a treatment for histologically proven chronic active hepatitis.

RESULTS

Four months after the start of treatment the patient developed multiple cutaneous lesions on her hands, feet and back. A skin biopsy led to the diagnosis of lichen planus. The withdrawal of interferon was followed by a marked improvement in the cutaneous lesions, but not complete regression.

CONCLUSION

This case shows that HCV-positive patients with chronic active hepatitis may develop lichen planus during interferon therapy.

Plasma beta-endorphin levels and glucose tolerance in patients with chronic renal failure

In order to examine the role of endogenous opioid peptides on glucose metabolism in uraemic patients, plasma concentrations of beta-endorphin, glucose, insulin and C-peptide were determined before and during an oral glucose tolerance test (OGTT) in nine non-dialysed patients with chronic renal failure (CRF). The results are compared with those obtained in a group of age-matched normal subjects. In CRF patients, plasma beta-endorphin fasting values (16.0 +/- 1.9 pmol/l) were significantly higher than those of the controls (6.6 +/- 0.6 pmol/l) and significantly correlated with the degree of renal function impairment. After glucose load, plasma beta-endorphin in CRF patients tended to decline, whereas in normal subjects increased. The fasting and the mean OGTT plasma beta-endorphin values negatively correlated with insulin initial response to glucose, insulin and C-peptide mean OGTT values, but not with glucose OGTT mean values. Data indicate that chronic uraemia induces a significant increase in circulating plasma beta-endorphin levels, with a loss of opioid system responsiveness to glucose. The possibility that this hyper-endorphinism may have a biological importance at least as a contributory factor of impaired glucose tolerance in uraemia may be suggested.

Twenty-four-hour beta-endorphin secretory pattern in stroke patients

BACKGROUND AND PURPOSE

Abnormalities of hypothalamo-pituitary-adrenocortical axis function have been observed frequently in stroke patients. The aim of this study was to investigate plasma beta-endorphin and cortisol 24-hour secretory patterns in patients early after stroke and in the convalescent period to evaluate a possible influence of brain damage on hormonal circadian pattern.

METHODS

Patients (n = 15; age, 46 to 75 years) were evaluated in the first 24 hours and 10 days after hospital admission for ischemic cerebral stroke and compared with 15 age- and sex-matched normal subjects. Blood samples for beta-endorphin and cortisol determination were drawn every 4 hours from 8 AM to 8 PM and every 2 hours from midnight to 6 AM.

RESULTS

Mean 24-hour beta-endorphin and cortisol levels, recorded in the acute phase, were significantly (P < .05) higher than those recorded in normal subjects; circadian rhythm was not demonstrable for either hormone. In the convalescent period, plasma cortisol 24-hour mean values and circadian rhythm returned to the normal range, whereas the plasma beta-endorphin 24-hour mean values and circadian rhythm did not.

CONCLUSIONS

Cerebral stroke induces abnormalities of beta-endorphin and cortisol circadian secretion. Whereas cortisol abnormalities are transient, those of beta-endorphin last longer. The dissociation between beta-endorphin and cortisol 24-hour secretory patterns might potentially serve as a marker of psychoneurological abnormalities occurring after stroke.

The effects of sumatriptan on pituitary secretion in man

Sumatriptan, a new antimigraine drug with high affinity and selectivity for certain 5-hydroxytryptamine (5-HT1D) receptor subtypes, was administered to 12 normal subjects, in order to investigate the effects of 5-HT receptor activation on anterior pituitary secretion. Sumatriptan increased plasma growth hormone (GH) levels from 2.5 +/- 0.5 mIU/l in basal conditions to 17.3 +/- 2.6 mIU/l 30 min after administration of the drug. After pre-treatment with cyproheptadine, an anti-serotoninergic drug known to inhibit GH secretion, the mean integrated sumatriptan-induced GH response decreased from 14.8 +/- 3.9 muI/l*hr to 3.7 +/- 1.7 mIU/l*hr. Sumatriptan administration did not have any effect on the secretion of the other anterior pituitary hormones. It is concluded that sumatriptan selectively increases GH secretion in man, but the exact nature of the receptors involved is not yet known.

Sumatriptan does not affect vasopressin secretion in humans

The aim of the study was to investigate the effects of a new serotoninergic drug, sumatriptan, on arginine vasopressin secretion in humans. Plasma vasopressin concentrations were determined in eight healthy volunteers, before and after administration of 6 mg of sumatriptan, or placebo. No changes in hormone levels were found after sumatriptan or placebo administration. The results suggest that in humans serotoninergic mechanisms, which modulate vasopressin secretion, do not involve the serotonin receptor activated by sumatriptan.

Sex hormones and sex hormone-binding globulin in males with chronic viral hepatitis during recombinant interferon-alpha 2b therapy

The effect of long-term treatment with recombinant interferon-alpha 2b (IFN-alpha 2b) on luteinizing hormone (LH), testosterone, free testosterone, and sex hormone-binding globulin (SHBG) was evaluated in 7 male patients suffering from chronic viral hepatitis. The drug was given three times a week for 6 months in a single standard dose of 3 x 10(6) units. Hormone evaluations were performed in basal conditions and every 2 months for 12 months. Serum testosterone values decreased after IFN treatment, reaching the lowest levels at the 6th month. However, testosterone values did not fall below the normal range. Serum SHBG concentrations, which were above the normal range in basal conditions, also decreased after IFN. Serum-free testosterone and LH concentrations did not change during IFN therapy. IFN-alpha 2b at the dose and schedule employed was not responsible for any measurable imbalance in male sex hormones.

Long term therapy with recombinant interferon alpha 2 b in patients with chronic hepatitis C: effects on thyroid function and autoantibodies

Twelve anti HCV-positive patients (8 males and 4 females; 37-62 yrs) suffering from chronic active viral hepatitis have been evaluated in order to determine serum thyroid hormones and autoantibody pattern during recombinant interferon alpha 2b (IFN-alpha 2b) therapy. The interferon was given subcutaneously three times per week for six months in a single standard dose of 3 MU. For a further six months 5 patients (Group A) received the same interferon at 1MU dose three times per week and 7 (Group B) had no treatment. Serum T3, T4, FT4, TBG, TSH, TGAb and TMAb were determined on serum collected before the start of the treatment and every month for 12 months thereafter. Except for one case, in which a transient reduction in thyroid hormone values and an increase in TSH levels was recorded, none of the patients studied showed a significant variation of serum hormonal parameters or appearance of pathological TGAb and/or TMAb levels. The data indicate that the administration of recombinant IFN-alpha 2b to HCV positive chronic active hepatitis patients at the dose and schedule employed in the present study may result in a reduction in the incidence of thyroid dysfunction related to the IFN therapy.

Calcitonin and beta-endorphin secretion

Calcitonin is a peptide hormone secreted by the C-cells of the thyroid gland. This hormone mainly acts in preventing bone resorption. Furthermore, calcitonin is involved in other biological actions, and in particular it is able to relieve pain independently of its peripheral effects on bone. Here, we examine the possible mechanisms of calcitonin-induced analgesia, with particular regard to the opioid system involvement. Several studies in animals and in humans demonstrate that calcitonin increases plasma beta-endorphin levels, acting at the hypothalamic and/or at the pituitary level, either directly or indirectly, through monoaminergic neurotransmitters. However, this calcitonin-induced beta-endorphin release has not always been observed. These different results are discussed, and a possible implication of sex and/or calcitonin dose employed has been examined. We conclude that the analgesic effects of calcitonin are multifactorial, and beta-endorphin plays its own specific role.

Thyroid hormones and atrial natriuretic hormone secretion: study in hyper- and hypothyroid patients

Plasma atrial natriuretic hormone (ANH) values were evaluated in 28 hyperthyroid patients and in 11 hypothyroid patients and compared with 20 healthy subjects. In hyperthyroid patients plasma ANH basal levels were significantly (p less than 0.01) higher (14.2 +/- 1.6 pmol/l) than in controls (7.8 +/- 0.4 pmol/l) and in hypothyroid patients (6.4 +/- 0.3 pmol/l). No significant differences were found between controls and hypothyroid patients. The propranolol-induced decrease in heart rate in hyperthyroid patients did not significantly affect the plasma ANH values. Conversely, after the methimazole-induced euthyroidism a return within the normal range of ANH values was observed. The thyroxine replacement in hypothyroid patients determined a small but significant (p less than 0.05) increase in plasma ANH values. Observed data suggest that in humans thyroid hormones may influence plasma ANH concentrations independently of their effect on heart rate.

Twenty-four-hour beta-endorphin secretory pattern in Alzheimer's disease

A chronobiological study was carried out in 6 male patients (67-71 years), suffering from Alzheimer-type dementia (ATD) and 6 male patients (52-74 years) suffering from multi-infarct dementia (MID), to evaluate their 24-hour beta-endorphin and cortisol secretory patterns. Six healthy male adults (28-37 years) and 6 healthy elderly male subjects (78-84 years) constituted the control groups. Blood samples were drawn every 4 h from 8.00 to 20.00 h and every 2 h from 24.00 to 6.00 h. Mean 24-hour beta-endorphin levels were significantly (p < 0.05) higher in the ATD patients (39.2 +/- 1.5 ng/l) than in the other groups (33.8 +/- 1.1, 30.1 +/- 1.6 and 33.2 +/- 1.1 ng/l in the elderly subjects, the adults and the MID patients, respectively). The circadian rhythm was absent in the ATP patients, in the elderly subjects and the MID patients. No differences in plasma cortisol circadian rhythm were observed among the four groups. Our data indicate that changes in circulating beta-endorphin concentrations and circadian pattern may be due to the aging process.

Effects of ursodeoxycholic acid (UDCA) on serum liver damage indices in patients with chronic active hepatitis. A double-blind controlled study

The effects of ursodeoxycholic acid (UDCA, 450 mg daily) in patients with histologically proven chronic active hepatitis (CAH) have been evaluated in a randomized, double-blind, placebo-controlled study. Twenty-six patients with serum alanine aminotransferase (ALT) values at least twice the normal upper limit in two of three pre-treatment tests received UDCA or a placebo for twelve weeks. In all UDCA-treated patients, serum aspartate amino-transferase (AST), ALT, gamma-glutamyl transpeptidase (GGT) and alkaline phosphatase (AP) fell significantly after 4 weeks of treatment. There was a further decrease at the end of therapy, as well as a small but significant fall in total serum bilirubin. Conversely, 4 weeks after suspension of therapy, serum enzyme levels had increased, reaching values not much lower than those recorded before treatment. Total serum protein, albumin and gamma-globulin did not change after UDCA treatment. In the placebo group no significant variation in the test results were found. The results indicate that UDCA therapy in CAH, as has been observed in primary biliary cirrhosis and primary sclerosing cholangitis, is able to improve several indices of liver damage, without producing any toxic adverse effects.

Plasma somatostatin response to an oral mixed test meal in cirrhotic patients

Ten patients with non-alcoholic cirrhosis and ten control subjects were studied in basal conditions and after ingestion of a standard mixed test meal. Plasma somatostatin, blood glucose, plasma insulin, C-peptide and glucagon were determined before and 15, 30, 45, 60, 90, 120 and 180 min after the start of the meal. Basal somatostatin levels in patients (31.9 +/- 1.8 ng/l) were significantly higher (p less than 0.01) than in controls (12.5 +/- 0.9 ng/l). The time-course of the somatostatin secretory response after the meal was similar in the two groups, but the increase, evaluated as incremental area above baseline, was significantly smaller (p less than 0.01) in cirrhotics (804 +/- 134 ng/l per min) than in controls (1482 +/- 149 ng/l per min). Data indicate that elevated basal plasma somatostatin concentrations in cirrhosis may be consequent to elevated gastrointestinal and/or pancreatic secretion, whereas the blunted somatostatin response to the mixed test meal may derive from the hyperinsulinemia which occurs in the postprandial period.

Metoclopramide increases plasma but not cerebrospinal fluid vasopressin levels in man: study in hydrocephalic patients

Arginine vasopressin (AVP) concentrations were determined in plasma and in cerebrospinal fluid (CSF) in 8 adult male patients suffering from hydrocephalus of various etiologies, before and after intravenous administration of 10 mg metoclopramide. Metoclopramide was able to increase the plasma (2.6 +/- 0.2 ng/l in basal conditions and 6.1 +/- 0.6 ng/l at 30 min) but not the CSF AVP levels. The results suggest that the neurons which secrete AVP into the CSF may be functionally different from those secreting into the peripheral circulation.

Influence of suckling on plasma concentrations of somatostatin, insulin and gastrin in lactating women

The effects of suckling on plasma somatostatin, insulin and gastrin values were evaluated in eight nursing women on the 3rd to 4th day postpartum. Plasma prolactin levels were also determined. Prolactin levels increased in response to suckling, as expected. Insulin levels also rose, whereas somatostatin and gastrin concentrations did not change after suckling. It is possible that the suckling-induced hyperinsulinemia blunts the somatostatin response to suckling in humans.

Twenty-four-hour secretory pattern of vasoactive intestinal polypeptide in the elderly

A chronobiological study was carried out in 8 elderly male subjects (74-85 years) to evaluate the 24-hour vasoactive intestinal polypeptide (VIP) secretory pattern. Eight young adult males (21-32 years) made up the control group. Blood samples were drawn from each subject every 2 h during the day and hourly during the night for a 24-hour period. Mean 24-hour VIP values in elderly (21.1 +/- 0.3 pg/ml) and young adults (19.1 +/- 0.3 pg/ml) did not differ statistically, but daytime VIP values observed in elderly subjects (21.4 +/- 0.5 pg/ml) were higher (p less than 0.05) than those recorded in young adults (17.5 +/- 0.5 pg/ml). The young adults showed significant (p less than 0.05) circadian VIP fluctuations with highest values during the nighttime, while the elderly subjects did not. An age-related decreased activity of the peripheral neuronal VIP-ergic network is hypothesized.

Plasma beta-endorphin concentrations during suckling in lactating women

Beta-endorphin appears to be involved in the hormonal response to suckling in some animals. The peripheral secretory patterns of beta-endorphin, prolactin and cortisol were investigated in serial venous blood samples taken during suckling from eight healthy women who were breast-feeding on the third or fourth day of the puerperium. Plasma levels of prolactin and beta-endorphin increased significantly during suckling reaching a peak after 20 min, levels of cortisol remained unaffected. It is suggested that the increased beta-endorphin derives from an extra-hypophyseal source.

Plasma beta-endorphin, ACTH and cortisol secretion in man after nasal spray administration of calcitonin

Beta-endorphin, ACTH and cortisol secretion were measured in twelve healthy adult males after nasal spray administration 200 IU salmon calcitonin. A significant increase in plasma beta-endorphin, from 19.2 ng/l under basal conditions to a peak of 27.1 ng/l at 30 min was recorded. Plasma ACTH and cortisol were not affected. In individual subjects the beta-endorphin level was increased in eight of the twelve, ACTH rose in three and cortisol did not change in any of them. The data indicate that calcitonin induced a beta-endorphin increase independent of enhanced corticotrophin-cortisol release.

Plasma somatostatin and vasoactive intestinal polypeptide responses to an oral mixed test meal in obese patients

Ten obese and 10 control subjects were studied in basal conditions and after ingestion of a standard mixed test meal. Blood glucose, insulin, somatostatin (SLI) and vasoactive intestinal polypeptide (VIP) concentrations were determined before and 30, 60, 90, 120, 180 and 240 min after the start of the meal. Basal SLI levels in the obese (14.4 +/- 0.7 ng/l) were not significantly different from those in the controls (15.5 +/- 0.8 ng/l), whereas after the meal a blunted secretory response was recorded. Baseline plasma VIP levels were higher in the obese (29.7 +/- 1.5 ng/l) than in the control subjects (19.8 +/- 1.3 ng/l) and, similarly to the controls, were unaffected by meal ingestion. Data suggest that in the course of obesity an enhanced VIP secretion in association with a diminished SLI responsiveness to meals occurs.

Diurnal changes of plasma and cerebrospinal fluid somatostatin and 24-h growth hormone secretory pattern in man. A study in hydrocephalic patients

Somatostatin concentration was determined in plasma and in cerebrospinal fluid during a 24-h period in 7 male patients suffering from hydrocephalus of differing aetiologies. Blood and ventricular cerebrospinal fluid samples were taken every 2 h during the day (08.00-22.00 h) and every hour during the night (24.00-07.00 h). Simultaneously, plasma growth hormone levels were also evaluated. Plasma SRIH levels showed significant circadian variations with highest values in the daytime and lowest values during the night. Cerebrospinal fluid SRIH did not show any significant time-related circadian changes. Plasma GH levels showed the well-known circadian pattern in the majority of patients. No significant correlation was found between the plasma GH and plasma or cerebrospinal fluid SRIH values recorded during the 24-h period. Results suggest that peripheral SRIH does not play any major role in the control of the 24-h GH secretory pattern in man.

Hormonal pattern and testicular histology in patients with prostatic cancer after long-term treatment with a gonadotropin-releasing hormone agonist analogue

Seven patients suffering from prostatic cancer were treated with a depot form of D-Trp-6-luteinizing hormone-releasing hormone (LH-RH), a LH-RH agonist analogue (3 mg i.m. every 28 days) for a period of 24-32 months. The peptide induced a sharp and long-lasting inhibition of both gonadotropin and testosterone secretion. A sustained suppression of pituitary and testicular function was observed 40 days after the treatment was suspended. Testicular biopsies performed in all patients showed a marked impairment of Leydig cell mass and a complete spermatogenic arrest with a tubular derangement and fibrosis. Results indicate that the long-term continued gonadotropin-releasing hormone agonist analogue therapy induces not only a functional inhibition of testicular androgenesis but also anatomical testicular damage whose reversibility does not seem to be probable.

Diurnal pattern of plasma and cerebrospinal-fluid vasopressin levels in hydrocephalic patients: absence of a circadian rhythm and of a correlation between plasma and cerebrospinal-fluid variations

The arginine vasopressin (AVP) concentrations were determined in plasma and in cerebrospinal fluid (CSF) during a 24-hour period in 7 male patients suffering from hydrocephalus of differing etiologies. Blood and ventricular CSF samples were simultaneously collected every 2 h during the day (08.00-22.00) and every hour during the night (24.00-07.00). In both plasma and CSF, the AVP levels did not show significant time-related circadian variations. No significant correlation was found between the plasma and CSF AVP values during the 24-hour period. The data obtained indicate the absence of the plasma and CSF AVP circadian rhythm in hydrocephalic patients and suggest that in these patients, and possibly in healthy humans, physiological stimuli which are able to induce variations in the plasma AVP concentration during daily life do not alter the CSF AVP content.

Sustained impairment of pituitary and testicular function in prostatic cancer patients treated with a depot form of a GnRH agonist

Seven patients suffering from prostatic cancer were treated with a slow-release D-Trp-6-LHRH preparation for a period of 24-32 months. LH, FSH, PRL and testosterone levels were evaluated before and at the end of treatment and then 40 days later. Baseline and GnRH-, TRH-, and HCG-stimulated hormonal values decreased after treatment. The possibility that a long-term treatment with GnRH analogues induces a sustained suppression of pituitary and testicular function is suggested.

Twenty-four-hour beta-endorphin secretory pattern in the elderly

A chronobiological study was carried out in seven elderly male subjects (78-84 years) to evaluate the 24-h beta-endorphin secretory pattern. Seven young adult males (28-37 years) made up the control group. Blood samples were drawn every four hours from 08.00 to 20.00 h and every two hours from 24.00 to 06.00 h. ACTH and cortisol levels were also determined in the same plasma samples. Mean 24-h beta-endorphin values in the elderly (32.6 +/- 1.1 ng/l) and in the young adult male subjects (29.5 +/- 1.4 ng/l) did not differ statistically, but the circadian rhythm was absent in the elderly subjects. In the elderly, plasma ACTH and cortisol concentrations showed a circadian rhythm similar to that observed in the adult subjects. However, in the elderly patients, in contrast to that in the adult subjects, the multilinear regression analysis did not show any statistically significant correlation between the beta-endorphin, ACTH and cortisol 24-h plasma concentrations.

Somatostatin in the elderly: diurnal plasma profile and secretory response to meal stimulation

Plasma somatostatin levels were determined during a 24-hour period and after a meal test in 7 and 5 elderly subjects (76-90 years), respectively. The data obtained were compared with those recorded in young adult subjects (22-30 years). Increased basal somatostatin values were found in elderly subjects (20.0 +/- 1.5 pg/ml) when compared to young adults (14.1 +/- 0.6 pg/ml; p less than 0.01). Also, the mean 24-hour somatostatin levels were higher in the elderly (21.3 +/- 0.8 pg/ml) than in young adults (16.7 +/- 0.5 pg/ml; p less than 0.01), and minor diurnal variations were found in the former group. The response to the meal test was less evident in the elderly than in the control group. The data obtained indicate an increased basal somatostatin production associated with a diminished variability throughout the 24-hour period and in relation to meals.

Possible role of vasoactive intestinal polypeptide on prolactin release during suckling in lactating women

The effect of suckling on plasma vasoactive intestinal polypeptide (VIP) values was evaluated in 6 nursing women on the 3rd to 4th day postpartum. Plasma prolactin (PRL) concentrations were also measured. Plasma VIP values (20.6 +/- 3.2 pg/ml in baseline) significantly (p less than 0.05) increased, reaching a maximum (53.5 +/- 10.9 pg/ml) 20 min after the starting of suckling. A possible role of VIP in the suckling-induced PRL release in humans cannot be excluded.

Diurnal beta-endorphin changes in human cerebrospinal fluid

Plasma and cerebrospinal fluid (CSF) beta-endorphin levels were determined by a RIA method in seven hydrocephalic male patients. The samples were simultaneously collected every two hours from 8 AM to 12 midnight and every hour from 1 AM to 7 AM. In both plasma and CSF beta-endorphin levels showed significant time-related variations during the 24 hour period. These results suggest the existence of diurnal CSF beta-endorphin variations analogous to those observed in plasma.

Blunted response of serum aldosterone to metoclopramide in the male elderly

Serum aldosterone values were determined in 6 elderly (70-82 years) and in 6 adult (31-43 years) male subjects after the intravenous administration of 10 mg of metoclopramide. A significant difference in the metoclopramide-induced serum aldosterone rise was found between the two groups, it being blunted in the older subjects (serum aldosterone peak values: 15.8 +/- 3.6 ng/dl and 38.7 +/- 4.9 ng/dl in elderly and in adult subjects, respectively). The existence of an impaired aldosterone secretion in response to dopaminergic blockade in the elderly is postulated.

Inhibition of prolactin and aldosterone secretion by the dopamine derivative ibopamine

In 7 patients with congestive heart failure acute oral administration of ibopamine, a new dopamine derivative, induced a significant decrease in serum prolactin and aldosterone without affecting serum growth hormone or cortisol. The Metoclopramide-induced secretion of prolactin and aldosterone was blunted in 6 patients pretreated with 200 mg ibopamine. The data are consistent with a dopaminergic effect of ibopamine due to a peripheral action, probably on D-2 receptors.

Suppression of testicular androgenesis by D-tryptophan-6-luteinizing hormone-releasing hormone does not affect TSH secretion in male subjects

Basal and TRH-stimulated TSH secretion was evaluated in six patients suffering from prostatic cancer, before and after antiandrogenic treatment performed using a long-acting LHRH analogue, D-Trp-6-LHRH. Although serum testosterone values dropped to minimal levels after treatment, TSH secretion remained unchanged. Observed results suggest that pharmacological castration does not affect the regulatory mechanisms involved in the control of TSH secretion.

Treatment of prostatic cancer with a depot form of a luteinizing hormone-releasing hormone analogue

Chronic administration of a depot form of D-Trp6 luteinizing hormone-releasing hormone (LH-RH), an LH-RH analogue (3 mg i.m. every 28 days for a mean period of 9.1 months), to 14 patients with locally extended or metastatic cancer of the prostate provided a good degree of disease control. After a slight and transient increase in gonadotropin secretion, the peptide induced a sharp and long-lasting inhibition of both gonadotropin and testosterone secretion, contemporaneously with clinical improvement and without any important side effects. These results are comparable to those recorded by others after daily administration of LH-RH analogues.

Variations of prolactin content in human cerebrospinal fluid after metoclopramide and morphine

Serum and cerebrospinal fluid (CSF) prolactin (PRL) concentrations were determined in fourteen patients of both sexes suffering from hydrocephalus, in basal conditions and after i.m. administration of 10 mg metoclopramide or 10 mg morphine. A significant increase in both serum and CSF hormone values was found after administration of both drugs. Serum and CSF PRL values after metoclopramide administration increased earlier and to a greater extent than after morphine. Furthermore, the metoclopramide induced CSF PRL increase immediately followed the serum peak, whereas after morphine administration an evident delay in the CSF hormone peak with respect to the serum increase was found. These data suggest that PRL entry in the CSF compartment is subject to a controlling mechanism which acts at the blood/brain barrier.

Comparison of pituitary responses to physical exercise in athletes and sedentary subjects

Serum growth hormone (GH), prolactin (PRL), cortisol, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH) levels were evaluated before and after a bicycle ergometer exercise test in 8 male competitive volleyball players and in 8 sedentary healthy males of the same age. Increased serum GH and cortisol values after exercise in both groups were found, whereas an exercise-induced PRL release was observed in athletes only. Serum levels of LH, FSH and TSH were unaffected by the test in all subjects. A possible role of training in conditioning the hypothalamopituitary exercise-induced secretion is suggested.

Stimulation of growth hormone release by thyrotropin-releasing hormone in elderly subjects

The effect of thyrotropin-releasing hormone (TRH) on the release of growth hormone (GH) was investigated in 16 elderly male subjects aged 74-88 years. Intravenous injection of 200 micrograms TRH induced a clear-cut GH rise (greater than or equal to 10 ng/ml) in 7 of 16 subjects. TRH administration did not raise plasma GH in 10 adult subjects aged 36-58 years. The results suggest disorders in neurobiochemical mechanisms regulating hypothalamopituitary function in elderly men.