Selective monoalkylation of p-tert-butylcalix-[4]-arene in a methyl carbonate ionic liquid.

Methyl carbonate ionic liquids are shown to readily mono-deprotonate p-tert-butylcalix-[4]-arenes initiating the formation of an organic mono-anionic p-tert-butylcalix-[4]-arate salt, methanol and carbon dioxide. These calix-[4]-arate salts have been successfully used in alkylation reactions with dialkyl sulfates and alkyl halides to form a mono-alkylated single product with high yield. This method avoids the common use of alkali metal bases such as caesium fluoride hence providing a safer and more selective synthetic route.

Spontaneous Substitutions at Phosphorus Trihalides in Imidazolium Halide Ionic Liquids: Grotthuss Diffusion of Anions?

PX compounds (X=Cl, Br, I) in imidazolium halide ionic liquids combine with the anion Z (Z=Cl, Br, I) of the solvent to form [PX Z] complex anions. These anions have a sawhorse shape in which the lone pair of the phosphorus atom fills the third equatorial position of the pseudotrigonal bipyramid. Theoretical results show that this association remains incomplete due to strong hydrogen bonding with the cations of the ionic liquid, which competes with the phosphorus trihalide for interaction with the Z anion.

Comparison of cartilage histopathology assessment systems on human knee joints at all stages of osteoarthritis development.

Objective: To compare the MANKIN and OARSI cartilage histopathology assessment systems using human articular cartilage from a large number of donors across the adult age spectrum representing all levels of cartilage degradation.

Design: Human knees (n=125 from 65 donors; age range 23-92) were obtained from tissue banks. All cartilage surfaces were macroscopically graded.

Effective lubrication of articular cartilage by an amphiphilic hyaluronic acid derivative.

Background: Intra-articular injection of hyaluronic acid based therapies is gaining popularity as a treatment option for non-operative management of patients with symptomatic osteoarthritis. Although there is an abundance of evidence for both biological and mechanical mechanisms of joint protection by hyaluronic acid, one clear intention of viscosupplementation is to reduce friction and wear by providing an extrinsic lubricant. We tested the in vitro friction response of a novel hyaluronic acid derivative that presents amphiphilic features to promote adhesion to the cartilage surface and thereby improve cartilage lubrication.

Preclinical Studies for Cartilage Repair: Recommendations from the International Cartilage Repair Society.

Investigational devices for articular cartilage repair or replacement are considered to be significant risk devices by regulatory bodies. Therefore animal models are needed to provide proof of efficacy and safety prior to clinical testing. The financial commitment and regulatory steps needed to bring a new technology to clinical use can be major obstacles, so the implementation of highly predictive animal models is a pressing issue.

Identification of markers to characterize and sort human articular chondrocytes with enhanced in vitro chondrogenic capacity.

Objective: To identify markers associated with the chondrogenic capacity of expanded human articular chondrocytes and to use these markers for sorting of more highly chondrogenic subpopulations.

Methods: The chondrogenic capacity of chondrocyte populations derived from different donors (n = 21) or different clonal strains from the same cartilage biopsy specimen (n = 21) was defined based on the glycosaminoglycan (GAG) content of tissues generated using a pellet culture model. Selected cell populations were analyzed by microarray and flow cytometry.

Cartilage tissue engineering for degenerative joint disease.

Pain in the joint is often due to cartilage degeneration and represents a serious medical problem affecting people of all ages. Although many, mostly surgical techniques, are currently employed to treat cartilage lesions, none has given satisfactory results in the long term. Recent advances in biology and material science have brought tissue engineering to the forefront of new cartilage repair techniques.

Impact loading of articular cartilage during transplantation of osteochondral autograft.

Surgical reconstruction of articular surfaces by transplantation of osteochondral autografts has shown considerable promise in the treatment of focal articular lesions. During mosaicplasty, each cylindrical osteochondral graft is centred over the recipient hole and delivered by impacting the articular surface. Impact loading of articular cartilage has been associated with structural damage, loss of the viability of chondrocytes and subsequent degeneration of the articular cartilage.

Artefacts in the mechanical characterization of porcine articular cartilage due to freezing.

Many experimental protocols for investigating articular cartilage mechanics have involved the use of a freeze-thaw cycle for storage or tissue manipulation. It was hypothesized that mechanical properties are altered due to freeze-thaw cycling. The aim of this study, therefore, was to examine the possibility of protocol-induced artefacts in the mechanical properties of porcine articular cartilage specimens related specifically to freeze-thaw events.

Biomechanical assessment of lateral stiffness elements in the suspension system of a backpack.

The purpose of this study was to examine the change in load distribution characteristics associated with adding lateral stiffness elements (rods) to a rucksack (backpack). A load distribution mannequin was instrumented with two 3D load cells to allow determination of the load applied to the shoulders and upper torso independent of the load applied to the hips and lower trunk. Position and mass of the payload (25 kg) were fixed at the centre of the volume of the rucksack and held constant during all testing.

Short-term load bearing capacity of osteochondral autografts implanted by the mosaicplasty technique: an in vitro porcine model.

Articular surface congruency and graft stability are considered essential factors in the success of osteochondral grafting; however, quantitative measures of short-term load bearing capacity of grafts implanted by the mosaicplasty technique have not been reported. The purpose of this study was to develop a live tissue in vitro model to examine short-term fixation strength of mosaicplasty autografts immediately after and 1 week following graft implantation. Cylindrical osteochondral autografts were implanted in vitro by the mosaicplasty technique on five pairs of porcine femoral condyles within one and a half hours of animal sacrifice.

Development of a three-dimensional finite element model for carpal load transmission in a static neutral posture.

A three-dimensional developmental finite element model has been created to analyze load transmission pathways in the constrained carpus during static compressive loading. The bone geometry was extracted from an in vivo computed tomography scan using a combination of commercial and proprietary software. The complete geometry, including bone, cartilage, and ligament tissues, was compiled using a commercial finite element program.

Pseudo-renal failure following the delayed diagnosis of bladder perforation after diagnostic laparoscopy.

We present a case of bladder injury as a complication of gynaecological laparoscopic surgery. A young female presented with peritonitis, an acute systemic inflammatory response and biochemical features of acute renal failure secondary to urinary peritonitis. Laparotomy with drainage of urine from the peritoneal cavity and repair of the bladder perforation resulted in rapid resolution of the biochemical abnormalities.

The effect of a disposable probe cover on pulse oximetry.

The re-use of pulse oximeter probes presents the possibility of between-patient contamination. Use of a disposable polyethylene cover may reduce this risk. In a controlled, prospective study we examined the effect of such a cover on the accuracy of pulse oximetry.

Industrial scale-up of countercurrent chromatography: predictive scale-up.

This study describes how scale-up in countercurrent chromatography (CCC) can be simply predicted on a process scale CCC device by running a preliminary analytical-sized sample and having knowledge of the stationary-phase retention at scale-up conditions. Results have shown that simple experimentation can lead within a day to a process with the capability of several kilograms per day (tons per year) compound yield, and that this is feasible with benchtop CCC units.

Epidural ropivacaine with fentanyl following major gynaecological surgery: the effect of volume and concentration on pain relief and motor impairment.

In a prospective, randomized, double-blind study, 40 patients undergoing gynaecological oncology surgery received either 0.1% ropivacaine with fentanyl 1 microgram ml-1 or 0.2% ropivacaine with fentanyl 2 micrograms ml-1.

Economic value of gemcitabine compared to cisplatin and etoposide in non-small cell lung cancer.

Although chemotherapy costs have not been highlighted traditionally, there is increasing pressure to demonstrate the value of new treatments within the health care budget. Pharmaceutical companies are assessing the economic value of their products before launch. Gemcitabine is a nucleoside analogue developed for use in solid tumours.

Structured role assignment and other techniques for facilitating process in adolescent psychotherapy groups.

The application of various types of techniques for structuring the interchange and feedback process in adolescent psychotherapy groups is described. Techniques include random assignment of "roles" for each member during sessions, "parent hot seat" exercises, group goal booklets, and negotiation exercises. These have proved helpful in ensuring effective group participation, providing practice in social skills and verbalization of feelings, and in the development of other specific mastery skills.

Biofeedback, cognitive training and relaxation techniques as multimodal adjunct therapy for hospitalized adolescents: a pilot study.

Modifications and adjuncts to traditional therapy techniques appear to be necessary for successfully treating hospitalized adolescents with impaired social and verbal skills, and a history of acting-out behavior. Modified therapy groups were combined with a structured biofeedback and cognitive training program to help these adolescents control anger and modify their behavior. Used in conjunction with training and practice in relaxation techniques, this multimodal treatment approach appeared to be helpful in both reducing incidents of acting out on residential units, and in reaching individualized therapeutic goals.

Legal issues affecting residential child care workers.

Most respondents felt that child care workers' legal concerns should be addressed by requiring (1) thorough, legally approved written procedures and guidelines for all day-to-day procedures and responsibilities; (2) legally approved comprehensive record-keeping systems; and (3) access to legal support and counsel. When child care workers follow legal guidelines and a facility's procedure manuals carefully, documenting their activities in an approved record-keeping system, they can expect to be in a positive situation in any legal contest and to have behavior measured from a legal standpoint by a standard described as what a "reasonable person" would be expected to do in a similar situation and circumstance.

An experimental study of the effect of structured videotape feedback on adolescent group psychotherapy process.

Group psychotherapy with disturbed undersocialized adolescents requires modification of traditional group psychotherapy methods. The effectiveness of a structured, brief video-tape feedback and discussion on group psychotherapy process with this population was studied by an analysis of detailed ratings of each "statement", or process unit; in randomly selected videotapes from a control and experimental group during a nine-month period. Significant differences in level of intimacy of verbal content and in frequency of feedback about behavior in content indicate that this technique is effective in facilitating group psychotherapy goals.

Pre-therapy training for adolescents in group psychotherapy: contracts, guidelines, and pre-therapy preparation.

Although adolescents in psychotherapy groups have been described as requiring more structure and preparation than adults, and as generally showing more critical deficits in verbal feedback and other interpersonal skills necessary for successful group functioning, no specific, detailed programs for preparation and pretraining of adolescents for group therapy are described in the literature. The present paper outlines a specific program developed for outpatient adolescent psychotherapy groups which has successfully speeded development of group cohesion, increased expression of positive expectancies for treatment reduced time spent in "pass-time" discussion, decreased verbalized concerns over confidentiality issues, and facilitated growth of patient skills in giving and receiving verbal feedback.