Advances in the treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future

The molecular logic of endocannabinoid signalling

The endocannabinoids are a family of lipid messengers that engage the cell surface receptors that are targeted by Δ9-tetrahydrocannabinol, the active principle in marijuana (Cannabis). They are made on demand through cleavage of membrane precursors and are involved in various short-range signalling processes. In the brain, they combine with CB1 cannabinoid receptors on axon terminals to regulate ion channel activity and neurotransmitter release. Their ability to modulate synaptic efficacy has a wide range of functional consequences and provides unique therapeutic possibilities. © 2003, Nature Publishing Group. All rights reserved

Polymeric AdditiveS' Effect on Crystallization of Calcium Oxalate Scales

Laboratory studies concerned with the effects of polymeric additives on the crystallization of calcium oxalate dihydrate and calcium oxalate monohydrate are described and the results obtained are discussed. These compounds are major components of scales formed in some Australian sugar mills. The studies involved the measurement of crystallization induction periods and rates, in the presence and absence of additives. Crystal morphologies were also examined. A range of experimental conditions were employed, from studies in pure solutions of the lattice ions to those more directly comparable with the mill operation.</p

Polymeric additives: Effects on crystallization of hydroxyapatite scales

The effects of some commercial polymeric additives on the nucleation (induction period), crystal growth, and morphology of hydroxyapatite precipitated from pure solutions of the lattice ions have been examined. The inhibitory capacities of these additives for hydroxyapatite scale formed from whole juice samples under conditions similar to those operating in sugar mills have also been determined. The results show that poly (aspartic acid) with Mw of 5700 is the most effective scale inhibitor.</p

The preparation of calcium oxalate dihydrate crystals

Two simple related methods for exclusively preparing well‐developed tetragonal bipyramidal crystals of calcium oxalate dihydrate at moderate supersaturations and at ambient temperature are reported. These crystals have an average length of 5.7–7.2 μm and are easy to wash and filter. One of the methods is suitable for studies of the kinetics of spontaneous precipitation and crystal morphology of the oxalate in the presence and absence of additives. A tentative mechanism is given to account for the sole formation of this particular hydrate. At 70 °C a mixture of the monohydrate and dihydrate phase were formed with various crystal shapes and sizes. These phases were also identified in the presence of sucrose at this temperature, although some of the crystals contained tetragonal habit as obtained at ambient temperature.</p

The Effects of Polymeric Additives on the Crystallization of Compounds Found in the Evaporator Scales of Australian Sugar Mills (I), Compositions of the Scale Deposits

The composition of scales formed in multiple evaporator units at three Australian sugar mills have been determined using X‐ray fluorescence (XRF), high performance liquid chromatography (HPLC), X‐ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA) and other analytical methods. The composition of the scales formed in each mill have been found to be significantly different and to depend on whether they originated from early or later stages of the evaporation process. Calcium oxalate (present as the di and monohydrate) was identified as a major component of the scales from one mill but was found to be only a minor component of the scales from the other two. The latter were shown to contain two or more forms of calcium phosphate as dominant phases. Amorphous or crystalline silica was found to be present in most of the scales examined.</p