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Biomedical subjects

E Galbiati

Publications and source records attributed to E Galbiati.

At least 19 recordsLinked to original sources
PubMed2004

Mast cell--pituitary interaction: modulation by serine phospholipids.

The influence of mast cell activation on the secretion of prolactin has been studied in rats receiving lysophosphatidylserine, a natural occurring phospholipid with secretagogue activity in these cells. After the i.v. injection of lysophosphatidylserine (10 mg/kg) a plasma prolactin peak correlates with an increased blood histamine level. Following the secretory event, which is inhibited by the H1 anti-histamine tripelenamine, plasma prolactin level drops below the basal line. Repeated lysophosphatidylserine administrations induce mast cell desensitisation, thus reducing also the pituitary response. Under these conditions a decrease in prolactin basal level is still observed, although the pituitary stores of this hormone are preserved. Control tests in vitro with lysophosphatidylserine, show that the diacyl lysophosphatidylserine derivative amplifies the inhibitory effect of dopamine on prolactin secretion from isolated pituitaries. The data suggests that lysophosphatidylserine induces prolactin secretion through mast cell activation. After this event, the reacylation of this phospholipid into lysophosphatidylserine in the pituitary membrane may enhance the inhibitory control by dopamine.

Animals↗
PubMed2003

Bone mineral density and bone metabolism in Duchenne muscular dystrophy.

Very few studies on bone mineral density and bone metabolism in Duchenne muscular dystrophy (DMD) have been reported. DMD is a severe, progressive muscular disease resulting in death at a young age. No specific therapies are available, but corticosteroids induce improvement and slower progression of the disease. However, long-term steroid therapy is a serious risk factor for osteoporosis. This study was aimed at evaluating bone mineral density and calciotropic hormones in a group of children affected by DMD, with or without steroid therapy. Bone mineral density was measured by DXA scan on lumbar spine and total body. Evaluation of calcium, phosphorus, bone turnover markers and calciotropic hormones was performed. Thirty-two children affected by DMD were studied: twenty-two on long-term prednisone therapy, ten not taking corticosteroids. Bone mineral density was lower than normal for age in all patients, and even lower in the group of steroid-treated children. Trunk and lower limb bone mineral densities were more reduced than upper limb mineral density, especially in the steroid-treated subjects. A marked reduction in spine bone mineral density, hypocalciuria, low 25-hydroxyvitamin D levels, and increased bone turnover markers were observed, and even these especially in the steroid-treated group. In conclusion, decreased bone mineral density and derangement of calcium metabolism were present in DMD patients, and were worsening during corticosteroid therapy. It is thus recommended that bone and mineral metabolism be carefully evaluated in patients with DMD, so that appropriate measures could be taken, especially now that chronic corticosteroid therapy is frequently given.

25-Hydroxyvitamin D 2↗
PubMed2001

Effects of 12-month GH treatment on bone metabolism and bone mineral density in adults with adult-onset GH deficiency.

Serum bone-Gla protein (BGP), bone alkaline phosphatase (B-AP), and C-terminal cross-linked telopeptide of type I collagen (ICTP) levels were evaluated in 18 adults with acquired GH deficiency (GHD, 14 males and 4 females, age range: 25-59 yr) before, at 3, 6, 9 and 12 months of rec-GH treatment (0.125 IU/kg/week for the first month, followed by 0.25 IU/kg/week for 11 months) and 6 months after the withdrawal of therapy. Total body bone mineral density (BMD, g/cm2) was measured with dual energy X-ray absorptiometry (Hologic QDR 1000/W) before, at 12 months of GH treatment and 6 months after its withdrawal. Before treatment, BGP (mean+/-SE: 5.1+/-0.4 ng/ml), B-AP (59.4+/-6.5 IU/l), ICTP (3.1+/-0.3 ng/ml) levels of patients were similar to in healthy controls (BGP: 5.4+/-0.1 ng/ml; B-AP: 58.2+/-2.0 IU/l; ICTP: 4.1+/-0.3 ng/ml). GH treatment caused a significant increase of BGP, B-AP, ICTP levels, the maximal stimulation of bone resorption, occurring after 3 months of GH treatment, while the maximal effect on bone formation being evident later (at 6th month). A slight decline in BGP, B-AP, T-AP and ICTP levels occurred at 9-12 months of therapy, although the values remained significantly higher than in basal conditions and with respect to healthy controls. Before treatment, mean total body BMD of patients (1.110+/-0.027 g/cm2, range: 0.944-1.350 g/cm2) was not significantly different (z-score: +0.47+/-0.31, NS) from that observed in healthy controls (1.065+/-0.008 g/cm2, range: 1.008-1.121 g/cm2). GH therapy was associated with a significant reduction of mean total body BMD values (6th month: -1.8+/-0.5%, p<0.01; 12th month: -2.1+/-1.0%, p<0.05 vs baseline), particularly evident in the first six months of treatment. Six months after the withdrawal of GH therapy, BGP (5.9+/-0.5 ng/ml), B-AP (57.3+/-7.0 IU/l) and ICTP (3.2+/-0.1 ng/ml) levels returned similar to those recorded before treatment, while total BMD increased (+1.5+/-0.7, p<0.05), remaining however slightly lower than in basal conditions (-0.6+/-1.2, NS). In conclusion, our study shows that: a) acquired GHD in adulthood is associated with both normal bone formation/resorption indexes and normal total body BMD; b) GH therapy causes a significant rise of bone formation/resorption markers (earlier and greater for bone resorption); c) one-year GH therapy is associated with a reduction of total body BMD values, particularly evident in the first 6 months of treatment; d) the effects of GH therapy on bone turnover are transient, being completely reverted six months after the withdrawal of GH therapy; e) the increase of total body BMD (up to baseline values) after GH withdrawal might be explained as consequence of persisting effects of previous GH stimulation on bone remodeling.

Absorptiometry, Photon↗
PubMed2001

Leukotriene D4-induced activation of smooth-muscle cells from human bronchi is partly Ca2+-independent.

Cysteine-containing leukotrienes (cysteinyl-LTs) are potent bronchoconstrictors and play a key role in asthma. We found that histamine and LTD4 markedly constrict strips of human bronchi (HB) with similar efficacy. However, in human airway smooth-muscle (HASM) cells, LTD4, at variance with histamine, elicited only a small, transient change in intracellular calcium ion concentration. HASM cells express both Ca2+-dependent and -independent isoforms of protein kinase C (PKC) (i.e., PKC-alpha and PKC-alpha ). Western blot analysis showed that PKC-alpha is activated by histamine and, to a lesser extent, by LTD4, whereas only LTD4 translocates PKC-alpha. This translocation was specifically inhibited by the LTD4 antagonist pobilukast. Phorbol-dibutyrate ester (PDBu) (a PKC activator) contracted HB strips to the same extent in the presence as in the absence of extra- and intracellular Ca2+. In the absence of Ca2+, LTD4 contracted HB strips to the same extent as did PDBu, suggesting the involvement of a Ca2+-independent PKC in LTD4-mediated signal transduction. PDBu-induced desensitization and the PKC inhibitor H7 abolished the slow and sustained LTD4-triggered contraction of HB strips in the absence of Ca2+, although H7 did not greatly affect the response in the presence of the ion. Thus, in human airways, we identified a novel LTD4 transduction mechanism linked to bronchial smooth-muscle contraction, which is partly independent of Ca2+ and involves the activation of PKC-alpha.

Bronchi↗
PubMed2000

Efficacy and safety of alendronate for the treatment of osteoporosis in diffuse connective tissue diseases in children: a prospective multicenter study.

OBJECTIVE: Osteopenia/osteoporosis is being increasingly reported as a complication of many chronic diseases, even in children. In this preliminary study, we evaluated the effect of an oral bisphosphonate (alendronate) on bone mass in children with diffuse connective tissue diseases. METHODS: Thirty-eight children with low bone mass were treated with alendronate for 1 year; 38 children who had the same primary disorders as the study patients but in a less severe form served as untreated control patients. We were also able to evaluate changes in bone mass (before and after alendronate) in 16 of the treated patients whose bone mineral density (BMD) had been routinely measured before the present study was initiated. RESULTS: BMD increased by a mean +/- SD of 14.9 +/- 9.8% (P < 0.002 versus baseline) in the treated patients (reaching the normal range in 13 patients), while the BMD was 2.6 +/- 5% (not significant versus baseline) in the control group (15 had a decrease). Most interestingly, there was a large increase in BMD (15.3 +/-9.9%) after alendronate therapy in the 16 children who had their BMD followed up in the year before the study, during which time they had shown little increase in BMD (1.03 +/- 6.3%), and often a decrease. Considering their condition, increases in the height of all patients was satisfactory. No new fractures were observed after alendronate therapy was initiated. CONCLUSION: Bisphosphonates can be considered essential components of the treatment of secondary osteoporosis, not only in adults, but also in pediatric patients. Alendronate has a positive effect on secondary osteopenia/osteoporosis in children with connective tissue diseases.

Adolescent↗
PubMed1999

Bone mass change during methotrexate treatment in patients with juvenile rheumatoid arthritis.

Thirty-two children affected by juvenile rheumatoid arthritis (JRA) were studied with serial measurements of bone mass for an average of 18 months, to evaluate the effects of long-term methotrexate (MTX) treatment on bone. Bone mineral density (BMD) was measured on lumbar spine and total body. During MTX therapy some increase in BMD was observed, though this was smaller than in a control group of healthy children. Axial (spine and trunk) and appendicular (upper and lower limbs) BMD showed similar increases. BMD, either as an absolute value or as a percent variation from baseline, did not correlate with either MTX dose or length of therapy. In children treated also with corticosteroids, these drugs negatively influenced bone mass increase. The main determinant of absolute spine BMD value appeared to be weight, while height and lean mass seemed to be the determinants of total body BMD. Pubertal stage and disease activity significantly influenced the yearly change in BMD. In conclusion, our data suggest that long-term, low-dose therapy with MTX does not induce osteopenia in children with JRA.

Adolescent↗
PubMed1996

Effects of recombinant growth hormone (GH) treatment on bone mineral density and body composition in adults with childhood onset growth hormone deficiency.

Lumbar spine, whole proximal femur and total body bone mineral density (BMD, g/cm2) and the regional soft tissue composition were measured with dual energy X-ray absorptiometry (Hologic QDR 1000/W) in eight adults with childhood onset GHD, before and after 6 months of recombinant GH treatment (0.5 IU/kg/week). Data obtained from patients were compared with those recorded in an age and sex matched control group. Before treatment, lumbar (L2-L4) spine BMD (mean +/- SD: 0.811 +/- 0.159 g/cm2), whole proximal femur BMD (0.739 +/- 0.094 g/cm2) and total body BMD (0.946 +/- 0.087 g/cm2) of patients were significantly (p < 0.001, 0.01 and 0.001, respectively) lower than those recorded in an age- and sex-matched control group (1.077 +/- 0.155 g/cm2, 0.968 +/- 0.166 g/cm2 and 1.168 +/- 0.058 g/cm2, respectively), although three patients showed BMD values at the lower limit of the normal range. Mean lumbar spine BMD, whole proximal femur BMD and total body BMD did not significantly change alter 6 months' GH treatment (-1.4 +/- 3.7%, +2.7 +/- 3.7% and -1.1 +/- 5.0% vs basal values, respectively). On the other hand, trochanteric subregion showed a significant 4.8 +/- 5.3% increase (vs basal, p < 0.05), while other hip subregions did not show significant changes. GH therapy caused marked effects on body composition; in fact, a significant decrease (p < 0.01) of trunk fat (-25.2 +/- 15.0%) and a marked increase (p < 0.01) of limbs lean mass (+10.0 +/- 5.3%), resulting in a significant (p < 0.02) reduction (-16.5 +/- 13.5%) of the axial to peripheral fat ratio (APFR), were clearly evident after six months of therapy. In conclusion, our study shows that six months of GH treatment do not exert relevant effects on the BMD of adults with childhood onset GHD. On the contrary, the effects of GH therapy on body composition are more marked, being clearly appreciable after six months of treatment.

Adult↗
PubMed1995

Effects on bone mineral density of 12-month goserelin treatment in over 40-year-old women with uterine myomas.

We evaluated the effects on bone mineral density (BMD) of a 12-month treatment with goserelin depot, a gonadotropin-releasing hormone agonist, in a group of women with symptomatic uterine myomas requiring hysterectomy. Sixteen women, mean age 45.6 +/- 5.0, reporting menorrhagia associated with uterine myomas, candidates for hysterectomy, were scheduled to be treated with goserelin depot for 12 months. BMD was measured at the vertebral (L2-L4) and proximal femur level (femoral neck and trochanter) at the start of therapy and 6, 12, and 18 months later using dual energy X-ray absorptiometry (Hologic QDR 1000/W). The patients were followed for a minimum of 6 months after the end of treatment. Thirteen of the 16 women enrolled completed the treatment and three suspended it after 5, 6, and 7 months, respectively, because of side effects (hot flashes, insomnia, depression). Of the 13 women who completed the treatment, three underwent hysterectomy because of myoma regrowth and the recurrence of symptoms 3-18 months later; four reached the menopause 5-16 months later, and six were all menstruating normally with a follow-up varying from 6 to 18 months. After 12 months of therapy we observed a bone loss at vertebral, femoral neck, and trochanter of 4.4% (P < 0.05 versus baseline; P = not significant versus 6 months), 7.5% (P < 0.01 versus baseline, P < 0.01 versus 6 months), and 7.6% (P < 0.001 versus baseline, P < 0.05 versus 6 months), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Sexually dimorphic effects of aging on rat somatotropes and lactotropes.

During the aging process modified functions of hypothalamic factors may cause sexually dimorphic changes in pituitary somatotropes and lactotropes. To test this hypothesis, pituitary tissue from young adult (4 months) and old (20-22 months) male and female rats was labeled immunocytochemically for growth hormone (GH) and prolactin (PRL). The total amount of immunoreactive material as well as the total area and number of immunoreactive structures were evaluated. With increasing age the intracellular GH content was moderately increased in male and decreased in female rats. An age-dependent PRL increase, due both to increased cell number and intracellular hormone content, was present only in female rats. The amount of GH- and PRL-immunoreactive material, distributed into classes of increasing density, differed both between sex and age groups. Our results indicate that the aging process of the somatotrope and lactotrope cell populations in rats appears to be different in the two sexes.

Aging↗
PubMed1987

Age-dependent changes in the mechanisms controlling prolactin secretion and phosphatidylinositol turnover in male rats: effect of phosphatidylserine.

The present study was undertaken in order to better characterize the functional state of anterior pituitary gland in young and old rats by using prolactin secretion and incorporation of radioactive phosphate into phosphatidylinositol (PI) as markers. The in vitro incorporation of radiolabeled phosphate into anterior pituitary PI was significantly (p less than 0.01) greater in young (3-5 months) than in aged (24-25 months) male Sprague-Dawley rats. No significant difference was found in the incorporation by pituitary tissue of 32P into phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Also, the extent of prolactin secretion from isolated pituitary was significantly greater in young than in aged rats, while the prolactin pituitary content was significantly higher in aged animals. In vitro dopamine (DA) decreased the incorporation of 32P into PI, both in young and old pituitary glands, and inhibited prolactin secretion into the incubation medium. Brain cortex-phosphatidylserine (BC-PS), a pharmacologically active purified phospholipid, capable of stimulating the dopaminergic system in the hypothalamus and of decreasing prolactin secretion both in humans and rats in vitro and in vivo, inhibited the incorporation of labeled phosphate into PI of pituitary glands from either young or old rats, but did not alter the prolactin secretion from the glands incubated in vitro. Baseline prolactin plasma levels did not differ significantly between young and old rats either when blood was collected from the trunk after decapitation or underwent sampling from chronically cannulated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1986

Phorbol 12-myristate 13-acetate induces prolactin secretion from rat anterior pituitary gland by the activation of protein kinase-C.

The purpose of this study was to characterize the action of phorbol 12-myristate 13-acetate (PMA), a tumor-promoting agent, on rat anterior pituitary gland, focusing the attention on prolactin secretion. PMA elicited a significant increase in prolactin secretion without affecting phosphatidylinositol turnover, considered as an early post-receptor event controlling PRL secretion. However incubation of anterior pituitary glands with PMA caused a loss of protein kinase-C activity in cytoplasm concomitant with an increased enzyme activity in the membrane. The action of PMA on prolactin secretion seems to be mainly dependent from the redistribution and activation of protein kinase-C. In fact, the phorbol ester did not affect pituitary cAMP and cGMP metabolism either in basal conditions or after theophylline.

Animals↗