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R Whiteside

Publications and source records attributed to R Whiteside.

13 recordsLinked to original sources
PubMed2005

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. Twenty-eight osteochondral specimens [14 from the femoral condyles (FCs) and 14 from the patella-femoral (PF) groove] were tested in confined compression before and after being frozen at -20 degrees C for 7 days. The fluid-independent and fluid-dependent mechanical properties (aggregate modulus of the solid phase and the half-life of stress relaxation respectively) were determined and compared. The aggregate modulus decreased by 13.5 per cent and 20.1 per cent for the PF and FC regions respectively (p = 0.002) and the half-life of the stress relaxation at 10 per cent strain decreased by 6.4 per cent and 12.6 per cent for the PF and FC specimens respectively (p = 0.0341). In conclusion, it has been shown that the protocol used, which involved freezing to -20 degrees C and thawing after 7 days, caused artefacts in the mechanical properties of porcine osteochondral specimens. It is suggested that protocols requiring freezing must be critically reviewed to eliminate such artefacts.

Animals↗
PubMed2002

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. Each of ten volunteer subjects was monitored simultaneously by two identical Nellcor pulse oximeters, one with a plastic cover and the other, without a cover, used as a control. The pulse oximetry (SpO2) reading for each probe was recorded while subjects breathed 21% O2 and again while they breathed 10% O2. The probe cover was then swapped onto the other probe and the recordings were repeated. Ninety-five per cent limits of agreement in SpO2 (mean difference in SpO2 (1.95 x standard deviation of difference) between covered and non-covered probes were -0.6% to 0.6% while breathing 21% oxygen and -2.0% to 2.9% while breathing 10% oxygen. We conclude that a protective plastic sheath may induce a small error in pulse oximetry reading that is most marked during hypoxaemia. This error is unlikely to be of clinical significance.

Adult↗
PubMed2001

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.

Journal Article↗
PubMed2000

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. A PCEA pump was set to deliver ropivacaine 8 mg with fentanyl 8 micrograms with each successful demand and a lockout period of 15 min without background infusion. Patients were observed for rest and activity pain VAS, side effect incidence, peak expiratory flow rate (PEFR), leg strength, sensory block to cold and pinprick, and PCEA usage into the second postoperative day. Passive and active pain scores for both groups were both satisfactory and comparable for the duration of the study. There were no differences between groups with regard to side effects. There was a 24% increase in total drug used in the high-concentration/low-volume group (P < 0.05). The study demonstrated that PCEA ropivacaine with fentanyl is an effective means of postoperative analgesia for this patient population. Reduced drug consumption with high-volume/low-concentration solution confirms similar findings by other investigators using alternate local anaesthetic agents, and suggests that the therapeutic ratio of ropivacaine is widened if a low-concentration/high-volume solution is used.

Adult↗
PubMed1996

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. The purpose of this model was to investigate the clinical outcomes and potential cost savings for gemcitabine used as monotherapy compared to cisplatin and etoposide combination therapy in late stage non-small cell lung cancer (NSCLC), in a palliative (as opposed to aggressive) chemotherapy setting. Gemcitabine treatment data were taken from a large NSCLC study and data from retrospective chart reviews identified through the National Oncology Data Base. The model population and effectiveness of the two regimens were judged to be similar, except for baseline performance status. If drug costs were not included, the probability distribution resulting from the simulation showed median cost savings per cycle ranging from $US 1504 to $US 7425, with a medium value of $US 2154. The model suggested that gemcitabine would result in cost savings per cycle more than 90% of the time. Outpatient versus inpatient drug administrations accounted for the majority of potential cost savings. Most of the remaining cost savings were attributable to the difference in febrile neutropenia and antiemetic use. This economic model showed susbstantial savings if gemcitabine was used instead of cisplatin and etoposide combination therapy in the United States' community care setting. Some savings would be realized even if the location of treatment for both regimens was mostly outpatient. Assessment of the product's economic value before launch has assisted in our understanding of the potential areas of cost savings for gemcitabine and has guided us in the design of prospective randomized studies which included pharmacoeconomic endpoints.

Antimetabolites, Antineoplastic↗
PubMed1990

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.

Adolescent↗
PubMed1986

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. The present paper describes use of this multimodal approach within selected residential settings, and outlines the structured materials developed by the authors.

Acting Out↗
PubMed1980

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.

Attitude↗
PubMed1979

Development of a closed-loop artificial pancreas.

A closed-loop glucose controlled insulin infusion system was developed, consisting of elements for continuous blood glucose analysis, a computer control system, and infusion systems. Improvements include decreased size, cost reduction and better performance. The algorithm used was a piecewise linear representation of the sigmoidal curve commonly employed. The apparatus has been applied to simulation of the healthy beta cell and glucose clamp studies.

Artificial Organs↗
PubMedDate not supplied

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.

Acting Out↗