938 resultados para PITUITARY ADENOMA


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ectopic parathyroid adenoma, including intrathyroid adenoma, is a common cause of failed parathyroid operations. The aim of this study was to evaluate the operative strategy/outcome in patients with primary hyperparathyroidism (pHPT), with special regard to intrathyroid adenomas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Epidemiologic research of the last half-century has clearly shown that psychosocial factors related to the social environment, personality characteristics, and negative affect increase the risk of incident CVD and also impact prognosis of cardiac patients. Several mechanisms may explain this link, including a genetic predisposition, poor lifestyle choices, low adherence to health recommendations, and direct pathophysiologic perturbations. The latter include alteration of the hypothalamic-pituitary adrenal axis and autonomic dysfunction resulting in endothelial dysfunction, inflammation, and a prothrombotic state further downstream. Screening for psychosocial factors seems appropriate as part of the standard history and based on the clinician's knowledge of the patient and the purpose of the visit. Psychological interventions generally alleviate distress in cardiac patients, but whether they reduce the risk of hard cardiovascular endpoints and all-cause mortality is less evident. Cardiac patients with more severe depression may particularly profit from antidepressant medications. Due to their pharmacologic properties, selective serotonin reuptake inhibitors were shown to improve cardiovascular outcome. The most effective psychosocial treatment is multicomponent therapy that combines elements of cognitive behaviour therapy ("stress management") and changes in health behaviours, including the adoption of a regular exercise regimen. Gender-specific issues should probably be considered. The field of behavioural cardiology has accumulated a wealth of epidemiological, mechanistic and clinical knowledge that undoubtedly has furthered our understanding about the important role of psychosocial risk factors in patients with a heart disease.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Congenital isolated ACTH deficiency (IAD) is a rare disease characterized by low plasma ACTH and cortisol levels and preservation of all other pituitary hormones. This condition was poorly defined before we identified TPIT, a T-box transcription factor with a specific role in differentiation of the corticotroph lineage in mice and humans, as its principal molecular cause.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

When a child is not following the normal, predicted growth curve, an evaluation for underlying illnesses and central nervous system abnormalities is required and, appropriate consideration should be given to genetic defects causing GH deficiency (GHD). Because Insulin-like-Growth Factor-I (IGF-I) plays a pivotal role, GHD could also be considered as a form of IGF-I deficiency (IGFD). Although IGFD can develop at any level of the GHRH-GH-IGF axis, a differentiation should be made between GHD (absent to low GH in circulation) and IGFD (normal to high GH in circulation). The main focus of this review is on the GH-gene, the various gene alterations and their possible impact on the pituitary gland. However, although transcription factors regulating the pituitary gland development may cause multiple pituitary hormone deficiency they may present initially as GHD. These defects are discussed in various different chapters within this book, whereas, the impact of alterations of the GHRH-, GHRH-receptor- --as well as the GH-receptor (GHR) gene--will be discussed here.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

After a proper medical history, growth analysis and physical examination of a short child, followed by radiological and laboratory screening, the clinician may decide to perform genetic testing. We propose several clinical algorithms that can be used to establish the diagnosis. GH1 and GHRHR should be tested in children with severe isolated growth hormone deficiency and a positive family history. A multiple pituitary dysfunction can be caused by defects in several genes, of which PROP1 and POU1F1 are most common. GH resistance can be caused by genetic defects in GHR, STAT5B, IGF1, IGFALS, which all have their specific clinical and biochemical characteristics. IGF-I resistance is seen in heterozygous defects of the IGF1R. If besides short stature additional abnormalities are present, these should be matched with known dysmorphic syndromes. If no obvious candidate gene can be determined, a whole genome approach can be taken to check for deletions, duplications and/or uniparental disomies.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

β-blockers and β-agonists are primarily used to treat cardiovascular diseases. Inter-individual variability in response to both drug classes is well recognized, yet the identity and relative contribution of the genetic players involved are poorly understood. This work is the first genome-wide association study (GWAS) addressing the values and susceptibility of cardiovascular-related traits to a selective β(1)-blocker, Atenolol (ate), and a β-agonist, Isoproterenol (iso). The phenotypic dataset consisted of 27 highly heritable traits, each measured across 22 inbred mouse strains and four pharmacological conditions. The genotypic panel comprised 79922 informative SNPs of the mouse HapMap resource. Associations were mapped by Efficient Mixed Model Association (EMMA), a method that corrects for the population structure and genetic relatedness of the various strains. A total of 205 separate genome-wide scans were analyzed. The most significant hits include three candidate loci related to cardiac and body weight, three loci for electrocardiographic (ECG) values, two loci for the susceptibility of atrial weight index to iso, four loci for the susceptibility of systolic blood pressure (SBP) to perturbations of the β-adrenergic system, and one locus for the responsiveness of QTc (p<10(-8)). An additional 60 loci were suggestive for one or the other of the 27 traits, while 46 others were suggestive for one or the other drug effects (p<10(-6)). Most hits tagged unexpected regions, yet at least two loci for the susceptibility of SBP to β-adrenergic drugs pointed at members of the hypothalamic-pituitary-thyroid axis. Loci for cardiac-related traits were preferentially enriched in genes expressed in the heart, while 23% of the testable loci were replicated with datasets of the Mouse Phenome Database (MPD). Altogether these data and validation tests indicate that the mapped loci are relevant to the traits and responses studied.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The main activation route for the stress response is the hypothalamo-pituitaryadrenal axis (HPA) and the sympatho-adrenomedullary system. The HPA axis is a neuroendocrine feedback loop mediated by an array of tissue specific hormones, receptors and neurotransmitters that regulate glucocorticoid (GC) release. GCs are steroidal hormones produced by the adrenal glands and are key players in a negativefeedback loop controlling HPA activity. They influence the HPA axis through glucocorticoid receptors in the hypothalamus and pituitary and through both glucocorticoid (GR) and mineralcorticoid receptors (MR) that are co-localized in the hippocampus. Repeated or chronic stress exerts a negative influence on these HPA axis regulatory sites and contributes to potentially pathological conditions, especially during early development. For example, chronic stress promotes increased maternal adrenal gland secretion of glucocortiocoid, leading to abnormally high concentrations of GC inthe fetal environment. The timing and maturation of the HPA axis relative to birth is highly species specific and is closely linked to landmarks in fetal development. In rats this development of the HPA axis takes place in utero and continues even shortly after birth. It is likely that the maternal endocrine environment will affect fetal development during this critical time point and may alter the overall set point for the expression ofgenes and their protein products that mediate fetal HPA axis function. Dexamethasone (DEX) is a synthetic glucocorticoid (sGC) and is a consensus treatment in preterm pregnancies used to expedite fetal lung development. However it has been shown that DEX causes long term physiological and behavioral disorders in prenatally-exposed laboratory animals. Previous studies have also shown that it alters the MR: GR receptor ratio in the hippocampus. Taking into consideration corticosteroid regulation of serotonin receptors, especially 5HT1A receptors and their putative interaction with glucocorticoid receptors in the hippocampus, we hypothesized that prenatal DEX exposure would lead to changes in the expression and function of 5HT1A receptors in the hippocampus. We administered DEX to rat dams during the last trimester of gestation and investigated the changes in these receptors in the adult rat offspring. Radioligand receptor binding assays were used to study hippocampal 5HT1A receptor binding affinity and number. Our results demonstrate that hippocampal 5HT1A receptors are increased in the DEX animalscompared with controls by 36%, with no change in binding affinity. The efficiency of ligand-induced receptor signal transduction via G-protein activation was also studied using [35S]GTPγS incorporation assay. Using this technique, we showed that there was no significant difference in the maximum ligand mediated stimulation (Emax) of 5HT1Areceptors between control and dex exposed animals. However, the intracellular signalling efficiency of hippocampal 5HT1A receptors was diminished, since a significant increase in EC50 values was obtained with the dex exposed group showing a value 51% higherEC50 than controls. Taken together these data illustrate a considerable change in the 5HT1A component of the serotonergic system following prenatal DEX exposure.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Isolated growth hormone deficiency type-2 (IGHD-2), the autosomal-dominant form of GH deficiency, is mainly caused by specific splicing mutations in the human growth hormone (hGH) gene (GH-1). These mutations, occurring in and around exon 3, cause complete exon 3 skipping and produce a dominant-negative 17.5 kD GH isoform that reduces the accumulation and secretion of wild type-GH (wt-GH). At present, patients suffering from IGHD-2 are treated with daily injections of recombinant human GH (rhGH) in order to reach normal height. However, this type of replacement therapy, although effective in terms of growth, does not prevent toxic effects of the 17.5-kD mutant on the pituitary gland, which can eventually lead to other hormonal deficiencies. Considering a well-known correlation between the clinical severity observed in IGHD-2 patients and the increased expression of the 17.5-kD isoform, therapies that specifically target this isoform may be useful in patients with GH-1 splicing defects. This chapter focuses on molecular strategies that could represent future directions for IGHD-2 treatment.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Familial isolated growth hormone deficiency (IGHD) is a disorder with about 5-30% of patients having affected relatives. Among those familial types, IGHD type II is an autosomal dominant form of short stature, associated in some families with mutations that result in missplicing to produce del32-71-GH, a GH peptide which cannot fold properly. The mechanism by which this mutant GH may alter the controlled secretory pathway and therefore suppress the secretion of the normal 22-kDa GH product of the normal allele is not known in detail. Previous studies have shown variance depending on cell type, transfection technique used, as well as on the method of analysis performed. AIM: The aim of our study was to analyse and compare the subcellular distribution/localization of del32-71-GH or wild-type (wt)-GH (22-kDa GH), each stably transfected into AtT-20, a mouse pituitary cell line endogenously producing ACTH, employed as the internal control for secretion assessment. METHODS: Colocalization of wt- and del32-71 mutant GH form was studied by quantitative confocal microscopy analysis. Using the immunofluorescent technique, cells were double stained for GH plus one of the following organelles: endoplasmic reticulum (ER anti-Grp94), Golgi (anti-betaCOP) or secretory granules (anti-Rab3a). In addition, GH secretion and cell viability were analysed in detail. RESULTS/CONCLUSIONS: Our results show that in AtT-20 neuroendocrine cells, in comparison to the wt-GH, the del32-71-GH has a major impact on the secretory pathway not only affecting GH but also other peptides such as ACTH. The del32-71-GH is still present at the secretory vesicles' level, albeit in reduced quantity when compared to wt-GH but, importantly, was secretion-deficient. Furthermore, while focusing on cell viability an additional finding presented that the various splice site mutations, even though leading eventually to the same end product, namely del32-71-GH, have different and specific consequences on cell viability and proliferation rate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We present the case of a 60 year old male patient with incidentally detected visual abnormalities. Detailed personal history revealed a hypogonadism that had been present for several years. Further investigations established the diagnosis of an infiltrative macroadenoma. Medical treatment with cabergoline led to a rapid regression of ophthalmologic symptoms and, subsequently, of tumor size. In male subjects symptoms of hypogonadism are often reported only late in the course of the disease, thereby leading to a generally larger tumor size at the point of diagnosis. In contrast to other pituitary tumors that are mainly treated by surgery, medical treatment with dopamine agonists is the principal therapeutic option in prolactinomas.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A 40-year-old man was admitted to the emergency department with psychotic symptoms and marked hypothermia. He was known to have had a macroadenoma of the pituitary gland which had been excised 10 years before. No information about his current medication was available. Several hours after admission the patient developed signs of acute cardiac failure and cardiogenic shock. He was admitted to the intensive care unit, intubated and treated with vasoactive drugs. Later investigations revealed that the patient had stopped his hormonal therapy (hydrocortisone and thyroxine) at least 3 months previously.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Benign Prostatic Hyperplasia is a common entity among the aging male population. Its prevalence is increasing with age and is around 80% in the over 80-years old. The androgen-estrogen ratio changes in favor of the estrogens, which leads to a growth of prostatic tissue, presenting histologically as hyperplasia. BPH can cause irritative or obstructive symptoms or both. Nowadays we speak of bladder storage or bladder voiding symptoms, summarised as LUTS (Lower Urinary Tract Symptoms). LUTS has a structural and a functional component, the structural being caused by the size of the adenoma itself the functional depending on the muscle tone of the bladder neck and the prostatic urethra. To investigate LUTS, we use validated symptom scores, sonography for residual urine and eventually a urodynamic evaluation. There are 3 grades of BPH. The indication for an interventional therapy is relative in BPH II, and absolute in BPH III. Prior to treatment, other diseases mimicking the same symptoms, have to be ruled out and adequatly treated. Electro-resection of the prostate (TUR-P) remains the standard therapy and the benchmark any new technology has to compete with. TUR-P has good short- and longterm results, but can be associated with a considerable perioperative morbidity, and the learning curve for the operator is long. The most promising of the newer techniques is the Holmium-Laser-Enucleation of the prostate (Laser-TUR-P), showing at least identical short- and median-term results, but a lower perioperative morbidity than TUR-P For several minimally-invasive techniques, indications are limited. TUMT TUNA, WIT and laser-coagulation all produce a coagulation necrosis of the prostatic tissue by thermic damage with secondary tissue shrinking. Urodynamic results however, are not comparable to TUR-P or Laser-TUR-P, and significantly more secondary interventions within 2 to 5 years are required. Minimal-invasive techniques present a favorable alternative for younger patients without complications of BPH, and for older patients with relevant comorbidities, and can usually be performed under local anaesthesia. The morbidity is low and further therapies remain possible later, if necessary.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Acute mental stress induces a significant increase in plasma interleukin (IL)-6 levels as a possible mechanism for how psychological stress might contribute to atherosclerosis. We investigated whether the IL-6 response would habituate in response to a repetitively applied mental stressor and whether cortisol reactivity would show a relationship with IL-6 reactivity. Study participants were 21 reasonably healthy men (mean age 46+/-7 years) who underwent the Trier Social Stress Test (combination of a 3-min preparation, 5-min speech, and 5-min mental arithmetic) three times with an interval of 1 week. Plasma IL-6 and free salivary cortisol were measured immediately before and after stress, and at 45 and 105 min of recovery from stress. Cortisol samples were also obtained 15 and 30 min after stress. Compared to non-stressed controls, IL-6 significantly increased between rest and 45 min post-stress (p=.022) and between rest and 105 min post-stress (p=.001). Peak cortisol (p=.034) and systolic blood pressure (p=.009) responses to stress both habituated between weeks one and three. No adaptation occurred in diastolic blood pressure, heart rate, and IL-6 responses to stress. The areas under the curve integrating the stress-induced changes in cortisol and IL-6 reactivity were negatively correlated at visit three (r=-.54, p=.011), but not at visit one. The IL-6 response to acute mental stress occurs delayed and shows no adaptation to repeated moderate mental stress. The hypothalamus-pituitary-adrenal axis may attenuate stress reactivity of IL-6. The lack of habituation in IL-6 responses to daily stress could subject at-risk individuals to higher atherosclerotic morbidity and mortality.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Several studies suggested an association between Helicobacter pylori infection and colorectal carcinoma or adenoma risk. However, different authors reported quite varying estimates. We carried out a systematic review and meta-analysis of published studies investigating this association and paid special attention to the possibility of publication bias and sources of heterogeneity between studies. Materials and METHODS: An extensive literature search and cross-referencing were performed to identify all published studies. Summary estimates were obtained using random-effects models. The presence of possible publication bias was assessed using different statistical approaches. RESULTS: In a meta-analysis of the 11 identified human studies, published between 1991 and 2002, a summary odds ratio of 1.4 (95% CI, 1.1-1.8) was estimated for the association between H. pylori infection and colorectal cancer risk. The graphical funnel plot appeared asymmetrical, but the formal statistical evaluations did not provide strong evidence of publication bias. The proportion of variation of study results because of heterogeneity was small (36.5%). CONCLUSIONS: The results of our meta-analysis are consistent with a possible small increase in risk of colorectal cancer because of H. pylori infection. However, the possibility of some publication bias cannot be ruled out, although it could not be statistically confirmed. Larger, better designed and better controlled studies are needed to clarify the situation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Microcystic adenoma or serous cystadenoma is an uncommon tumor and accounts for 1-2% of the exocrine neoplasms of the pancreas. Usually unifocal, they present as single, large, well-demarcated multiloculated cystic tumors, ranging in size from 1 to 25 cm. Multifocal variants or diffuse serous cystadenomas are extremely rare. We present 2 cases of which 1 is a diffuse variant affecting the body, tail and part of the neck of the pancreas. In both the patients the tumors were detected incidentally. We highlight on the diffuse variant in view of its rarity and present a review of literature. In this case the entire body and tail of the pancreas was spongy replaced by multicystic lobules and hyalinized fibrocollagenous stroma. The cysts were lined by low cuboidal glycogen containing bland cells. Such a unique presentation wherein the entire body and tail of the pancreas is replaced with multiple cysts is a diffuse presentation of microcystic adenoma and a search through literature revealed only 7 such cases among the 15 cases with multifocal presentation reported.