Use of calcium hydroxylapatite (Radiesse?) for facial augmentation

Radiesse^® (Bioform Inc, USA) is a sterile, latex-free, non-pyrogenic, semi-solid, cohesive subdermal, injectable implant, whose principal component is synthetic calcium hydroxylapatite, a biocompatible material with over 20 years of use in medicine. The semi-solid nature of the product is created by suspending calcium hydroxylapatite microspheres of 25–45 microns diameter in a gel carrier of carboxymethylcellulose. The product has FDA approval for esthetic facial augmentation in the US. Such approval includes the long-lasting correction of moderate to severe facial wrinkles and folds and the treatment of facial fat loss due to immunodeficiency virus infection. Diverse facial regions can be injected in order to ameliorate or enhance some features: glabellar lines, subdermal support of the brows, malar and buccal fat pads, tear troughs, nasolabial folds, nose, lips, perioral region, marionette lines, oral commisures and chin among others, as well as saucerized acne scars. Other medical indications include nipple projection for nipple areolar reconstruction, urinary incontinence, vesicoureteral reflux, vocal cord augmentation, and use as a radiographic tissue marker. The average lasting result is from 12 to 18 months. Radiesse can be considered an effective soft-tissue filler for overall longevity, biocompatibility, and low rate of side effects.     

Neurogenic disorders of osmoregulation

The osmolality of body fluids is normally maintained within a narrow range. This constancy is achieved largely via hypothalamic osmoreceptors that regulate thirst and arginine vasopressin, the antidiuretic hormone (ADH). Anything that interferes with the full expression of either osmoregulatory function exposes the patient to the hazards of abnormal increases or decreases in plasma osmolality. Hyposmolarity is almost always due to a defect in water excretion. Increased intake may contribute to the problem but is rarely, if ever, a sufficient cause. Impaired water excretion can be due to a primary defect in the osmoregulation of ADH (inappropriate antidiuresis) or secondary to nonosmotic stimuli like hypovolemia or nausea. The two types differ in clinical presentation and treatment. Resetting of the ADH osmostat is commonly associated with resetting of the thirst osmostat. Hyperosmolarity is almost always due to deficient water intake. Excessive excretion may contribute to the problem but is never a sufficient cause. Impaired water intake can result from a defect in either the osmoregulation of thirst or the necessary motor responses. Thirst may be deficient because of primary osmoreceptor damage as in the syndrome of adipsic hypernatremia or secondary to nonomsotic influences on the set of the system. They are distinguishable by the clinical presentation as well as the type of ADH defects with which they are associated. So-called essential hypernatremia due to primary resetting of the osmostat has been postulated, but unambiguous evidence for such an entity has not yet been reported.     

A knowledge based method for the medical question answering problem

In this paper, a restricted domain question answering (QA) system is described. The design architecture of this QA system and the features that allow the adaptation of the QA system to the medical domain are also presented. The advantages of this QA system include the simple process of defining the question taxonomy answered by the system as well as the possibility of locally or remotely managed document collections. The main computing methods of the QA system are based on the application of natural language processing (NLP) techniques to infer the logic forms and on the treatment of the logic forms. The knowledge of the system is acquired through the use of two different resources: Unified Medical Language System (UMLS) to handle the medical terminology and WordNet to manage the open-domain terminology.