Maintenance of glomerular filtration barrier integrity requires laminin alpha5.

Mutation of the mouse laminin alpha5 gene results in a variety of developmental defects, including defects in kidney structure and function. Whereas the total absence of laminin alpha5 results in breakdown of the glomerular basement membrane (GBM) and failed glomerular vascularization, a hypomorphic Lama5 mutation (the Lama5(neo) allele) results in proteinuria, hematuria, polycystic kidney disease (PKD), and death 3 to 4 weeks after birth. Here, we examined the role of podocyte-derived laminin alpha5 via podocyte-specific inactivation of Lama5 and podocyte-specific rescue of the Lama5(neo) mutation. Podocyte-specific inactivation of Lama5 resulted in varying degrees of proteinuria and rates of progression to nephrotic syndrome. The GBM of proteinuric mice appeared thickened and "moth-eaten," and podocyte foot processes became effaced. Podocyte-specific restoration of laminin alpha5 production using two distinct strategies in Lama5(neo/neo) mice resulted in the resolution of proteinuria, hematuria, and PKD. These results suggest that the development of normal GBM structure and function requires podocyte-derived laminin alpha5 during and after glomerulogenesis and present a unique mechanism for the pathogenesis of PKD in these mice.

Biochemical profile of human infant cerebrospinal fluid in intraventricular hemorrhage and post-hemorrhagic hydrocephalus of prematurity.

BACKGROUND: Intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus (PHH) have a complex pathophysiology involving inflammatory response, ventricular zone and cell-cell junction disruption, and choroid-plexus (ChP) hypersecretion. Increased cerebrospinal fluid (CSF) cytokines, extracellular matrix proteins, and blood metabolites have been noted in IVH/PHH, but osmolality and electrolyte disturbances have not been evaluated in human infants with these conditions. We hypothesized that CSF total protein, osmolality, electrolytes, and immune cells increase in PHH. METHODS: CSF samples were obtained from lumbar punctures of control infants and infants with IVH prior to the development of PHH and any neurosurgical intervention. Osmolality, total protein, and electrolytes were measured in 52 infants (18 controls, 10 low grade (LG) IVH, 13 high grade (HG) IVH, and 11 PHH). Serum electrolyte concentrations, and CSF and serum cell counts within 1-day of clinical sampling were obtained from clinical charts. Frontal occipital horn ratio (FOR) was measured for estimating the degree of ventriculomegaly. Dunn or Tukey's post-test ANOVA analysis were used for pair-wise comparisons. RESULTS: CSF osmolality, sodium, potassium, and chloride were elevated in PHH compared to control (p = 0.012 - < 0.0001), LGIVH (p = 0.023 - < 0.0001), and HGIVH (p = 0.015 - 0.0003), while magnesium and calcium levels were higher compared to control (p = 0.031) and LGIVH (p = 0.041). CSF total protein was higher in both HGIVH and PHH compared to control (p = 0.0009 and 0.0006 respectively) and LGIVH (p = 0.034 and 0.028 respectively). These differences were not reflected in serum electrolyte concentrations nor calculated osmolality across the groups. However, quantitatively, CSF sodium and chloride contributed 86% of CSF osmolality change between control and PHH; and CSF osmolality positively correlated with CSF sodium (r, p = 0.55,0.0015), potassium (r, p = 0.51,0.0041), chloride (r, p = 0.60,0.0004), but not total protein across the entire patient cohort. CSF total cells (p = 0.012), total nucleated cells (p = 0.0005), and percent monocyte (p = 0.016) were elevated in PHH compared to control. Serum white blood cell count increased in PHH compared to control (p = 0.042) but there were no differences in serum cell differential across groups. CSF total nucleated cells also positively correlated with CSF osmolality, sodium, potassium, and total protein (p = 0.025 - 0.0008) in the whole cohort. CONCLUSIONS: CSF osmolality increased in PHH, largely driven by electrolyte changes rather than protein levels. However, serum electrolytes levels were unchanged across groups. CSF osmolality and electrolyte changes were correlated with CSF total nucleated cells which were also increased in PHH, further suggesting PHH is a neuro-inflammatory condition.

A new paradigm in threshold of toxicological concern based on chemoinformatics analysis of a highly curated database enriched with antimicrobials.

A new database of antimicrobial-enriched chemicals for the Threshold of Toxicological Concern (TTC) approach has been compiled, comprising 1357 chemicals with 276, 54, and 1027 substances in Cramer Classes I, II, and III, respectively. To enrich the chemical space of the No-/Lowest-Observed-Adverse Effect Level (NOAEL/LOAEL) database, a reference Antimicrobial (AM) Inventory (681) was established for chemical inclusion. To this database, the three existing TTC datasets were combined via robust data fusion process. From the final AM TTC Dataset, the fifth percentiles were derived to be 2.7, 0.43, and 0.12 mg/kg-bw/day for Cramer Classes I, II, and III, respectively. Considering the high percentage of AMs being Cramer Class III, the thresholds are remarkably stable across various TTC datasets. Based on the AM-enriched database, a set of AM categories stratified across potency were developed to classify AMs beyond the capability of the conventional Cramer Tree approach. Grouping the query chemical within the AM category, further distribution analyses were conducted to identify subclasses and differentiate potency. This study proposes a new framework for potential assessment of chronic toxicity made possible with the power of modern reliable databases and chemoinformatic methods.

Surgical-Site Infection Prevention After Hysterectomy: Use of a Consensus Bundle to Guide Improvement.

Hysterectomy is one of the most commonly performed surgeries in women. Surgical-site infections (SSI) after hysterectomy can lead to increased morbidity and mortality as well as readmission, which is associated with increased costs for health systems. The aim of the project was to improve standardization of preoperative education on infection prevention and incorporate the use of preoperative chlorhexidine (CHG) bathing for patients undergoing hysterectomy to decrease rates of SSI. Data on SSI after hysterectomy were reviewed. Tracer methodology was used to identify gaps in the preoperative process by comparing the current process to the Council on Patient Safety in Women's Health Care Patient Safety Bundle "Prevention of Surgical Site Infection after Gynecologic Surgery." After implementation, survey data were collected on adherence to the washing protocol, and SSI data were monitored. Survey results reflected high compliance with the CHG washing protocol, provision of patient education, and overall patient satisfaction with the process. Before implementation in 2016, we reported 8 deep or organ/space SSI to the National Healthcare Safety Network. After implementation in 2018, we reported 3 deep or organ/space SSI. Standardizing infection prevention processes to align with safety bundles improves the quality of care provided to patients.

Glomerular filtration is normal in the absence of both agrin and perlecan-heparan sulfate from the glomerular basement membrane.

BACKGROUND: For several decades, it has been thought that the glomerular basement membrane (GBM) provides a charge-selective barrier for glomerular filtration. However, recent evidence has presented challenges to this concept: selective removal of heparan sulfate (HS) moieties that impart a negative charge to the GBM causes little if any increase in proteinuria. Removal of agrin, the major GBM HS-proteoglycan (HSPG), from the GBM causes a profound reduction in the glomerular anionic charge without changing the excretion of a negatively charged tracer. Perlecan is another HSPG present in the GBM, as well as in the mesangium and Bowman's capsule, that could potentially contribute to a charge barrier in the absence of agrin. METHODS: Here we studied the nature of the glomerular filtration barrier to albumin in mice lacking the HS chains of perlecan either alone or in combination with podocyte-specific loss of agrin. RESULTS: The results show significant reductions in anionic sites within the GBM in perlecan-HS and in perlecan-HS/agrin double mutants. Podocyte and overall glomerular architecture were normal, and renal function was normal up to 15 months of age with no measurable proteinuria. Moreover, excretion of a negatively charged Ficoll tracer was unchanged as compared to control mice. CONCLUSIONS: These findings cast further doubt upon a critical role for the GBM in charge selectivity.

Podocyte-specific deletion of dicer alters cytoskeletal dynamics and causes glomerular disease.

MicroRNAs (miRNAs) regulate gene expression by binding the 3' untranslated region of mRNAs. To define their role in glomerular function, miRNA biogenesis was disrupted in mouse podocytes using a conditional Dicer allele. Mutant mice developed proteinuria by 3 wk after birth and progressed rapidly to end-stage kidney disease. Podocyte pathology included effacement, vacuolization, and hypertrophy with crescent formation. Despite normal expression of WT1, podocytes underwent dedifferentiation, exemplified by cytoskeletal disruption with early transcriptional downregulation of synaptopodin. These abnormalities differed from Cd2ap(-/-) mice, indicating they were not a general consequence of glomerular disease. Glomerular labeling of ezrin, moesin, and gelsolin was altered at 3 wk, but expression of nestin and alpha-actinin was unchanged. Abnormal cell proliferation or apoptosis was not responsible for the glomerular injury. Mutant podocytes were incapable of synthesizing mature miRNA, as revealed by their loss of miR-30a. In contrast, expression of glomerular endothelial and mesangial cell miRNAs (miR-126 and miR-145, respectively) was unchanged. These findings demonstrate a critical role for miRNA in glomerular function and suggest a pathway that may participate in the pathogenesis of kidney diseases of podocyte origin. The unique architecture of podocytes may make them especially susceptible to cytoskeletal alterations initiated by aberrant miRNA dynamics.

A randomized multicenter trial of paricalcitol versus calcitriol for secondary hyperparathyroidism in stages 3-4 CKD.

BACKGROUND AND OBJECTIVES: Calcitriol is used to treat secondary hyperparathyroidism in patients with CKD. Paricalcitol is less calcemic and phosphatemic in preclinical studies and in some trials in dialysis patients, but head-to-head comparisons in nondialysis patients are lacking. A large meta-analysis of trials concluded that these agents did not consistently reduce parathyroid hormone (PTH) and increased the risk of hypercalcemia and hyperphosphatemia. Therefore, the objective of this multicenter trial was to compare the rate of hypercalcemia between calcitriol and paricalcitol, while suppressing PTH 40%-60%. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Patients with stages 3-4 CKD (n=110) with a PTH level >120 pg/ml were recruited and randomized to 0.25 µg/d of calcitriol or 1 µg/d of paricalcitol between April 2009 and July 2011. Subsequent dose adjustments were by protocol to achieve 40%-60% PTH suppression below baseline. The primary endpoint was the rate of confirmed hypercalcemia of >10.5 mg/dl between groups. RESULTS: Forty-five patients in each group completed the 24 weeks of treatment. Both agents suppressed PTH effectively (-52% with paricalcitol and -46% with calcitriol; P=0.17), although the paricalcitol group reached a 40% reduction in PTH sooner at a median 8 weeks (interquartile range [IQR], 4, 12) versus 12 weeks (IQR, 8, 18; P=0.02) and had a lower pill burden of 240 (IQR, 180, 298) versus 292 (IQR, 231, 405; P=0.01). Confirmed hypercalcemia was very low in both groups (three with paricalcitol and one with calcitriol) and was not significantly different (P=0.36). Both groups had small increases in calcium and phosphorus levels (0.3-0.4 mg/dl in each electrolyte) and significant decreases in alkaline phosphatase, a marker of high bone turnover, with no significant differences between groups. CONCLUSIONS: These results show that both calcitriol and paricalcitol achieved sustained PTH and alkaline phosphatase suppression in stages 3-4 CKD, with small effects on serum calcium and phosphorus and a low incidence of hypercalcemia.

Incidence of hepatic dysfunction is equivalent in burn patients receiving oxandrolone and controls.

Oxandrolone has been shown to improve lean muscle mass in patients with burns. Hepatic dysfunction is a known side effect of treatment with oxandrolone. The purpose of this study was to examine the incidence of hepatic dysfunction in our series of burn patients receiving oxandrolone. Fourteen patients who received oxandrolone (5 mg, n = 8; 10 mg, n = 6) were identified from our prospectively collected burn database. The records of 61 control patients also were reviewed. Demographics such as age, comorbidities, and burn size were recorded. The incidence of hepatic dysfunction was determined by the presence of abnormal liver function tests. The study and control groups were similar in age and burn size. Two of the eight (25%) oxandrolone patients receiving 5 mg and four of the six (67%) oxandrolone patients receiving 10 mg had evidence of hepatic dysfunction. Twenty six of the 61 (43%) control patients had evidence of hepatic dysfunction (P = NS). There appears no significant increased incidence of hepatic dysfunction in burn patients who received oxandrolone compared to those who did not.

Empiric treatment of minimally abnormal papanicolaou smears with 0.75% metronidazole vaginal gel.

BACKGROUND: The purpose of this study was to compare the efficacy of 0.75% metronidazole vaginal gel with no treatment in patients who have had a minimally abnormal Papanicolaou smear. METHODS: One hundred forty-five patients whose initial Papanicolaou smears were limited by inflammation or benign cellular changes, reactive cellular changes, or atypical squamous cells of undetermined significance that did not favor a neoplastic process were randomized to 5 days of treatment with 0.75% metronidazole vaginal gel or to a control group receiving no treatment. Papanicolaou smears were repeated after 3 to 4 months. RESULTS: Cytologic findings of the follow-up Papanicolaou smears were normal in 61 of 114 (54%) of patients. Sixty-two percent (n = 37) of the Papanicolaou smears in the control group converted to normal on follow-up, whereas 44% (n = 24) of the Papanicolaou smears in the treatment group converted to normal (P = .07). Only one follow-up Papanicolaou smear worsened to low-grade squamous intraepithelial lesion. In no subgroup was treatment effective. CONCLUSIONS: Empiric treatment for an asymptomatic, minimally abnormal Papanicolaou smear with 0.75% metronidazole vaginal gel before a repeated cytologic examination did not improve the rate of reversion to normal cytologic findings.