Projected Savings to Canadian Provincial Budgets from Reduced Long-Term Care Home Utilization Due to a Disease-Modifying Alzheimer's Treatment

BACKGROUND

A disease-modifying Alzheimer's treatment could provide budgetary savings to Canadian provinces from a reduction in long-term care home use, yet we do not know the magnitude of those potential savings.

OBJECTIVE

We project savings to each Canadian province's budget from 2023 to 2043.

DESIGN

Annual savings are projected using a Markov model. We account for reduction in long-term care home use and in use of Alternative Level of Care (ALC) beds, which are hospital beds occupied by care home-eligible patients on the wait list for admission.

RESULTS

A treatment that delays disease progression by 40% is projected to avoid 142,507 long-term care home and ALC years, resulting in $17.2 billion cumulative savings across all Canadian provinces, a 21% relative reduction among treatment eligible patients. Average per capita savings were $1,132, ranging from $734 (Alberta) to $2,895 (Prince Edward Island). Cumulative savings could increase to $22.7 billion with enhanced triage of patients in primary care stages and to $25.6 billion if all capacity constraints for diagnosis and treatment were removed.

CONCLUSION

A disease-modifying treatment could create budgetary savings from lower long-term care home use, offsetting part of the treatment cost. With the increasing demand for long-term care home beds and the high rates of patients being held in hospitals while wait-listed, such a treatment could additionally provide relief to the overburdened long-term care system in Canada.

Health Economic Considerations in the Deployment of an Alzheimer's Prevention Therapy

INTRODUCTION

As treatments for secondary prevention of Alzheimer's disease (AD) are being studied, concerns about their value for money have appeared. We estimate cost-effectiveness of a hypothetical screening and prevention program.

METHODS

We use a Markov model to project cost-effectiveness of a treatment that reduces progression to symptomatic AD by 50% with either chronic treatment until progression to mild cognitive impairment or treatment for one year followed by monitoring with AD blood tests and retreatment with one dose in case of amyloid re-accumulation. Diagnoses would be made with an AD blood test with sensitivity and specificity of 80%, and inconclusive results in 20%. Individuals testing negative would be re-tested in five years and those with inconclusive results in one.

RESULTS

The program would generate per-person value of $53,721 from a payer (reduction of direct cost and patient QALY gains) and $69,861 from a societal perspective (adding valuation of reduced caregiver burden). With chronic treatment, it would be cost-effective up to annual drug prices of $7,000 and $10,300, respectively. Time-limited treatment would be cost-effective at annual drug prices of $54,257 and $78,458 from a payer and societal perspective, respectively. Higher specificity of the blood test would decrease cost per person with similar value generation DISCUSSION: A hypothetical prevention treatment for AD could be economically viable from a payer and societal perspective.

Detection Rates of Mild Cognitive Impairment in Primary Care for the United States Medicare Population

BACKGROUND

Existing evidence points to substantial gaps in detecting mild cognitive impairment in primary care but is based on limited or self-reported data. The recent emergence of disease-modifying treatments for the Alzheimer's disease, the most common etiology of mild cognitive impairment, calls for a systematic assessment of detection rates in primary care.

OBJECTIVES

The current study aims to examine detection rates for mild cognitive impairment among primary care clinicians and practices in the United States using Medicare claims and encounter data.

DESIGN

Observational study.

SETTING

Medicare administrative data.

PARTICIPANTS

The study sample includes a total of 226,756 primary care clinicians and 54,597 practices that had at least 25 patients aged 65 or older, who were enrolled in Medicare fee-for-service or a Medicare Advantage plan between 2017 and 2019.

MEASUREMENTS

The detection rate for mild cognitive impairment is assessed as the ratio between the observed diagnosis rate of a clinician or practice as documented in the data, and the expected rate based on a predictive model.

RESULTS

The average detection rates for mild cognitive impairment is 0.08 (interquartile range=0.00-0.02) for both clinicians and practices, suggesting that only about 8% of expected cases were diagnosed on average. Only 0.1% of clinicians and practices had diagnosis rates within the expected range.

CONCLUSIONS

Mild cognitive impairment is vastly underdiagnosed, pointing to an urgent need to improve early detection in primary care.

Chemistry and microstructure of C-supported Ru catalyst nanoparticles: A correlative study

Ru@Pt core shell nanoparticles possess optimal catalytic properties that facilitate the anodic oxidation reaction of H2 with decreased Pt loading in hydrogen fuel cells. Moreover, since they preferentially oxidize CO, Pt poisoning is considerably reduced, which significantly improves the stability of the cell. The Ru cores used in this system are usually synthesized by dissolving a RuCl3*H2O precursor in an ethylene glycol-carbon black-NaOH mixture. However, the possibility that remnant Cl and Na from the synthesis process are present in the Ru nanoparticles has not been extensively studied. Therefore, due to the challenges in detecting impurities with traditional characterization methods, here correlative atom probe tomography (APT) with scanning transmission electron microscopy ((S)TEM) techniques were implemented. The capabilities of APT to obtain chemical information with high sensitivity at the nanoscale, in combination with the high spatial resolving power of (S)TEM, provide the necessary resolution to fully characterize the structure and chemical makeup of Ru nanoparticles.

Tracking the Mn Diffusion in the Carbon-Supported Nanoparticles Through the Collaborative Analysis of Atom Probe and Evaporation Simulation

Carbon-supported nanoparticles have been used widely as efficient catalysts due to their enhanced surface-to-volume ratio. To investigate their structure–property relationships, acquiring 3D elemental distribution is required. Here, carbon-supported Pt, PtMn alloy, and ordered Pt3Mn nanoparticles are synthesized and analyzed with atom probe tomography as model systems. A significant difference of Mn distribution after the heat-treatment was found. Finally, the field evaporation behavior of the carbon support was discussed and each acquired reconstruction was compared with computational results from an evaporation simulation. This paper provides a guideline for studies using atom probe tomography on the heterogeneous carbon-supported nanoparticle system that leads to insights toward a wide variety of applications.

Shear band-driven precipitate dispersion for ultrastrong ductile medium-entropy alloys

Precipitation strengthening has been the basis of physical metallurgy since more than 100 years owing to its excellent strengthening effects. This approach generally employs coherent and nano-sized precipitates, as incoherent precipitates energetically become coarse due to their incompatibility with matrix and provide a negligible strengthening effect or even cause brittleness. Here we propose a shear band-driven dispersion of nano-sized and semicoherent precipitates, which show significant strengthening effects. We add aluminum to a model CoNiV medium-entropy alloy with a face-centered cubic structure to form the L2₁ Heusler phase with an ordered body-centered cubic structure, as predicted by ab initio calculations. Micro-shear bands act as heterogeneous nucleation sites and generate finely dispersed intragranular precipitates with a semicoherent interface, which leads to a remarkable strength-ductility balance. This work suggests that the structurally dissimilar precipitates, which are generally avoided in conventional alloys, can be a useful design concept in developing high-strength ductile structural materials.

Atom Probe Tomography Investigations of Ag Nanoparticles Embedded in Pulse-Electrodeposited Ni Films

Atomic mapping of nanomaterials, in particular nanoparticles, using atom probe tomography (APT) is of great interest, as their properties strongly depend on shape, size, and composition. However, APT analyses of nanoparticles are extremely challenging, and there is an urgent need for developing robust and universally applicable sample preparation methods. Herein, we explored a method based on pulse electrodeposition to embed Ag nanoparticles in a Ni matrix and prepare APT specimens from the resulting composite film. By systematically varying the duty cycle during pulse electrodeposition, the dispersion and number density of the nanoparticles within the matrix was significantly enhanced as compared to DC electrodeposition. Several Ag nanoparticles were analyzed with APT from such samples. Shape distortions and biased compositions were observed for the Ag nanoparticles after applying a standard data reconstruction protocol. Numerical simulations of the field evaporation process showed that such artifacts were caused by a difference in the evaporation field of Ni and Ag and a local magnification effect. We expect such detrimental effects to be mitigated by a careful selection of the matrix material, matching the evaporation field of the nanoparticles. Furthermore, we anticipate that the method presented herein can be extended to a wider range of nanomaterials.

Reducing Time to Discovery: Materials and Molecular Modeling, Imaging, Informatics, and Integration

Multiscale and multimodal imaging of material structures and properties provides solid ground on which materials theory and design can flourish. Recently, KAIST announced 10 flagship research fields, which include KAIST Materials Revolution: Materials and Molecular Modeling, Imaging, Informatics and Integration (M3I3). The M3I3 initiative aims to reduce the time for the discovery, design and development of materials based on elucidating multiscale processing-structure-property relationship and materials hierarchy, which are to be quantified and understood through a combination of machine learning and scientific insights. In this review, we begin by introducing recent progress on related initiatives around the globe, such as the Materials Genome Initiative (U.S.), Materials Informatics (U.S.), the Materials Project (U.S.), the Open Quantum Materials Database (U.S.), Materials Research by Information Integration Initiative (Japan), Novel Materials Discovery (E.U.), the NOMAD repository (E.U.), Materials Scientific Data Sharing Network (China), Vom Materials Zur Innovation (Germany), and Creative Materials Discovery (Korea), and discuss the role of multiscale materials and molecular imaging combined with machine learning in realizing the vision of M3I3. Specifically, microscopies using photons, electrons, and physical probes will be revisited with a focus on the multiscale structural hierarchy, as well as structure-property relationships. Additionally, data mining from the literature combined with machine learning will be shown to be more efficient in finding the future direction of materials structures with improved properties than the classical approach. Examples of materials for applications in energy and information will be reviewed and discussed. A case study on the development of a Ni-Co-Mn cathode materials illustrates M3I3's approach to creating libraries of multiscale structure-property-processing relationships. We end with a future outlook toward recent developments in the field of M3I3.

An OLTAM system for analysis of brown/beige fat thermogenic activity

BACKGROUND/OBJECTIVES

Thermogenic fat is present in humans and emerging evidence indicates that increasing the content and activity of these adipocytes may lead to weight loss and improved metabolic health. Multiple reporter systems have been developed to assay thermogenic fat activity based on the transcriptional and translational activation of Ucp1, the key molecule that mediates nonshivering thermogenesis. Our study aims to develop a much-needed tool to monitor thermogenic fat activity through a mechanism independent of Ucp1 regulation, therefore effectively assaying not only canonical β-adrenergic activation but also various non-UCP1-mediated thermogenic pathways that have been increasingly appreciated.

METHODS

We detected increased luciferase activity upon thermogenic activation in interscapular brown and inguinal subcutaneous fat in ODD-Luc mice, a hypoxia reporter mouse model. We then developed an OLTAM (ODD-Luc based Thermogenic Activity Measurement) system to assay thermogenic fat cell activity.

RESULTS

In both primary murine and human adipocytes and an immortalized adipose cell line that were transduced with the OLTAM system, luciferase activity can be readily measured and visualized by bioluminescence imaging in response to a variety of stimuli, including UCP1-independent thermogenic signaling. This system can offer a convenient method to assay thermogenic activity for both basic and translational research.

CONCLUSIONS

The OLTAM system offers a convenient way to measure of the activation of thermogenic fat and presents opportunities to discover novel signaling pathways and unknown compounds targeting metabolically active adipocytes to counteract human obesity.

Kidney Donor Risk Index as the Predictor for the Short-term Clinical Outcomes After Kidney Transplant From Deceased Donor With Acute Kidney Injury

BACKGROUND

The Kidney Donor Risk Index (KDRI) scoring system for deceased donors has been widely introduced for postoperative evaluation of graft function. We analyzed the usefulness of the KDRI in deceased donors with acute kidney injury (AKI).

METHODS

Forty-nine recipients from deceased donors with AKI between January 2009 and December 2014 were reviewed retrospectively. Data collected from donor medical records included age, height, weight, hypertension or diabetes history, cause of death, serum creatinine (sCr), and donation after cardiac death. Graft function data including sCr, estimated glomerular filtration rate (eGFR), and acute rejection episodes were monitored for 1 year. Correlations between KDRI score and factors indicating graft function were analyzed. A cutoff value for KDRI score was calculated using a receiver operating characteristic (ROC) curve for significant graft function.

RESULTS

The mean ages of donors and recipients were 46.81 ± 13.13 and 47.69 ± 11.43, respectively. The mean KDRI score was 1.24 ± 0.40. Univariable analysis of KDRI score and factors indicating graft function indicated that sCr at 6 to 12 months, eGFR at 1 year, and slow graft function (SGF) had statistical significance. The ROC curve of KDRI score for SGF showed an optimal cutoff value of 1.20, with sensitivity of 69.2% and specificity of 69.4% (area under the curve = 0.75) in deceased donors with AKI.

CONCLUSIONS

KDRI score in deceased donors with AKI was correlated with postoperative graft values including eGFR and SGF. KDRI could be used as a predictor for the short-term clinical outcome after kidney transplant from deceased donor with AKI.

Localized CT-guided irradiation inhibits neurogenesis in specific regions of the adult mouse brain

Radiation is used in the study of neurogenesis in the adult mouse both as a model for patients undergoing radiation therapy for CNS malignancies and as a tool to interrupt neurogenesis. We describe the use of a dedicated CT-guided precision device to irradiate specific sub-regions of the adult mouse brain. Improved CT visualization was accomplished with intrathecal injection of iodinated contrast agent, which enhances the lateral ventricles. T2-weighted MRI images were also used for target localization. Visualization of delivered beams (10 Gy) in tissue was accomplished with immunohistochemical staining for the protein γ-H2AX, a marker of DNA double-strand breaks. γ-H2AX stains showed that the lateral ventricle wall could be targeted with an accuracy of 0.19 mm (n = 10). In the hippocampus, γ-H2AX staining showed that the dentate gyrus can be irradiated unilaterally with a localized arc treatment. This resulted in a significant decrease of proliferative neural progenitor cells as measured by Ki-67 staining (P < 0.001) while leaving the contralateral side intact. Two months after localized irradiation, neurogenesis was significantly inhibited in the irradiated region as seen with EdU/NeuN double labeling (P < 0.001). Localized radiation in the rodent brain is a promising new tool for the study of neurogenesis.

Whitening effect of alpha-bisabolol in Asian women subjects

SYNOPSIS

Although skin pigmentation, which results from the production and distribution of melanin in the epidermis, is the major physiological defence against solar irradiation, hyperpigmentation is a common and distressing problem caused by various inflammatory skin disorders, such as eczema, allergic contact dermatitis and irritant contact dermatitis. We evaluated the effects of a preparation containing alpha-bisabolol on pigmented skin of a group of subjects. The effectiveness of the active compound, alpha-bisabolol, in a base-cream preparation for the treatment of pigmented skin was tested on 28 female subjects as follows: the cream was applied once a day to the back for 8 weeks. These same women also applied a vehicle control cream to the pigmented skin. The results were evaluated by clinical and biophysical test methods. After 8 weeks of treatment of the alpha-bisabolol-containing cream, there was significant lightening effect in the pigmented skin for the majority of the subjects who tested the cream.

Lymphatic drainage of the skull base: comparative anatomic and advanced imaging studies in the rabbit and human with implications for spread of nasopharyngeal carcinoma

This preliminary study investigated the lymphatic drainage and distribution of lymphatic structures in the skull base. Characteristics of the rabbit skull base were analyzed and compared correspondingly with those of the human skull. The lymphatic circulation in the rabbit cranial base was detected by digital subtraction angiography (DSA), and lymph drainage in the human skull base was illustrated by interstitial magnetic resonance lymphography (MRL). Lymphatic structures and their distribution in MRL were identified by comparing with contrast-enhanced MRI and clinical data on basilar metastasis of nasopharyngeal carcinoma (NPC) in the human skull base. Anatomic similarity was found between the rabbit and human basilar regions. Well-visualized lymphatic pathways were found in the rabbit cranial base, and human lymphatic structures showed high signal intensity in enhanced T1-weighted MRL images. Lymphatic tissues in the human basilar region were found mainly distributed in the areas of the jugular foramen, foramen lacerum, and petrosal section of the internal carotid artery (ICA). Their distribution in the human basilar region was similar to the distribution in the rabbit basilar region and consistent with our clinical findings of the predilection sites of NPC metastasis in the skull base. Our studies show that bilateral symmetrical lymphatic structures were distributed along the ICA, internal jugular vein, and dura of cranial base in the central part of the middle and posterior skull base.

Distributed modelling of urban runoff using a meta-channel concept

Hydraulic flood routing is advantageous for computational accuracy; however, it requires individual calculations of an extensive pipe network in the case of a two-dimensional analysis. In this study, a method for considering the characteristics of a two-dimensional pipe network has been developed using the meta-channel concept to simplify the detailed calculations involved in the estimation of runoff from urban catchments. In essence, the meta-channel concept turns a two-dimensional pipe network into a one-dimensional pipe with an effective hydraulic geometry. Once such geometry has been identified, the flood routing can then be performed for an urban drainage system. A nonlinear diffusion wave equation, derived from the Saint-Venant equation, was used for flood routing, with an explicit method used for the numerical solution. The celerity and diffusion coefficients, which are two parameters of the diffusion wave equation, were estimated for the Goonja drainage from a two-dimensional pipe network using the meta-channel concept. A comparison of the results of the meta-channel-based pipe routing with the distributed SWMM simulation and observed data, showed close similarities, and identified the applicability of the meta-channel concept in an urban drainage setting.

Clinical significance of type 1 insulin-like growth factor receptor and insulin-like growth factor binding protein-3 expression in squamous cell carcinoma of head and neck

6036

Background: Type 1 insulin-like growth factor receptor (IGF-1R) plays an important role in the growth and apoptosis of cancer cell. The activities of IGF-1R are modulated by a family of high-affinity insulin-like growth factor binding proteins (IGFBPs), of which IGFBP-3 is the major serum carrier protein. The expression and significance of IGF-1R and IGFBP-3 in squamous cell carcinoma of the head and neck (SCCHN) is unknown. Methods: This study explored immunohistochemical expression of IGF-1R and IGFBP-3 in tumor samples from 131 patients with surgically resected SCCHN. Results: The positive expression of IGF-1R and IGFBP-3 was observed in 96 (73.3%) and 117 (89.3%) patients. There were no significant differences in baseline characteristics between the positive and negative expressed groups of IGF-1R and IGFBP-3. With the median follow up of 53.5 months, 3 year progression free (PFS) and overall (OS) survival rate was 64.0% and 72.9%, neither IGF-1R nor IGFBP-3 expression had prognostic values in the whole cohort. Thirty-seven (67.3%) of 55 stage IV patients demonstrated IGF-1R positivity. The subgroup analysis of in stage IV patients showed the poor PFS ( = 0.029) and OS (pp = 0.025) in IGF-1R positive groups. In a multivariate analysis using IGF-1R expression and other clinicopathological parameters, the IGF-1R expression was remained as an independent factor for PFS (p = 0.037, HR = 2.816, 95% C.I. 1.065 - 7.446) and OS (p = 0.034, HR = 3.169, 95% C.I. 1.089 - 9.225). Conclusions: Our work exhibited that IGF-1R expression is frequent in SCCHN patients and related with poor survival in advanced stage, this could support the attempts using the IGF-1R inhibitor for treatment of SCCHN.

No significant financial relationships to disclose.

Clinical significance of ERCC1 expression in advanced squamous cell carcinoma of the head and neck treated with cisplatin- based concurrent chemoradiation

6061

Background: The cytotoxic effect of cisplatin is based on the DNA cross linking. Nucleotide excision repair is associated with resistant to platinum-based chemotherapy. The excision repair cross-complementation group 1 (ERCC1) enzyme plays a rate-limiting role in nucleotide excision repair pathway. We evaluated the expression of ERCC1 as a predictive factor for survival in patients of squamous cell carcinoma of the head and neck (SCCHN) treated with cisplatin-based concurrent chemoradiotherapy (CCRT). Methods: We reviewed the clinical records and pathologic specimens of locally advanced SCCHN patients who had been treated with cisplatin-based definitive CCRT between 1995 and 2005. ERCC1 expression of the biopsy specimen was assessed by immunohistochemical (IHC) staining and a semi- quantitative grading system (H-score) was used for the evaluation. The median value of the H-score was chosen as the cutoff point for positive ERCC1 expression. Results: A total of 44 specimens and clinical data of the patients were reviewed. The median age was 59 years (range; 27–75), and 81.8% were male; 94.2% had ECOG performance status 0–1. The positive ERCC1 expression rate was 54.5% of all specimens (N=24/44). Overall tumor response rate for CCRT was 90.9% (CR=65.9%; PR=25.0%). With a median follow-up of 45.9 months (range; 5.4–133.0), 5-year progression free survival (PFS) rate was 58.0% and 5-year overall survival (OS) rate was 57.2%. Patients in group of positive ERCC1 expression showed poor survival in terms of PFS and OS (p=0.04; p=0.05), compared with negative ERCC1 expression group. Conclusions: The positive ERCC1 expression might be a predictive factor for poor survival and early progression in patients with locally advanced SCCHN treated with cisplatin-based CCRT.

No significant financial relationships to disclose.

Pharmacokinetic disposition of polyethylene glycol-modified salmon calcitonins in rats

This study first reports the pharmacokinetic disposition of polyethylene glycol (PEG)-modified salmon calcitonin (sCT) based on the number of attached PEG molecules. PEG-modified sCT was prepared by covalent linkage with succinimidyl carbonate monomethoxy polyethylene glycol. Mono- and di-PEG-sCTs were separated by size exclusion and reverse phase HPLC, and radioiodinated by the chloramine-T method with Na125I. 125I-mono-PEG sCT, 125I-di-PEG-sCT and unmodified 125I-sCT were administered to rats by i.v. injection. Serial blood samples, urine and various tissue samples were taken for the determination of radioactivity. Di-PEG-sCT exhibited significantly reduced systemic clearance (2.3 vs. 11.1 ml/min/kg) and steady-state volume of distribution (229.9 vs. 603.1 ml/kg), while mono-PEG-sCT showed a prolonged elimination half-life (189.1 min vs. 59.8 min) compared with unmodified sCT. The extent of urinary excretion of the PEG-modified sCTs was higher than for the unmodified sCT, but all these chemicals were excreted in urine in small quantities (< or = 0.6%). There was a tendency toward reduced accumulation of PEGylated sCTs in tissues, with its reduction being inversely proportional to the molecular size. Accumulation of the total radioactivity of the unmodified and PEG-modified sCTs was highest in the liver, followed by kidneys, lungs, spleen, heart and thyroid. When expressed per tissue gram weight, however, the highest radioactivity was found in the kidneys. PEGylated sCTs may have greater therapeutic potential via reduced systemic clearance and prolonged elimination half-life over unmodified sCT.

Absorption, first-pass metabolism, and disposition of itraconazole in rats

This study examined the pharmacokinetic disposition, oral absorption and hepatic extraction of itraconazole and its active metabolite, hydroxyitraconazole, in rats. After i.v. injection, serum itraconazole concentrations decreased biexponentially, with an average terminal elimination half-life, volume of distribution and systemic clearance of 4.9 h, 6.0 l/kg and 14.2 ml/min/kg, respectively. When given orally, its absorption was low, with a mean absolute bioavailability of 16.6%. The metabolite to parent drug area under the curve (AUC) ratio was higher after oral administration compared with i.v. injection (mean ratio, 2.7 vs. 0.9). The hepatic drug extraction ratio determined after femoral and portal vein administration averaged 18.5%. When hydroxyitraconazole was injected i.v., the elimination half-life, volume of distribution and systemic clearance of itraconazole averaged 10.0 h, 2.4 l/kg and 3.4 ml/min/kg, respectively. The fraction of the systemically available itraconazole that was metabolized to hydroxyitraconazole was 21.0% and 76.0% after i.v. and oral administration, respectively. In summary, this study is the first reporting the hepatic extraction of itraconazole and the i.v. disposition characteristics of hydroxyitraconazole in rats. Itraconazole is a drug with a low hepatic extraction ratio and its systemic clearance appears to be largely accounted for by hepatic metabolism.

Comparison of a new screw-tipped intraosseous needle versus a standard bone marrow aspiration needle for infusion

The purpose of this study is to compare the speed and ease of establishing intraosseous infusion using a standard bone marrow needle (SBMN; $8) and a new screw-tipped intraosseous needle (Sur-Fast; $42). The study is an experimental design. A total of 42 medical students, without prior IO experience, were recruited as study subjects. Subjects were randomized to perform the IO procedures in one of two models: (1) turkey femur or (2) pork ribs. Each subject performed an initial trial using both IO needles without practice (inexperienced) and a second trial using both IO needles after practice (experienced attempt), such that in total, each subject completed four attempts (two with each needle type). IO placement times were measured, and placement difficulty scores were measured using a 10 cm visual analog scale (VAS). The averaged elapsed time to successful IO completion was significantly shorter for the SBMN in the initial "inexperienced" attempt (33 versus 54 seconds, P = .019), but there was no significant difference in the postpractice "experienced" attempt. VAS difficulty scores were lower (easier) for the SBMN for both inexperienced and experienced trials. Success rates were significantly higher for the Sur-Fast needle during the experienced attempt (95% versus 79%, P < .05), but there was no significant difference in success rates during the inexperienced attempt. The Sur-Fast screw-tipped intraosseous needle does not show superiority over the SBMN in this intraosseous model, therefore its higher cost is difficult to justify based on this study.

Bioavailability of itraconazole in rats and rabbits after administration of tablets containing solid dispersion particles

A tablet dosage form containing solid dispersions of itraconazole (Asd tablets) was prepared by using the spray-drying and wet granulation methods. The dissolution rate of itraconazole from Asd tablets was fast, with more than 90% released within 10 min, compared to less than 20% for a marketed product, Sporanox capsules. The oral absorption of itraconazole from Asd tablets was determined in rats and rabbits and was compared with that for Sporanox capsules. In the rat, there was no difference between the Asd tablets and Sporanox capsules in the mean area under the curve (AUC) (3089.5 +/- 4332.8 ng.hr/ml and 3653.9 +/- 2348.9 ng.hr/ml, respectively) and Cmax (295.0 +/- 344.5 and 390.5 +/- 169.4 ng/ml, respectively). Also, in the rabbit, no difference was found between the two products in the mean AUC (AUMC; 19357.9 +/- 5117.5 ng.hr/ml and 23382.2 +/- 6236.5 ng.hr/ml, respectively) and Cmax (766.4 +/- 276.5 and 1127.5 +/- 577.9 ng/ml, respectively). Despite the rapid in vitro release characteristics of itraconazole from the Asd tablets, the in vivo absorption of itraconazole was comparable to that of Sporanox capsules, with no difference in Tmax in both animal species. Serum levels of the major active metabolite hydroxyitraconazole were also measured. Itraconazole was rapidly converted to hydroxyitraconazole in both rats and rabbits, but there were species-specific differences in their pharmacokinetics. It is concluded that, in addition to drug solubility and dissolution characteristics, other formulation factors such as the physical state of the drug and the granulation process, may also need to be considered in the prediction of the in vivo absorption of itraconazole based on in vitro data.

Photobleaching of astaxanthin and canthaxanthin. Quantum-yields dependence of solvent, temperature, and wavelength of irradiation in relation to packaging and storage of carotenoid pigmented salmonoids

The quantum yield for the photobleaching of astaxanthin (the carotenoid of wild salmonoids) and of canthaxanthin (the closely related carotenoid used as a feeding additive for farmed salmonoids) has been determined for monochromatic light at different wavelengths and in different solvents. Astaxanthin is less sensitive to light than canthaxanthin. The photobleaching is strongly wavelength dependent, and the quantum yield for astaxanthin dissolved in chloroform at 22 degrees C is 3.2 x 10(-1) mol.Einstein-1 at 254 nm, 3.1 x 10(-2) at 313 nm, and 1.6 x 10(-6) at 436 nm, respectively. The quantum yields are less dependent on the nature of the solvent and show no simple correlation with oxygen solubility, i.e. for 366 nm excitation of astaxanthin the quantum yields are 6.1 x 10(-5) mol.Einstein-1 in acetone, 1.2 x 10(-4) in saturated vegetable oil, 1.9 x 10(-4) in chloroform, and 3.4 x 10(-4) solubilized in water, respectively. The photobleaching quantum yield provides an objective measure of the light sensitivity of the carotenoids in relation to the discolouration of carotenoid-pigmented salmonoids. The quantum yield was also found to be independent of the carotenoid concentration and, in a homogenous solution, of light intensities. For astaxanthin solubilized in water, the quantum yield increases for low light intensities. Excitation of astaxanthin solubilized in water using visible light shows that the photobleaching quantum yield is independent of temperature, while excitation at 313 nm shows an increase in the quantum yield with increasing temperatures, corresponding to an energy of activation of 28 kJ.mol-1.(ABSTRACT TRUNCATED AT 250 WORDS)