Nicotinamide riboside activates renal metabolism and protects the kidney in a model of Alport syndrome

Chronic kidney disease (CKD) is associated with renal metabolic disturbances, including impaired fatty acid oxidation (FAO). Nicotinamide adenine dinucleotide (NAD + ) is a small molecule that participates in hundreds of metabolism-related reactions. NAD + levels are decreased in CKD, and NAD + supplementation is protective. However, both the mechanism of how NAD + supplementation protects from CKD, as well as the cell types most responsible, are poorly understood. Using a mouse model of Alport syndrome, we show that nicotinamide riboside (NR), an NAD + precursor, stimulates renal peroxisome proliferator-activated receptor α signaling and restores FAO in the proximal tubules, thereby protecting from CKD in both sexes. Bulk RNA-sequencing shows that renal metabolic pathways are impaired in Alport mice and dramatically activated by NR in both sexes. These transcriptional changes are confirmed by orthogonal imaging techniques and biochemical assays. Single nuclei RNA-sequencing and spatial transcriptomics, both the first of their kind from Alport mice, show that NAD + supplementation restores FAO in the proximal tubules with minimal effects on the podocytes. Finally, we also report, for the first time, sex differences at the transcriptional level in this Alport model. Male Alport mice had more severe inflammation and fibrosis than female mice at the transcriptional level. In summary, the data herein identify both the protective mechanism and location of NAD + supplementation in this model of CKD.

Estrogen-Related Receptor Agonism Reverses Mitochondrial Dysfunction and Inflammation in the Aging Kidney

A gradual decline in renal function occurs even in healthy aging individuals. In addition to aging, per se, concurrent metabolic syndrome and hypertension, which are common in the aging population, can induce mitochondrial dysfunction and inflammation, which collectively contribute to age-related kidney dysfunction and disease. This study examined the role of the nuclear hormone receptors, the estrogen-related receptors (ERRs), in regulation of age-related mitochondrial dysfunction and inflammation. The ERRs were decreased in both aging human and mouse kidneys and were preserved in aging mice with lifelong caloric restriction (CR). A pan-ERR agonist, SLU-PP-332, was used to treat 21-month-old mice for 8 weeks. In addition, 21-month-old mice were treated with a stimulator of interferon genes (STING) inhibitor, C-176, for 3 weeks. Remarkably, similar to CR, an 8-week treatment with a pan-ERR agonist reversed the age-related increases in albuminuria, podocyte loss, mitochondrial dysfunction, and inflammatory cytokines, via the cyclic GMP-AMP synthase-STING and STAT3 signaling pathways. A 3-week treatment of 21-month-old mice with a STING inhibitor reversed the increases in inflammatory cytokines and the senescence marker, p21/cyclin dependent kinase inhibitor 1A (Cdkn1a), but also unexpectedly reversed the age-related decreases in PPARG coactivator (PGC)-1α, ERRα, mitochondrial complexes, and medium chain acyl coenzyme A dehydrogenase (MCAD) expression. These studies identified ERRs as CR mimetics and as important modulators of age-related mitochondrial dysfunction and inflammation. These findings highlight novel druggable pathways that can be further evaluated to prevent progression of age-related kidney disease.

Farnesoid X receptor prevents neutrophil extracellular traps via reduced sphingosine-1-phosphate in chronic kidney disease

Farnesoid X receptor (FXR) activation reduces renal inflammation, but the underlying mechanisms remain elusive. Neutrophil extracellular traps (NETs) are webs of DNA formed when neutrophils undergo specialized programmed cell death (NETosis). The signaling lipid sphingosine-1-phosphate (S1P) stimulates NETosis via its receptor on neutrophils. Here, we identify FXR as a negative regulator of NETosis via repressing S1P signaling. We determined the effects of the FXR agonist obeticholic acid (OCA) in mouse models of adenosine phosphoribosyltransferase (APRT) deficiency and Alport syndrome, both genetic disorders that cause chronic kidney disease. Renal FXR activity is greatly reduced in both models, and FXR agonism reduces disease severity. Renal NETosis and sphingosine kinase 1 (Sphk1) expression are increased in diseased mice, and they are reduced by OCA in both models. Genetic deletion of FXR increases Sphk1 expression, and Sphk1 expression correlates with NETosis. Importantly, kidney S1P levels in Alport mice are two-fold higher than controls, and FXR agonism restores them back to baseline. Short-term inhibition of sphingosine synthesis in Alport mice with severe kidney disease reverses NETosis, establishing a causal relationship between S1P signaling and renal NETosis. Finally, extensive NETosis is present in human Alport kidney biopsies (six male, nine female), and NETosis severity correlates with clinical markers of kidney disease. This suggests the potential clinical relevance of the newly identified FXR-S1P-NETosis pathway. In summary, FXR agonism represses kidney Sphk1 expression. This inhibits renal S1P signaling, thereby reducing neutrophilic inflammation and NETosis.NEW & NOTEWORTHY Many preclinical studies have shown that the farnesoid X receptor (FXR) reduces renal inflammation, but the mechanism is poorly understood. This report identifies FXR as a novel regulator of neutrophilic inflammation and NETosis via the inhibition of sphingosine-1-phosphate signaling. Additionally, NETosis severity in human Alport kidney biopsies correlates with clinical markers of kidney disease. A better understanding of this signaling axis may lead to novel treatments that prevent renal inflammation and chronic kidney disease.

Fibrosis quantification using multiphoton excitation imaging of picrosirius red stained cardiac tissue

Traditional methodologies for fibrosis quantification involve histological measurements, staining with Masson's trichrome and picrosirius red (PSR), and label-free imaging using second harmonic generation (SHG). The difficulty of label-free cardiac SHG imaging is that both collagen (i.e., collagen 1 fibrils) and myosin are harmonophores that generate SHG signals, and specific identification of either collagen or myosin is difficult to achieve. Here we present an alternate method of quantifying cardiac fibrosis by using PSR staining followed by multiphoton excitation fluorescence imaging. Our data from the deoxycorticosterone model of cardiac fibrosis shows that this imaging method and downstream analyses, including background correction, are robust and easy to perform. These advantages are due to the high signal-to-noise ratio provided by PSR in areas of collagen fibers. Furthermore, the hyperspectral and fluorescence lifetime information of PSR-stained area of fibrosis shows better quantification can eventually be obtained using more complex instrumentation.

NAD metabolism modulates inflammation and mitochondria function in diabetic kidney disease

Diabetes mellitus is the leading cause of cardiovascular and renal disease in the United -States. Despite the beneficial interventions available for patients with diabetes, there remains a need for additional therapeutic targets and therapies in diabetic kidney disease (DKD). Inflammation and oxidative stress are increasingly recognized as important causes of renal diseases. Inflammation is closely associated with mitochondrial damage. The molecular connection between inflammation and mitochondrial metabolism remains to be elucidated. Recently, nicotinamide adenine nucleotide (NAD+) metabolism has been found to regulate immune function and inflammation. In the present studies, we tested the hypothesis that enhancing NAD metabolism could prevent inflammation in and progression of DKD. We found that treatment of db/db mice with type 2 diabetes with nicotinamide riboside (NR) prevented several manifestations of kidney dysfunction (i.e., albuminuria, increased urinary kidney injury marker-1 (KIM1) excretion, and pathologic changes). These effects were associated with decreased inflammation, at least in part via inhibiting the activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway. An antagonist of the serum stimulator of interferon genes (STING) and whole-body STING deletion in diabetic mice showed similar renoprotection. Further analysis found that NR increased SIRT3 activity and improved mitochondrial function, which led to decreased mitochondrial DNA damage, a trigger for mitochondrial DNA leakage which activates the cGAS-STING pathway. Overall, these data show that NR supplementation boosted NAD metabolism to augment mitochondrial function, reducing inflammation and thereby preventing the progression of diabetic kidney disease.

The role of FXR and TGR5 in reversing and preventing progression of Western diet-induced hepatic steatosis, inflammation, and fibrosis in mice

Nonalcoholic steatohepatitis (NASH) is the most common chronic liver disease in the US, partly due to the increasing incidence of metabolic syndrome, obesity, and type 2 diabetes. The roles of bile acids and their receptors, such as the nuclear receptor farnesoid X receptor (FXR) and the G protein-coupled receptor TGR5, on the development of NASH are not fully clear. C57BL/6J male mice fed a Western diet (WD) develop characteristics of NASH, allowing determination of the effects of FXR and TGR5 agonists on this disease. Here we show that the FXR-TGR5 dual agonist INT-767 prevents progression of WD-induced hepatic steatosis, inflammation, and fibrosis, as determined by histological and biochemical assays and novel label-free microscopy imaging techniques, including third harmonic generation, second harmonic generation, and fluorescence lifetime imaging microscopy. Furthermore, we show INT-767 decreases liver fatty acid synthesis and fatty acid and cholesterol uptake, as well as liver inflammation. INT-767 markedly changed bile acid composition in the liver and intestine, leading to notable decreases in the hydrophobicity index of bile acids, known to limit cholesterol and lipid absorption. In addition, INT-767 upregulated expression of liver p-AMPK, SIRT1, PGC-1α, and SIRT3, which are master regulators of mitochondrial function. Finally, we found INT-767 treatment reduced WD-induced dysbiosis of gut microbiota. Interestingly, the effects of INT-767 in attenuating NASH were absent in FXR-null mice, but still present in TGR5-null mice. Our findings support treatment and prevention protocols with the dual FXR-TGR5 agonist INT-767 arrest progression of WD-induced NASH in mice mediated by FXR-dependent, TGR5-independent mechanisms.

PodoCount: A Robust, Fully Automated, Whole-Slide Podocyte Quantification Tool

Introduction

Podocyte depletion is a histomorphologic indicator of glomerular injury and predicts clinical outcomes. Podocyte estimation methods or podometrics are semiquantitative, technically involved, and laborious. Implementation of high-throughput podometrics in experimental and clinical workflows necessitates an automated podometrics pipeline. Recognizing that computational image analysis offers a robust approach to study cell and tissue structure, we developed and validated PodoCount (a computational tool for automated podocyte quantification in immunohistochemically labeled tissues) using a diverse data set.

Methods

Whole-slide images (WSIs) of tissues immunostained with a podocyte nuclear marker and periodic acid–Schiff counterstain were acquired. The data set consisted of murine whole kidney sections (n = 135) from 6 disease models and human kidney biopsy specimens from patients with diabetic nephropathy (DN) (n = 45). Within segmented glomeruli, podocytes were extracted and image analysis was applied to compute measures of podocyte depletion and nuclear morphometry. Computational performance evaluation and statistical testing were performed to validate podometric and associated image features. PodoCount was disbursed as an open-source, cloud-based computational tool.

Results

PodoCount produced highly accurate podocyte quantification when benchmarked against existing methods. Podocyte nuclear profiles were identified with 0.98 accuracy and segmented with 0.85 sensitivity and 0.99 specificity. Errors in podocyte count were bounded by 1 podocyte per glomerulus. Podocyte-specific image features were found to be significant predictors of disease state, proteinuria, and clinical outcome.

Conclusion

PodoCount offers high-performance podocyte quantitation in diverse murine disease models and in human kidney biopsy specimens. Resultant features offer significant correlation with associated metadata and outcome. Our cloud-based tool will provide end users with a standardized approach for automated podometrics from gigapixel-sized WSIs.

Nuclear Receptors and Transcription Factors in Obesity-Related Kidney Disease

Both obesity and chronic kidney disease are increasingly common causes of morbidity and mortality worldwide. Although obesity often co-exists with diabetes and hypertension, it has become clear over the past several decades that obesity is an independent cause of chronic kidney disease, termed obesity-related glomerulopathy. This review defines the attributes of obesity-related glomerulopathy and describes potential pharmacologic interventions. Interventions discussed include peroxisome proliferator-activated receptors, the farnesoid X receptor, the Takeda G-protein-coupled receptor 5, and the vitamin D receptor.

Sacubitril/valsartan treatment has differential effects in modulating diabetic kidney disease in db/db mice and KKAy mice compared with valsartan treatment

Although renin-angiotensin blockade has shown beneficial outcomes in patients with diabetes, renal injury progresses in most of these patients. Therefore, there remains a need for new therapeutic targets in diabetic kidney disease. Enhancement of vasoactive peptides, such as natriuretic peptides, via neprilysin inhibition, has been a new approach. A first-in-class drug, sacubitril/valsartan (Sac/Val), a combination of the angiotensin II receptor blocker Val and neprilysin inhibitor prodrug Sac, has been shown to be more effective than renin-angiotensin blockade alone in the treatment of heart failure with reduced ejection fraction. In this study, we tested the effects of Sac/Val in diabetic kidney disease. We administered Sac/Val or Val to two type 2 diabetes mouse models, db/db mice or KKAy mice. After 3 mo of treatment, Sac/Val attenuated the progression of proteinuria, glomerulosclerosis, and podocyte loss in both models of diabetic mice. Val shared a similar improvement but to a lesser degree in some parameters compared with Sac/Val. Sac/Val but not Val decreased the blood glucose level in KKAy mice. Sac/Val exerted renal protection through coordinated effects on antioxidative stress and anti-inflammation. In both diabetic models, we revealed a new mechanism to cause inflammation, self-DNA-activated cGMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling, which was activated in diabetic kidneys and prevented by Sac/Val or Val treatment. The present data suggest that Sac/Val has sufficient therapeutical potential to counter the pathophysiological effects of diabetic kidney disease, and its effectiveness could be better than Val alone.NEW & NOTEWORTHY The first-in-class drug sacubitril/valsartan, a combination of the angiotensin II receptor blocker valsartan and neprilysin inhibitor sacubitril, was tested for its effects in diabetic kidney disease using db/db mice and KKAy mice. We found that Sac/Val has sufficient therapeutical potential to counter the pathophysiological effects of diabetic kidney disease. We further revealed a new mechanism to cause inflammation, self-DNA-activated cGAS-STING signaling, which was activated in diabetic kidneys and prevented by sacubitril/valsartan or valsartan treatment.

Bile acid sequestration reverses liver injury and prevents progression of nonalcoholic steatohepatitis in Western diet-fed mice

Nonalcoholic fatty liver disease is a rapidly rising problem in the 21st century and is a leading cause of chronic liver disease that can lead to end-stage liver diseases, including cirrhosis and hepatocellular cancer. Despite this rising epidemic, no pharmacological treatment has yet been established to treat this disease. The rapidly increasing prevalence of nonalcoholic fatty liver disease and its aggressive form, nonalcoholic steatohepatitis (NASH), requires novel therapeutic approaches to prevent disease progression. Alterations in microbiome dynamics and dysbiosis play an important role in liver disease and may represent targetable pathways to treat liver disorders. Improving microbiome properties or restoring normal bile acid metabolism may prevent or slow the progression of liver diseases such as NASH. Importantly, aberrant systemic circulation of bile acids can greatly disrupt metabolic homeostasis. Bile acid sequestrants are orally administered polymers that bind bile acids in the intestine, forming nonabsorbable complexes. Bile acid sequestrants interrupt intestinal reabsorption of bile acids, decreasing their circulating levels. We determined that treatment with the bile acid sequestrant sevelamer reversed the liver injury and prevented the progression of NASH, including steatosis, inflammation, and fibrosis in a Western diet-induced NASH mouse model. Metabolomics and microbiome analysis revealed that this beneficial effect is associated with changes in the microbiota population and bile acid composition, including reversing microbiota complexity in cecum by increasing Lactobacillus and decreased Desulfovibrio The net effect of these changes was improvement in liver function and markers of liver injury and the positive effects of reversal of insulin resistance.

Characterizing the Retinal Phenotype in the High-Fat Diet and Western Diet Mouse Models of Prediabetes

We sought to delineate the retinal features associated with the high-fat diet (HFD) mouse, a widely used model of obesity. C57BL/6 mice were fed either a high-fat (60% fat; HFD) or low-fat (10% fat; LFD) diet for up to 12 months. The effect of HFD on body weight and insulin resistance were measured. The retina was assessed by electroretinogram (ERG), fundus photography, permeability studies, and trypsin digests for enumeration of acellular capillaries. The HFD cohort experienced hypercholesterolemia when compared to the LFD cohort, but not hyperglycemia. HFD mice developed a higher body weight (60.33 g vs. 30.17g, p < 0.0001) as well as a reduced insulin sensitivity index (9.418 vs. 62.01, p = 0.0002) compared to LFD controls. At 6 months, retinal functional testing demonstrated a reduction in a-wave and b-wave amplitudes. At 12 months, mice on HFD showed evidence of increased retinal nerve infarcts and vascular leakage, reduced vascular density, but no increase in number of acellular capillaries compared to LFD mice. In conclusion, the HFD mouse is a useful model for examining the effect of prediabetes and hypercholesterolemia on the retina. The HFD-induced changes appear to occur slower than those observed in type 2 diabetes (T2D) models but are consistent with other retinopathy models, showing neural damage prior to vascular changes.

Dealing with double trouble: Combination deworming against double-drug resistant cyathostomins

An alternative control regimen for drug-resistant parasites is combination deworming, where two drugs with different modes of action are administered simultaneously to target the same parasite. Few studies have investigated this in equine cyathostomins. We previously reported that an oxibendazole (OBZ) and pyrantel pamoate (PYR) combination was not sustainable against a cyathostomin population with high levels of OBZ and PYR resistance. This study consisted of a field study and two computer simulations to evaluate the efficacy of a moxidectin-oxibendazole (MOX-OBZ) combination against the same cyathostomin population. In the field study, anthelmintic treatments occurred when ten horses exceeded 100 eggs per gram. Fecal egg counts and efficacy evaluations were performed every two weeks. The two simulations utilized weather data as well as equine and parasite population parameters from the field study. The first simulation repeated the treatment schedule used in the field study over a 40 year period. The second evaluated efficacies of combination treatments using selective therapy over 40 years. In the field study, efficacies of MOX and both combination treatments were 100%. The egg reappearance period for MOX was 16 weeks, and the two combination treatments were 12 and 18 weeks. The first (46.7%) and last (40.1%) OBZ efficacies were not significantly different from each other. In the simulation study, the combination treatment delayed MOX resistance development compared to when MOX was used as a single active. This occurred despite the low efficacy of OBZ. The second set of simulations identified combination treatments used with selective therapy to be the most effective at delaying MOX resistance. Overall, this study supports the use of combination treatment against drug-resistant cyathostomins, when one of the actives exhibits high efficacy, and demonstrates benefits of this approach despite substantially lowered efficacy of the other active ingredient.

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Oxibendazole-moxidectin combination treatments were 100% effective.

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Oxibendazole efficacies (<50%) did not differ pre and post combination treatment.

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The model observed oxibendazole-moxidectincombinationto delaymoxidectin resistance.

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Combination use in selective therapy delayed resistance most effectively.

Abstract PD4-07: Impact of breast density legislation on Hispanic / Latinas in the Northeast, US

Objective: Changes in health care delivery and policies resulting from translational research efforts are intended to benefit a broad segment of the affected population. Yet, uptake of new approaches may not occur at the same level and/or pace in all groups, inadvertently increasing disparities in cancer outcomes. Our objective is to explore the impact of recently enacted legislation associated with routine mammography screening on Hispanic /Latino women living in Connecticut. Background: Breast densities are the non-fat (epithelial and stromal) breast tissue observable on screening mammograms. They are associated with a 4 to 6 fold increase in breast cancer risk and complicate the reading of screening mammograms, resulting in lowered sensitivity. Connecticut (CT) and many other states have enacted legislation requiring supplemental testing to be offered to women with dense breasts. Per CT statute, insurance companies must cover the cost of ultrasound screening of an entire breast/breasts for women with heterogeneously or extremely dense breasts. Additionally, personal information on breast density must be included in the mailed result following a screening mammogram. The intent is to improve early detection in women with dense breasts and to increase awareness of the greater risk of associated with dense breast tissue. Methods: After this law was enacted in 2008, we undertook a large prospective study of mammography screening in community based Hispanic/Latinas. We enrolled women seeking care in primary health care settings in the 4 CT cities with the largest H/L populations. Eligible women were ages 40-75, self-identified as H/L, and had negative history for breast cancer or breast biopsy. With 75% participation for baseline interview and 98% consent for medical record review, we report baseline interview data and mammography results (medical records) over a 2.5 - 4 year follow-up on 668 H/L women, ages 40-79, living in CT at the time of enrollment (2009-2011). Results: The women in this study were mostly foreign or Puerto Rican born (84%), lower socioeconomic status (51% with household incomes less than $10,000 per year; 54% less had than a high school education) than the general population; median age was 51. Nearly half (46.0%) reported no usual care provider. Only 14% reported speaking English "very well". Most women reported that they received a mammogram in the previous year (65.0%). 21.4% of women met the criteria for receiving additional bilateral ultrasound testing due to heterogeneously dense (19.2%) or extremely dense (2.3%) breast tissue on screening mammograms occurring during follow up. Of the 128 women eligible for follow-up ultrasound, 18 (14%) received this exam. Conclusion: Although state law requires patient notification of breast density and insurance coverage for supplementary bilateral ultrasound tests in women with moderate to extremely dense breasts, our results show low uptake in Hispanic/Latino women in CT. In this largely foreign born, English second language population, effective communication regarding breast cancer risk, breast density, and the availability of follow-up ultrasound or other testing may represent a significant cancer care challenge.

Citation Format: Jones BA, Philpotts L, Cooley R, Silber A, Epstein L, Claye E. Impact of breast density legislation on Hispanic / Latinas in the Northeast, US. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD4-07.

Origin of Perpendicular Magnetic Anisotropy and Large Orbital Moment in Fe Atoms on MgO

We report on the magnetic properties of individual Fe atoms deposited on MgO(100) thin films probed by x-ray magnetic circular dichroism and scanning tunneling spectroscopy. We show that the Fe atoms have strong perpendicular magnetic anisotropy with a zero-field splitting of 14.0±0.3  meV/atom. This is a factor of 10 larger than the interface anisotropy of epitaxial Fe layers on MgO and the largest value reported for Fe atoms adsorbed on surfaces. The interplay between the ligand field at the O adsorption sites and spin-orbit coupling is analyzed by density functional theory and multiplet calculations, providing a comprehensive model of the magnetic properties of Fe atoms in a low-symmetry bonding environment.

Development and testing of a field diagnostic assay for peste des petits ruminants virus

We have developed an immunochromatographic test for the diagnosis of peste des petits ruminants (PPR) under field conditions. The diagnostic assay has been tested in the laboratory and also under field conditions in Ivory Coast, Pakistan, Ethiopia and Uganda. The test is carried out on a superficial swab sample (ocular or nasal) and showed a sensitivity of 84% relative to PCR. The specificity was 95% over all nasal and ocular samples. The test detected as little as 10³ TCID₅₀ (50% tissue culture infectious doses) of cell culture-grown virus, and detected virus isolates representing all four known genetic lineages of peste des petits ruminants virus. Virus could be detected in swabs from animals as early as 4 days post-infection, at a time when clinical signs were minimal. Feedback from field trials was uniformly positive, suggesting that this diagnostic tool may be useful for current efforts to control the spread of PPR.

Modelling the expected rate of laboratory biosafety breakdowns involving rinderpest virus in the post-eradication era

Now that we are in the rinderpest post-eradication era, attention is focused on the risk of re-introduction. A semi-quantitative risk assessment identified accidental use of rinderpest virus in laboratories as the most likely cause of re-introduction. However there is little data available on the rates of laboratory biosafety breakdowns in general. In addition, any predictions based on past events are subject to various uncertainties. The aims of this study were therefore to investigate the potential usefulness of historical data for predicting the future risk of rinderpest release via laboratory biosafety breakdowns, and to investigate the impacts of the various uncertainties on these predictions. Data were collected using a worldwide online survey of laboratories, a structured search of ProMED reports and discussion with experts. A stochastic model was constructed to predict the number of laboratory biosafety breakdowns involving rinderpest that will occur over the next 10 years, based on: (1) the historical rate of biosafety breakdowns; and (2) the change in the number of laboratories that will have rinderpest virus in the next 10 years compared to historically. The search identified five breakdowns, all of which occurred during 1970-2000 and all of which were identified via discussions with experts. Assuming that our search for historical events had a sensitivity of over 60% and there has been at least a 40% reduction in the underlying risk (attributable to decreased laboratory activity post eradication) the most likely number of biosafety events worldwide was estimated to be zero over a 10 year period. However, the risk of at least one biosafety breakdown remains greater than 1 in 10,000 unless the sensitivity was at least 99% or the number of laboratories has decreased by at least 99% (based on 2000-2010 during which there were no biosafety breakdowns).

Androgens increase survival of adult-born neurons in the dentate gyrus by an androgen receptor-dependent mechanism in male rats

Gonadal steroids are potent regulators of adult neurogenesis. We previously reported that androgens, such as testosterone (T) and dihydrotestosterone (DHT), but not estradiol, increased the survival of new neurons in the dentate gyrus of the male rat. These results suggest androgens regulate hippocampal neurogenesis via the androgen receptor (AR). To test this supposition, we examined the role of ARs in hippocampal neurogenesis using 2 different approaches. In experiment 1, we examined neurogenesis in male rats insensitive to androgens due to a naturally occurring mutation in the gene encoding the AR (termed testicular feminization mutation) compared with wild-type males. In experiment 2, we injected the AR antagonist, flutamide, into castrated male rats and compared neurogenesis levels in the dentate gyrus of DHT and oil-treated controls. In experiment 1, chronic T increased hippocampal neurogenesis in wild-type males but not in androgen-insensitive testicular feminization mutation males. In experiment 2, DHT increased hippocampal neurogenesis via cell survival, an effect that was blocked by concurrent treatment with flutamide. DHT, however, did not affect cell proliferation. Interestingly, cells expressing doublecortin, a marker of immature neurons, did not colabel with ARs in the dentate gyrus, but ARs were robustly expressed in other regions of the hippocampus. Together these studies provide complementary evidence that androgens regulate adult neurogenesis in the hippocampus via the AR but at a site other than the dentate gyrus. Understanding where in the brain androgens act to increase the survival of new neurons in the adult brain may have implications for neurodegenerative disorders.

Rapid isolation of leukocyte subsets from fresh and cryopreserved peripheral blood mononuclear cells in clinical research

Isolation and processing blood into leukocyte subsets are important processes in research. Although methods have been developed to fractionate small volumes of blood, optimizing the methods and balancing the underlying costs are often necessary. The need for such optimization is particularly critical when processing larger volumes of blood. We describe a simple and reproducible method for processing larger volumes of fresh blood rapidly and consistently, which yields peripheral blood mononuclear cells (PBMCs) and leukocyte subsets with high purity (81-96%; n=13) and higher yields relative to stored blood. RNA isolated from these cells was found to be suitable for downstream applications. Blood stored for 24 hours (n=4) before processing resulted in significantly lower yields of PBMCs (58 percent lower), T cells (52 percent lower), B cells (21 percent lower) and monocytes (25 percent lower) compared to fresh blood. However, the purity of the fractionated cells was comparable to that obtained with fresh blood. Furthermore, we report that the yield and purity of the leukocyte subsets isolated from cryopreserved PBMCs (n=4) were not compromised.

Analysis of the antiferromagnetic phase transitions of the 2D Kondo lattice

We study the antiferromagnetic quantum phase transition of a 2D Kondo-Heisenberg square lattice using the nonlinear sigma model. A renormalization group analysis of the competing Kondo-RKKY interaction is carried out to one-loop order in the expansion, and a new quantum critical point (QCP) strongly affected by Kondo fluctuations is found. Near this QCP, the spin-wave velocity scales logarithmically, i.e., breakdown of hydrodynamic behavior, and the spin wave is logarithmically frozen out. The renormalization group results also allow us to propose a new phase diagram near the antiferromagnetic fixed point of this 2D Kondo lattice model.

Planar spin-transfer device with a dynamic polarizer

In planar nano-magnetic devices magnetization direction is kept close to a given plane by the large easy-plane magnetic anisotropy, for example by the shape anisotropy in a thin film. In this case magnetization shows effectively in-plane dynamics with only one angle required for its description. Moreover, the motion can become overdamped even for small values of Gilbert damping. We derive the equations of effective in-plane dynamics in the presence of spin-transfer torques. The simplifications achieved in the overdamped regime allow to study systems with several dynamic magnetic pieces ("free layers"). A transition from a spin-transfer device with a static polarizer to a device with two equivalent magnets is observed. When the size difference between the magnets is less than critical, the device does not exhibit switching, but goes directly into the "windmill" precession state.

First-principles calculation of the single impurity surface Kondo resonance

We perform first-principles calculations of the surface and bulk wave functions of the Cu(111) surface and their hybridization energies to a Co adatom, including the potential scattering from the Co. By analyzing the calculated hybridization energies, we find the bulk states dominate the contribution to the Kondo temperature, in agreement with recent experiments. Furthermore, we also calculate the tunneling conductance of a scanning tunneling microscope and compare our results with recent experiments of Co impurities in the Cu(111) surface. Good quantitative agreement is found at short parallel impurity-tip distances (<6 A). Our results indicate the need for a new formulation of the problem at larger distances.

A prospective randomised controlled trial of the Kiwi Omnicup versus conventional ventouse cups for vacuum-assisted vaginal delivery

OBJECTIVE

To evaluate the performance and safety of the Kiwi Omnicup and compare it to conventional vacuum cups in routine clinical practice.

DESIGN

A randomised controlled trial of the Kiwi Omnicup versus conventional vacuum cups.

SETTING

Queen Charlotte's and Chelsea Hospital, a tertiary referral hospital in London from April 2001 to March 2004.

POPULATION

Women requiring assisted vaginal delivery by ventouse.

METHODS

Women were randomised to the Kiwi Omnicup (n=206) or conventional vacuum cups (n=198). Data regarding maternal demographics, labour, mode of delivery and maternal and neonatal outcome were collected.

MAIN OUTCOME MEASURES

Failure of delivery with instrument of first choice.

RESULTS

The Kiwi Omnicup was less successful at delivery with instrument of first choice than the conventional ventouse, failure rate 30.1 versus 19.2% (RR 1.58; 95% CI 1.10-2.24). It was associated with a greater number of cup detachments (mean 0.68 compared with 0.28, with 44% compared with 18% having at least one detachment [P<0.0001]). There was no difference in the incidence of severe maternal trauma, and there were no cases of serious neonatal injury.

CONCLUSIONS

The Kiwi Omnicup is less successful than conventional ventouse in achieving vaginal delivery, but its safety profile is comparable.

Distribution of androgen receptor immunoreactivity in the brainstem of male rats

Gonadal steroids such as testosterone and estrogen are necessary for the normal activation of male rat sexual behavior. The medial preoptic area (MPOA), an important neural substrate regulating mating, accumulates steroids and also expresses functional androgen receptors (AR). The MPOA is intimately connected with other regions implicated in copulation, such as the bed nucleus of the stria terminalis and medial amygdala. Inputs to the MPOA arise from several areas within the brainstem, synapsing preferentially onto steroid sensitive MPOA cells which are activated during sexual activity. Given that little is known about the distribution of AR protein in the brainstem of male rats, we mapped the distribution of AR expressing cells in the pons and medulla using immunocytochemistry. In agreement with previous reports, AR immunoreactivity (AR-ir) was detected in ventral spinal motoneurons and interneurons. In addition, AR-ir was detected in areas corresponding to the solitary tract, lateral paragigantocellular and alpha and ventral divisions of the gigantocellular reticular nuclei, area postrema, raphe pallidus, ambiguus nucleus, and intermediate reticular nucleus. Several regions within the pons contained AR-ir, such as the tegmental and central gray, parabrachial nucleus, locus coeruleus, Barrington's nucleus, periaqueductal gray, and dorsal raphe. In contrast with in situ hybridization studies, auditory and somatosensory areas were AR-ir negative, and, except for very light staining in the prepositus nucleus, areas carrying vestibular information did not display AR-ir. Additionally, cranial nerve motoneurons of the hypoglossal, facial, dorsal vagus, and spinal trigeminal did not display AR-ir in contrast to previous reports. The data presented here indicate that androgens may influence numerous cell groups within the brainstem. Some of these probably constitute a steroid sensitive circuit linking the MPOA to motoneurons in the spinal cord via androgen responsive cells in the caudal ventral medulla.

Social representations of stem cell research and preimplantation genetic diagnosis

The study examined public thinking about stem cell research and preimplantation genetic diagnosis (PGD) using social representation theory. Social representation theory is concerned with the movement of scientific knowledge from the realm of the specialist into lay knowledge. Participants were interviewed and the data analysed qualitatively. Three social representations were found for both stem cell research and PGD. For stem cell research, one was based on irrational fears, one was based on social concerns for the technology and the final was based on the notion of the 'slippery slope'. For PGD, the first social representation was based on concern for the human impact, the second was based, again, on irrational fear, and the third was based on medical applications. Participants rated stem cell research more positively than PGD. It was concluded that while information about both topics is in the process of being transformed, knowledge of stem cell research has been transformed into lay knowledge more completely than knowledge of PGD. Directions for future research included attitude surveys and discourse analyses.

Participatory analysis of seasonal incidences of diseases of cattle, disease vectors and rainfall in southern Sudan

During an investigation into a chronic wasting disease in southern Sudanese cattle, a participatory appraisal method called a 'seasonal calendar' was used to understand local perceptions of seasonal variations in cattle diseases, disease vectors, intermediate hosts and rainfall. Repetition of a standardized seasonal calendar with Dinka informants demonstrated good reproducibility of the method. Comparison of rainfall data produced by seasonal calendars and objective measures of rainfall demonstrated good validity of the seasonal calendar method. Subjective assessment of seasonal calendar scoring patterns by veterinarians indicated that herders' perceptions of seasonal populations of biting flies, ticks and snails were similar to modern veterinary knowledge. The uses of seasonal calendars in veterinary epidemiology are discussed.

Participatory diagnosis of a chronic wasting disease in cattle in southern Sudan

In southern Sudan, livestock keepers identified a chronic wasting disease in adult cattle as one of their most-serious animal-health problems. Participatory-appraisal (PA) methods and conventional veterinary-investigation methods were used to characterise the chronic wasting disease and identify linkages between indigenous knowledge and modern veterinary knowledge. The local characterisation of chronic wasting encompassed trypanosomosis, fasciolosis, parasitic gastroenteritis and schistosomosis (as both single and mixed infections).A standardised PA method called matrix scoring had good reproducibility when investigating local perceptions of disease-signs and disease causes. Comparison of matrix-scoring results showed much overlap with modern veterinary descriptions of cattle diseases and the results of conventional veterinary investigation. Applications of PA methods in remote areas with very limited veterinary infrastructure are discussed. The validation of data derived from PA is discussed by reference to the low sensitivity of 'field-friendly' diagnostic tests for important cattle diseases.

Nongynecologic cytology turnaround time: a College of American Pathologists Q-Probes study of 180 laboratories

OBJECTIVES

To determine the turnaround time for nongynecologic cytology and to identify laboratory and specimen characteristics associated with variations in turnaround time.

DESIGN AND SETTING

Prospective evaluation of nongynecologic cytology turnaround times in 180 laboratories.

MAIN OUTCOME MEASURE

Nongynecologic cytology case turnaround time.

RESULTS

Participants from 180 laboratories submitted turnaround times for 16 950 nongynecologic cytology cases and submitted information describing their laboratories' practice characteristics relating to the processing of nongynecologic cytology specimens. Half of the participating laboratories had mean receipt to report turnaround times of 1.6 calendar days or less and were able to complete 90% of their cases within 3.0 calendar days. Ten percent of participants had mean turnaround times greater than 3.2 days and required 6.0 or more days to report 90% of their cases. Longer turnaround times were associated with processing fluid and fine-needle aspiration specimens, issuing atypical/suspicious for malignancy and nondiagnostic diagnoses, having cytotechnologist students screen slides, having to contact the physician offices for additional information, having to retrieve prior case material for review, and having to perform cell blocks and/or special stains.

CONCLUSION

There is an opportunity for laboratories to shorten nongynecologic turnaround time by altering certain laboratory practices.

Usefulness of concurrent Papanicolaou smear at time of cervical biopsy

The reliability and cost-effectiveness of a repeat Papanicolaou (Pap) smear performed at the time of colposcopic biopsy is uncertain. To evaluate the usefulness of this practice, Pap smear and biopsy results of 718 patients were reviewed and compared: 619 patients had Pap smears performed prior to colposcopy with a 1.1% false-negative rate, 97.5% sensitivity, and 83.6% positive predictive value. Ninety-nine patients had Pap smears performed at the time of colposcopy with a 19.1% false-negative rate, 56.8% sensitivity, and 92.6% positive predictive value. Repeat Pap smear at the time of colposcopy resulted in significant changes in the management of only 2 patients (2%) and more careful follow-up in one (1%). Pap smears performed at colposcopic biopsy are less sensitive than those done prior to biopsy (P < 0.001). The clinical benefit of this practice is marginal, considering the added costs and potential detrimental effects to the colposcopic examination, provided patients receive adequate follow-up.

Race, anthropometric factors, and stage at diagnosis of breast cancer

A recent study suggested that the greater prevalence of severe obesity among African-American women explained almost one third of the observed differences between African-American and White women in stage at diagnosis of breast cancer. The objective of this investigation was to attempt to replicate these findings in a second, larger population and to expand the analyses by including a measure of body fat distribution, the waist:hip ratio. The authors used data from a population-based study in North Carolina comprising 791 breast cancer cases (302 in African-American women and 489 in White women) diagnosed between 1993 and 1996. African-American women were more likely to have later-stage (TNM stage >/=II) breast cancer (odds ratio (OR) = 2.2; 95% confidence interval (CI): 1.6, 2.9). They also were much more likely to be severely obese (body mass index >/=32.3) (OR = 9.7; 95% CI: 6.5, 14.5) and to be in the highest tertile of waist:hip ratio (OR = 5.7; 95% CI: 3.8, 8.6). In multivariate logistic regression models, adjustment for waist:hip ratio reduced the odds ratio for later-stage disease in African-American women by 20%; adjustment for both waist:hip ratio and severe obesity reduced the odds ratio by 27%. These observations suggest that obesity and body fat distribution, in addition to socioeconomic and medical care factors, contribute to racial differences in stage at breast cancer diagnosis.

Is variation in quality of mammographic services race linked?

The purpose of this investigation was to (1) determine whether there was variability in the quality of services offered in mammography facilities across Connecticut and (2) determine whether African American women were more likely than white women to receive mammograms in facilities that offered substandard services. Since most facilities do not routinely record information on race, this investigation represents a unique opportunity to address the question of race-linked variation in the quality of screening mammography. Information on equipment, personnel, and record keeping in mammography facilities was used to construct indices that represented separate domains of quality: technical attributes, educational practices, and tracking of clients. While some variation in the quality of mammography services was found, there were no significant differences between the two race categories in the mean scores for each of three quality indices. Thus, variation in quality of screening mammographic services does not appear to be race linked.

Quality management in gynecologic cytology using interlaboratory comparison

OBJECTIVE

To describe a comprehensive integrated laboratory quality management plan for gynecologic cytology.

DESIGN AND SETTING

Cytopathology laboratory performance monitors with interlaboratory comparison.

RESULTS

Utilizing College of American Pathologists Q-Probes studies, the College of American Pathologists Interlaboratory Comparison Program in Cervicovaginal Cytology, and other published data, a quality management program for gynecologic cytology involving diagnostic statistics, screening limits and competency assessment, retrospective rescreening, real-time rescreening, cytology-biopsy correlation, follow-up of patients with abnormal cytology results, turnaround time, examination of unknown slides (survey programs), and new technology is described.

CONCLUSION

Regular coordinated monitoring of performance, with longitudinal and interlaboratory comparison utilizing the methods described, provides an opportunity to optimize gynecologic cytology service.

Follow-up of abnormal gynecologic cytology: a college of American pathologists Q-probes study of 16132 cases from 306 laboratories

OBJECTIVES

To measure the percentage of women with abnormal gynecologic cytology who have follow-up within 1 year and to identify patient and laboratory characteristics associated with higher percentages of follow-up.

DESIGN AND SETTING

Retrospective identification of patients with abnormal cervicovaginal cytology and identification of the initial clinical follow-up activity during the 12 months following the cytologic diagnosis.

MAIN OUTCOME MEASURE

Percentage of women receiving follow-up.

RESULTS

Three hundred six laboratories reported follow-up information on 16 132 patients with gynecologic cytology diagnoses of carcinoma, high-grade squamous intraepithelial lesion, low-grade squamous intraepithelial lesion, or glandular intraepithelial lesion. The following percentages of women received follow-up within 1 year: 85.6% of patients with cytologic diagnoses of carcinoma, 87.2% with diagnoses of high-grade squamous intraepithelial lesion, 82.7% with diagnoses of low-grade squamous intraepithelial lesion, and 84.9% with diagnoses of glandular intraepithelial lesion. Within 6 months, 82.2% of patients with cytologic diagnoses of carcinoma, 82.4% with diagnoses of high-grade squamous intraepithelial lesion, 71.9% with diagnoses of low-grade squamous intraepithelial lesion, and 74.7% with diagnoses of glandular intra-epithelial lesion received follow-up. Overall, 90. 8% of patients who received follow-up within the 1-year time frame of this study had their follow-up completed within 6 months. Specific follow-up activities and their frequencies are listed for each diagnostic category. Patients 30 years old or younger and pregnant patients had lower follow-up percentages.

CONCLUSIONS

With less than 83% of patients with high-grade squamous intraepithelial lesion or carcinoma cytology findings having available documentation of follow-up within 6 months, and less than 88% within 1 year, there is room for improvement in this area of health care. Monitoring and critical analysis of the follow-up process is a starting point for improvement.

Use of selective hypothermia to protect the spinal cord during resection of thoracoabdominal aneurysms

Neurologic complications remain a threat to patients after repair of thoracoabdominal thoracic aneurysms. We have recently used a simple technique of selective hypothermia during such repairs in 7 high-risk patients. None of the patients had neurologic complications. In the 1st patient, we used cardiopulmonary bypass, but we have subsequently found that the procedure can be performed safely without an oxygenator in the circuit by using only a centrifugal pump, heat exchanger, thermistor, and pressure gauge. We believe that this technique deserves additional consideration for avoiding neurologic complications after repair of such lesions.

Modulation of endogenous GABA release by an antagonistic adenosine A1/dopamineD1 receptor interaction in rat brain limbic regions but not basal ganglia

Behavioral and biochemical studies suggest that a negative interaction exists between adenosine A(1) and dopamine D(1) receptors in the brain and that this may contribute to the psychomotor effects of adenosine receptor agonists and antagonists. We examined the functional significance of A(1) and D(1) receptor subtypes in modulating electrically evoked endogenous GABA release from slices/punches of rat basal ganglia (striatum, globus pallidus, striatum containing globus pallidus, and substantia nigra reticulata) and limbic regions (ventral pallidum and nucleus accumbens). In basal ganglia, stimulation of A(1) receptors with the selective agonist R-PIA (1-100 nM) resulted in a concentration-dependent decrease in GABA release. The selective A(1) antagonist DPCPX (10-100 nM) increased GABA release, suggesting that endogenous adenosine tonically inhibits GABA release. However, in basal ganglia, consistent dopamine D(1) receptor modulation of GABA, release was not observed in response to either D(1) agonists or antagonists. Furthermore, the A(1) receptor-mediated inhibition of GABA release was not changed by concurrent activation of D(1) receptors, thus confirming the lack of D(1) receptor modulation under these conditions. In contrast, in ventral pallidum and nucleus accumbens, stimulation of D(1) receptors with SKF-82958 (1 microM) increased GABA release significantly. The D(1) receptor-mediated increase in GABA release was attenuated by concurrent activation of adenosine A(1) receptors. These results are consistent with the hypothesis that an antagonistic A(1)/D(1) receptor interaction may be important in modulating GABA release in limbic regions.

Gynecologic cytology turnaround time. A College of American Pathologists Q-Probes Study of 371 laboratories

OBJECTIVES

To determine the turnaround time for gynecologic cytology in a large sample of laboratories and to identify laboratory and specimen characteristics associated with better and worse performance.

DESIGN AND SETTING

Prospective evaluation of gynecologic cytology turnaround times in 371 laboratories.

MAIN OUTCOME MEASURE

Gynecologic cytology case turnaround time.

RESULTS

Three hundred seventy-one laboratories submitted information regarding laboratory characteristics and processes, and turnaround times of 66 042 gynecologic cytology cases. Half of the participating laboratories had mean turnaround times of 6 calendar days or less and were able to complete 90% of their cases within 8 calendar days. Ten percent of participants had mean turnaround times greater than 13 days and required 19 or more days to report 90% of their cases. Longer turnaround times were associated with the use of reference laboratories for all or part of the evaluation; contacting the physician's office for additional information; using cytotechnology students, residents, or fellows in the evaluation; and providing service on the weekend.

CONCLUSION

Practice patterns contribute to the long turnaround times for gynecologic cytology found in some laboratories and may be improved by local site-specific process analysis.

Cholestasis confers resistance to the rat liver mitochondrial permeability transition

BACKGROUND & AIMS

Bile salts can cause hepatocyte death by inducing the mitochondrial permeability transition (MPT). However, the slow progression of human cholestatic liver diseases suggests that hepatocytes adapt to resist the MPT. Bcl-x, a protein, and increased mitochondrial cardiolipin, a membrane lipid, elevate the threshold for the MPT. Our aims were to determine if liver mitochondria become resistant to the MPT during cholestasis and, if so, if the resistance is mediated by Bcl-x and/or increased cardiolipin.

METHODS

Hepatocytes and liver mitochondria were obtained from bile duct-ligated (BDL) rats and sham-operated rats (control).

RESULTS

After addition of glycochenodeoxycholate (GCDC), the magnitude of the MPT was reduced in mitochondria from BDL rats vs. controls. Although Bcl-xL was not increased, mitochondrial cardiolipin content was significantly greater in BDL rats vs. controls. Cell viability was also increased in hepatocytes from BDL rats vs. controls after treatment with GCDC. Feeding BDL rats a fatty acid-deficient diet prevented the increase in mitochondrial cardiolipin content; mitochondria and hepatocytes from these rats were susceptible to the MPT and hepatocellular death by GCDC.

CONCLUSIONS

These data suggest that an increase in mitochondria cardiolipin content occurs during cholestasis as an adaptive phenomenon to resist cell death by the MPT.

Isolation and characterization of cDNAs encoding PDE5A, a human cGMP-binding, cGMP-specific 3',5'-cyclic nucleotide phosphodiesterase

Human cGMP-binding, cGMP-specific 3',5'-cyclic nucleotide phosphodiesterase (PDE5A) cDNAs were isolated. A 3.1-kb composite DNA sequence assembled from overlapping cDNAs encodes an 875-amino-acid protein with a predicted molecular mass of 100012 Da (PDE5A1). Extracts prepared from yeast expressing human PDE5A1 hydrolyzed cGMP. This activity was inhibited by the selective PDE5 inhibitors zaprinast and DMPPO. PDE5A mRNA is expressed in aortic smooth muscle cells, heart, placenta, skeletal muscle and pancreas and, to a much lesser extent, in brain, liver and lung. A 5'-splice variant, PDE5A2, encodes an 833-amino-acid protein with eight unique amino acids at the amino terminus. PDE5A maps to chromosome 4q 25-27.

Dysregulation of apoptosis as a mechanism of liver disease: an overview

Apoptosis is a morphologically distinct form of cell death which occurs in a wide variety of liver diseases. In this overview chapter, we review: (1) the current definitions of apoptosis; (2) the biochemical pathways effecting apoptosis; and (3) the intracellular pathways regulating apoptosis. We also describe how apoptosis is identified in the liver and review the ligand/receptor interactions which trigger hepatobiliary apoptosis. Finally, we speculate on potential therapeutic applications for modulating apoptosis in human liver diseases. This information is meant to provide a foundation for the following chapters each focused on a specific role of apoptosis in liver diseases.

Interinstitutional comparison of bedside blood glucose monitoring program characteristics, accuracy performance, and quality control documentation: a College of American Pathologists Q-Probes study of bedside blood glucose monitoring performed in 226 small hospitals

OBJECTIVES

To assess the accuracy of bedside blood glucose monitoring (BGM) in small hospitals, to assess the compliance with which hospital workers performing bedside BGM adhere to quality control (QC) procedures, and to identify those practice characteristics in small hospitals that are associated with better BGM accuracy and with better performance of BGM QC.

DESIGN

Over a 1-month period in 1996, voluntary participants in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively compared glucose results of 30 split samples run on BGM instruments with those performed on laboratory glucose analyzers, collected quality control data on up to five inpatient BGM instruments, and completed questionnaires profiling BGM practice characteristics in their institutions.

SETTING AND PARTICIPANTS

Two hundred twenty-six hospitals with 200 or fewer occupied beds.

MAIN OUTCOME MEASURES

The percentages of glucose determinations performed on BGM instruments differing by more than 10%, 15%, and 20% from those split-sample results performed on laboratory glucose analyzers; the percent of BGM QC determinations required by institutions' BGM QC programs that BGM operators actually performed; and the percent of patient values reported when BGM QC was documented to be out of range and uncorrected, or reported when BGM QC was not performed at all.

RESULTS

Of 6095 split-specimen glucose results that participants simultaneously performed on BGM instruments and on laboratory glucose analyzers, 45.6% differed from each other by more than 10%, approximately 25% differed from each other by more than 15%, and almost 14% differed from each other by more than 20%. Of 216 laboratories that performed at least 30 QC events during the study period, slightly over a third completed 100% of their required QC determinations, and 10% completed, at most, 77% of their required BGM QC determinations. Of 115,973 BGM determinations that participants reported on hospitalized patients, 3.3% were reported when QC was either out of range or when there was no documentation that QC had been performed at all. Better accuracy and/or better QC performance was associated with laboratory personnel rather than nursing personnel both supervising institutions' BGM QC programs and running institutions' daily routine BGM QC; with BGM operators both routinely running three, rather than two, levels of QC analytes; with BGM operators regularly comparing BGM results with laboratory analyzer glucose results; and with institutions participating in external proficiency programs. Institutions that completed all required BGM QC tasks tended to perform better on the BGM accuracy study than did those institutions that completed, at most, 77% of their required QC.

CONCLUSIONS

We found the rates of BGM accuracy and of QC performance adequacy achieved in small hospitals to be similar to those determined in previous Q-Probes studies conducted in large institutions. A significant amount of institutional bedside testing does not meet current standards for accuracy or for quality control. Some institutions may improve their accuracy and/or QC performances by having laboratory personnel intimately involved in their institution's BGM QC program, by routinely comparing BGM results with those performed using glucose analyzers in the clinical laboratory, by routinely running three rather than two glucose QC control levels, by participating in external proficiency programs, and by strictly adhering to institutional QC protocols.

Hepatobiliary malignancy

Chronic cholestatic liver disease may be complicated by hepatobiliary malignancy. The early detection of hepatocellular carcinoma and cholangiocarcinoma is of paramount importance in the evaluation of candidates for liver transplantation, which remains the only effective treatment modality for advanced primary biliary cirrhosis and primary sclerosing cholangitis. This article reviews the identification of patients at high risk, current techniques for diagnosis, and makes recommendations for screening high-risk patients. This article also reviews preliminary data from the Mayo Clinic regarding liver transplantation for cholangiocarcinoma following radiation therapy.

Remission of infantile systemic lupus erythematosus with intravenous cyclophosphamide

We report an 8-month-old boy with systemic lupus erythematosus and World Health Organization class IV lupus nephritis who has gone into complete clinical and serological remission with pulse i.v. cyclophosphamide therapy. To our knowledge this is the first case of pulse i.v. cyclophosphamide therapy in infantile systemic lupus erythematosus resulting in long-term remission.

Quality assurance/control issues. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial

ISSUES

General definitions of quality assurance and quality control (QA/C) have existed in many forms for decades, and a new discipline guides their application to diverse industrial and recently medical processes without much fanfare. However, in the field of cervical cytology screening, the range of QA/C options has recently broadened and become controversial. With the advent of new systems of terminology, larger-scale laboratories and new technologies--plus strong governmental and legal pressures in some nations--the range of extremely difficult and sometimes expensive QA/C choices our community faces is greater than ever.

CONSENSUS POSITION

At our conference, the basic definitions of QA/C posed little difficulty. Presentation of the range of methods in use today and of those based on new technologies where use is proposed or has just begun also was achieved with little or no dispute. However, there was lack of consensus on exactly how QA/C methods are to be assessed. Indeed, there was little consistency in the use of different outcome measures with which we can judge success or failure of specific QA/C options. In addition, the tension between pressure to adopt sometimes uncertain or expensive method enhancements and pressure to maintain affordability and the widest possible access for populations that most need cervical cytology screening is greater than ever.

ONGOING ISSUES

More data are required that would enable assessment of QA/C options with the clearest possible understanding of cost/benefits and current or new assumptions of risk. Other task forces, such as medicolegal, cost/benefit and those devoted to new technologies, are our essential partners in meeting the challenges described above.

Physiology and pathophysiology of apoptosis in epithelial cells of the liver, pancreas, and intestine

Cell death of gastrointestinal epithelial cells occurs by a process referred to as apoptosis. In this review, we succinctly define apoptosis and summarize the role of apoptosis in the physiology and pathophysiology of epithelial cells in the liver, pancreas, and small and large intestine. The physiological mediators regulating apoptosis in gastrointestinal epithelial cells, when known, are discussed. Selected pathophysiological consequences of excessive apoptosis and inhibition of apoptosis are used to illustrate the significance of apoptosis in disease processes. These examples demonstrate that excessive apoptosis may result in epithelial cell atrophy, injury, and dysfunction, whereas inhibition of apoptosis results in hyperplasia and promotes malignant transformation. The specific cellular mechanisms responsible for dysregulation of epithelial cell apoptosis during pathophysiological disturbances are emphasized. Potential future areas of physiological research regarding apoptosis in gastrointestinal epithelia are highlighted when appropriate.

Decreasing polypharmacy in clients most at risk

Approximately one third of all drugs prescribed in the United States are considered unnecessary. Polypharmacy, the unnecessary, excessive use of prescription and over-the-counter medications, increases clients' risk for adverse drug reactions and drug-drug interactions. Reducing the incidence of polypharmacy is a health protection goal of Healthy People 2000. Older clients, particularly older women living independently in the community, are at highest risk for polypharmacy caused by age-related changes in pharmacokinetics and pharmacodynamics, the presence of comorbidities requiring pharmacologic management, and high rates of unintentional noncompliance with their therapeutic regimen. Health providers may contribute to polypharmacy directly by excessive or inappropriate prescribing practices or indirectly through their inability to resist client's demands for pharmacologic interventions. Strategies to prevent and detect polypharmacy are suggested to reduce its incidence and the severity of its consequences.

False positive cervicovaginal cytology. A follow-up study

OBJECTIVE

To determine what percentage of cervical cytologic diagnoses initially classified as false positives (based on a negative cervical biopsy within three months of the cervical cytologic smear) are recategorized as histologic false negatives when subsequent studies reveal abnormalities.

STUDY DESIGN

A three-year review of 1,242 cervicovaginal biopsies with corresponding cytology in the preceding three months revealed 68 cases (5.5%) where the cytology was positive for a squamous intraepithelial lesion but the biopsy was within normal limits or showed benign cellular changes. Follow-up cytologic and/or histologic diagnoses were obtained for 53 of the 68 cases from the patients' hospital and physician office records.

RESULTS

Of the 53 cases with follow-up, 24 (45%) were found to have a subsequent squamous intraepithelial lesion (indicating a sampling error at the time of the initial biopsy), and 9 showed atypical squamous cells of undetermined significance. In addition, 9 of the 20 patients (45%) who had negative follow-up studies had benign abnormalities on the initial, noncorrelating biopsy that may have contributed to the discrepancy.

CONCLUSION

This study emphasized the importance of diligent follow-up of patients with noncorrelating studies since they represent a population at high risk for the subsequent detection of premalignant conditions.

Severe obesity as an explanatory factor for the black/white difference in stage at diagnosis of breast cancer

Black women with breast cancer are less likely than white women to be diagnosed while their disease is still at a localized stage. Racial differences in the prevalence of obesity in the United States have also been documented. This study was undertaken to determine the extent to which the observed racial difference in stage at diagnosis of breast cancer could be explained by racial differences in obesity, specifically severe obesity. This was a population-based, retrospective study of 145 black women and 177 white women in Connecticut who were diagnosed with breast cancer between January 1987 and March 1989. Severe obesity was associated with both race and stage at diagnosis: Black women were significantly more likely than white women to be severely obese (26% vs. 7%, respectively), and severe obesity was significantly associated with diagnosis at TNM stage II or greater (multivariate-adjusted odds ratio = 3.10, 95% confidence interval (CI) 1.28-7.52). Adjustment for severe obesity in a logistic regression model reduced the risk of later stage at diagnosis in blacks relative to whites by 33%, from an odds ratio of 1.98 (95% CI 1.22-3.19) to one of 1.66 (95% CI 1.01-2.73). The higher prevalence of severe obesity among black women may play an important role in explaining their relative disadvantage in stage at diagnosis of breast cancer.

Bile salt-induced apoptosis of hepatocytes involves activation of protein kinase C

Toxic bile salts induce hepatocyte apoptosis, a model relevant to liver injury during cholestasis. However, the signaling mechanisms culminating in bile salt-induced apoptosis remain unclear. Because protein kinase C (PKC) is activated by bile salts in hepatocytes and causes apoptosis in other cells, we tested the hypothesis that bile salt-induced hepatocyte apoptosis is mediated by PKC. The PKC inhibitors chelerythrine and Gö-6976 reduced, whereas a PKC agonist, phorbol 12-myristate 13-acetate (PMA), increased glycochenodeoxycholate (GCDC)-induced hepatocyte apoptosis. Membrane-associated total PKC activity was increased in GCDC-treated hepatocytes. Quantitative immunoblot analysis demonstrated membrane translocation of PKC-alpha, PKC-delta, and PKC-epsilon to hepatocyte membranes after administration of GCDC. Direct activation of PKC-alpha and PKC-delta by GCDC was also demonstrated using recombinant, baculovirus-expressed PKC isoforms in a medium of defined lipid composition. Chelerythrine and Gö-6976 reduced, whereas PMA enhanced, cathepsin B activity during treatment of hepatocytes with GCDC, demonstrating coupling of PKC activity to the protease effector mechanisms of apoptosis. In conclusion, our data suggest for the first time that PKC-dependent signaling pathways play a critical role in bile salt-induced hepatocyte apoptosis.