Prosthodontics and the patient. Part 2: Need becoming demand, demand becoming utilization

PURPOSE: Patients' oral health needs are estimated through dialogue and professional assessment. The concepts of need and demand are vital to studies of dental care and oral health. Need does not always lead to demand for treatment or to utilization, depending on the gatekeeping processes between need and demand and between demand and utilization. Demand must be accepted with the understanding that there is no objective need and that demand depends on the patient's opinion. In accordance with this, the need for prosthodontic treatment is highly individual and is not automatically related to oral health status, making need and demand difficult to measure in that respect. Therefore, sociodental factors should be included and evaluated in studies of need and demand for utilization of prosthodontic care. MATERIALS AND METHODS: This theoretical and analytic paper focuses on the gatekeeping processes between need and demand and between demand and utilization of prosthodontic care. RESULTS: The concept of gatekeeping refers to the social and psychologic processes that transform need into demand and demand into utilization. It implies that they are complex processes that can render great differences between demand and actual utilization. CONCLUSION: It is not possible to estimate a patient's needs for prosthodontic care, since there is no objective need. Demand and utilization are factors that play an important role in the gatekeeping process. These factors are dependent on the patient's opinion, which is influenced by numerous factors.     

Multicenter evaluation of parametric response mapping as an indicator of bronchiolitis obliterans syndrome after hematopoietic stem cell transplantation

Parametric response mapping (PRM) is a novel computed tomography (CT) technology that has shown potential for assessment of bronchiolitis obliterans syndrome (BOS) after hematopoietic stem cell transplantation (HCT). The primary aim of this study was to evaluate whether variations in image acquisition under real‐world conditions affect the PRM measurements of clinically diagnosed BOS. CT scans were obtained retrospectively from 72 HCT recipients with BOS and graft‐versus‐host disease from Fred Hutchinson Cancer Research Center, Karolinska Institute, and the University of Michigan. Whole lung volumetric scans were performed at inspiration and expiration using site‐specific acquisition and reconstruction protocols. PRM and pulmonary function measurements were assessed. Patients with moderately severe BOS at diagnosis (median forced expiratory volume at 1 second [FEV1] 53.5% predicted) had similar characteristics between sites. Variations in site‐specific CT acquisition protocols had a negligible effect on the PRM‐derived small airways disease (SAD), that is, BOS measurements. PRM‐derived SAD was found to correlate with FEV1% predicted and FEV1/ forced vital capacity (R = ?0.236, P = .046; and R = ?0.689, P < .0001, respectively), which suggests that elevated levels in the PRM measurements are primarily affected by BOS airflow obstruction and not CT scan acquisition parameters. Based on these results, PRM may be applied broadly for post‐HCT diagnosis and monitoring of BOS.     

Use of a linearization approximation facilitating stochastic model building

The objective of this work was to facilitate the development of nonlinear mixed effects models by establishing a diagnostic method for evaluation of stochastic model components. The random effects investigated were between subject, between occasion and residual variability. The method was based on a first-order conditional estimates linear approximation and evaluated on three real datasets with previously developed population pharmacokinetic models. The results were assessed based on the agreement in difference in objective function value between a basic model and extended models for the standard nonlinear and linearized approach respectively. The linearization was found to accurately identify significant extensions of the model’s stochastic components with notably decreased runtimes as compared to the standard nonlinear analysis. The observed gain in runtimes varied between four to more than 50-fold and the largest gains were seen for models with originally long runtimes. This method may be especially useful as a screening tool to detect correlations between random effects since it substantially quickens the estimation of large variance–covariance blocks. To expedite the application of this diagnostic tool, the linearization procedure has been automated and implemented in the software package PsN.     

Reflux from the continent ileostomy reservoir

The reflux from the continent ileostomy reservoir was studied with radiologic and pressure recording techniques in ten patients. The contrast used was poly-iodine-styrene with a density of 0.8 to 1.1 gm/cm3. Reflux into the afferent loop was demonstrated in all patients at a filling volume of approximately 30 percent of the maximal volume capacity of the reservoir. The magnitude of reflux increased with the increasing volume of the reservoir contents and a rise in reservoir pressure. The reflux could temporarily be influenced by antiperistaltic or isoperistaltic motor activity in the afferent loop. Although no adverse effects were seen from the amount of reflux demonstrated in the present investigation, the finding of increasing reflux with increased fullness and intraluminal pressure of the reservoir would indicate that the reservoir should be emptied at regular intervals and before high pressures are built up.     

Neurotrophic factor intervention restores auditory function in deafened animals

A primary cause of deafness is damage of receptor cells in the inner ear. Clinically, it has been demonstrated that effective functionality can be provided by electrical stimulation of the auditory nerve, thus bypassing damaged receptor cells. However, subsequent to sensory cell loss there is a secondary degeneration of the afferent nerve fibers, resulting in reduced effectiveness of such cochlear prostheses. The effects of neurotrophic factors were tested in a guinea pig cochlear prosthesis model. After chemical deafening to mimic the clinical situation, the neurotrophic factors brain-derived neurotrophic factor and an analogue of ciliary neurotrophic factor were infused directly into the cochlea of the inner ear for 26 days by using an osmotic pump system. An electrode introduced into the cochlea was used to elicit auditory responses just as in patients implanted with cochlear prostheses. Intervention with brain-derived neurotrophic factor and the ciliary neurotrophic factor analogue not only increased the survival of auditory spiral ganglion neurons, but significantly enhanced the functional responsiveness of the auditory system as measured by using electrically evoked auditory brainstem responses. This demonstration that neurotrophin intervention enhances threshold sensitivity within the auditory system will have great clinical importance for the treatment of deaf patients with cochlear prostheses. The findings have direct implications for the enhancement of responsiveness in deafferented peripheral nerves.     

ATPases and phosphate exchange activities in magnesium chelatase subunits of Rhodobacter sphaeroides

Three separate proteins, BchD, BchH, and BchI, together with ATP, insert magnesium into protoporphyrin IX. An analysis of ATP utilization by the subunits revealed the following: BchH catalyzed ATP hydrolysis at the rate of 0.9 nmol per min per mg of protein. BchI and BchD, tested individually, had no ATPase activity but, when combined, hydrolyzed ATP at the rate of 117.9 nmol/min per mg of protein. Magnesium ions were required for the ATPase activities of both BchH and BchI+D, and these activities were inhibited 50% by 2 mM o-phenanthroline. BchI additionally catalyzed a phosphate exchange reaction from ATP and ADP. We conclude that ATP hydrolysis by BchI+D is required for an activation step in the magnesium chelatase reaction, whereas ATPase activity of BchH and the phosphate exchange activity of BchI participate in subsequent reactions leading to the insertion of Mg²⁺ into protoporphyrin IX.     

Preservation of Red Blood Cells: Studies of Erythrocyte Adenine Nucleotides Using Luminescence Analysis

The levels of ATP and total adenine nucleotides (ATP + ADP + AMP) were determined by firefly luciferase assay in red blood cells during storage for 5 weeks at 4 degrees C. With few exceptions, no significant differences in nucleotide levels were found between whole blood stored in CPD-adenine and various preparations of red blood cells in CPD-adenine or CPD with saline-adenine-glucose (SAG) as additive. The levels of ATP and total adenine nucleotides during storage are discussed in relation to glucose levels, extracellular pH and shelf life of the red blood cells.     

Cocaine use in Europe - a multi-centre study. Methodology and prevalence estimates

An increase in the use of cocaine and crack in several parts of Europe has raised the question whether this trend is similar to that of the USA in the 1980s. However, research in the field of cocaine use in Europe has been only sporadic. Therefore, a European multi-centre and multi-modal project was designed to study specific aspects of cocaine and crack use in Europe, in order to develop guidelines for public health strategies. Data on prevalence rates were analysed for the general population and for specific subgroups. Despite large differences between countries in the prevalence of cocaine use in the general population, most countries show an increase in the last few years. The highest rate with a lifetime prevalence of 5.2% was found for the United Kingdom, although with a plateau effect around the year 2000. With regard to specific subgroups, three groups seem to show a higher prevalence than the general population: (1) youth, especially in the party scene; (2) socially marginalized groups, such as homeless and prostitutes or those found in open drug scenes; (3) opiate-dependent patients in maintenance treatment who additionally use cocaine. Specific strategies need to be developed to address problematic cocaine use in these subgroups.