A test of the hypothesis that oxalate secretion produces proximal tubule crystallization in primary hyperoxaluria type I

The sequence of events by which primary hyperoxaluria type 1 (PH1) causes renal failure is unclear. We hypothesize that proximal tubule (PT) is vulnerable because oxalate secretion raises calcium oxalate (CaOx) supersaturation (SS) there, leading to crystal formation and cellular injury. We studied cortical and papillary biopsies from two PH1 patients with preserved renal function, and seven native kidneys removed from four patients at the time of transplant, after short-term (2) or longer term (2) dialysis. In these patients, and another five PH1 patients without renal failure, we calculated oxalate secretion, and estimated PT CaOx SS. Plasma oxalate was elevated in all PH1 patients and inverse to creatinine clearance. Renal secretion of oxalate was present in all PH1 but rare in controls. PT CaOx SS was >1 in all nonpyridoxine-responsive PH1 before transplant and most marked in patients who developed end stage renal disease (ESRD). PT from PH1 with preserved renal function had birefringent crystals, confirming the presence of CaOx SS, but had no evidence of cortical inflammation or scarring by histopathology or hyaluronan staining. PH1 with short ESRD showed CaOx deposition and hyaluronan staining particularly at the corticomedullary junction in distal PT while cortical collecting ducts were spared. Longer ESRD showed widespread cortical CaOx, and in both groups papillary tissue had marked intratubular CaOx deposits and fibrosis. CaOx SS in PT causes CaOx crystal formation, and CaOx deposition in distal PT appears to be associated with ESRD. Minimizing PT CaOx SS may be important for preserving renal function in PH1

Hearing and cognitive impairments increase the risk of long-term care admissions

Background and Objectives: The objective of the study was to understand how sensory impairments, alone or in combination with cognitive impairment (CI), relate to long-term care (LTC) admissions. Research Design and Methods: This retrospective cohort study used existing information from two interRAI assessments; the Resident Assessment Instrument for Home Care (RAI-HC) and the Minimum Data Set 2.0 (MDS 2.0), which were linked at the individual level for 371,696 unique individuals aged 65+ years. The exposure variables of interest included hearing impairment (HI), vision impairment (VI) and dual sensory impairment (DSI) ascertained at participants’ most recent RAI-HC assessment. The main outcome was admission to LTC. Survival analysis, using Cox proportional hazards regression models and Kaplan–Meier curves, was used to identify risk factors associated with LTC admissions. Observations were censored if they remained in home care, died or were discharged somewhere other than to LTC. Results: In this sample, 12.7% of clients were admitted to LTC, with a mean time to admission of 49.6 months (SE = 0.20). The main risk factor for LTC admission was a diagnosis of Alzheimer’s dementia (HR = 1.87; CI: 1.83, 1.90). A significant interaction between HI and CI was found, whereby individuals with HI but no CI had a slightly faster time to admission (40.5 months; HR = 1.14) versus clients with both HI and CI (44.9 months; HR = 2.11). Discussion and Implications: Although CI increases the risk of LTC admission, HI is also important, making it is imperative to continue to screen for sensory issues among older home care clients

A Newly Identified Impairment in Both Vision and Hearing Increases the Risk of Deterioration in Both Communication and Cognitive Performance

Vision and hearing impairments are highly prevalent in adults 65 years of age and older. There is a need to understand their association with multiple health-related outcomes. We analyzed data from the Resident Assessment Instrument for Home Care (RAI-HC). Home care clients were followed for up to 5 years and categorized into seven unique cohorts based on whether or not they developed new vision and/or hearing impairments. An absolute standardized difference (stdiff) of at least 0.2 was considered statistically meaningful. Most clients (at least 60%) were female and 34.9 per cent developed a new sensory impairment. Those with a new concurrent vison and hearing impairment were more likely than those with no sensory impairments to experience a deterioration in receptive communication (stdiff = 0.68) and in cognitive performance (stdiff = 0.49). After multivariate adjustment, they had a twofold increased odds (adjusted odds ratio [OR] = 2.1; 95% confidence interval [CI]:1,87, 2.35) of deterioration in cognitive performance. Changes in sensory functioning are common and have important effects on multiple health-related outcomes

Combined Impairments in Vision, Hearing and Cognition are Associated with Greater Levels of Functional and Communication Difficulties Than Cognitive Impairment Alone: Analysis of interRAI Data for Home Care and Long-Term Care Recipients in Ontario

Objectives: The objective of the current study was to understand the added effects of having a sensory impairment (vision and/or hearing impairment) in combination with cognitive impairment with respect to health-related outcomes among older adults (65+ years old) receiving home care or residing in a long-term care (LTC) facility in Ontario, Canada. Methods: Cross-sectional analyses were conducted using existing data collected with one of two interRAI assessments, one for home care (n = 291,824) and one for LTC (n = 110,578). Items in the assessments were used to identify clients with single sensory impairments (e.g., vision only [VI], hearing only [HI]), dual sensory impairment (DSI; i.e., vision and hearing) and those with cognitive impairment (CI). We defined seven mutually exclusive groups based on the presence of single or combined impairments. Results: The rate of people having all three impairments (i.e., CI+DSI) was 21.3% in home care and 29.2% in LTC. Across the seven groups, individuals with all three impairments were the most likely to report loneliness, to have a reduction in social engagement, and to experience reduced independence in their activities of daily living (ADLs) and instrumental ADLs (IADLs). Communication challenges were highly prevalent in this group, at 38.0% in home care and 49.2% in LTC. In both care settings, communication difficulties were more common in the CI+DSI group versus the CI-alone group. Conclusions: The presence of combined sensory and cognitive impairments is high among older adults in these two care settings and having all three impairments is associated with higher rates of negative outcomes than the rates for those having CI alone. There is a rising imperative for all health care professionals to recognize the potential presence of hearing, vision and cognitive impairments in those for whom they provide care, to ensure that basic screening occurs and to use those results to inform care plans

Risk adjustment methods for Home Care Quality Indicators (HCQIs) based on the minimum data set for home care

BACKGROUND: There has been increasing interest in enhancing accountability in health care. As such, several methods have been developed to compare the quality of home care services. These comparisons can be problematic if client populations vary across providers and no adjustment is made to account for these differences. The current paper explores the effects of risk adjustment for a set of home care quality indicators (HCQIs) based on the Minimum Data Set for Home Care (MDS-HC). METHODS: A total of 22 home care providers in Ontario and the Winnipeg Regional Health Authority (WRHA) in Manitoba, Canada, gathered data on their clients using the MDS-HC. These assessment data were used to generate HCQIs for each agency and for the two regions. Three types of risk adjustment methods were contrasted: a) client covariates only; b) client covariates plus an "Agency Intake Profile" (AIP) to adjust for ascertainment and selection bias by the agency; and c) client covariates plus the intake Case Mix Index (CMI). RESULTS: The mean age and gender distribution in the two populations was very similar. Across the 19 risk-adjusted HCQIs, Ontario CCACs had a significantly higher AIP adjustment value for eight HCQIs, indicating a greater propensity to trigger on these quality issues on admission. On average, Ontario had unadjusted rates that were 0.3% higher than the WRHA. Following risk adjustment with the AIP covariate, Ontario rates were, on average, 1.5% lower than the WRHA. In the WRHA, individual agencies were likely to experience a decline in their standing, whereby they were more likely to be ranked among the worst performers following risk adjustment. The opposite was true for sites in Ontario. CONCLUSIONS: Risk adjustment is essential when comparing quality of care across providers when home care agencies provide services to populations with different characteristics. While such adjustment had a relatively small effect for the two regions, it did substantially affect the ranking of many individual home care providers

Effects of Sperm Conjugation and Dissociation on Sperm Viability In Vitro

Sperm conjugation is an unusual variation in sperm behavior where two or more spermatozoa physically unite for motility or transport through the female reproductive tract. Conjugation has frequently been interpreted as sperm cooperation, including reproductive altruism, with some sperm advancing their siblings toward the site of fertilization while ostensibly forfeiting their own ability to fertilize through damage incurred during conjugate break-up. Conversely, conjugation has been proposed to protect sensitive regions of spermatozoa from spermicidal conditions within the female reproductive tract. We investigated the possibility of dissociation-induced sperm mortality and tested for a protective function of conjugation using the paired sperm of the diving beetle, Graphoderus liberus. Sperm conjugates were mechanically dissociated and exposed to potentially damaging tissue extracts of the female reproductive tract and somatic tissue. We found no significant difference in viability between paired sperm and dissociated, single sperm. The results further indicate that the reproductive tract of female G. liberus might not be spermicidal and conjugation is not protective of sperm viability when damaging conditions do exist. Our results support the interpretation that, at least in some taxa, sperm conjugation is neither protective nor damaging to sperm viability