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Biomedical subjects

F Fraschini

Publications and source records attributed to F Fraschini.

229 records · Page 13Linked to original sources
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Serum levels of melatonin in cancer patients and their relation to body sizes.

Melatonin secretion is often enhanced in patients with cancer. In the light of a reported correlation between melatonin levels and body size, we investigated blood levels of this pineal hormone in a group of 72 patients affected by cancer, 30 of whom had body weight within the normal range, 30 were obese and the last 12 cases had body weight below the normal range, in order to establish whether in fact melatonin blood concentrations were related to body size. Melatonin levels were high in 19/72 patients (26%). The mean levels of the pineal hormone were similar in patients with normal, low and high body weight. Finally, there was no significant correlation between melatonin values and body weight, height or surface. Melatonin secretion thus does not appear to be influenced by body size in cancer patients.

Body Constitution↗
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[Non-visual effects of light mediated via the optical route: review of the literature and implications for occupational medicine].

Artificial light which now plays an essential role in industrialized society differs from natural light both in intensity which is usually lower, and in spectrum, which is usually smaller. It is now a well-known fact that the human body is able to use luminous stimulation for aims other than sight; the pineal gland, though no longer directly sensitive to light as in lower animals, is nevertheless the fulcrum of a complex neuro-endocrine system which makes an interaction between light and the human body possible by means of the production of a number of substances of which melatonin is the most widely investigated. Melatonin is secreted at a circadian rhythm characterized by high nocturnal seric levels and low diurnal levels. This secretion appears to be correlated not only with the intensity of the light but also with its spectrum and time exposure. Even though the function of melatonin is still not fully understood, it seems possible to assign a mainly modulatory role to the pineal gland and melatonin. On the basis of studies performed on the pituitary-gonadal and/or hypothalamic axis and the reproductive system in animals, melatonin would appear to affect some endocrine functions (i.e., puberty) in man, too. Changes in melatonin secretion have been found in psychiatric illness, especially in cyclical affective disorders. Melatonin seems to be involved in stress-associated mechanisms, probably with an agonistic role, and also in carcinogenesis, where it seems to play a role in the growth of several tumors. Melatonin also affects both tumoral and cellular immune responses. Lastly, melatonin may be able to reduce the symptoms of the Jet Lag Syndrome. The consequences that prolonged and marked reduction in daylight exposure for occupational reasons could have on operators, especially young people, therefore constitute an interesting subject for occupational health; environmental photometry at the work-place, if adequately performed, could make a useful contribution to the development of this field of research.

Adolescent↗
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[Changes in hormonal and biochemical parameters in gastric adenocarcinoma].

In 51 patients with gastric adenocarcinoma the fasting blood concentrations of hCG, beta hCG, alpha subunits, ADH, calcitonin, enteroglucagon, gastrin, GH, melatonin, somatostatin, estradiol, CEA and pepsinogen I in the peripheral vein were estimated by radioimmunoassay at the time of diagnosis and, in those who underwent surgery, 7 days after the operation, to determine the incidence of the modifications of the above mentioned substances' blood levels and the existence of possible markers. In presence of increases of the examined parameters greater than 50%, considering M +/- 2 SD of 10 control subjects as normal range, the tumours were examined immunohistochemically. In patients with gastric adenocarcinoma, in comparison with normal subjects, we found significant higher blood levels of hCG alpha subunits, gastrin and CEA and lower of melatonin, pepsinogen I and GH. The immunohistological results demonstrated CEA in both examined cases, alpha subunits in 2 of 6 (respectively in dysplasic areas and in surrounding non neoplastic mucosa) and enteroglucagon in 1 of 3 (dysplasic areas). Our results indicate that none of the parameters we examined, because of their non-specificity or of the low incidence of their modifications, can be considered a marker of gastric adenocarcinoma.

Adenocarcinoma↗
PubMedDate not supplied

Ultradian chronomodulation by melatonin of a Placebo effect upon human killer cell activity.

The effect of melatonin injection evaluated earlier with respect to placebo-treated controls is reevaluated, also with reference to spontaneous changes in natural killer cell activity. This effect consists, first, of stimulation of natural killer cell activity over and above any changes brought about by placebo (saline). After 6 h, the melatonin effect appears to be an inhibition as compared to values from placebo-treated subjects, or no effect as compared to values from untreated subjects. In this case, amplification and attenuation of the placebo effect by melatonin are found within the relatively short span of 1/4 of a day, rather than within a day or a week. An ultradian 'feed-sideward' by melatonin may be aligned with the corresponding previously reported circadian and infradian chronomodulation.

Activity Cycles↗
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Chemotherapeutic agents and future fertility.

The recent progress in antiblastic therapy has achieved significant successes in the treatment of tumors, obtaining in some cases a complete recovery and very frequently a remission of the disease for a considerable number of years. Therefore the clinician has to deal with the problem of long term toxicity which always accompanies these therapies. This aspect was once considered as a secondary feature in respect to the severity of prognosis quod vitam of the subjects affected with cancer, while now, with a significant increase of survival, it is preeminent that there be the possibility to offer these patients an acceptable quality of life under both physical and social profiles. The reintroduction of patients affected with cancer or treated ones into their social and familiar functions must take into account many factors which are bound to the degree of physical integrity, to psychological conditioning and problems of resumption of working activity. Under a strictly social profile it is fundamental to have knowledge of troubles and disturbances that may involve the reproductive sphere.

Antineoplastic Agents↗
PubMedDate not supplied

High affinity melatonin receptors in the vertebrate brain: implications for the control of the endogenous oscillatory systems.

Currently, the melatonin receptor is depicted as a membrane-associated protein, linked to a guanine nucleotide-binding protein (G-protein), and thus the melatonin receptor represents a member of a receptor superfamily, acting through G-proteins in the first step of their signal-transduction pathways. Although on a number of occasions specific binding of radioactive melatonin has been demonstrated in a wide variety of tissues and organs, to date, high affinity G-protein-regulated melatonin binding sites, suggestive for a functional melatonin receptor, have been convincingly confirmed in the brain only. There is a significant species variation in the distribution of the melatonin receptor in the vertebrate brain. The limited number of studies prevents any definitive conclusion in terms of phylogeny, though generally speaking, the lower vertebrates' brains tend to express melatonin receptors with wider distribution. Two sites have been consistently found to express high density of melatonin receptors: the pars tuberalis of the adenohypophysis and the hypothalamic suprachiasmatic nuclei (SCN). It must be pointed out, however, that there are some exceptions. Binding in the human pars tuberalis has not been reported, and apparently, the sheep and the mustelids' suprachiasmatic nuclei do not express detectable binding. The function of melatonin in pars tuberalis is unclear, and the control of the synthesis (and release) of paracrine factors that act at site(s) distant from the melatonin target cells, have been suggested.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗