Significant benefits of AIP testing and clinical screening in familial isolated and young-onset pituitary tumors

Context Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are responsible for a subset of familial isolated pituitary adenoma (FIPA) cases and sporadic pituitary neuroendocrine tumors (PitNETs). Objective To compare prospectively diagnosed AIP mutation-positive (AIPmut) PitNET patients with clinically presenting patients and to compare the clinical characteristics of AIPmut and AIPneg PitNET patients. Design 12-year prospective, observational study. Participants & Setting We studied probands and family members of FIPA kindreds and sporadic patients with disease onset ≤18 years or macroadenomas with onset ≤30 years (n = 1477). This was a collaborative study conducted at referral centers for pituitary diseases. Interventions & Outcome AIP testing and clinical screening for pituitary disease. Comparison of characteristics of prospectively diagnosed (n = 22) vs clinically presenting AIPmut PitNET patients (n = 145), and AIPmut (n = 167) vs AIPneg PitNET patients (n = 1310). Results Prospectively diagnosed AIPmut PitNET patients had smaller lesions with less suprasellar extension or cavernous sinus invasion and required fewer treatments with fewer operations and no radiotherapy compared with clinically presenting cases; there were fewer cases with active disease and hypopituitarism at last follow-up. When comparing AIPmut and AIPneg cases, AIPmut patients were more often males, younger, more often had GH excess, pituitary apoplexy, suprasellar extension, and more patients required multimodal therapy, including radiotherapy. AIPmut patients (n = 136) with GH excess were taller than AIPneg counterparts (n = 650). Conclusions Prospectively diagnosed AIPmut patients show better outcomes than clinically presenting cases, demonstrating the benefits of genetic and clinical screening. AIP-related pituitary disease has a wide spectrum ranging from aggressively growing lesions to stable or indolent disease course

Novel concept of antisurvival factor (ASF) therapy produces an objective clinical response in four patients with hormone-refractory prostate cancer: Case report

BACKGROUND. Osteoblasts and osteoblast-derived survival growth factors, such as insulin-like growth factor I (IGF I), inhibit chemotherapy apoptosis of prostate cancer cells, thereby producing cytotoxic drug-resistant tumor growth, in vitro. METHODS. We tested a novel therapeutic approach, referred to as antisurvival factor (AFS) therapy, that aimed at reduction of osteoblast-derived IGFs, using dexamethasone (4 mg per os, qD) and growth hormone (GH)-dependent liver-derived IGFs, using a somatostatin-analog (lanreotide, 30 mg, intramuscularly (IM), q14D) in combination with triptorelin (3.75 mg, intramuscularly, q28D) to produce a clinical response in 4 patients with progressing hormone-refractory prostate cancer. RESULTS. The patients given ASF therapy exhibited an excellent improvement of clinical performance and a decline of prostate-specific antigen (PSA) within 2 months of ASF therapy. One of them experienced excellent clinical response (normalization of PSA), two experienced good clinical response (decline of PSA of more than 50%), and one experienced stabilization (decline of PSA of less than 50%). CONCLUSIONS. We conclude that this novel concept of combination therapy, using ASF with hormone ablation, is a promising salvage therapy that should be further assessed with a randomized clinical trial

Diabetes insipidus, secondary hypoadrenalism and hypothyroidism after traumatic brain iInjury: Clinical implications

Adequate ADH secretion, adrenal and thyroid functions are vital during the acute and post-acute phases of TBI. Deficiencies of these functions as a result of TBI are increasingly recognized. During the acute phase of TBI the incidence of severe DI is 2.9%; the incidence of less severe forms of DI is 21.6-26%. The development of DI seems to correlate with the severity of trauma. In most occasions DI is transient, but persisting DI may develop with an incidence of 6.9-7.5% amongst TBI victims. The assessment of the adequacy of adrenal function during the acute phase of TBI remains a diagnostic challenge. A few studies demonstrated an incidence of hypoadrenalism of 15-16% uring the early phase of TBI. It should be noted that early hypoadrenalism may be due to either a structural damage at the level of the hypothalamo-pituitary unit or it may develop in the context of the so-called "relative adrenal insufficiency", a functional abnormality that is currently increasingly recognized during the course of severe illness. Secondary hypoadrenalism during the late phases of TBI appears with an incidence of 7.1-12.7%. The "low-T3 syndrome" compromises the assessment of thyroid function during the acute phase of TBI; the incidence of TSH insufficiency during the recovery phase varies widely between 1-21%. In summary, diabetes insipidus, secondary hypoadrenalism and hypothyroidism may develop in a small albeit significant proportion of patients during the course of TBI. Therefore, assessment of the integrity of ADH secretion, hypothalamic-pituitary adrenal (HPA) axis and thyroid axis is crucial to ensure survival and optimal rehabilitation of TBI patients. © Springer Science + Business Media, Inc. 2006

Recombinant human growth hormone-binding protein fails to enhance the in vivo bioactivity of human growth hormone in normal rats

GH circulates in the plasma partially bound with a GH-binding protein (GHBP), but the physiological significance of the GHBP and how it affects GH bioactivity in vive is still unknown. In the present study, we took advantage of the known biological action of exogenous human (h) GH to inhibit endogenous rat (r) pulsatile GH release and examined the effect of combining hGH with recombinant hGHBP on this response in normal rats. Spontaneous 7-h plasma rGH and hGH profiles were obtained from four groups of free-moving adult male rats sc administered either: 1) 200 μg hGH alone; 2) a mixture of 200 μg hGH and 200 μg hGHBP preincubated for 30 min before injection; 3) 200 μg hGHBP alone; or 4) Tris buffer (vehicle) alone. Rats administered the vehicle or hGHBP separately exhibited the typical pulsatile pattern of rGH secretion. Injection of hGH alone resulted in a marked (P <0.01) suppression of spontaneous rGH pulses for approximately 3.5 h after the injection compared with vehicle-injected controls; during the subsequent 3.5- to 7-h period, recovery of spontaneous rGH peaks was evident. Plasma levels of hGH in these animals reached a peak within 1 h after hGH injection and declined to near undetectable levels by the end of the sampling period. In contrast, the disappearance rate of hGH was markedly slower in rats administered the hGH + hGHBP complex; plasma hGH concentrations at 7 h after injection were 14-fold higher than those in animals administered hGH alone, and hGH was still readily detectable up to 24 h after injection. However, despite the markedly higher levels of hGH persisting throughout the sampling period in complex-injected rats, both the time course of hGH-induced inhibition of rGH and the recovery of spontaneous rGH pulses were similar to those of animals administered hGH alone. Moreover, there were no significant modifications of plasma insulin-like growth factor-1 levels for up to 24 h after injection of the hGH + hGHBP complex. Computer simulations revealed that most of the total hGH observed during the 3.5- to 7-h period was circulating in the bound form. These results demonstrate that, despite hGHBP's ability to markedly prolong the bioavailability of hGH, precomplexing hGH with hGHBP failed to enhance hGH's in vive bioactivity in the inhibition of endogenous pulsatile rGH release. Our findings do not provide: support for the concept that the GHBP enhances the bioactivity of GH in vivo, at least over the time course examined here

Luteinising hormone-releasing hormone antagonists in prostate cancer therapy

The introduction of androgen blockade therapy using luteinising hormone-releasing hormone (LHRH)/gonadotropin-releasing hormone analogues alone or in combination with non-steroidal antiandrogens has a major impact in both survival and quality of life of patients with locally advanced and metastatic prostate cancer. The effect of LHRH agonists is based on the continuous binding to the LHRH receptor (LHRH-R) on the gonadotrope cells of the pituitary, which although initially stimulate LH release, consequently downregulates the LHRH-R, thereby suppressing serum LH, testosterone levels and 5α- dihydrotestosterone levels. Because this initial surge of LH and testosterone can cause adverse consequences in these patients (the so-called flare-up symptoms), immediate inhibition of LH release and testosterone production is desirable and this can be achieved with the use of the LHRH antagonists. In addition, there exist data to support a direct anticancer effect of LHRH antagonists on prostate cancer cells. This review summarises the potential clinical use of the LHRH antagonists in prostate cancer patients. © 2007 Informa UK Ltd

Thyroid function during critical illness

The metabolic support of the critically ill patient is a relatively new target of active research and little is as yet known about the effects of critical illness on metabolism. The nonthyroidal illness syndrome, also known as the low T3 syndrome or euthyroid sick syndrome, describes a condition characterized by abnormal thyroid function tests encountered in patients with acute or chronic systemic illnesses. The laboratory parameters of this syndrome include low serum levels of triiodothyronine (T3) and high levels of reverse T3, with normal or low levels of thyroxine (T4) and normal or low levels of thyroid-stimulating hormone (TSH). This condition may affect 60 to 70% of critically ill patients. The changes in serum thyroid hormone levels in the critically ill patient seem to result from alterations in the peripheral metabolism of the thyroid hormones, in TSH regulation, in the binding of thyroid hormone to transport-protein and in receptor binding and intracellular uptake. Medications also have a very important role in these alterations. Hormonal changes can be seen within the first hours of critical illness and, interestingly, these changes correlate with final outcome. Data on the beneficial effect of thyroid hormone treatment on outcome in critically ill patients are so far controversial. Thyroid function generally returns to normal as the acute illness resolves