Melphalan dosing regimens for management of recurrent melanoma by isolated limb perfusion: Application of a physiological pharmacokinetic model based on melphalan distribution in the isolated perfused rat hindlimb

The optimal dosing schedule for melphalan therapy of recurrent malignant melanoma in isolated limb perfusions has been examined using a physiological pharmacokinetic model with data from isolated rat hindlimb perfusions (IRHP), The study included a comparison of melphalan distribution in IRHP under hyperthermia and normothermia conditions. Rat hindlimbs were perfused with Krebs-Henseleit buffer containing 4.7% bovine serum albumin at 37 or 41.5 degrees C at a flow rate of 4 ml/min. Concentrations of melphalan in perfusate and tissues were determined by high performance liquid chromatography with fluorescence detection, The concentration of melphalan in perfusate and tissues was linearly related to the input concentration. The rate and amount of melphalan uptake into the different tissues was higher at 41.5 degrees C than at 37 degrees C. A physiological pharmacokinetic model was validated from the tissue and perfusate time course of melphalan after melphalan perfusion. Application of the model involved the amount of melphalan exposure in the muscle, skin and fat in a recirculation system was related to the method of melphalan administration: single bolus > divided bolus > infusion, The peak concentration of melphalan in the perfusate was also related to the method of administration in the same order, Infusing the total dose of melphalan over 20 min during a 60 min perfusion optimized the exposure of tissues to melphalan whilst minimizing the peak perfusate concentration of melphalan. It is suggested that this method of melphalan administration may be preferable to other methods in terms of optimizing the efficacy of melphalan whilst minimizing the limb toxicity associated with its use in isolated limb perfusion.

Models of alcohol use by young adults: An examination of various attitude-behavior theories

Objective: The aim of this study was to test the effectiveness of various attitude-behavior theories in explaining alcohol use among young adults. The theory of reasoned action (TRA), the theory of planned behavior and an extension of the TRA that incorporates past behavior were compared by the method of maximum-likelihood estimation, as implemented in LISREL for Windows 8.12. Method: Respondents consisted of 122 university students (82 female) who were questioned about their attitudes, subjective norms, perceived behavioral control, past behavior and intentions relating to drinking behavior. Students received course credit for their participation in the research. Results: Overall, the results suggest that the extension of the theory of reasoned action which incorporates past behavior provides the best fit to the data. For these young adults, their intentions to drink alcohol were predicted by their past behavior as well as their perceptions of what important others think they should do (subjective norm). Conclusions: The main conclusions drawn from the research concern the importance of focusing on normative influences and past behavior in explaining young adult alcohol use. Issues regarding the relative merit of various alternative models and the need for greater clarity in the measure of attitudes are also discussed.

The pattern and control of reproductive development in non-astringent persimmon (Diospyros kaki L.): a review

Non-astringent persimmon is rapidly expanding as a new fruit crop in warm subtropical regions of the world, Most research and development of this fruit crop has occurred in Japan, where there is a considerable amount of published literature on its performance. Much of this information is not readily accessible to other countries and needs to be interpreted and modified for other climatic regions. This paper reviews reproductive events from floral initiation to the completion of fruit growth. The timing and significance of these events is described in relation to the phenological cycle. Method of improving flowering, reducing fruit drop and altering the fruit maturity period are discussed. (C) 1997 Elsevier Science B.V.

The impact of staff empowerment and communication style on customer evaluations: The special case of service failure

Empowering front-line staff to deal with service failures has been proposed as a method of recovering from service breakdown and ensuring greater customer satisfaction. However, no empirical study has investigated consumer responses to empowerment strategies. This research investigates the effect on customer satisfaction and service quality of two employee characteristics: the degree to which the employee is empowered (full, limited, and none), and the employee's communication style (accommodative - informal and personal, and underaccommodative-formal and impersonal). These employee characteristics are studied within the context of service failures. Subjects were shown videotaped service scenarios, and asked to complete satisfaction and service quality ratings. Results revealed that the fully empowered employee produced more customer satisfaction than the other conditions, but only when the service provider used an accommodating style of communication. Fully empowered and nonempowered employees were not judged differently when an underaccommodating style of communication was adopted. (C) 1997 John Wiley & Sons, Inc.

A simple solution of the laminar dam break wave

The sudden release of a mass of fluid in a channel generates a highly unsteady flow motion, called dam break wave. While industrial fluids exhibit sometimes non-Newtonian behaviours, the viscous fluid flow assumption remains a useful approximation for simplified analyses. In this study, new solutions of laminar dam break wave are proposed for a semi-infinite reservoir based upon the method of characteristics. The solutions yield simple explicit expressions of the wave front location, wave front celerity and instantaneous free-surface profiles that compare favourably with experimental observations. Both horizontal and sloping channel configurations are treated. The simplicity of the equations may allow future extension to more complicated fluid flows.

Analyzing the researcher's work in generating data: The case of complaints

This article investigates the researcher's work in the coproduction (or not) of complaint sequences in research interviews. Using a conversation analytic approach, we show how the interviewer's management of complaint sequences in a research setting is consequential for subsequent talk and thus directly affects the data generated. In the examples shown here, researchers sharing cocategorial incumbency with respondents may well provide spaces for research participants to formulate complaints. This article examines sequences of talk surrounding complaints to show how researchers generate complaints (or not) and handle unsafe complaints. Researchers are able to provoke specific types of accounts from respondents, whereas their respondents may actively resist the researchers' direction. For researchers using the interview as a method of data generation, examination of complaint sequences and how these appear in interview data provides insight into how interview talk is coproduced and managed within a socially situated setting.

Assessment of body composition by bioelectrical impedance analysis without the need for measurement of height

Conventional whole-body single frequency bioelectrical impedance analysis (BIA) of body composition typically uses height as a surrogate measure of conductor length. A new method of BIA analysis for the prediction of body cell mass (BCM) and extracellular water (ECW, as % body weight) not using height has been introduced-the Soft Tissue Analyser (STA(TM), Akern Sri, Florence, Italy)-making it ideal for use in subjects where measurement of height is difficult or impossible. The performance of the new analytical method in predicting BCM and ECW in 139 normal control subjects was assessed by comparison with reference data obtained from a four-component (4-C) model of body composition and with predictions obtained from conventional BIA analysis. Both predicted BCM and ECW were strongly (r = 0.82, SEE = 6.3 kg and 0.89, SEE = 1.3 kg respectively) correlated with the corresponding 4-C model measurements although differing significantly from the lines of identity (P < 0.0001). Fat-free mass, calculated from STA estimates of BCM and ECW, was better predicted (r = 0.91, SEE = 5.6 kg). The significant differences in STA-group mean values for BCM and ECW and wide limits of agreement compared with the reference data indicate that the method cannot be used with confidence for prediction of these body compartments despite the obvious advantage of not requiring an accurate measurement of height. (C) 2001 Harcourt Publishers Ltd.

Localization of small esophageal cancers for radiation planning using endoscopic contrast injection: report on a series of eight cases

Recently, Barrett's esophagus and early adenocarcinomas have been detected increasingly frequently in routine follow-up of patients with gastroesophageal reflux. Although surgery is the treatment of choice, some patients are medically unfit for esophagectomy and, in this case, the only alternative curative therapy is radical chemoradiation therapy. In addition, some patients who present with symptoms have small tumors that cannot be localized accurately using routine imaging techniques. This report describes a series of eight patients with small esophageal cancers in whom the tumors were successfully localized following endoscopic injection of contrast, and treated with chemoradiation therapy. The treatment was successful in seven patients. This method of tumor localization demonstrated that conventional techniques are mostly, unreliable when applied to very early cancers.

Specification, refinement and verification of concurrent systems - An integration of Object-Z and CSP

This paper presents a method of formally specifying, refining and verifying concurrent systems which uses the object-oriented state-based specification language Object-Z together with the process algebra CSP. Object-Z provides a convenient way of modelling complex data structures needed to define the component processes of such systems, and CSP enables the concise specification of process interactions. The basis of the integration is a semantics of Object-Z classes identical to that of CSP processes. This allows classes specified in Object-Z to he used directly within the CSP part of the specification. In addition to specification, we also discuss refinement and verification in this model. The common semantic basis enables a unified method of refinement to be used, based upon CSP refinement. To enable state-based techniques to be used fur the Object-Z components of a specification we develop state-based refinement relations which are sound and complete with respect to CSP refinement. In addition, a verification method for static and dynamic properties is presented. The method allows us to verify properties of the CSP system specification in terms of its component Object-Z classes by using the laws of the the CSP operators together with the logic for Object-Z.

Development and implementation of the population Fisher information matrix for the evaluation of population pharmacokinetic designs.

In population pharmacokinetic studies, the precision of parameter estimates is dependent on the population design. Methods based on the Fisher information matrix have been developed and extended to population studies to evaluate and optimize designs. In this paper we propose simple programming tools to evaluate population pharmacokinetic designs. This involved the development of an expression for the Fisher information matrix for nonlinear mixed-effects models, including estimation of the variance of the residual error. We implemented this expression as a generic function for two software applications: S-PLUS and MATLAB. The evaluation of population designs based on two pharmacokinetic examples from the literature is shown to illustrate the efficiency and the simplicity of this theoretic approach. Although no optimization method of the design is provided, these functions can be used to select and compare population designs among a large set of possible designs, avoiding a lot of simulations.

SAR imaging of buried objects from MoM modelled scattered field

Synthetic aperture radar (SAR) images of resonant buried objects are modelled in the presence of ground surface clutter. The method of moments (MoM) is used to model scattered fields from a resonant buried conductor and clutter is modelled as a bivariant Gaussian distribution. A diffraction stack SAR imaging technique is applied to the ultra-wideband waveforms to give a bipolar signal image. A number of examples have been computed to illustrate the combined effects of SAR processing with resonant targets and clutter. SAR images of different targets show differences which may facilitate target identification. To maximise the peak signal-to-clutter ratio, an image correlation technique is applied and the results are shown.

Complex natural resonances of conducting planar objects buried in a dielectric half-space

A scheme is presented to incorporate a mixed potential integral equation (MPIE) using Michalski's formulation C with the method of moments (MoM) for analyzing the scattering of a plane wave from conducting planar objects buried in a dielectric half-space. The robust complex image method with a two-level approximation is used for the calculation of the Green's functions for the half-space. To further speed up the computation, an interpolation technique for filling the matrix is employed. While the induced current distributions on the object's surface are obtained in the frequency domain, the corresponding time domain responses are calculated via the inverse fast Fourier transform (FFT), The complex natural resonances of targets are then extracted from the late time response using the generalized pencil-of-function (GPOF) method. We investigate the pole trajectories as we vary the distance between strips and the depth and orientation of single, buried strips, The variation from the pole position of a single strip in a homogeneous dielectric medium was only a few percent for most of these parameter variations.

Heat of desorption measured by means of electrical heat excitation

A new method of measuring heat of desorption is proposed in this Letter. The principle of the method is to measure the amount of mass released when a controlled amount of energy is supplied directly to a solid adsorbent. This is in contrast to conventional methods such as microcalorimetry, where heat released upon adsorption is measured. In this method, a quantified heat supply is generated by passing a de current through a carbon pellet, which is equilibrated with a gas phase confined in a closed vessel. As a consequence of the heating, the particle temperature is increased, resulting in partial desorption of adsorbed molecules. The variations of pellet temperature and the system pressure with respect to time are used to determine the heat of desorption as a function of loading.

Prospective survey of tick paralysis in dogs

Objective To obtain information on tick paralysis in dogs, including the nature of disease, host signalment, tick-host relationship, treatment, disease progression and recovery, and preventive measures. Design A prospective survey of 577 dogs affected by tick paralysis was conducted during 1998. Forty-two veterinary clinics along the eastern coast of Australia were instructed to complete survey forms for the first 15 dogs that presented with tick paralysis during September to November. Results Five percent of dogs died from tick paralysis. Younger dogs were more likely to survive. Long coat length was associated with a greater tick burden but not greater tick size, whereas coat thickness had no bearing on either. Dogs with mild disease recovered more quickly from tick paralysis. Respiratory and gait scores reflected disease severity and were good prognostic indicators. The size of the tick did not reflect the severity of the clinical condition it induced in the host. No method of tick removal or in situ treatment improved recovery time or reduced mortality. However, the time spent in hospital was significantly less for dogs from which the live tick was manually removed. Inspiratory strider. evident in some dogs with tick paralysis, was not related to tick attachment on the neck. The use of acepromazine maleate or dexamethasone did not reduce recovery time or mortality. Increasing the dose of tick antitoxin serum (TAS) above 0.1 mL/kg had no effect on mortality or recovery time. Dogs with severe disease that received an additional dose of TAS were significantly less likely to survive. Subcutaneous use of TAS at the site of tick attachment was of no benefit in reducing mortality or time to initial clinical improvement. A registered preventative product had not been used on the majority of dogs. Clipping the coat to search for ticks did not reduce mortality. Conclusions Therapy needs to address cardiopulmonary dysfunction that may be due directly to the effect of tick toxin and not just respiratory compromise caused by progressive respiratory muscle failure.

Minimum acceptable standards for digital compression of a fetal ultrasound video-clip

If the Internet could be used as a method of transmitting ultrasound images taken in the field quickly and effectively, it would bring tertiary consultation to even extremely remote centres. The aim of the study was to evaluate the maximum degree of compression of fetal ultrasound video-recordings that would not compromise signal quality. A digital fetal ultrasound videorecording of 90 s was produced, resulting in a file size of 512 MByte. The file was compressed to 2, 5 and 10 MByte. The recordings were viewed by a panel of four experienced observers who were blinded to the compression ratio used. Using a simple seven-point scoring system, the observers rated the quality of the clip on 17 items. The maximum compression ratio that was considered clinically acceptable was found to be 1:50-1:100. This produced final file sizes of 5-10 MByte, corresponding to a screen size of 320 x 240 pixels, running at 15 frames/s. This study expands the possibilities for providing tertiary perinatal services to the wider community.