Hemodynamic, renal, and endocrine effects of acute inhibition of nitric oxide synthase in compensated cirrhosis

To assess whether an increased production of nitric oxide is involved in the circulatory and renal alterations of cirrhosis, we evaluated systemic hemodynamics (echocardiography), renal hemodynamics, and sodium handling (lithium clearance method), plasma renin activity (PRA), aldosterone (PAC), and norepinephrine in 7 patients (3 men, mean age 65 +/- 2 years) with compensated cirrhosis, portal hypertension, and hyperdynamic circulation during intravenous N(G)-monomethyl-L-arginine (L-NMMA) (3 mg/kg bolus plus 0.05 mg/kg. min for 120 minutes) or placebo (the vehicle) in a randomized, placebo-controlled, crossover study. Administration of L-NMMA resulted in significant reductions in plasma and urinary nitrite levels and plasma cyclic guanosine monophosphate (cGMP), indicating effective inhibition of nitric oxide synthase. L-NMMA also significantly reduced cardiac index (-13%) and increased systemic vascular resistance (+26%), arterial pressure (+9%), renal blood flow (+12%), glomerular filtration rate (+12%), and sodium excretion (+25%). Changes in sodium excretion were caused by both enhanced filtered sodium load and reduced sodium reabsorption in the proximal tubule. Plasma norepinephrine significantly decreased in response to L-NMMA, and there was a trend for reductions in PRA and PAC. Placebo had no appreciable effect on any of the measured parameters. These results indicate that in patients with compensated cirrhosis, portal hypertension and hyperdynamic circulation inhibition of nitric oxide synthase corrects the altered systemic hemodynamics and improves renal function and sodium excretion.

Randomized trial of adjuvant chemotherapy versus control after curative resection for gastric cancer: 5-year follow-up

Adjuvant chemotherapy of gastric cancer after curative resection is still subject to discussion. In this study 137 patients with gastric adenocarcinoma, all with positive nodes, were randomized after curative resection so that 69 received epidoxorubicin (EPI), leucovorin (LV) and 5-fluorouracil (5-FU) on days 1-3 every 3 weeks for 7 months, whereas the remaining 68 did not. After a follow-up period of 5 years, 21 of the 69 treated patients (30%) and nine controls (13%) were still alive; median survival time was 18 months for the controls and 31 months for the patients treated with adjuvant chemotherapy (P< 0.01).

Nocturnal melatonin patterns in children

Time patterns in nocturnal concentrations of circulating melatonin of children are quantified in 8 girls and 8 boys, 8.7-16.8 yr of age, classified by Tanner pubertal stage. Between 1900 and 0700 h, each provided blood samples at 30-min intervals for melatonin RIA. Associations with gender, body mass index, and chronological and pubertal age determined by multiple linear regression and ANOVA reveal that the area under the curve of 12-h melatonin concentrations was affected by pubertal rather than chronological age, an effect to which data collected during darkness contributed the most. Each data series was also analyzed by a least squares spectrum at frequencies of 1-20 cycles/day. Ultradian changes with periods of 3.4 and 1.5 h, putatively associated with rapid eye movement sleep cycles, characterize nocturnal melatonin in boys and girls.

ADMA correlates with portal pressure in patients with compensated cirrhosis

BACKGROUND

Chronic liver diseases are frequently complicated by portal hypertension, an important component of which is the increased intrahepatic vascular resistance, in part related to endothelial dysfunction. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, is an established mediator and marker of endothelial dysfunction. We therefore investigated the possible implication of ADMA in chronic liver diseases-induced portal hypertension.

MATERIALS AND METHODS

We studied 39 consecutive patients with compensated hepatitis C virus (HCV) related chronic liver diseases. All patients underwent hepatic venous pressure gradient (HVPG) measurement, and simultaneous blood sampling from the hepatic vein and the pulmonary artery, for ADMA and nitrite/nitrate (NOx) plasma level determinations.

RESULTS

A positive correlation between HVPG and ADMA concentrations in hepatic veins (ADMA-h) was found (r = 0.77, P < 0.0001). Moreover, a negative correlation between HVPG and NOx concentrations in the hepatic veins (NO-h) (r = -0.50, P = 0.005), and between ADMA-h and NO-h was observed (r = -0.40, P = 0.02). ADMA concentrations in pulmonary artery (ADMA-p) (0.55 +/- 0.13 micromol L(-1)) were significantly higher than in hepatic veins (0.47 +/- 0.09 micromol L(-1)) (P < 0.0001).

CONCLUSIONS

These results suggest that ADMA may play a pathophysiological role in portal hypertension by contributing to the relative intrahepatic NO deficiency typical of endothelial dysfunction.

Evidence for bone mass and body fat distribution relationship in postmenopausal obese women

The measurement of bone mass, a reliable predictor of osteoporotic fractures, in obese subjects has yielded conflicting results and bone mass has been reported to be elevated, normal or decreased. These observations indicate that factors other than body weight may be involved in the less risk for osteoporosis in obese subjects. In order to clarify the role of body fat distribution on bone density we studied sixty postmenopausal overweight/obese women with Body Mass Index (BMI) over 25 kg/m(2). Thirty five age-matched, nonobese postmenopausal women, served as controls. Bone mineral density (BMD) was measured at the proximal and ultradistal non dominant forearm using a double energy X-ray absorption (DEXA) apparatus. The waist/hip circumferences ratio (WHR) was used, in obese group, as an anthropometric estimation of the abdominal (WHR>0.85) to lower-extremity (WHR>0.85) fat proportion. The results were analyzed by Student t-test, ANOVA, and multiple linear regression analysis. No difference was found in BMD between obese group and controls, but a highly significant (P<0.001) positive correlation has been documented between proximal and ultradistal radius bone mineral density and waist/hip ratio in the obese group. Instead not significant correlation was found with BMI. Regional fat topography may influence the bone mass independently of total adiposity and visceral fat was the primary parameter accounting for higher bone mineral density values. These finding suggest that women with android-like obesity are protected from osteoporosis.

Influence of non-insulin-dependent diabetes mellitus on plasma endothelin-1 levels in patients with advanced atherosclerosis

Endothelin-1 (ET-1) is an endothelium-derived vasoactive peptide with mitogen properties. Increased circulating ET-1 levels were found in patients with atherosclerosis as well as in patients with non-insulin-dependent diabetes mellitus (NIDDM) suggesting a role in the pathogenesis of these disorders. The aim of the present study was to ascertain the influence of the NIDDM on plasma ET-1 levels in patients with advanced atherosclerotic lesions. The circulating ET-1 levels were measured in 16 NIDDM patients (68.4 +/- 8.4 years) with macroangiopathy and in ten patients (65.3 +/- 11 years) with atherosclerosis without NIDDM. Twenty-two healthy subjects (43.1 +/- 18.3 years) served as controls. Circulating ET-1 levels were higher in NIDDM patients (6.8 +/- 2.8 pg/mL) than both controls (3.1 +/- 1 pg/mL; p < 0.001) and patients with vascular disease but without NIDDM (4.7 +/- 1.6 pg/mL; p < 0.04). No significant relationship was found between age and ET-1 concentrations, and no differences were noted between men and women in the control group. This study demonstrated that circulating ET-1 levels are increased in patients with atherosclerosis and that those with NIDDM showed the highest ET-1 levels. These observations strongly support a role for ET-1 in the pathogenesis of atherosclerosis and also suggest that this peptide may be involved in the development of atherosclerotic lesions in the NIDDM. We speculated that chronic exposure to hyperinsulinemia and hypertriglyceridemia in the diabetic patients could account for the increased ET-1 levels found in these patients.

Liver failure complicating segmental hepatic ischaemia induced by a PTFE-coated TIPS stent

The use of polytetrafluoroethylene (PTFE)-covered prostheses improves trans-jugular intrahepatic porto-systemic shunt (TIPS) patency and decreases the incidence of clinical relapses and re-interventions. Therefore, the improvement provided by covered stents might expand the currently accepted recommendations for TIPS use. Stent-related occlusion of the hepatic vein with consequent ischaemia of the corresponding liver parenchyma emerges as a novel complication reported in at least 5% of patients implanted with coated stents. However, this complication was reported to be mild, without signs or symptoms of liver failure, and self-limiting. We report a case of segmental liver ischaemia following PTFE-covered stent placement resulting in a marked impairment in liver function in a patient with hepatitis C virus cirrhosis implanted because of refractory oesophageal bleeding, thus expanding the severity range of this new procedural complication. Moreover, we discuss the possible involvement of additional pathogenetic mechanisms other than out-flow obstruction in the onset of coated-stent induced congestive liver ischaemia.

Immune system alterations in lung cancer patients

The immune system plays an important role in the defense against neoplastic disease and immune responses show temporal changes related to circadian variations of antibodies, total lymphocytes in the peripheral blood and cell mediated immune responses. In this study we evaluate. lymphocyte subpopulations and interleukin-2 (IL-2) serum levels in peripheral blood samples collected at four-hour intervals for 24-hours starting at 06.00 h from ten healthy subjects aged 65-79 years (mean age +/- s.e. 67.28 +/- 3.11) and from ten subjects suffering from untreated non small cell lung cancer aged 65-78 years (mean age +/- s.e. 68.57 +/- 1.81). Areas under the curve, mean diurnal levels (mean of 06.00-10.00-14.00 h) and mean nocturnal levels (mean of 18.00-22.00-02.00 h) were calculated, and the presence of circadian rhythmicity was evaluate. When we compared AUC values there was a decrease in CD8bright (T suppressor subset) and an increase in CD16 (natural killer cells) and of IL-2 serum levels in cancer patients. When we compared mean diurnal levels, CD8 (T suppressor/cytotoxic subset) and CD8bright levels were lower, and CD16 levels were higher in cancer patients. When we compared mean nocturnal levels, CD16 and CD25 (T and B activated lymphocytes with expression of the a chain of IL-2 receptor) levels were higher, while CD8, CD8bright, CD20 (total B-cells), TcRd1 (epitope of the constant domain of d chain of T-cell receptor 1) and dTcS1 (epitope of the variable domain of d chain of T-cell receptor1) levels were lower in cancer patients. A clear circadian rhythm was validated for the time-qualified changes in CD4, CD20, HLA-DR with acrophase at night, and CD8, CD8 bright, CD8 dim, CD16, TcRd1 and dTcS1 with acrophase in the morning in the control group. A clear circadian rhythm was validated for the time-qualified changes in CD4 with acrophase at night, in the group of cancer patients. Results obtained in our study show that lung cancer is associated with anomalies of proportion and circadian variations of lymphocyte subsets that must be considered when adoptive immunotherapy has to be planned.

Endothelin-1's chronome indicates diabetic and vascular disease chronorisk

Plasma endothelin-1 was measured around the clock in 72 subjects. Cosinor methods were used to assess circadian and other recurrent variation and trends, that is, the time structure (chronome) of this peptide. Multifactorial analyses of variance and linear regressions assessed chronome alterations associated with different risk factors: diabetes, obesity, high cholesterol, high blood pressure, vascular disease, smoking, and age. The rhythm-adjusted mean (MESOR) of endothelin-1 is elevated in diabetes and vascular disease. Diabetes is also associated with a larger circadian amplitude. A circadian variation in a subgroup of low-risk subjects is modulated by components with both lower and higher frequency.

Circadian variations of cortisol, melatonin and lymphocyte subpopulations in geriatric age

A number of age-related changes in the 24-hour hormonal and non-hormonal rhythms have been found in older human beings. Lymphocyte subpopulations present circadian variation of some of their subsets and this variation may influence magnitude and expression of the immune responses. Numerous interactions exist among the nervous, endocrine and immune systems, mediated by neurotransmitters, hormones and cytokines. The aim of this study is to evaluate circadian variations of some endocrine and immune factors in older adults. Cortisol and melatonin serum levels were measured and lymphocyte subpopulation analyses were performed on blood samples collected every four hours for 24 hours from ten healthy young and middle-aged subjects and from ten healthy elderly subjects. There was a statistically significant difference between the groups in the observed values of CD20 (higher in young and middle-aged subjects) and CD25 and DR+ T cells (higher in elderly subjects). In the group of young and middle-aged subjects a clear circadian rhythm was validated for the time-qualified changes of all the factors studied. In the group of elderly subjects a number of rhythms were absent or altered. The results of the current study show that aging is associated with enhanced responsiveness of T cell compartment and alterations of circadian rhythmicity.

Genetic and environmental influences on human cord blood leptin concentration

OBJECTIVE

To examine in a population sample of cord blood the time structure (chronome) of leptin, an adipocyte-derived hormone, and to assess any effect of a familial history of noninsulin-dependent diabetes mellitus and obesity, separately, on both the maternal and the paternal side.

SUBJECTS AND METHODS

Leptin concentration was determined in cord blood from 93 infants. Effects of gender, gestational age, birth weight, maternal weight, familial antecedents of obesity and noninsulin-dependent diabetes mellitus, and circadian and about-yearly stage were assessed by linear regression and ANOVA.

RESULTS

Cord blood leptin concentration is elevated in the presence of a family history of obesity on the paternal side, but not on the maternal side. Leptin concentrations are higher in spring and summer than in fall and are higher in infants born before noon. In keeping with earlier work, leptin concentration in cord blood correlates positively with birth weight and height and is higher in infants who are appropriate for or large for gestational age than in infants who are small for gestational age or born prematurely.

DISCUSSION

Changes along the scales of the day and the seasons point to synchronizing environmental as well as genetic influence. An association of cord blood leptin concentration with obesity on the paternal side may help clarify the role of leptin in parental contributions to human obesity and may prompt focus on cholesterol metabolism.

Chronomics, neuroendocrine feedsidewards and the recording and consulting of nowcasts--forecasts of geomagnetics

A multi-center four-hourly sampling of many tissues for 7 days (00:00 on April 5-20:00 to April 11, 2004), on rats standardized for 1 month in two rooms on antiphasic lighting regimens happened to start on the day after the second extremum of a moderate double magnetic storm gauged by the planetary geomagnetic Kp index (which at each extremum reached 6.3 international [arbitrary] units) and by an equatorial index Dst falling to -112 and -81 nT, respectively, the latter on the first day of the sampling. Neuroendocrine chronomes (specifically circadian time structures) differed during magnetically affected and quiet days. The circadian melatonin rhythm had a lower MESOR and lower circadian amplitude and tended to advance in acrophase, while the MESOR and amplitude of the hypothalamic circadian melatonin rhythm were higher during the days with the storm. The circadian parameters of circulating corticosterone were more labile during the days including the storm than during the last three quiet days. Feedsidewards within the pineal-hypothalamic-adrenocortical network constitute a mechanism underlying physiological and probably also pathological associations of the brain and heart with magnetic storms. Investigators in many fields can gain from at least recording calendar dates in any publication so that freely available information on geomagnetic, solar and other physical environmental activity can be looked up. In planning studies and before starting, one may gain from consulting forecasts and the highly reliable nowcasts, respectively.

Circulating leptin levels in juvenile idiopathic arthritis: a marker of nutritional status?

BACKGROUND

Weight loss is common in juvenile idiopathic arthritis (JIA) and has been positively correlated with an increase in the production of proinflammatory cytokines.

OBJECTIVE

To assess if plasma leptin is a mediator of cytokine dependent decreased food intake during inflammatory diseases and if it is increased in JIA.

METHODS

Leptin levels were determined in 31 patients with polyarticular disease and in 37 with oligoarticular disease; 32 healthy children served as controls.

RESULTS

Patients had significantly reduced body mass index (BMI) compared with controls (17.3 (3) v 19.1 (3) kg/m(2); p<0.005). Leptin was significantly lower in patients than controls (8.1 (4.8) v 10.7 (7.3) ng/ml; p = 0.036), but leptin/BMI values were similar. Absolute (8.2 (4.8) v 8 (4.9); p>0.05) and normalised (0.45 (0.24) v 0.47 (0.24); p>0.05) leptin levels were not significantly different between patients with active and inactive disease and between patients with oligoarticular and polyarticular arthritis (7.8 (4.4) v 8.6 (5.3); p>0.05 and 0.45 (0.23) v 0.48 (0.26); p>0.05, respectively).

CONCLUSIONS

Leptin production per unit of fat mass is similar in patients and controls. The hypothesis that high levels of proinflammatory cytokines that characterise JIA might induce an increase of adipocytes leptin production is not supported by the results. Leptin may be a marker of nutritional status of JIA.

About-half-weekly (circasemiseptan) component of the endothelin-1 (ET-1) chronome and vascular disease risk

Plasma ET-1 was measured around the clock on different calendar dates in healthy subjects and in subjects with diabetes and/or with high blood pressure and/or a history of vascular complications (HVDR). A transverse approach, with each subject contributing a single 24-h mean, assessed any about-weekly or half-weekly variation in ET-1. A circasemiseptan component resolved by single cosinor for nondiabetic (but not for diabetic) HVDR subjects (p = 0.010) differs in its timing of overall high values (p < 0.050) from that found in healthy subjects (p = 0.006). The results are aligned with circasemiseptan patterns in other circulatory variables and morbidity/mortality statistics.

Feedsidewards: intermodulation (strictly) among time structures, chronomes, in and around us, and cosmo-vasculo-neuroimmunity. About ten-yearly changes: what Galileo missed and Schwabe found

The spectrum of biological rhythms is extended far beyond circadians, circannuals, and ultradians, such as 1.5-hourly melatonin and 8-hourly endothelin-1 (ET-1) rhythms by statistics of natality, growth, morbidity, and mortality, some covering decades or centuries on millions of individuals. These reveal infradian cycles to be aligned with half-weekly rhythms in ET-1, weekly and half-yearly ones in melatonin, and even longer--about 50-, about 20-, and about 10-year cycles found in birth statistics. About daily, weekly, yearly, and ten-yearly patterns are also found in mortality from myocardial infarctions; the 10-yearly ones are also in heart rate and its variability; in steroid excretion, an aspect of resistance, for example, to bacteria; and in the genetic changes of the bacteria themselves. Automatic physiological measurements cover years and, in one case, cover a decade; the latter reveal an about 10-year (circadecennial) cycle. ECGs, covering months beat-to-beat, reveal circaseptans, gaining prominence in response to magnetic storms or after coronary artery bypass grafting. A spectrum including cycles from fractions of 1 Hz to circasemicentennians is just one element in biological time structures, chronomes. Chaos, trends, and any unresolved variability are the second to fourth elements of chronomes. Intermodulations, feedsidewards, account for rhythmically and thus predictably recurring quantitive differences and even for opposite treatment effects of the same total dose(s) of (1) immunomodulators inhibiting or stimulating DNA labeling of bone in health or speeding up versus slowing down a malignant growth and thus shortening or lengthening survival time, or (2) raising or lowering blood pressure or heart rate in the vascular aspect of the body's defense. Latitude-dependent competing photic and nonphotic solar effects upon the pineal are gauged by alternating yearly (by daylight) and half-yearly (by night) signatures of circulating melatonin at middle latitudes and by half-yearly signatures at noon near the pole. These many (including novel near 10-yearly) changes, for example, in 17-ketosteroid excretion, heart rate, heart rate variability, and myocardial infarction in us and those galactic, solar, and geophysical ones around us have their own special signatures and contribute to a cosmo-vasculo-immunity and, if that fails, to a cosmo(immuno?) pathology.

Endothelin-1 and Paget's bone disease: is there a link?

The abundance of endothelial cells in bone marrow and the proximity of these cells to osteoclasts and osteoblasts suggest a role for endothelin-1 (ET-1) on bone metabolism. In vitro, the direct contact with bone endothelial cells induces osteoclastic progenitors to differentiate into mature elements. Recently it has been reported that ET-1 inhibits osteoclastic bone resorption and cell mobility through a specific receptor on osteoclasts; other authors demonstrated that ET-1 exerts a mitogenic activity on osteoblast-like cells (MC3T3) by stimulating tyrosin phosphorylation. We measured ET-1 circulating levels in patients with active Paget's bone disease, a condition with accelerated bone turnover. For the study we recruited 11 patients with Paget's bone disease (5F, 6M; mean age 68.2 +/- 3.6) in the acute stage of the disease; 10 healthy subjects (7F, 3M; mean age 66.5 +/- 3.9) were also enrolled as controls. Plasma ET-1 levels were measured with RIA kits provided by Nichols Institute. Patients showed significantly (P < 0.01) higher ET-1 circulating levels than controls (6.35 +/- 1.9 versus 3.4 +/- 1.2 pg/ml) with a positive correlation (r = 0.63; P = 0.038) with serum alkaline phosphatase (ALP), but not with urinary hydroxyproline. The higher levels of ET-1 in our patients suggest a physiopathological role for this peptide in the disease and, could perhaps represent a new useful marker of Paget's bone disease activity.

Different circulatory response to melatonin in postmenopausal women without and with hormone replacement therapy

In young men and women, melatonin influences vascular reactivity and reduces blood pressure and norepinephrine levels. Herein, we investigated whether these effects are conserved in postmenopausal women without and with hormone replacement therapy (HRT). Oral melatonin (1 mg) or placebo was randomly and in double blind fashion administered to 18 untreated and 13 postmenopausal women who were treated continuously with transdermal estradiol (50 microg/day) plus cyclic medroxyprogesterone acetate (5 mg/day x 12 days every 28 days). Internal carotid artery pulsatility index (PI), an index of downstream resistance to blood flow, blood pressure and catecholamine levels were evaluated. In untreated postmenopausal women, melatonin was ineffective, while in HRT-treated women, studied during the only estrogenic phase, melatonin reduced, within 90 min, systolic (-8.1 +/- 9.9 mmHg; P = 0.054), diastolic (-5.0 +/- 7.0 mmHg; P = 0.049) and mean (- 6.0 +/- 6.6 mmHg; P = 0.037) blood pressure. Norepinephrine (-50.1 +/- 66.7 pg/mL; P = 0.019), but not epinephrine levels, were also significantly reduced. Similarly, resistance to blood flow in the internal carotid artery, as evaluated by the PI, decreased (-0.190 +/- 0.15; P = 0.0006) in a way that was linearly related to pre-existing PI values (r2 = 0.5; P = 0.0059). These data show that the circulatory response to melatonin is conserved in postmenopausal women on HRT but not in untreated postmenopausal women. Possible physiological and pharmacological implications of these data on the cardiovascular risk of postmenopausal women can be envisioned.

Circasemidian rather than circadian variation of circulating osteoprotegerin in clinical health

Osteoprotegerin (OPG) serves as a soluble decoy receptor for RANKL to inhibit osteoclast formation and activity. Hormones such as PTH and glucocorticoids have been reported to decrease OPG concentrations, while estrogens, transforming growth factor b, related bone morphogenic factor and thrombopoietin reportedly enhance the OPG production in the osteoblastic and bone stromal cells. Since bone turnover shows a prominent circadian rhythm in laboratory animals and humans, with bone resorption increasing at night, we investigated the time structure of circulating OPG concentrations in a group of nine healthy subjects (six women and three men; in the age range of 26-49 years). Blood samples for OPG determination were collected every 4 h for 24 h on the same day, starting at 08:00 in the morning. Data were analyzed by inferential statistical procedures, including the single and population-mean cosinor. A 12-h component was found to characterize serum OPG concentrations (P = 0.038) with peak concentrations around noon and midnight. No statistically significant circadian rhythm of OPG concentrations could be found by cosinor in our study population. The mean 24-h OPG concentration was higher in women than in men (mean +/- S.E.: 3.13 +/- 0.44 vs. 1.94 +/- 0.26 pmol/l, Student t = 2.325, P = 0.053). Since PTH concentrations also exhibit a bimodal pattern along the 24-h scale, PTH may be tested as a putative determinant of the observed changes in serum concentrations of osteoprotegerin.

Adiponectin and the cardiovascular system: from risk to disease

Adiponectin is known to play a role in fatty acid and glucose metabolism through a change in insulin sensitivity and activation of fuel oxidation by AMP-activated protein kinase. Adiponectin can be considered an important factor able to modulate the adipovascular axis which, through genomic and environmental influences, affects the cardiovascular risk milieu, from the pre-metabolic syndrome-- through the metabolic syndrome--to the overt atherosclerotic process and its clinical manifestations. Hypoadiponectinaemia can be viewed as an early sign of a complex cardiovascular risk factor predisposing to the atherosclerosis process as well as a contributing factor accelerating the progress of the atherosclerotic plaque. In addition, adiponectin per se holds a protective role thanks to its anti-inflammatory and antiatherogenic properties. The early identification of patients "at cardiovascular risk" means in the current practice to search for indexes of metabolic derangements and pro-inflammatory status (adiponectin) from adolescence and childhood.

Change of γδTCR-Expressing T Cells in Healthy Aging

A mature T-cell lineage with the capacity to proliferate in response to receptor-mediated signals and to display non-major histocompatibility complex (MHC)-restricted cytolysis expresses a CD3-associated heterodimer made up of the protein encoded by the T-cell receptor (TCR) gamma-gene. We investigated the possible differences in lymphocyte subpopulations between healthy young-middle-aged and elderly subjects, focusing attention on y8-TCR-expressing cells. The study was carried out on fifteen healthy young-middle-aged male subjects (age range 36–55 years) and fifteen healthy elderly male subjects (age range 67–79 years). Lymphocyte subpopulations were analyzed in blood samples collected every four hours for 24 hours. The presence of circadian rhythmicity on absolute counts was validated to evaluate the periodicity of variation, and the fractional variation between single time point values was calculated to evaluate the dynamics of variation. In the group of young and middle-aged subjects a clear circadian rhythm was validated for the time-qualified changes of all the lymphocyte subpopulations (CD3, CD4, CD4/CD8 ratio, CD20, CD25 and HLA-DR with acrophase at night, CD8, CD16 and TcRγδ with acrophase at noon). In the group of elderly subjects a clear circadian rhythm was validated for the nyctohemeral changes of CD3, CD8, CD4/CD8 ratio, CD 16, CD25. There was a statistically significant difference for the Midline Estimating Statistic of Rhythm (MESOR) of CD3 (p=0.001), CD25 (p=0.003) and γδ-TCR- expressing cells (p=0.004), higher in the elderly, and for the MESOR of HLA-DR (p=0.002) and CD20 (p=0.002) higher in the young and middle-aged subjects. There was a statistically significant difference between the groups in the fractional variation of TcRγδ-expressing cells between 18:00h and 22:00h values (higher in elderly subjects, p=0.007). In conclusion, specific lymphocyte subsets present different levels and different profiles of nyctohemeral changes in healthy young-middle aged in respect to elderly subjects, since B cells are decreased, whereas CD25 and γδ-TCR-bearing cells are higher in the elderly, but the rhythm and the dynamics of variation of this lymphocyte subset is severely altered and this phenomenon might contribute to the onset of age-related variations of the immune responses.

Daytime Circulating Melatonin Levels in Smokers

Aims and background

Melatonin secretion is required to be a potential inhibitor of the development and growth of tumors, and cigarette smoking is a well established risk factor for cancer at various sites.

Methods

Circulating melatonin levels of 20 smokers and 20 non smokers (controls), sampled at the same hour from awaking in order to obtain a comparable circadian synchronization, were compared.

Results

Our data showed higher melatonin circulating levels in smokers (17.44 ±1.8 pg/ml) than in nonsmokers (9.77 ± 1.4 pg/ml).

Conclusions

The causes, mechanism and meaning of this phenomenon are still unknown. The most actractive hypothesis considers higher melatonin levels in smokers as an attempt to counterbalance cellular growth stimulus, a natural “brake” mechanism to restrain the proliferation of normally differentiated tissues: smoke is a prominent risk factor for several different tumors.

Angiopathy affects circulating endothelin-1 levels in type 2 diabetic patients

To evaluate the role of endothelin-1 (ET-1), a vasoconstrictor and mitogenic peptide synthesized by endothelial cells, on the endothelial dysfunction in non-insulin-dependent diabetic (type 2) patients, we have measured the circulating ET-1 levels in 25 patients with and without clinically evident vascular complications and in a control group. Circulating ET-1 levels were significantly higher in diabetic patients with angiopathy than in diabetics without angiopathy and in controls (7.02 +/- 2.9 pg/ml vs 4.4 +/- 1.1 pg/ml and 3.08 +/- 0.7 pg/ml, respectively; P < 0.001). No difference was demonstrated between diabetic patients without angiopathy and controls. These findings suggest that ET-1 may be a marker for arterial vascular disease only in patients with overt angiopathy. It is unclear whether it participates in the endothelial injury process or it is merely released from damaged endothelial cells.

Hormone and cytokine circadian alteration in non-small cell lung cancer patients

Alterations in hormone secretion and cytokine levels have been evidenced in many neoplastic diseases. In this study we have evaluated the circadian profile of growth hormone (GH), insulin-like growth factor-1 (IGF-1), interleukin-2 (IL2), melatonin (MEL) and cortisol (COR) serum levels in non-small cell lung cancer patients. Blood was sampled every 4 h for 24 h in 11 healthy (H) men (ages 35-53 years) and 9 men with stage 2, 3 or 4 non-small cell lung cancer (C) (ages 43-63 years). Serum GH, total IGF1, IL2, MEL and COR were measured and examined for group differences, trends, and rhythm characteristics. 24-h means were significantly higher in C234 vs H for GH, GH/IGF1, IL2 and COR, and lower for IGF1, but IL2 and COR were not different for C23 vs H. A linear regression across 4 groups (H, C2, C3, C4) found a positive trend for COR, GH, GH/IGF1 and IL2, and a negative trend for IGF1. A linear regression run between the 24-h mean levels of GH, IGF1, COR, MEL and IL2 in healthy subjects evidenced a statistically significant positive trend between MEL and GH (R = 0.281, p = 0.022) and in cancer patients showed a statistically significant negative trend between GH and IGF1 (R = 0.332, p = 0.01), COR and IGF1 (R=0.430, p=0.001), and a statistically significant positive trend between the 24-h mean of COR and GH (R = 0.304, p = 0.02). Rhythms in MEL and COR (peaks near 01:00h and 08:00h, respectively) indicated identical synchronization to the light-dark cycle for both groups. A circadian rhythm was detected in GH and GH/IGF1 for C23 and H, with IGF1 and IL2 non-rhythmic in any group. In conclusion, an increasing trend and progressive loss of circadian rhythmicity in GH and GH/IGF1, an increasing trend in cortisol and IL2, and a decreasing trend in IGF1 in C, reflect a complex chain of events that could be involved in progression of neoplastic disease. A therapeutic strategy needs to take into account circadian patterns and complex interactions of the multiple functions that characterize the hormone and cytokine levels in the frame cancer progression.