A new device to detect early cartilage degeneration

BACKGROUND: Currently available arthroscopic techniques do not allow the quantification of cartilage stiffness without direct mechanical indentation or penetration of the tissue. PURPOSE: A novel device, capable of quantifying cartilage stiffness during arthroscopy, is believed to detect degenerated cartilage. STUDY DESIGN: Controlled laboratory study. METHODS: The stiffness of biological materials was measured arthroscopically without contact between the instrument and the examined object. Object deformation was produced by a flow of sodium chloride and measured optically. Eight ovine femoral condyles and tibial plateaus were tested in a native and degenerated (0.1% trypsin solution) state. Cartilage stiffness was nondestructively determined by using the new device and by indentation methods. In addition, a standard probe was measured by 5 independent users. RESULTS: The trypsin caused cartilage degeneration and consequently stiffness reduction, measured at 30.8% by the new device and 33.0% by indentation. A good correlation (r = 0.69) between the new device and the standard indentation procedure was observed. Intraindividual and interindividual variability of the new device were low (<10%). CONCLUSIONS: The developed device has demonstrated the ability to quantify the mechanical quality of cartilage by means of mechanical stiffness measurements. Clinical Relevance: The findings suggest that this device has the capability to detect cartilage degeneration at an early stage.     

Crystal forms of LY334370 HCl: isolation,solid-state characterization,and physicochemical properties

LY334370 HCl, a 5HT1f agonist investigated for the treatment of migraines, was identified in five crystal forms: three anhydrates (I-III), a dihydrate, and an acetic acid solvate. The identification and characterization of these crystal forms by optical microscopy, differential scanning calorimetry, thermogravimetric and moisture sorption analyses, solid-state NMR spectroscopy, and X-ray crystallography (Form I only) are presented. Physical properties, including hygroscopicity, solubility, and intrinsic dissolution rate, were assessed for Form I and the dihydrate, the two most viable crystal forms for commercial development. Surprisingly, anhydrous Form I was found to be the thermodynamically most stable crystal form in water, dissolving six times slower than the dihydrate, a difference that correlates well with the rank order of aqueous solubility.     

Tyrosine-kinase expression profiles in human gastric cancer cell lines and their modulations with retinoic acids

Many protein tyrosine kinases are key regulators involved in cellular growth, differentiation, development, apoptosis and signal transduction pathways. Obtaining a comprehensive tyrosine-kinase expression profile in tumour cells is essential to learning more about their oncogenic potentials and responses to various chemotherapeutic reagents - such as retinoic acid, which has been shown to suppress the growth of gastric cancer cells and modulate gene expression. Expression of tyrosine kinases in retionic acid-treated cancer cells was investigated by reverse trancriptase-polymerase chain reaction (RT-PCR) and a novel restriction analysis of gene expression (RAGE) display technique. We first established comprehensive tyrosine-kinase profiles in different human gastric cancer cell lines. In cells treated with 9-cis-retinoic acid or all-trans-retinoic acid, we found that two PTKs (Eph and Hek5) appeared to be upregulated. In the present study, we demonstrate an efficient and simple RAGE approach for examining tyrosine kinases' expression in tumour cells and their alterations following drug treatments.     

The use of the laryngeal mask--a practical method?

In 1985 Brain et al. published their first experience with the laryngeal mask, developed by themselves. With this mask it is possible to seal the larynx and ventilate a patient during anesthesia without endotracheal intubation. Meanwhile, further reports of successful use have been published, especially in Great Britain. We decided to investigate this new anesthetic device. In 15 patients (ASA groups I and II) undergoing elective operations in the supine position the laryngeal mask was inserted after induction of anesthesia with propofol and alfentanil (Fig. 1). Positioning of the laryngeal mask was carried out as described by Brain. In all patients the laryngeal masks could be inserted without any problems, manual ventilation of the patient was performed immediately, and ventilating pressures never exceeded 15 cm H2O. We observed neither complications related to airway control nor technical problems. Cardiovascular parameters and arterial oxygen saturations were always in the normal range (Fig. 2). In 3 patients quick movements of the head were carried out during repositioning of a fractured zygomatic arch, but no complications due to a possible changed position of the laryngeal mask occurred. Postoperatively two patients reported airway complaints such as sore throat. Our investigation confirmed the previously described advantages of the laryngeal mask. We consider its use to be especially indicated in general anesthesia for short surgical or diagnostic procedures or if specific complications of endotracheal intubation should be avoided. A critical aspect in the use of the laryngeal mask is the fact that there is no complete isolation of the trachea and, therefore, an insufflation of the stomach or aspiration could occur, especially during critical situations (e.g. bronchospasms).(ABSTRACT TRUNCATED AT 250 WORDS)