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Biomedical subjects

R Artese

Publications and source records attributed to R Artese.

14 recordsLinked to original sources

Altered circadian blood pressure profile in patients with active acromegaly. Relationship with left ventricular mass and hormonal values.

To determine the relationships between the circadian blood pressure profile and left ventricular mass, hormonal pattern and insulin sensitivity indices in patients with active acromegaly, ambulatory 24-h blood pressure monitoring (ABPM) was recorded in 25 subjects (47.0 +/- 15.1 years, range 23-72). Serum growth hormone (GH) and insulin-like growth factor-1, fasting and mean plasma glucose and insulin during oral glucose tolerance test (OGTT), insulinogenic index, the sum of the plasma insulin levels and the homeostasis model insulin resistance index (Homa's index) were determined. Left ventricular mass index (LVMI) was calculated from two-dimensional guided M-mode echocardiogram. The prevalence of hypertension was 56% (n = 14) and 40% (n = 10) according to sphygmomanometric measurements and ABPM, respectively. Non-dipping profile was observed in six of 10 hypertensives and in six of 15 normotensives. Serum growth hormone, fasting glucose, the area under the serum insulin curve and LVMI were higher for acromegalics with non-dipping profile than for dippers (all of them, P < 0.05). In non-dippers daytime heart rate was higher than night time (P < 0.001). In conclusion, the main observations in the present study suggested that both normotensive and hypertensive acromegalics had a highly prevalent non-dipping profile with a preserved circadian pattern of heart rate, that was associated with higher levels of serum GH. The disturbance in nocturnal blood fall in normotensives was associated with a decreased insulin sensitivity. The role of GH in blood pressure circadian rhythm regulation in essential hypertension deserves further studies.

Acromegaly↗

[Hyperprolactinemia in subclinical hypothyroidism].

Most patients with subclinical hypothyroidism are asymptomatic; however, when this disorder is associated with alterations of the lactotroph, clinical and biochemical manifestations are evident, along with involvement of the gonadotrophic function. In this report, we selected 11 women with hypothyroidism, 5 of them in stage I and 6 in stage II. In all of them, the thyroid function was altered while the most affected was the gonadal axis. The available literature on this subject is scarce, so that we propose a systematic investigation in order to exclude other associated disorders.

Adolescent↗

Alpha subunit of glycoprotein hormones in the sera of acromegalic patients and its mRNA in the tumors.

Within a population of 16 pituitary adenomas we found high levels of glycoprotein alpha subunits in the sera of patients with somatotrophic tumors. This finding was correlated with the presence of mRNA alpha subunit in these tumors indicating the adenomas themselves as the origin of the circulating alpha-subunit. Synthesis of these two hormones, which are chemically very different, by the same tumor cells indicates a high degree of differentiation of these cells. We are unable at this time to conclusively correlate differentiation of these tumors aggressively.

Acromegaly↗

Expression of c-myc and c-fos and binding sites for estradiol and progesterone in human pituitary tumors.

We studied the concentration of mRNA from the oncogenes c-myc and c-fos in human pituitary adenomas by Northern blot hybridization (35 somatotrophinomas, 9 prolactinomas, 21 nonsecreting and 3 adrenocorticotrophinomas). The concentration of estrogens and progesterone receptors was also investigated. The levels of c-myc and c-fos mRNA was higher in nonsecreting tumors which were generally the largest and had a higher percentage of recurrence after surgery than the other groups. High concentration of estrogen receptors was observed in tumors derived from cells which are normally the target of this hormone, mainly prolactinomas. They were also present in somatotrophic and nonsecreting adenomas, related to the presence of prolactin or gonadotrophin cells in these tumors. The presence of estrogen receptors indicates that the tumor cells maintain their differentiation and a good prognosis as is the case for prolactinomas. We did not find any relationship between estrogen receptors and the concentration of c-myc and c-fos oncogenes. Larger adenomas (mainly nonsecreting) had higher levels of c-myc and c-fos mRNA than the other tumors and they had an important percentage of recurrence after surgery. It is clear that tumor size is related to the outcome after surgery and that nonsecreting adenomas are usually large because of the late diagnosis. However two large somatotrophinomas with extrasellar expansion also had overexpression of both oncogenes and both relapsed after surgery.

Adenoma↗

Pituitary tumors in adolescent patients.

We report on a series of 48 patients, ages 14 to 20 year, with hypophyseal adenomas. Of these, 46 (96%) had secreting tumors, 3 had Cushing's disease, 9 had somatotrophinomas, and 34 (29 females and 5 males) had prolactinomas. Thirty cases were diagnosed as intrasellar adenomas (62%) while the remaining eighteen (38%) presented extrasellar expansion. Of 9 acromegalic patients, 7 had typical clinical and biochemical features 2 were exclusively prognatic with normal basal GH levels, but abnormal dynamic tests. Prolactinomas were noninvasive in women and faster growing and more extensive in men. Forty seven patients underwent surgery. Five of these required craniotomy and the rest approached through the sphenoidal bone (TSE). Remission was achieved in Cushing's disease, acromegaly, and female intrasellar prolactinomas. Larger tumors such as nonsecreting adenomas and male prolactinomas showed poor results after undergoing subtotal resections, with persistence of endocrinological disturbances. From our findings it appears that these tumors are aggressive in youth than in adults. Because there was a close relationship between tumor size, invasiveness, and the patients' final outcome, we conclude that early diagnosis and treatment is essential. Frequent complaints in adolescents such as irregular menses, retarded puberty, and growth disorders should be thoroughly investigated and not merely considered as transient or 'functional'.

Acromegaly↗