1,159 research outputs found
Growth hormone, prolactin, and sexuality.
No full textGH and PRL, although not considered as 'classical' sexual hormones, could play a role in the endocrine control of sexual function both in men and women. Physiologically, PRL seems to be involved in the central control of sexual behavior and activity, by modulating mainly the effects of dopaminergic and serotoninergic systems on sexual function. Indeed, circulating PRL levels increase after orgasm and may potentially play a role in the acute regulation of further sexual arousal following orgasm both in men and women. On the other hand, either short-term or long-term PRL increase can modulate central nervous system areas involved in the control of sexual function and, peripherally, can directly influence mechanisms of penile erection in men, and presently only as an hypothesis, mechanisms related to the sexual response of genitalia in women. Furthermore, chronic hyperprolactinemia is classically associated with hypogonadotropic hypogonadism and sexual dysfunction in both sexes. Successful treatment of chronic hyperprolactinemia generally restores normal sexual function both in men and women although this effect is not only related to relapse of gonadal function. Hypoprolactinemia is recently recognised as a possible risk factor of arteriogenic erectile dysfunction while a possible role on female sexual function is not known. The physiological role of GH on sexual function is not fully elucidated. GH is an important regulator of hypothalamuspituitary- gonadal axis and seems to participate in the regulation of the sexual response of genitalia in men, and potentially also in women. Sexual function in men and women with GH deficiency (GHD) and GH excess, particularly in acromegaly, is scantily studied and GH- or IGF-I-dependent effects are difficult to quantify. Nevertheless, a decrease of desire and arousability both in men and women, together with an impairment of erectile function in men, have been described both in patients with GHD and acromegaly, although it is not clear whether they are dependent directly on the hormone defect or excess or they are consequence of the hypogonadism or the different clinical complications or the physical disfigurement and psychological imbalance, which are associated with the diseases, and are potentially affecting sexual function. Data on beneficial effects of GH replacement therapy and specific surgical or pharmacological approach for acromegaly are far to be fully elucidated although restoring normal GH/IGF-I levels have been associated to improvement of sexual function
Cushing, acromegaly, GH deficiency and tendons
No full textCushing’s syndrome, induced by an endogenous or exogenous cortisol excess, and acromegaly, the clinical syndrome caused by growth hormone (GH) excess in adulthood, as well as the disease induced by GH deficiency (GHD), represent perfect models for the evaluation of the effects induced by chronic exposure in vivo, respectively, to cortisol and GH/IGF-1 excess or deficiency on the complex structure of the tendons as well as on the related post-traumatic repair mechanism. Although the literature is still scant, here in main scientific evidence on this topic is summarized in order to provide suggestions about the management of the above mentioned illnesses, to translate such information in the field of sports medicine and/or traumatology, and to increase and to disseminate knowledge on this misunderstood theme
Effects of initial therapy for five years with somatostatin analogs foracromegaly on growth hormone and insulin-like growth factor-I levels, tumorshrinkage, and cardiovascular disease: a prospective study.
No full textOBJECTIVE: The objective of the study was to evaluate the efficacy of 5 yr of
depot somatostatin analogs (SSAs) as first-line therapy in acromegaly.
PATIENTS: Patients included 45 de novo patients (18 women and 27 men, aged 20-82
yr); 28 were treated with octreotide-long-acting release and 17 with lanreotide.
RESULTS: GH was controlled in 100% and IGF-I levels in 97.8%, tumor shrinkage was
74.9 +/- 22.1 and 78.2+/-14.5%, in the octreotide-long-acting release and
lanreotide groups, respectively. There was a significant improvement in the
prevalence of hypertension (from 46.7 to 22.2%, P = 0.027), arrhythmias (from
17.8% to zero, P = 0.01), left ventricular hypertrophy (from 82.2 to 42.2%, P <
0.0001), diastolic dysfunction (from 60.0 to 15.6%, P < 0.0001), systolic
dysfunction (from 40.0 to 4.4%, P < 0.0001), and hypertriglyceridemia (from 40.0
to 4.4%, P < 0.0001). The prevalence of impaired glucose tolerance (IGT; from
28.9 to 20.0%. P = 0.46) and diabetes mellitus (from 22.4 to 31.1%, P = 0.64) did
not change.
CONCLUSIONS: In patients with severe comorbidities and those who refuse surgery,
5 yr of exclusive SSA therapy induce successful control of GH and IGF-I; tumor
shrinkage (by median 80%), and improvement of hypertension, cardiac performance;
and dyslipidemia. No patient was withdrawn from treatment because of side
effects, and glucose tolerance was stable. We suggest that first-line SSA
treatment may be safely continued in patients with acromegaly, according to an
individual patient's indications and preferences
Viral Peptide Targeted Delivery of Nano-Therapeutics
No full textOver the past decade, an increasing number of potential drugs have been suggested for therapeutic applications. Often bio-macromolecules show a limited ability to cross the plasma membrane resulting in poor cellular access, which largely prevents them from reaching intracellular targets and from crossing epithelial or endothelial barriers. Moreover, neurological disorders contribute significantly to the global burden of disease and are likely to increase in the coming years due to an aging population; however, significant efforts have been devoted towards the development of improved therapies for central nervous system (CNS) diseases, treatments remain limited due to the inability of therapeutic agents to effectively cross the blood-brain-barrier (BBB).[1] The development of nanotechnology provides powerful tools to deliver therapeutics to target sites. This presentation targets major advances in the design and realization of nano-scaffolds for theranostics. A fundamental limitation of current diagnostics and therapeutics is the lack of a single delivery system that has the potential to not only deliver therapeutics to the disease site of interest with high fidelity, i.e. target delivery, but also allows for diagnostics and cell delivery, i.e. cell penetration and uptake and thus the obtainment of a toolbox that combines targeting and delivery with imaging and targeted cell uptake. The discovery of several peptides with the ability to cross the plasma membrane of eukaryotic cells by a possibly receptor- and endocytosis-independent mechanism, has opened a new avenue in biomedical research. Among the so-called cell penetrating peptides (CPPs), Tat, penetratin and VP22 have been widely used and have shown to be entrapped in intracellular organelles. Thus, one of the main goals of recent research is the obtainment of novel delivery systems that are able to cross membranes without being entrapped in intracellular organelles[2]. Viral derived peptides, and in particular those derived by viral entry proteins, may be useful as delivery vehicles due to their intrinsic properties of inducing membrane perturbation. The present talk will describe results obtained with the use of a peptide derived from Herpes simplex virus type 1 for the delivery of bioactive molecules or fluorescent dyes inside the host cell. In particular, its use for the intracellular delivery of quantum dots (QDs), liposomes, dendrimers and nanoparticles will be addressed
Acromegaly and the cardiovascular system
No full textAcromegaly is characterized by an increased cardiovascular morbidity and mortality. In fact, growth hormone and insulin-like growth factor-I excess induces a specific cardiomyopathy. The heart is involved from the very early stages of the disease in which the hyperkinetic syndrome (high heart rate and increased systolic output) takes place. Frequently, if the disease is untreated for many years or unsuccessfully treated, concentric biventricular hypertrophy and diastolic dysfunction can develop and, at least, lead to diastolic congestive heart failure. Rhythm disturbances and valve dysfunction are also frequently described in acromegaly. The coexistence of other complications, such as diabetes and arterial hypertension, can induce the worsening of acromegalic cardiomyopathy. Control of acromegaly by surgery or pharmacotherapy could improve cardiovascular morbidity thanks to decreasing left ventricular mass and reducing cardiac dysfunction. In conclusion, an early diagnosis and a careful evaluation of cardiac function, morphology and activity seem to be mandatory in acromegaly
Beneficial effect of dose escalation of octreotide-LAR as first-line therapy in patients with acromegaly.
No full textOBJECTIVE: To evaluate the efficacy of dose escalation of Octreotide-long-acting repeatable (LAR) up to 40 mg/month we studied 56 newly diagnosed patients with acromegaly (24 women, 32 men; age 20-82 years). DESIGN: Analytical, observational, open and prospective. METHODS: Three months after LAR treatment beginning with a dose of 20 mg /q28d (every 28 days), 24 patients maintained the same dose (Group A), while 32 required a dose of 30 mg/q28d (Group B). The dose was further increased to 40 mg/q28d in 17 out of the 32 patients of Group B for another 12 months (Group C). RESULTS: After 24 months, serum GH and IGF-I levels decreased by 93.1 +/- 8.6% (95% confidence limit (CL) 90.8-95.4%) and 62.7 +/- 13.4% (95% CL 59.1-66.3%) respectively. Control of GH and IGF-I levels was achieved in 45 patients (80.3%). Tumor shrinkage after 12 months was 49.8 +/- 23%; the relative tumor shrinkage during the second 12 months of treatment was 35.3 +/- 13.1% and overall tumor volume was 68.1 +/- 16.5% (95% CL 63.7-72.5%). Glucose tolerance impaired in eight patients (14.3%): four in Group A and four in Group C (16.7% vs 36.4%, P=0.39). The final dose was predicted by the patient's age at diagnosis (t=-2.2; P=0.032) and baseline tumor volume (t=2.1; P=0.043). CONCLUSION: An increase of the LAR dose up to 40 mg/q28d in patients resistant to 30 mg/q28d is followed by greater suppression of GH and IGF-I levels and tumor shrinkage without further significant impairment of glucose tolerance when compared with lower doses. These results suggest that a new dosage schedule of 40 mg every 28 days is applied in patients with acromegaly mostly of young age and with bigger tumors who are likely to be poorly responsive to standard doses of Octreotide-LAR
Glucose tolerance and somatostatin analog treatment in acromegaly: a 12-monthstudy.
No full textOBJECTIVE: The objective of the study was to investigate the impact of first-line
somatostatin analogs (SSAs) on glucose tolerance (GT) in acromegaly.
DESIGN: The design was open and prospective.
PATIENTS: One hundred twelve patients [63 with normal GT (56.2%), 24 with
impaired GT (21.4%), and 25 with diabetes (22.3%)] were treated with depot SSAs
for 12 months: 54 patients (48.2%) achieved mean fasting GH levels less than 2.5
microg/liter in presence of normal IGF-I levels (controlled) during SSA.
PRIMARY OUTCOME MEASURES: Fasting glucose and glycosylated hemoglobin levels were
measured.
RESULTS: At study end, 57 patients had normal GT (50.1% vs. baseline; P = 0.55),
30 had impaired fasting glucose or impaired GT (26.8%, P =0.43) and 25 had
diabetes (22.3%; P = 1.0). Twenty-eight patients (25.0%), modified their GT [11
improved (9.8%), 17 worsened (15.2%)]: 90% of the patients with GT improvement
achieved control of acromegaly and 89% of those having GT worsening did not (P <
0.0001). The major predictors of GT changing were disease control (t = -4.99; P <
0.0001), baseline GT (t = -2.84; P = 0.0054), and GH levels (t = 2.70; P =
0.008). Fasting glucose levels were predicted by patients' age (t = 2.74; P =
0.0071) and IGF-I levels (t = 2.14; P = 0.035). Glycosylated hemoglobin levels
were predicted by disease duration (t = 3.53; P = 0.0006), GH levels (t = 2.70; P
= 0.0071), and IGF-I levels (t = 2.11; P = 0.037).
CONCLUSIONS: This study showed a similar prevalence of deterioration and
improvement of GT 12 months after first-line SSA treatment. Uncontrolled
acromegaly during SSA treatment and abnormal GT at baseline were associated with
GT worsening
Medical consequences of acromegaly: what are the effects of biochemical control?
No full textThis chapter discusses the effects of biochemical control of acromegaly on cardiovascular diseases, metabolic complications, respiratory abnormalities, malignancies and bone alterations. Acromegaly is associated with increased morbidity and mortality for cardiovascular and respiratory complications, whereas neoplasms seem to be a minor cause of increased risk of death. Other associated diseases are osteoarthritis, carpal tunnel syndrome, fatigue, visual abnormalities and reproductive disorders. Acromegaly results in premature death because of prolonged elevation of GH an IGF-I levels, and a strong biochemical control improves well-being and restores life expectancy to normal. The main goals of medical treatment of acromegaly include normalization of biochemical markers of disease activity, improvement in signs and symptoms of the disease, removal or reduction of tumor mass and preservation of pituitary function
The Author and Authorship in the Internet Society. New Perspectives for Scientific Communication
No full textThe Internet is the most recent and relevant innovation in the field of
media communication, as well as the medium that reproduces most of the characteristics
of global society. In trying to describe contemporary society, we cannot
neglect the social implication of the web. Our assumption is that the evolution of
the Internet has led to problematic effects on the relevance of concepts such as
individuality, author, authorship and copyright, as commonly used up till now.
The first part of the article focuses on individuality as a means to describe individual
actors and social structures in the first modernity, paying particular attention
to the idea of the author as an individual in the field of intellectual products.
New communication forms online make the connection between the individuality
of the author and the text weaker and less recognizable. The second part develops
the theme of scientific knowledge in contemporary society, with regard to scholarly
authorship. The Internet has produced deep transformations in scholarly
publications. Technical and structural characteristics of the Internet suggest possibilities
for a reorganization of the scientific system towards the replacement of
authorship and reputation with innovative mechanisms of information processing
and selection
- …
