Virtual implant planning in the edentulous maxilla: criteria for decision making of prosthesis design

OBJECTIVES To evaluate prosthetic parameters in the edentulous anterior maxilla for decision making between fixed and removable implant prosthesis using virtual planning software. MATERIAL AND METHODS CT- or DVT-scans of 43 patients (mean age 62 ± 8 years) with an edentulous maxilla were analyzed with the NobelGuide software. Implants (≥3.5 mm diameter, ≥10 mm length) were virtually placed in the optimal three-dimensional prosthetic position of all maxillary front teeth. Anatomical and prosthetic landmarks, including the cervical crown point (C-Point), the acrylic flange border (F-Point), and the implant-platform buccal-end (I-Point) were defined in each middle section to determine four measuring parameters: (1) acrylic flange height (FLHeight), (2) mucosal coverage (MucCov), (3) crown-Implant distance (CID) and (4) buccal prosthesis profile (ProsthProfile). Based on these parameters, all patients were assigned to one of three classes: (A) MucCov ≤ 0 mm and ProsthProfile≥45(0) allowing for fixed prosthesis, (B) MucCov = 0-5 mm and/or ProsthProfile = 30(0) -45(0) probably allowing for fixed prosthesis, and (C) MucCov ≥ 5 mm and/or ProsthProfile ≤ 30(0) where removable prosthesis is favorable. Statistical analyses included descriptive methods and non-parametric tests. RESULTS Mean values were for FLHeight 10.0 mm, MucCov 5.6 mm, CID 7.4 mm, and ProsthProfile 39.1(0) . Seventy percent of patients fulfilled class C criteria (removable), 21% class B (probably fixed), and 2% class A (fixed), while in 7% (three patients) bone volume was insufficient for implant planning. CONCLUSIONS The proposed classification and virtual planning procedure simplify the decision-making process regarding type of prosthesis and increase predictability of esthetic treatment outcomes. It was demonstrated that in the majority of cases, the space between the prosthetic crown and implant platform had to be filled with prosthetic materials.

Measuring motor activity in major depression: the association between the Hamilton Depression Rating Scale and actigraphy

Despite the use of actigraphy in depression research, the association of depression ratings and quantitative motor activity remains controversial. In addition, the impact of recurring episodes on motor activity is uncertain. In 76 medicated inpatients with major depression (27 with a first episode, 49 with recurrent episodes), continuous wrist actigraphy for 24h and scores on the Hamilton Depression Rating Scale (HAMD) were obtained. In addition, 10 subjects of the sample wore the actigraph over a period of 5 days, in order to assess the reliability of a 1-day measurement. Activity levels were stable over 5 consecutive days. Actigraphic parameters did not differ between patients with a first or a recurrent episode, and quantitative motor activity failed to correlate with the HAMD total score. However, of the motor-related single items of the HAMD, the item activities was associated with motor activity parameters, while the items agitation and retardation were not. Actigraphy is consistent with clinical observation for the item activities. Expert raters may not correctly rate the motor aspects of retardation and agitation in major depression.

Duplex sonographic criteria for measuring carotid stenoses

PURPOSE: The aim of this retrospective study was to determine optimal duplex sonographic criteria for use in our institution for diagnosing severe carotid stenoses and to correlate those findings with angiographic measurements obtained by the European Carotid Surgery Trial (ECST), North American Symptomatic Carotid Endarterectomy Trial (NASCET), and Common Carotid (CC) methods of grading carotid stenoses. METHODS: We analyzed the angiographic data using the ECST, NASCET, and CC methods and compared the results with the duplex sonographic findings. We then calculated the sensitivity, specificity, positive and negative predictive values, and accuracy of the duplex sonographic method. Taking these parameters into account, the optimal intrastenotic peak systolic velocity (PSV) and end diastolic velocity (EDV) were derived for diagnosing severe stenoses according to the 3 angiographic methods. RESULTS: Optimal PSV and EDV values for diagnosing a 70% or greater stenosis in our laboratory were as follows: with the NASCET method of angiographic grading of stenoses, PSV 220 cm/second or greater and EDV 80 cm/second or greater, and with the ECST and CC methods, PSV 190 cm/second or greater, and EDV 65 cm/second or greater. The optimal PSV and EDV for diagnosing a stenosis of 80% or greater with the ECST grading method were 215 cm/second or greater and 90 cm/second or greater, respectively. CONCLUSIONS: Duplex sonography is a sensitive and accurate tool for evaluating severe carotid stenoses. Optimal PSVs and EDVs vary according to the angiographic method used to grade the stenosis. They are similar for stenoses 70% or greater with the NASCET method and for stenoses 80% or greater with the ECST method.

Effects of cognitive behavioral stress management on HIV-1 RNA, CD4 cell counts and psychosocial parameters of HIV-infected persons

OBJECTIVE: To determine the effects of cognitive-behavioral stress management (CBSM) training on clinical and psychosocial markers in HIV-infected persons. METHODS: A randomized controlled trial in four HIV outpatient clinics of 104 HIV-infected persons taking combination antiretroviral therapy (cART), measuring HIV-1 surrogate markers, adherence to therapy and well-being 12 months after 12 group sessions of 2 h CBSM training. RESULTS: Intent-to-treat analyses showed no effects on HIV-1 surrogate markers in the CBSM group compared with the control group: HIV-1 RNA < 50 copies/ml in 81.1% [95% confidence interval (CI), 68.0-90.6] and 74.5% (95% CI, 60.4-85.7), respectively (P = 0.34), and mean CD4 cell change from baseline of 53.0 cells/microl (95% CI, 4.1-101.8) and 15.5 cells/microl (95% CI, -34.3 to 65.4), respectively (P = 0.29). Self-reported adherence to therapy did not differ between groups at baseline (P = 0.53) or at 12 month's post-intervention (P = 0.47). Significant benefits of CBSM over no intervention were observed in mean change of quality of life scores: physical health 2.9 (95% CI, 0.7-5.1) and -0.2 (95% CI, -2.1 to 1.8), respectively (P = 0.05); mental health 4.8 (95% CI, 1.8-7.3) and -0.5 (95% CI, -3.3 to 2.2) (P = 0.02); anxiety -2.1 (95% CI, -3.6 to -1.0) and 0.3 (95% CI, -0.7 to 1.4), respectively (P = 0.002); and depression -2.1 (95% CI, -3.2 to -0.9) and 0.02 (95% CI, -1.0 to 1.1), respectively (P = 0.001). Alleviation of depression and anxiety symptoms were most pronounced among participants with high psychological distress at baseline. CONCLUSION: CBSM training of HIV-infected persons taking on cART does not improve clinical outcome but has lasting effects on quality of life and psychological well-being.

Measuring the mechanical properties of plant cells by combining micro-indentation with osmotic treatments

Growth in plants results from the interaction between genetic and signalling networks and the mechanical properties of cells and tissues. There has been a recent resurgence in research directed at understanding the mechanical aspects of growth, and their feedback on genetic regulation. This has been driven in part by the development of new micro-indentation techniques to measure the mechanical properties of plant cells in vivo. However, the interpretation of indentation experiments remains a challenge, since the force measures results from a combination of turgor pressure, cell wall stiffness, and cell and indenter geometry. In order to interpret the measurements, an accurate mechanical model of the experiment is required. Here, we used a plant cell system with a simple geometry, Nicotiana tabacum Bright Yellow-2 (BY-2) cells, to examine the sensitivity of micro-indentation to a variety of mechanical and experimental parameters. Using a finite-element mechanical model, we found that, for indentations of a few microns on turgid cells, the measurements were mostly sensitive to turgor pressure and the radius of the cell, and not to the exact indenter shape or elastic properties of the cell wall. By complementing indentation experiments with osmotic experiments to measure the elastic strain in turgid cells, we could fit the model to both turgor pressure and cell wall elasticity. This allowed us to interpret apparent stiffness values in terms of meaningful physical parameters that are relevant for morphogenesis.

Measuring localized viscoelasticity of the vitreous body using intraocular microprobes.

Vitrectomy is a standard ophthalmic procedure to remove the vitreous body from the eye. The biomechanics of the vitreous affects its duration (by changing the removal rate) and the mechanical forces transmitted via the vitreous on the surrounding tissues during the procedure. Biomechanical characterization of the vitreous is essential for optimizing the design and control of instruments that operate within the vitreous for improved precision, safety, and efficacy. The measurements are carried out using a magnetic microprobe inserted into the vitreous, a method known as magnetic microrheology. The location of the probe is tracked by a microscope/camera while magnetic forces are exerted wirelessly by applied magnetic fields. In this work, in vitro artificial vitreous, ex vivo human vitreous and ex vivo porcine vitreous were characterized. In addition, in vivo rabbit measurements were performed using a suturelessly injected probe. Measurements indicate that viscoelasticity parameters of the ex vivo human vitreous are an order of magnitude different from those of the ex vivo porcine vitreous. The in vivo intra-operative measurements show typical viscoelastic behavior of the vitreous with a lower compliance than the ex vivo measurements. The results of the magnetic microrheology measurements were validated with those obtained by a standard atomic force microscopy (AFM) method and in vitro artificial vitreous. This method allows minimally-invasive characterization of localized mechanical properties of the vitreous in vitro, ex vivo, and in vivo. A better understanding of the characteristics of the vitreous can lead to improvements in treatments concerning vitreal manipulation such as vitrectomy.