A few patients may be of normal intelligence but have difficulties in reading, writing, and spelling, which are the main precipitants of a psychiatric disorder. In seven patients this illiteracy emerged only after intensive examination, as they had hidden it from employers, friends, and children. Characteristically these patients are often very sensitive about this disability and marital fricti...

If possible, precipitating factors should be identified. As an example, the use of caffeine may exacerbate migraine and should be eliminated. Sleep disturbances, such as snoring or frequent awakenings, may precipitate headache. Rarely, a temporal relationship is established between diet and headache; in these cases, an elimination diet may be helpful. Dehydration and missing meals are also comm...

Single crystals of three different isoenzymes of (R)-(+) mandelonitrile lyase (hydroxynitrile lyase) from almonds (Prunus amygdalus) have been obtained by hanging drop vapor diffusion using polyethylene glycol 4000 and isopropanol as co-precipitants. The crystals belong to the monoclinic space group P2(1) with unit cell parameters a = 69.9, b = 95.1, c = 95.6 A, and beta = 118.5 degrees. A comp...

Pyrrolidone carboxyl peptidase from the hyperthermophilic archaeon Thermococcus litoralis has been crystallized in a form suitable for X-ray diffraction from ammonium sulfate or ammonium dihydrogen orthophosphate using the vapour-phase diffusion method. Crystals from both precipitants are of the orthorhombic space group P21212 with unit-cell dimensions a = 94.06, b = 149.06, c = 73.54 A. A comp...

This article reviews current issues in the understanding and clinical management of trichotillomania (TTM). After diagnostic considerations and epidemiology are discussed, a brief update on biologic and environmental precipitants is provided, and emerging research on possible TTM subtypes is discussed. Current strategies for assessing TTM and t heir applicability to clinical practice are review...

X-ray crystallography is a method used in determining the arrangement of atoms within a crystal. This method of examining a molecular structure can be applied to biological compounds, such as proteins and enzymes. By allowing researchers to know the structure of an enzyme, the function of such a molecule can be fully understood. Often, chemical properties may be known of an enzyme, but how such...

Dysphagia can arise from a multitude of underlying pathologies affecting any of the three stages of swallowing; oral, pharyngeal and or oesophageal; and can be further classified as intraluminal, intramural or extramural. We discuss an unusual case of acute dysphagia secondary to haematoma formation within one of a number of potential neck spaces. We report on a novel precipitant; routine elect...

In the search for macromolecular crystallization conditions, the precipitant is probably the most important variable, such that when problematic crystals are encountered there is always the question of whether an alternative precipitant might resolve the problem. During an effort to obtain high-quality crystals of several problematic proteins, two new agents, pentaerythritol propoxylate and pen...

Fifteen patients who experienced epileptic seizures while playing video games are described together with a review of 20 cases in the English literature. Nine of the 15 cases and all but two of the reported cases experienced their first seizure while playing video games. Two thirds of patients had idiopathic generalised epilepsy and mainly reported generalised tonic clonic seizures, but some ha...