Nanoparticle-Enhanced RT-QuIC (Nano-QuIC) Diagnostic Assay for Misfolded Proteins.

Misfolded proteins associated with various neurodegenerative diseases often accumulate in tissues or circulate in biological fluids years before the clinical onset, thus representing ideal diagnostic targets. Real-time quaking-induced conversion (RT-QuIC), a protein-based seeded-amplification assay, holds great potential for early disease detection, yet challenges remain for routine diagnostic application. Chronic Wasting Disease (CWD), associated with misfolded prion proteins of cervids, serves as an ideal model for evaluating new RT-QuIC methodologies. In this study, we investigate the previously untested hypothesis that incorporating nanoparticles into RT-QuIC assays can enhance their speed and sensitivity when applied to biological samples. We show that adding 50 nm silica nanoparticles to RT-QuIC experiments (termed Nano-QuIC) for CWD diagnostics greatly improves the performance by reducing detection times 2.5-fold and increasing sensitivity 10-fold by overcoming the effect of inhibitors in complex tissue samples. Crucially, no false positives were observed with these 50 nm silica nanoparticles, demonstrating the enhanced reliability and potential for diagnostic application of Nano-QuIC in detecting misfolded proteins.

A field-deployable diagnostic assay for the visual detection of misfolded prions.

Diagnostic tools for the detection of protein-misfolding diseases (i.e., proteopathies) are limited. Gold nanoparticles (AuNPs) facilitate sensitive diagnostic techniques via visual color change for the identification of a variety of targets. In parallel, recently developed quaking-induced conversion (QuIC) assays leverage protein-amplification and fluorescent signaling for the accurate detection of misfolded proteins. Here, we combine AuNP and QuIC technologies for the visual detection of amplified misfolded prion proteins from tissues of wild white-tailed deer infected with chronic wasting disease (CWD), a prion disease of cervids. Our newly developed assay, MN-QuIC, enables both naked-eye and light-absorbance measurements for detection of misfolded prions. MN-QuIC leverages basic laboratory equipment that is cost-effective and portable, thus facilitating real-time prion diagnostics across a variety of settings. In addition to laboratory-based tests, we deployed to a rural field-station in southeastern Minnesota and tested for CWD on site. We successfully demonstrated that MN-QuIC is functional in a non-traditional laboratory setting by performing a blinded analysis in the field and correctly identifying all CWD positive and CWD not-detected deer at the field site in 24 h, thus documenting the portability of the assay. White-tailed deer tissues used to validate MN-QuIC included medial retropharyngeal lymph nodes, parotid lymph nodes, and palatine tonsils. Importantly, all of the white-tailed deer (n = 63) were independently tested using ELISA, IHC, and/or RT-QuIC technologies and results secured with MN-QuIC were 95.7% and 100% consistent with these tests for positive and non-detected animals, respectively. We hypothesize that electrostatic forces help govern the AuNP/prion interactions and conclude that MN-QuIC has great potential for sensitive, field-deployable diagnostics for CWD, with future potential diagnostic applications for a variety of proteopathies.

Open-channel microfluidics via resonant wireless power transfer.

Open-channel microfluidics enables precise positioning and confinement of liquid volume to interface with tightly integrated optics, sensors, and circuit elements. Active actuation via electric fields can offer a reduced footprint compared to passive microfluidic ensembles and removes the burden of intricate mechanical assembly of enclosed systems. Typical systems actuate via manipulating surface wettability (i.e., electrowetting), which can render low-voltage but forfeits open-microchannel confinement. The dielectric polarization force is an alternative which can generate open liquid microchannels (sub-100 µm) but requires large operating voltages (50-200 VRMS) and low conductivity solutions. Here we show actuation of microchannels as narrow as 1 µm using voltages as low as 0.5 VRMS for both deionized water and physiological buffer. This was achieved using resonant, nanoscale focusing of radio frequency power and an electrode geometry designed to abate surface tension. We demonstrate practical fluidic applications including open mixing, lateral-flow protein labeling, filtration, and viral transport for infrared biosensing-known to suffer strong absorption losses from enclosed channel material and water. This tube-free system is coupled with resonant wireless power transfer to remove all obstructing hardware - ideal for high-numerical-aperture microscopy. Wireless, smartphone-driven fluidics is presented to fully showcase the practical application of this technology.

Effects of manual therapy on fear avoidance, kinesiophobia and pain catastrophizing in individuals with chronic musculoskeletal pain: Systematic review and meta-analysis.

OBJECTIVE: To systematically review the effectiveness of manual therapy on fear-avoidance, kinesiophobia, and pain catastrophizing in patients with chronic musculoskeletal pain. LITERATURE SEARCH: Databases (Medline, EMBASE, CINAHL, PEDro, CENTRAL, Web of Science, and SCOPUS) were searched from inception up to March 2020. STUDY SELECTION CRITERIA: Two reviewers independently selected randomized controlled trials that investigated the effects of manual therapy associated or not with other interventions on fear-avoidance, kinesiophobia and pain catastrophizing in patients with chronic musculoskeletal pain. DATA SYNTHESIS: Standardized Mean Differences (SMD) and 95% confidence interval (CI) were calculated using a random-effects inverse variance model for meta-analysis according to the outcome of interest, comparison group and follow-up period. The level of evidence was synthesized using GRADE. RESULTS: Eleven studies were included with a total sample of 717 individuals. Manual therapy was not superior to no treatment on reducing fear-avoidance at short-term (low quality of evidence; SMD = -0.45, 95% CI -0.99 to 0.09), and intermediate-term (low quality of evidence; SMD = -0.48, 95% CI -1.0 to 0.04). Based on very-low quality of evidence, manual therapy was not better than other treatments (SMD = 0.10, 95% CI -0.56 to 0.77) on reducing fear-avoidance, kinesiophobia (SMD = -0.12, 95% CI -0.87 to 0.63) and pain catastrophizing (SMD = -0.16, 95% CI -0.48 to 0.17) at short-term. CONCLUSION: Manual therapy may not be superior to no treatment or other treatments on improving fear-avoidance, kinesiophobia and pain catastrophizing, based on very low or low quality of evidence. More studies are necessary to strengthen the evidence of effects of manual therapy on pain-related fear outcomes.

Prospective, Randomized Clinical Trial of Povidone-Iodine 1.25% Solution Versus Topical Antibiotics for Treatment of Bacterial Keratitis.

PURPOSE: To compare povidone-iodine 1.25% ophthalmic solution with topical antibiotics for treatment of bacterial keratitis in areas of the world where use of effective topical antibiotics may not be an option. STUDY DESIGN: Randomized, controlled, investigator-masked clinical trial. METHODS: We randomized 172 individuals with bacterial keratitis to topical treatment with povidone-iodine or antibiotics (neomycin-polymyxin B-gramicidin in the Philippines; ciprofloxacin 0.3% in India). Using survival analysis, we compared intervals from start of treatment to "presumed cure" (primary outcome measure, defined as a closed epithelial defect without associated inflammatory signs) and to "recovering" (residual epithelial defect <1 mm2 with only minimal inflammation). RESULTS: Median interval to presumed cure in the Philippines was 7 days for povidone-iodine and 7 days for neomycin-polymyxin B-gramicidin (95% confidence interval [CI] for difference in median interval, -9.5 to 0.7 days) and in India was 12 days for povidone-iodine and 17 days for ciprofloxacin (95% CI, -35.2 to 3.2 days). Hazard ratio (HR) for presumed cure among those treated with povidone-iodine (vs antibiotics) was 1.46 in the Philippines (95% CI, 0.90-2.36; P = .13) and 1.70 in India (95% CI, 0.73-3.94; P = .22). Comparisons of intervals to recovering and HR for recovering also revealed no significant differences between treatment groups in either country. CONCLUSIONS: There is no significant difference between the effect of topical povidone-iodine 1.25% and topical antibiotics commonly available in the developing world for treatment of bacterial keratitis. Povidone-iodine 1.25%, which is widely available and inexpensive, can be considered for treatment of bacterial keratitis when antibiotic treatment is not practical.

Impact of hospital variables on case mix index as a marker of disease severity.

Case mix index (CMI) has become a standard indicator of hospital disease severity in the United States and internationally. However, CMI was designed to calculate hospital payments, not to track disease severity, and is highly dependent on documentation and coding accuracy. The authors evaluated whether CMI varied by characteristics affecting hospitals' disease severity (eg, trauma center or not). The authors also evaluated whether CMI was lower at public hospitals than private hospitals, given the diminished financial resources to support documentation enhancement at public hospitals. CMI data for a 14-year period from a large public database were analyzed longitudinally and cross-sectionally to define the impact of hospital variables on average CMI within and across hospital groups. Between 1996 and 2007, average CMI declined by 0.4% for public hospitals, while rising significantly for private for-profit (14%) and nonprofit (6%) hospitals. After the introduction of the Medicare Severity Diagnosis Related Group (MS-DRG) system in 2007, average CMI increased for all 3 hospital types but remained lowest in public vs. private for-profit or nonprofit hospitals (1.05 vs. 1.25 vs. 1.20; P<0.0001). By multivariate analysis, teaching hospitals, level 1 trauma centers, and larger hospitals had higher average CMI, consistent with a marker of disease severity, but only for private hospitals. Public hospitals had lower CMI across all subgroups. Although CMI had some characteristics of a disease severity marker, it was lower across all strata for public hospitals. Hence, caution is warranted when using CMI to adjust for disease severity across public vs. private hospitals.

Booze, drugs, and pop music: trends in substance portrayals in the billboard top 100-1968-2008.

This paper presents the results of a content analysis of alcohol and drug portrayals in the top 100 Billboard songs from each of the years 1968, 1978, 1988, 1998, and 2008, thus allowing both a characterization of substance portrayals in music generally and an analysis of changes over time. Of the final sample of 496 songs, 10.3% contained a reference to alcohol and 5.7% contained a reference to drugs. A substantial increase was found over the decades, and in particular over the last two: in 1988, 12% of songs referred to either or both classes of substance, compared to 30% in 2008. Marijuana was by far the most frequently mentioned drug. Both alcohol and drugs were much more likely to be portrayed positively than negatively, especially in recent decades. The results are discussed in terms of relevant theories of media processing and impact.

Characterization of the anaemia associated with Graves' disease.

BACKGROUND: Graves' disease (GD) is associated with hyperthyroidism. Thyrotoxicosis adversely affects multiple organ systems including haematopoiesis. Anaemia occurring specifically in GD has not been systematically studied previously. OBJECTIVE: To define the prevalence and characteristics of the anaemia associated with GD. DESIGN: Eighty-seven newly diagnosed patients with GD were recruited. Haematological indices, thyroid function and inflammatory parameters were examined at presentation and following successful treatment of hyperthyroidism. SETTING: Tertiary care academic referral centre. RESULTS: Thirty-three per cent of subjects presented with anaemia. The prevalence of anaemia not attributable to other causes (GD anaemia) was 22%. GD anaemia affected 41.6% (10/24) of men compared to 17.5% of women (11/63). Mean erythropoietin (EPO) levels (15.5 +/- 5.3 mIU/ml) were within normal reference limits but significantly higher (P = 0.004) than those of the non-anaemic controls. Hgb correlated inversely with EPO (P = 0.05) and CRP (P = 0.04) levels, a relationship that persisted after multivariate adjustment for TT3 or TT4. With antithyroid therapy for 16 +/- 6.3 weeks, Hgb levels normalized in 8 out of 9 subjects with GD anaemia (10.7 +/- 0.8 to 13.5 +/- 1.3 g/dl, P = 0.0001). After normalization of Hgb, mean MCV and TIBC were significantly increased, and median ferritin and mean EPO were significantly decreased. CONCLUSIONS: GD anaemia is common, resembles the anaemia of chronic disease, and is associated with markers of inflammation. It corrects promptly with return to the euthyroid state following treatment.

Emergency Department Allies: a Web-based multihospital pediatric asthma tracking system.

OBJECTIVE: To describe the development of a Web-based multihospital pediatric asthma tracking system and present results from the initial 18-month implementation of patient tracking experience. DESIGN: The Emergency Department (ED) Allies tracking system is a secure, password-protected data repository. Use-case methodology served as the foundation for technical development, testing, and implementation. Seventy-seven data elements addressing sociodemographics, wheezing history, quality of life, triggers, and ED managment were included for each subject visit. SETTING: The ED Allies partners comprised 1 academic pediatric ED and 5 community EDs. POPULATION: Subjects with a physician diagnosis of asthma who presented to the ED for acute respiratory complaints composed the asthma group; subjects lacking a physician diagnosis of asthma but presenting with wheezing composed the wheezing group. RESULTS: The tracking-system development and implementation process included identification of data elements, system database and use case development, and delineation of screen features, system users, reporting functions, and help screens. For the asthma group, 2005 subjects with physician-diagnosed asthma were enrolled between July 15, 2002 and January 14, 2004. These subjects accounted for 2978 visits; 10.4% had > or = 3 visits. Persistent asthma was noted in 68% of the subjects. During the same time period, 1297 wheezing subjects with a total of 1628 ED visits (wheezing group) were entered into the tracking system. After enrollment, 57% of the subjects with > or = 1 subsequent ED visits received a physician diagnosis of asthma. CONCLUSIONS: Our sophisticated tracking system facilitated data collection and identified key intervention opportunities for a diverse ED wheezing population. A significant asthma burden was identified with significant rates of hospitalization, acute care visits and persistent asthma in 68% of subjects. The surveillance component provided important insights into health care issues of both asthmatic subjects and wheezing subjects, many of whom subsequently were diagnosed with asthma.

Rate, extent, and modifiers of spermatogenic recovery after hormonal male contraception: an integrated analysis.

BACKGROUND: Hormonal methods for safe, reliable, and reversible contraception based on the suppression of spermatogenesis could soon become available. We have investigated the rate, extent, and predictors of reversibility of hormonal male contraception. METHODS: We undertook an integrated multivariate time-to-event analysis of data from individual participants in 30 studies published in 1990-2005, in which sperm output was monitored every month until recovery. The primary outcome was the time for the sperm concentration to recover to a threshold of 20 million per mL, an indicator of fertility. We undertook univariate and multivariate analyses, using Kaplan-Meier and Cox's methods. FINDINGS: 1549 healthy eugonadal men who were white (n=965), Asian (almost all Chinese men; n=535), or of other origins (n=49) and aged 18-51 years underwent 1283.5 man-years of treatment and 705 man-years of post-treatment recovery. These data represented about 90% of all published data from individuals using androgen or androgen-progestagen regimens. The median times for sperm to recover to thresholds of 20, 10, and 3 million per mL were 3.4 months (95% CI 3.2-3.5), 3.0 months (2.9-3.1), and 2.5 months (2.4-2.7), respectively. Multivariate Cox's analysis showed higher rates of recovery with older age, Asian origin, shorter treatment duration, shorter-acting testosterone preparations, higher sperm concentrations at baseline, faster suppression of spermatogenesis, and lower blood concentrations of luteinising hormone at baseline. The typical probability of recovery to 20 million per mL was 67% (61-72) within 6 months, 90% (85-93) within 12 months, 96% (92-98) within 16 months, and 100% within 24 months. INTERPRETATION: Hormonal male contraceptive regimens show full reversibility within a predictable time course. Various covariables affect the rate but not the extent of recovery, although their effect sizes are minor. These data are crucial for the further safe and practical development of such regimens.

Acute secondary adrenal insufficiency after traumatic brain injury: a prospective study.

OBJECTIVE: To determine the prevalence, time course, clinical characteristics, and effect of adrenal insufficiency (AI) after traumatic brain injury (TBI). DESIGN: Prospective intensive care unit-based cohort study. SETTING: Three level 1 trauma centers. PATIENTS: A total of 80 patients with moderate or severe TBI (Glasgow Coma Scale score, 3-13) and 41 trauma patients without TBI (Injury Severity Score, >15) enrolled between June 2002 and November 2003. MEASUREMENTS: Serum cortisol and adrenocorticotropic hormone levels were drawn twice daily for up to 9 days postinjury; AI was defined as two consecutive cortisols of < or =15 microg/dL (25th percentile for extracranial trauma patients) or one cortisol of < 5 microg/dL. Principal outcome measures included: injury characteristics, hemodynamic data, usage of vasopressors, metabolic suppressive agents (high-dose pentobarbital and propofol), etomidate, and AI status. MAIN RESULTS: AI occurred in 42 TBI patients (53%). Adrenocorticotropic hormone levels were lower at the time of AI (median, 18.9 vs. 36.1 pg/mL; p = .0001). Compared with patients without AI, those with AI were younger (p = .01), had higher injury severity (p = .02), had a higher frequency of early ischemic insults (hypotension, hypoxia, severe anemia) (p = .02), and were more likely to have received etomidate (p = .049). Over the acute postinjury period, patients with AI had lower trough mean arterial pressure (p = .001) and greater vasopressor use (p = .047). Mean arterial pressure was lower in the 8 hrs preceding a low (< or =15 microg/dL) cortisol level (p = .003). There was an inverse relationship between cortisol levels and vasopressor use (p = .0005) and between cortisol levels within 24 hrs of injury and etomidate use (p = .002). Use of high-dose propofol and pentobarbital was strongly associated with lower cortisol levels (p < .0001). CONCLUSIONS: Approximately 50% of patients with moderate or severe TBI have at least transient AI. Younger age, greater injury severity, early ischemic insults, and the use of etomidate and metabolic suppressive agents are associated with AI. Because lower cortisol levels were associated with lower blood pressure and higher vasopressor use, consideration should be given to monitoring cortisol levels in intubated TBI patients, particularly those receiving high-dose pentobarbital or propofol. A randomized trial of stress-dose hydrocortisone in TBI patients with AI is underway.

Serum fetuin-A in nondialyzed patients with diabetic nephropathy: relationship with coronary artery calcification.

BACKGROUND: Fetuin-A is the most potent circulating inhibitor of calcium phosphorus precipitation and, possibly, an important mediator of insulin resistance. METHODS: In order to determine the role of fetuin-A in the high coronary artery calcification (CAC) burden seen in nondialyzed individuals with diabetic nephropathy (DN), post-hoc analyses of data collected from a cross-sectional study of 88 patients with type 2 diabetes mellitus was done [age, 40-65 years; normoalbuminuria, N= 30 (Latinos); DN, N= 58 (Latinos and African Americans)]. RESULTS: The serum levels of fetuin-A were significantly higher among Latinos with DN when compared to either African Americans with DN or Latino diabetics with normoalbuminuria. Upon adjusting the data for race/ethnicity, there was a strong, direct relationship between serum fetuin-A levels and the CAC score (r= 0.22, P= 0.038) in the study cohort; however, a strong interaction between the nephropathy status and relationship of serum fetuin-A levels with CAC score was present (DN: r= 0.36, P= 0.006; diabetic controls, r= 0.0, P= 0.98). Among individuals with DN, the significance of the association persisted even after controlling the data for other predictors of CAC (partial r= 0.33, P= 0.018). Furthermore, there was a significant direct relationship between serum fetuin-A and serum triglycerides (partial r= 0.27, P= 0.01) and albumin (partial r= 0.30, P= 0.005), and an inverse relationship with glomerular filtration rate (r=-0.24, P= 0.03). CONCLUSION: This first study in early stages of diabetic chronic kidney disease shows that the role of serum fetuin-A may be far more complex than previously described. During predialysis stage of DN, there is a direct relationship between serum fetuin-A levels and CAC score. The reasons for this association in the presence of nephropathy are unclear, but may be secondary to proatherogenic insulin resistance.

Non-linear cardiac output dynamics during ramp-incremental cycle ergometry.

Published literature asserts that cardiac output (Q(.) = V(.) >O(2)x1/C((a-v))O(2)) increases as a linear function of oxygen uptake with a slope of approximately 5-6 during constant work rate exercise. However, we have previously demonstrated that C((a-v))O(2) has a linear relationship as a function of V(.)O(2) during progressively increasing work rate incremental exercise. Therefore, we hypothesized that Q(.) may indeed have a non-linear relationship with respect to V(.)O(2) during incremental, non-steady state exercise. To investigate this hypothesis, we performed five maximal progressive work rate exercise studies in healthy human subjects. Q(.) was determined every minute during exercise using measured breath-by-breath V(.) >O(2), and arterial and pulmonary artery measurements of PO(2), hemoglobin saturation, and content. Q(.) was plotted as a function of V(.) >O(2) and the linear and non-linear (first order exponential and hyperbolic) fits determined for each subject. Tests for linearity were performed by assessing the significance of the quadratic terms added to the linear relation using least squares estimation in linear regression. Linearity was inadequate in all cases (group P<0.0001). We conclude that cardiac output is a non-linear function of V(.)O(2 )during ramp-incremental exercise; the pattern of non-linearity suggests that while the kinetics of Q(.) > are faster than those of V(.) >O(2) they progressively slow as work rate (and V(.) >O(2)) increases.

Influence of body mass index and gender on growth hormone (GH) responses to GH-releasing hormone plus arginine and insulin tolerance tests.

The aim of this study is to assess whether gender and body mass index (BMI) should be considered in developing thresholds to define GH deficiency, using GH responses to GHRH + arginine (ARG) stimulation and insulin tolerance test (ITT). Thirty-nine healthy subjects (19 males, 20 females; ages 21-50 yr) underwent GHRH + ARG, and another 27 subjects (19 males, 8 females; ages 20-49 yr) underwent ITT. Peak GH response was significantly higher (P = 0.005) after GHRH + ARG than with ITT, and this difference could not be explained by age, gender, or BMI. Peak GH response was negatively correlated with BMI in both tests (GHRH + ARG, r = -0.76; and ITT, r = -0.65). Peak GH response to GHRH + ARG was higher in females than males (P = 0.004; ratio = 2.4), but it was attenuated after eliminating the influence of BMI (P = 0.13; ratio = 1.6). No significant gender differences were found in peak GH responses to ITT, which could be due to the smaller number of female subjects studied. GH response to GHRH + ARG and ITT stimulation is sensitive to BMI differences and less so to gender differences. A higher BMI is associated with a depressed GH response to both stimulation tests. BMI should therefore be considered as a factor when defining the diagnostic cut-off points in the assessment of GH deficiency, whereas whether gender should be likewise used is inconclusive from this study.

Corneal topography of neonates and infants.

OBJECTIVE: To evaluate corneal curvature by direct topographic analysis during the first 6 months of life. METHODS: We evaluated corneal topography in 200 infants using a specialized handheld topographic instrument at a mean of 1.6 days after birth, and in some again at 3 and 6 months in the newborn nursery and ophthalmology clinic of a public hospital. RESULTS: At birth, the mean central corneal power measured 48.5 diopters (D) (95% confidence interval [CI], 48.2-48.8 D; range, 41.4-56.0 D) and astigmatism measured 6.0 D (95% CI, 5.6-6.3 D), usually "with the rule" (80%) with a mean axis of 95 degrees . The mean astigmatism on the semimeridian map at 3 mm was 6.4 D (95% CI, 6.0-6.8 D); and at 5 mm, 5.9 D (95% CI, 5.4-6.3 D). At birth, neonates delivered vaginally had a greater frequency of with-the-rule astigmatism than those delivered by cesarean section (P = .02). By 6 months, the mean central corneal power and astigmatism decreased to 43.0 (95% CI, 41.3-43.1) D and 2.3 (95% CI, 1.4-3.2) D, respectively (P<.005 for each). CONCLUSIONS: Newborns have steep, high, astigmatic (generally with-the-rule) corneas at birth that flatten significantly by the age of 6 months. The method of delivery can affect the astigmatic axis at birth.

Determinants of coronary artery calcification in diabetics with and without nephropathy.

BACKGROUND: In the general population, including those with diabetes mellitus, coronary artery calcification (CAC) correlates with atherosclerotic plaque burden. On the other hand, accumulating evidence suggests that disordered mineral metabolism significantly contributes to the vascular calcification in individuals with end-stage renal disease (ESRD). METHODS: In order to determine the relative contribution of accelerated atherosclerosis and disordered mineral metabolism to CAC in chronic kidney disease, a pilot study of 90 patients with type 2 diabetes mellitus was done [age, 40-65 years; normoalbuminuria, N= 30; diabetic nephropathy (DN), N= 60]. RESULTS: CAC was more prevalent and severe among individuals with DN compared to diabetic controls (odds ratio for prevalence 8.1, 95% CI 2.3-28.5; median scores, 66 vs. 4, P < 0.001). None of the 4 measures of disordered mineral metabolism evaluated in this study (serum calcium, phosphorus, parathyroid hormone, and 1,25 di-hydroxy vitamin D levels) correlated with the prevalence or severity of CAC, or accounted for the differences seen between DN and diabetic controls. On the other hand, the difference in the severity of hypertension (number of antihypertensive medications) appeared to account for the differences in CAC burden seen between DN and diabetic controls. CONCLUSION: This first such study of nondialyzed individuals with DN suggests that, unlike ESRD patients, the high CAC burden seen at earlier stages of diabetic chronic kidney disease is probably unrelated to disordered mineral metabolism. The relationship between the severity of hypertension and CAC burden provides a probable target for intervention in the predialysis phase of DN.