Prostate Artery Embolization Used in the Management of Transfusion-Dependent Hematuria After Prostatic Urethral Lift Procedure in a Patient with Thrombocytopenia: A Case Report.

Background: The prostatic urethral lift (PUL) procedure is a novel therapeutic method to treat lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH). Gross hematuria after this procedure has been reported to be mild and transient. This report highlights a case of refractory transfusion-dependent hematuria after the PUL procedure in addition to its management with selective prostatic arterial embolization (PAE). Case Presentation: A 78-year-old Caucasian man with a history of myelodysplastic syndrome, thrombocytopenia, and intermittent urinary retention secondary to BPH underwent a PUL procedure. Before the procedure he received a platelet transfusion making his platelet count 58,000/µL. The day after the procedure he was admitted to a hospital for gross hematuria with clot retention. He was started on continuous bladder irrigation and taken to the operating room for clot evacuation and fulguration of prostate. His thrombocytopenia and anemia were managed with transfusions. He was treated with desmopressin, aminocaproic acid, and intravesical 1% alum without improvement. He returned to the operating room for clot evacuation in addition to photoselective vaporization of the prostate laser ablation of the prostatic fossa. He eventually required a total of four transurethral fulgurations without improvement in transfusion-dependent hematuria. Ultimately, resolution of the hematuria was achieved through bilateral PAE with Embosphere® Microspheres performed by interventional radiology. He was discharged home 2 days after the embolization procedure without recurrence of hematuria or urinary retention at a 6-month follow-up visit. Conclusion: The PUL procedure has been shown to be an effective alternative to more invasive surgical options for LUTS caused by BPH. Despite careful consideration in an attempt to alleviate urinary retention, PUL still resulted in significant bleeding in this patient with thrombocytopenia. This is the first report to highlight the use of bilateral PAE as a method for achieving control of severe refractory hematuria after PUL.

Urinary Stone Disease in Pregnancy: Current Management Practices in a Large National Cohort.

OBJECTIVE: To define current national practice patterns of imaging modalities and urologic procedures in pregnant women with urinary stone disease. METHODS: Using the IBM MarketScan national insurance claims database, we identified pregnant women with urinary stone disease and their corresponding gestational age between 2011 and 2016 using administrative claims data. We then assessed each encounter for urinary stone disease or stone-related urologic procedure during their pregnancy. We abstracted demographic information as well as codes for stone procedures and imaging. RESULTS: We identified 14,298 pregnant women with urinary stone disease during the study period. Of the 12,315 undergoing abdominal imaging (86.1%), magnetic resonance imaging was used in 2.8%, x-ray in 9%, and ultrasound in 74.3%. Computed tomography was not used as a diagnostic modality during pregnancy. Procedural intervention was performed in 749 women (5.2%): 476 (3.3%) ureteral stent placement without definitive stone treatment, 93 (0.6%) percutaneous nephrostomy placement, and 180 (1.3%) ureteroscopy (URS) for definitive stone treatment. URS was most commonly performed before 34 weeks gestation with only 27 cases (15%) performed after. CONCLUSION: This large national cohort reveals the current imaging and procedural practice patterns for urinary stone disease during pregnancy and provides a critical baseline as these practice patterns evolve in the future.

Function and Aggregation in Structural Eye Lens Crystallins.

Crystallins are transparent, refractive proteins that contribute to the focusing power of the vertebrate eye lens. These proteins are extremely soluble and resist aggregation for decades, even under crowded conditions. Crystallins have evolved to avoid strong interprotein interactions and have unusual hydration properties. Crystallin aggregation resulting from mutation, damage, or aging can lead to cataract, a disease state characterized by opacity of the lens.Different aggregation mechanisms can occur, following multiple pathways and leading to aggregates with varied morphologies. Studies of variant proteins found in individuals with childhood-onset cataract have provided insight into the molecular factors underlying crystallin stability and solubility. Modulation of exposed hydrophobic surface is critical, as is preventing specific intermolecular interactions that could provide nucleation sites for aggregation. Biophysical measurements and structural biology techniques are beginning to provide a detailed picture of how crystallins crowd into the lens, providing high refractivity while avoiding excessively tight binding that would lead to aggregation.Despite the central biological importance of refractivity, relatively few experimental measurements have been made for lens crystallins. Our work and that of others have shown that hydration is important to the high refractive index of crystallin proteins, as are interactions between pairs of aromatic residues and potentially other specific structural features.This Account describes our efforts to understand both the functional and disease states of vertebrate eye lens crystallins, particularly the γ-crystallins. We use a variety of biophysical techniques, notably NMR spectroscopy, to investigate crystallin stability and solubility. In the first section, we describe efforts to understand the relative stability and aggregation propensity of different γS-crystallin variants. The second section focuses on interactions of these proteins with the holdase chaperone αB-crystallin. The third, fourth, and fifth sections explore different modes of aggregation available to crystallin proteins, and the final section highlights the importance of refractive index and the sometimes conflicting demands of selection for refractivity and solubility.

Urinary Stone Disease in Pregnancy: A Claims Based Analysis of 1.4 Million Patients.

PURPOSE: Urinary stone disease during pregnancy is poorly understood but is thought to be associated with increased maternal and fetal morbidity. We determined the prevalence of urinary stone disease in pregnancy and whether it is associated with adverse pregnancy outcomes. MATERIALS AND METHODS: We identified all pregnant women from 2003 through 2017 in the Optum® national insurance claims database. We used diagnosis claims to identify urinary stone disease and assess medical comorbidity. We established the prevalence of urinary stone disease during pregnancy stratified by week of pregnancy. We further evaluated associations among urinary stone disease, maternal complications and pregnancy outcomes in univariable and multivariable analyses. RESULTS: Urinary stone disease affects 8 per 1,000 pregnancies and is more common in white women and women with more comorbid conditions. In fully adjusted models pregnancies complicated by urinary stone disease had higher rates of adverse fetal outcomes including prematurity and spontaneous abortions. This analysis is limited by its retrospective, administrative claims design. CONCLUSIONS: The rate of urinary stone disease during pregnancy is higher than previously reported. Urinary stone disease is associated with adverse pregnancy outcomes.

Payer Type, Race/Ethnicity, and the Timing of Surgical Management of Urinary Stone Disease.

PURPOSE: Surgery for upper tract urinary stone disease is often reserved for symptomatic patients and those whose stone does not spontaneously pass after a trial of passage. Our objective was to determine whether payer type or race/ethnicity is associated with the timeliness of kidney stone surgery. MATERIALS AND METHODS: A population-based cohort study was conducted using the California Office of Statewide Health Planning and Development dataset from 2010 to 2012. We identified patients who were discharged from an emergency department (ED) with a stone diagnosis and who subsequently underwent a stone surgery. Primary outcome was time from ED discharge to urinary stone surgery in days. Secondary outcomes included potential harms resulting from delayed stone surgery. RESULTS: Over the study period, 15,193 patients met the inclusion criteria. Median time from ED discharge to stone surgery was 28 days. On multivariable analysis patients with Medicaid, Medicare, and self-pay coverage experienced adjusted mean increases of 46%, 42%, and 60% in time to surgery, respectively, when compared with those with private insurance. In addition, patients of Black and Hispanic race/ethnicity, respectively, experienced adjusted mean increases of 36% and 20% in time to surgery relative to their White counterparts. Before a stone surgery, underinsured patients were more likely to revisit an ED three or more times, undergo two or more CT imaging studies, and receive upper urinary tract decompression. CONCLUSIONS: Underinsured and minority patients are more likely to experience a longer time to stone surgery after presenting to an ED and experience potential harm from this delay.

Peripheral complement interactions with amyloid ß peptide in Alzheimer's disease: Polymorphisms, structure, and function of complement receptor 1.

INTRODUCTION: Genome-wide association studies consistently show that single nucleotide polymorphisms (SNPs) in the complement receptor 1 (CR1) gene modestly but significantly alter Alzheimer's disease (AD) risk. Follow-up research has assumed that CR1 is expressed in the human brain despite a paucity of evidence for its function there. Alternatively, erythrocytes contain >80% of the body's CR1, where, in primates, it is known to bind circulating pathogens. METHODS: Multidisciplinary methods were employed. RESULTS: Conventional Western blots and quantitative polymerase chain reaction failed to detect CR1 in the human brain. Brain immunohistochemistry revealed only vascular CR1. By contrast, erythrocyte CR1 immunoreactivity was readily observed and was significantly deficient in AD, as was CR1-mediated erythrocyte capture of circulating amyloid ß peptide. CR1 SNPs associated with decreased erythrocyte CR1 increased AD risk, whereas a CR1 SNP associated with increased erythrocyte CR1 decreased AD risk. DISCUSSION: SNP effects on erythrocyte CR1 likely underlie the association of CR1 polymorphisms with AD risk.

Peripheral complement interactions with amyloid ß peptide in Alzheimer's disease: 2. Relationship to amyloid ß immunotherapy.

INTRODUCTION: Our previous studies have shown that amyloid ß peptide (Aß) is subject to complement-mediated clearance from the peripheral circulation, and that this mechanism is deficient in Alzheimer's disease. The mechanism should be enhanced by Aß antibodies that form immune complexes (ICs) with Aß, and therefore may be relevant to current Aß immunotherapy approaches. METHODS: Multidisciplinary methods were employed to demonstrate enhanced complement-mediated capture of Aß antibody immune complexes compared with Aß alone in both erythrocytes and THP1-derived macrophages. RESULTS: Aß antibodies dramatically increased complement activation and opsonization of Aß, followed by commensurately enhanced Aß capture by human erythrocytes and macrophages. These in vitro findings were consistent with enhanced peripheral clearance of intravenously administered Aß antibody immune complexes in nonhuman primates. DISCUSSION: Together with our previous results, showing significant Alzheimer's disease deficits in peripheral Aß clearance, the present findings strongly suggest that peripheral mechanisms should not be ignored as contributors to the effects of Aß immunotherapy.

Peripheral complement interactions with amyloid ß peptide: Erythrocyte clearance mechanisms.

INTRODUCTION: Although amyloid ß peptide (Aß) is cleared from the brain to cerebrospinal fluid and the peripheral circulation, mechanisms for its removal from blood remain unresolved. Primates have uniquely evolved a highly effective peripheral clearance mechanism for pathogens, immune adherence, in which erythrocyte complement receptor 1 (CR1) plays a major role. METHODS: Multidisciplinary methods were used to demonstrate immune adherence capture of Aß by erythrocytes and its deficiency in Alzheimer's disease (AD). RESULTS: Aß was shown to be subject to immune adherence at every step in the pathway. Aß dose-dependently activated serum complement. Complement-opsonized Aß was captured by erythrocytes via CR1. Erythrocytes, Aß, and hepatic Kupffer cells were colocalized in the human liver. Significant deficits in erythrocyte Aß levels were found in AD and mild cognitive impairment patients. DISCUSSION: CR1 polymorphisms elevate AD risk, and >80% of human CR1 is vested in erythrocytes to subserve immune adherence. The present results suggest that this pathway is pathophysiologically relevant in AD.

Analysis of the Putative Role of CR1 in Alzheimer's Disease: Genetic Association, Expression and Function.

Chronic activation of the complement system and induced inflammation are associated with neuropathology in Alzheimer's disease (AD). Recent large genome wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) in the C3b/C4b receptor (CR1 or CD35) that are associated with late onset AD. Here, anti-CR1 antibodies (Abs) directed against different epitopes of the receptor, were used to localize CR1 in brain, and relative binding affinities of the CR1 ligands, C1q and C3b, were assessed by ELISA. Most Abs tested stained red blood cells in blood vessels but showed no staining in brain parenchyma. However, two monoclonal anti-CR1 Abs labeled astrocytes in all of the cases tested, and this reactivity was preabsorbed by purified recombinant human CR1. Human brain-derived astrocyte cultures were also reactive with both mAbs. The amount of astrocyte staining varied among the samples, but no consistent difference was conferred by diagnosis or the GWAS-identified SNPs rs4844609 or rs6656401. Plasma levels of soluble CR1 did not correlate with diagnosis but a slight increase was observed with rs4844609 and rs6656401 SNP. There was also a modest but statistically significant increase in relative binding activity of C1q to CR1 with the rs4844609 SNP compared to CR1 without the SNP, and of C3b to CR1 in the CR1 genotypes containing the rs6656401 SNP (also associated with the larger isoform of CR1) regardless of clinical diagnosis. These results suggest that it is unlikely that astrocyte CR1 expression levels or C1q or C3b binding activity are the cause of the GWAS identified association of CR1 variants with AD. Further careful functional studies are needed to determine if the variant-dictated number of CR1 expressed on red blood cells contributes to the role of this receptor in the progression of AD, or if another mechanism is involved.

Exploring the aggregation propensity of γS-crystallin protein variants using two-dimensional spectroscopic tools.

The formation of amyloid fibrils is associated with many serious diseases as well as diverse biological functions. Despite the importance of these aggregates, predicting the aggregation propensity of a particular sequence is a major challenge. We report a joint 2D nuclear magnetic resonance (NMR) and ultraviolet (2DUV) study of fibrillization in the wild-type and two aggregation-prone mutants of the eye lens protein γS-crystallin. Simulations show that the complexity of 2DUV signals as measured by their "approximate entropy" is a good indicator for the conformational entropy and in turn is strongly correlated with its aggregation propensity. These findings are in agreement with high-resolution NMR experiments and are corroborated for amyloid fibrils. The 2DUV technique is complementary to high-resolution structural methods and has the potential to make the evaluation of the aggregation propensity for protein variant propensity of protein structure more accessible to both theory and experiment. The approximate entropy of experimental 2DUV signals can be used for fast screening, enabling identification of variants with high fibrillization propensity for the much more time-consuming NMR structural studies, potentially expediting the characterization of protein variants associated with cataract and other protein aggregation diseases.

Preferential and specific binding of human αB-crystallin to a cataract-related variant of γS-crystallin.

Transparency in the eye lens is maintained via specific, functional interactions among the structural ßγ- and chaperone α-crystallins. Here, we report the structure and α-crystallin binding interface of the G18V variant of human γS-crystallin (γS-G18V), which is linked to hereditary childhood-onset cortical cataract. Comparison of the solution nuclear magnetic resonance structures of wild-type and G18V γS-crystallin, both presented here, reveal that the increased aggregation propensity of γS-G18V results from neither global misfolding nor the solvent exposure of a hydrophobic residue but instead involves backbone rearrangement within the N-terminal domain. αB-crystallin binds more strongly to the variant, via a well-defined interaction surface observed via chemical shift differences. In the context of the αB-crystallin structure and the finding that it forms heterogeneous multimers, our structural studies suggest a potential mechanism for cataract formation via the depletion of the finite αB-crystallin population of the lens.

Prevention of de novo hepatitis B in recipients of core antibody-positive livers with lamivudine and other nucleos(t)ides: a 12-year experience.

BACKGROUND: Lamivudine (LAM) has been shown to prevent de novo hepatitis B virus (HBV) infection in recipients of hepatitis B core antibody (HBcAb)-positive liver transplants (LT) but primarily in small studies with limited follow-up. METHODS: We conducted a retrospective cohort study of HBcAb+ graft recipients at our institution from October 1999 to August 2008. RESULTS: One hundred nineteen recipients without prior HBV were identified (median age, 54 years; 70% male), of which 62 received LAM. The median follow-up was 2.6 years overall and 5.3 years in the LAM group. Among LAM recipients, 44% were HBV naïve (HBsAb-/HBcAb-) at LT, of which 6% developed HBsAb+ and 3% developed HBcAb+ after LT. Eight percent developed de novo HBV: two recipients became hepatitis B surface antigen positive at 70 and 23 months and three experienced breakthrough with HBV DNA more than 2000 IU at 1 to 9 months after LT. Sixty percent (3 of 5) were HBV naïve. Four (6%) other recipients also had transiently detectable HBV less than 2000 IU, which did not require any changes to their prophylaxis regimen. When compared with recipients who received other nucleos(t)ide analogues, there was no difference in de novo rates: LAM 8% (5 of 62), adefovir 15% (5 of 33), tenofovir 0% (0 of 3), entecavir 0% (0 of 1), and 5% (1 of 20) for those not given prophylaxis (P=0.59). CONCLUSIONS: LAM monoprophylaxis was effective in preventing de novo HBV in the vast majority of recipients over long-term follow-up. Adefovir had a higher rate of de novo infections numerically, whereas tenofovir and entecavir had no cases and may be more effective, but this was limited by a small sample size.

¹H, ¹³C, and ¹5N assignments of wild-type human γS-crystallin and its cataract-related variant γS-G18V.

We present the backbone and sidechain NMR assignments and a structural analysis of the 178-residue wild-type γS-crystallin and the cataract-related point mutant, γS-G18V. γS-crystallin is a structural component of the eye lens, which maintains its solubility and stability over many years. NMR assignments and continued structural investigations of γS-crystallin and aggregation-prone variants will advance understanding of cataract formation.

Separating instability from aggregation propensity in γS-crystallin variants.

Molecular dynamics (MD) simulations, circular dichroism (CD), and dynamic light scattering (DLS) measurements were used to investigate the aggregation propensity of the eye-lens protein γS-crystallin. The wild-type protein was investigated along with the cataract-related G18V variant and the symmetry-related G106V variant. The MD simulations suggest that local sequence differences result in dramatic differences in dynamics and hydration between these two apparently similar point mutations. This finding is supported by the experimental measurements, which show that although both variants appear to be mostly folded at room temperature, both display increased aggregation propensity. Although the disease-related G18V variant is not the most strongly destabilized, it aggregates more readily than either the wild-type or the G106V variant. These results indicate that γS-crystallin provides an excellent model system for investigating the role of dynamics and hydration in aggregation by locally unfolded proteins.