The Impact of Storage Temperature and Time on Ergot Alkaloid Concentrations.

Ergot sclerotia produce toxic secondary metabolites, ergot alkaloids, that infect cereal crops and grasses. Ergot alkaloids have two isomeric configurations: the C-8-R-isomer (R-epimer), and the C-8-S-isomer (S-epimer). Ergot contaminated matrices, such as cereal grains or grasses, may be stored for extended periods at various temperatures before being analyzed, utilized, or consumed. This study assessed the concentration of six common ergot alkaloids in both configurations found in naturally contaminated wheat over time (one, two, and four months) at different temperatures (room temperature, +4 °C, and -20 °C) using ultra-high-performance liquid chromatography-tandem mass spectrometry. The data indicate that the total ergot concentration within a natural contaminated sample varies over time at room temperature, +4 °C, and -20 °C. The total ergot concentration increased until month two, and decreased at month four, independent of temperature (p < 0.05). The total R-epimer concentration appeared to be less stable over time than the total S-epimer concentration. The changes in the total R and total S-epimer concentrations may have been caused by changes in the ergocristine and ergocristinine concentrations, respectively. Time and temperature should be considered when storing potentially contaminated matrices in a laboratory or practical agriculture situations. Quantification of ergot contaminated matrices should occur prior to their use to ensure the most reliable estimates of the concentration of ergot.

Risk factors for insidious uveitis in the Knabstrupper breed.

BACKGROUND: Equine recurrent uveitis (ERU) is the leading cause of blindness for horses; previous research implicated the leopard complex spotting allele (LP) as a genetic risk factor for insidious uveitis in the Appaloosa. There is limited information about risk in the Knabstrupper. OBJECTIVE: To evaluate clinical manifestations, disease frequency and potential risk factors for ERU in Knabstrupper horses. STUDY DESIGN: Cross-sectional study. METHODS: Ocular examinations were performed on 116 horses, and based on identified anomalies, horses were classified as suspect, ERU-affected or having no clinical signs. Microagglutination testing (MAT) of serum assessed exposure to Leptospira spp. Clinical signs, age, sex, base colour, coat pattern, LP and PATN1 genotypes, percent white at birth, progressive roaning and Leptospira were assessed as risk factors using multivariable exact logistic regression, accounting for clustering at the barn level. Additionally, a pedigree analysis was performed (n = 20 cases and 21 controls), and coefficients of coancestry (CC) and inbreeding were calculated. RESULTS: Prevalence of insidious uveitis in this sample of Knabstruppers was 20.7%. Similar to findings for Appaloosas, LP homozygotes had higher odds of uveitis compared with true solid (N/N) horses (LP/LP OR = 7.64, 95% CI [0.8 to +INF], p = 0.04) and age was also identified as a risk factor. After accounting for LP, the 16-20 age group had higher odds compared with the youngest group (OR = 13.36, 95% CI [1.4-213.4], p = 0.009). The distributions of average CC were significantly different between cases and controls (p = 0.01). MAIN LIMITATIONS: A relatively small sample size decreased the power for detecting additional associations. The progressive nature of insidious uveitis may have prevented identification of younger affected horses. CONCLUSIONS: Our data support genotyping for LP to assess risk of ERU in Knabstruppers. Additional studies are necessary to develop more robust risk models across LP breeds for earlier detection and improved clinical management.

"Put a mark on the errors": Seventeenth-century medicine and science.

Error is a neglected epistemological category in the history of science. This neglect has been driven by the commonsense idea that its elimination is a general good, which often renders it invisible or at least not worth noticing. At the end of the sixteenth century across Europe, medicine increasingly focused on "popular errors," a genre where learned doctors addressed potential patients to disperse false belief about treatments. By the mid-seventeenth century, investigations into popular error informed the working methodology of natural philosophers, rather than just physicians. In 1646, Thomas Browne published Pseudodoxia Epidemica, a large volume on popular error. Despite Browne's formal training as a physician, this work examined only a few medical errors and instead aspired to be an encyclopedia of error. Pseudodoxia Epidemica was highly popular, running to six editions, and was known by the Fellows of the Royal Society. Influenced by Browne, alongside Bacon's theory of the idols, natural philosophic practice in the late sixteenth and seventeenth century developed a focus on error that revised traditional attention to the discovery of knowledge. Fellows such as Robert Boyle and Robert Hooke proposed new ways to secure truth under the far-reaching influence of Bacon's refutations of "natural human reason" distorted by false idols, of syllogistic logic, and of "theories," his label for traditional philosophical systems that bias thought toward falsity. In three parts, this article traces the progression in early modern scientific approaches to handling error, and especially medical error - from physicians' efforts to identify and eradicate it through collaborative effort, to the striking tension in Browne's work between seeking to eliminate error while also showing a marked tolerance for it, to the Royal Society's Baconian objective of instrumentalizing error to find truth. Error emerges as its own epistemic category that serves as a driving force toward knowledge production.

Evaluation of conjunctival graft procedures and factors that lead to graft complications in canine cases.

PURPOSE: To describe the complications of conjunctival graft surgery occurring in cases at a referral ophthalmic service and evaluate factors that lead to occurrence of complications in canine cases. METHODS: A retrospective case-control study was completed using data from the Veterinary Medical Center at the Western College of Veterinary Medicine, Saskatoon, Canada, between May 2015 and March 2020. Case records from dogs that underwent conjunctival pedicle graft surgery and subsequently either did or did not develop a conjunctival graft complication were reviewed. RESULTS: One hundred and six dogs undergoing conjunctival graft surgeries were identified. Sixteen conjunctival graft complications occurred, of which, eight led to negative outcomes. Univariable analysis comparing canine eyes that developed complications to control eyes revealed potential (p ≤ .05) differences between the groups in post-operative fluoroquinolone use, Streptococcus canis isolation, intraoperative intravenous cefazolin use, corneal stromal white cell infiltrate, and mean ulcer diameter. The use of intraoperative cefazolin could not be effectively evaluated with available data; however, no dogs (n = 22) receiving intraoperative cefazolin developed complications. Multivariable analysis revealed that dogs that were treated with a second-generation fluoroquinolone and that had S. canis isolated had higher odds of experiencing complications than dogs that were not treated with a second-generation fluoroquinolone and that were S. canis negative (Odds ratio = 64.7 [95% CI 6.3-669], p < .0001). CONCLUSIONS: Streptococcus species played a role in conjunctival graft complications in our study. Empiric selection of second-generation fluoroquinolone monotherapy may need reconsideration given the frequent isolation of Streptococcus spp. from canine ulcers. The use of intraoperative cefazolin may be associated with a lower complication rate.

Ammonization of the R- and S-Epimers of Ergot Alkaloids to Assess Detoxification Potential.

Detoxification of ergot-contaminated feed by ammonia would be a practical application, given that ammonia is routinely used in the agriculture industry. To assess the effects of ammonia on ergot alkaloids, natural ergot-contaminated wheat was ammoniated. The total concentration of ergot alkaloids (R- and S-epimers) decreased after exposure to ammonia (8-29%). Separately, the total R-epimers decreased in concentration (40-66%), whereas the total S-epimers increased (21-81%). Specific ergot alkaloids demonstrated degradation and/or epimerization after exposure to ammonia, potentially associated with structural differences, and influenced the total concentrations observed. Ammonization of ergot standards resulted in potential degradation products and epimerization, supporting the above results. The use of ultrahigh-performance liquid chromatography-tandem mass spectrometry provides an updated assessment of the detoxification potential of ammonia for ergot alkaloids and the quantification of the S-epimers. Ammonia alters the R- and S-epimers of ergot alkaloids, which may lead to a potential practical detoxification process of ergot-contaminated feed.

Sustained vascular contractile response induced by an R- and S-epimer of the ergot alkaloid ergocristine and attenuation by a noncompetitive antagonist.

Vasoconstriction is a known effect associated with ergot alkaloid consumption. The vascular contractile responses are often sustained for an extended period after exposure. Ergot alkaloids exist in two molecular configurations, the C-8-(R)-isomer (R-epimer) and the C-8-(S)-isomer (S-epimer). The sustained vascular contractile response to the R-epimers has been studied previously, unlike the S-epimers which are thought to be biologically inactive. Additionally, antagonists have been utilized to attenuate the vascular contraction associated with the R-epimers of ergot alkaloids utilizing ex vivo techniques. This study utilized an arterial tissue bath to examine and compare the sustained vascular contractile response attributed to ergocristine (R) and ergocristinine (S) using dissected bovine metatarsal arteries. The contractile blocking effect of a noncompetitive alpha-adrenergic antagonist, phenoxybenzamine (POB), was also investigated in precontracted arteries. Arteries (n = 6/epimer) were exposed to a single dose of ergocristine or ergocristinine (1 × 10-6 M in buffer). Each of the epimer doses was followed by a POB (1 × 10-3 M) or methanol (control) treatment at 90 min and the response was observed for another 90 min. Both epimers produced a sustained contractile response over the 180-min incubation period in the control groups. The R-epimer caused a greater sustained contractile response from 60 to 180 min post epimer exposure, compared to the S-epimer (P < 0.05, generalized estimating equations, independent t-test). Phenoxybenzamine caused a decrease in the contractile response induced by ergocristine and ergocristinine from 105 to 180 min, compared to the control (P < 0.05, generalized estimating equations, paired t-test). Overall, these results demonstrate the presence of a sustained vascular contractile response attributed to the R- and S-epimer of an ergot alkaloid with differences in contractile response between the epimers, suggesting differences in receptor binding mechanisms. Furthermore, this study demonstrated that a noncompetitive antagonist could attenuate the sustained arterial contractile effects of both ergot configurations ex vivo. Additional investigation into S-epimers of ergot alkaloids is needed. This research contributes to the understanding of the ergot epimer-vascular receptor binding mechanisms, which may support the investigation of different approaches of minimizing ergot toxicity in livestock.

Ergot alkaloids cause blood vessels to contract when contaminated feed is consumed by animals. Vascular contraction often remains for a prolonged period and involves the binding of ergot to specific receptors in the blood vessels. This study assessed and compared the sustained contraction of cow arteries after exposure to two forms of an ergot alkaloid, namely, ergocristine and ergocristinine. The effects of a specific receptor blocker, phenoxybenzamine, on the vascular contraction induced by these forms were also examined. This study showed that both forms of ergot caused a sustained contraction of cow arteries but to different magnitudes. Differences in contraction could be related to differences in how each form of ergot binds to receptors. The receptor blocker decreased the sustained contractile response of both forms of ergot. Further understanding of how the different forms of ergot bind to receptors, and how to decrease the adverse effects, may help mitigate the toxic effects of ergotism.

The timing, duration and magnitude of the 8.2 ka event in global speleothem records.

Abrupt events are a feature of many palaeoclimate records during the Holocene. The best example is the 8.2 ka event, which was triggered by a release of meltwater into the Labrador Sea and resulted in a weakening of poleward heat transport in the North Atlantic. We use an objective method to identify rapid climate events in globally distributed speleothem oxygen isotope records during the Holocene. We show that the 8.2 ka event can be identified in >70% of the speleothem records and is the most coherent signal of abrupt climate change during the last 12,000 years. The isotopic changes during the event are regionally homogenous: positive oxygen isotope anomalies are observed across Asia and negative anomalies are seen across Europe, the Mediterranean, South America and southern Africa. The magnitude of the isotopic excursions in Europe and Asia are statistically indistinguishable. There is no significant difference in the duration and timing of the 8.2 ka event between regions, or between the speleothem records and Greenland ice core records. Our study supports a rapid and global climate response to the 8.2 ka freshwater pulse into the North Atlantic, likely transmitted globally via atmospheric teleconnections.

Prognostic indicators at presentation for canine parvoviral enteritis: 322 cases (2001-2018).

OBJECTIVE: To evaluate clinicopathological prognostic indicators associated with survival based on hematology and serum biochemistry profile findings at presentation of dogs with canine parvoviral enteritis (CPE). Secondary objectives were to describe the signalment, history, physical examination findings, and progression of disease while in hospital and correlate them to survival. DESIGN: Retrospective study from medical records of dogs diagnosed with CPE between 2001 and 2018. SETTING: University teaching hospital. ANIMALS: Three hundred twenty-two dogs diagnosed with CPE that received in-hospital treatment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 322 hospitalized dogs, 294 dogs (91%) survived infection with a median hospitalization time of 79 hours. Multivariable analysis showed that glucose (P = 0.04), total magnesium (P = 0.011), and the dichotomized variable of a low HCT (P = 0.033) on presentation were significantly associated with survival. For every 1 mmol/L (18 mg/dL) decrease in glucose concentration, cases had 1.85 lower odds of survival. For every 0.1 mmol/L (0.2 mEq/L) increase in total magnesium concentration, cases had 2.50 lower odds of survival. Cases with a low HCT had 10.69 lower odds of survival. On univariable analyses, non-survivors had a lower median body weight (P = 0.006) and presented more commonly for diarrhea (P = 0.015). At least 1 episode of diarrhea (P = 0.003) and hematochezia or melena (P < 0.001) in hospital were negatively associated with outcome, in addition to the persistence of diarrhea (P = 0.026) and hyporexia (P = 0.018) in hospital for 5 to 6 days. CONCLUSIONS: Survival rates of 91% were achieved with in-hospital treatment in this cohort of dogs. Negative biochemical prognostic indicators affecting survival include a low HCT, decreased blood glucose concentrations, and increased total serum magnesium concentrations at presentation.

High prevalence, intensity, and genetic diversity of Trichinella spp. in wolverine (Gulo gulo) from Yukon, Canada.

BACKGROUND: Species of Trichinella are globally important foodborne parasites infecting a number of domestic and wild vertebrates, including humans. Free-ranging carnivores can act as sentinel species for detection of Trichinella spp. Knowledge of the epidemiology of these parasites may help prevent Trichinella spp. infections in northern Canadian animals and people. Previous research on Trichinella spp. in wildlife from Yukon did not identify risk factors associated with infection, or the diversity and identity of species of Trichinella in regional circulation, based on geographically extensive sampling with large sample sizes. METHODS: In a cross-sectional study, we determined the prevalence, infection intensity, risk factors, and species or genotypes of Trichinella in wolverine (Gulo gulo) in two regions of Yukon, Canada, from 2013-2017. A double separatory funnel digestion method followed by mutiplex PCR and PCR-RFLP were used to recover and identify species of Trichinella, respectively. RESULTS: We found larvae of Trichinella in the tongues of 78% (95% CI 73-82) of 338 wolverine sampled. The odds of adult (≥ 2 years) and yearling (1 year) wolverine being Trichinella spp.-positive were four and two times higher, respectively, compared to juveniles (<1 year). The odds of Trichinella spp. presence were three times higher in wolverine from southeast than northwest Yukon. The mean intensity of infection was 22.6 ± 39 (SD, range 0.1-295) larvae per gram. Trichinella T6 was the predominant genotype (76%), followed by T. nativa (8%); mixed infections with Trichinella T6 and T. nativa (12%) were observed. In addition, T. spiralis was detected in one wolverine. Out of 22 isolates initially identified as T. nativa in multiplex PCR, 14 were analyzed by PCR-RFLP to distinguish them from T. chanchalensis, a recently discovered cryptic species, which cannot be distinguished from the T. nativa on multiplex PCR. Ten isolates were identified either as T. chanchalensis alone (n = 7), or mixed infection with T. chanchalensis and T. nativa (n = 2) or T. chanchalensis and Trichinella T6 (n = 1)]. CONCLUSIONS: Wolverine hosted high prevalence, high larval intensity, and multiple species of Trichinella, likely due to their scavenging habits, apex position in the food chain, and wide home range. Wolverine (especially adult males) should be considered as a sentinel species for surveys for Trichinella spp. across their distributional range.

Assessment of the vasoactive effects of the (S)-epimers of ergot alkaloids in vitro.

Ergot alkaloids are produced by the fungus Claviceps purpurea and their levels are carefully monitored in animal and human diets due to their harmful effects and widespread contamination of cereal crops. Ergot alkaloids exist in two forms known as the (R)- and (S)-epimers with only the former being monitored in diets in North America. The (S)-epimers of ergot alkaloids are thought to be biologically inactive and, therefore, harmless. A major mechanism by which the (R)-epimers of ergot alkaloids produce their toxic effect is through vasoconstriction. Therefore, the objective of this study was to examine the vasoactivity potential (contractile response) of four (S)-epimers, namely ergocryptinine, ergocristinine, ergocorninine, and ergotaminine utilizing an in vitro arterial tissue bath system. Bovine metatarsal arteries (n = 6, ergocryptinine and ergocorninine; n = 6, ergocristinine and ergotaminine; n = 6 arteries/(S)-epimer, total n = 12) were collected from healthy mixed-breed beef steers immediately after slaughter, cut into 3-mm arterial cross sections, and suspended in a tissue bath with continuously oxygenated Krebs-Henseleit buffer. To assess the contractile response of each (S)-epimer, a cumulative contractile dose-response curve was constructed by incubating arteries with increasing concentrations (1 × 10-11 to 1 × 10-6 M) of that (S)-epimer. Contractile responses were recorded as grams of tension and were normalized to an initial contraction of phenylephrine. Contrary to the widespread belief, all tested (S)-epimers were found vasoactive and produced a concentration-dependent arterial contractile response similar to what has been reported for the (R)-epimers. The arterial contractile response to ergotaminine was strongest and was significantly greater than that of ergocryptinine and ergocristinine at the highest concentration used (P ≤ 0.01). Our results indicate that the (S)-epimers are biologically active and are likely harmful similar to the (R)-epimers. The levels of (S)-epimers should be carefully monitored in human and animal diets worldwide.

Gastrointestinal nematode management in western Canadian cow-calf herds.

There is a paucity of information from western Canadian beef cow-calf producers about how they control gastrointestinal nematodes. The objectives of this study were to describe cow-calf producers' management practices related to control of gastrointestinal nematodes including pasture management and use of parasite control products. A questionnaire was distributed to 105 producers in May 2015. Responses from 97 producers revealed the almost uniform dependence on the use of a pour-on macrocyclic lactone parasite control product in the fall as part of a routine farm management program. Control of external parasites was the primary reason for treatment, while none of the producers chose to treat specifically to manage internal parasites. The predominant management practices identified through this study increase the risk of development of anthelmintic resistance. The results also highlight the need to raise awareness of the importance of an evidence-based gastrointestinal nematode control program in beef cow-calf herds.

Gestion des nématodes gastro-intestinaux dans les troupeaux vaches-veaux de l'ouest canadien. Il y a une rareté d'informations provenant des producteurs de vaches-veaux de l'ouest canadien sur la façon dont ils maitrisent les nématodes gastro-intestinaux. Les objectifs de la présente étude étaient de décrire les pratiques de gestion des producteurs de vaches-veaux relativement à la maitrise des nématodes gastro-intestinaux incluant la gestion des pâturages et l'utilisation des produits antiparasitaires. Un questionnaire fut distribué à 105 producteurs en mai 2015. Des réponses en provenance de 97 producteurs ont révélé la dépendance presque généralisée sur l'utilisation d'un produit antiparasitaire à verser sur l'animal à base de lactone macrocyclique à l'automne comme faisant partie d'un programme de routine de gestion à la ferme. La maitrise des parasites externes était la principale raison pour le traitement, alors qu'aucun des producteurs n'avait choisi de traiter spécifiquement pour gérer les parasites internes. Les pratiques de gestion prédominantes identifiées dans la présente étude augmentent le risque de développement de résistance aux anthelmintiques. Les résultats mettent également en lumière le besoin d'augmenter la sensibilisation de l'importance d'une approche factuelle à un programme de gestion des nématodes dans les troupeaux vaches-veaux.(Traduit par Dr Serge Messier).

Tongue has higher larval burden of Trichinella spp. than diaphragm in wolverines (Gulo gulo).

Trichinella is an important zoonotic parasite found in a range of wildlife species harvested for food and fur in Canada. We compared larval intensity from tongue and diaphragm, the best predilection sites in other animal species, from naturally infected, wild wolverines (Gulo gulo) (n = 95). Muscle larvae of Trichinella spp. were recovered by the pepsin/HCl artificial digestion method (gold standard) using double separatory funnels, and species were identified using multiplex PCR. Prevalence was 83% (79/95). Of those positive for Trichinella spp. (n = 79), 76 (96.2%) were detected in both tissues, 2 (2.5%) were positive only on diaphragm, and 1 (1.3%) only on tongue. A total of 62 of 79 wolverines (78.5%) had higher larval burden in tongue than in diaphragm, whereas 17 wolverines (21.5%) had higher larval burden in diaphragm. The predilection site (higher larval burden) of Trichinella spp. larvae did not vary significantly between juvenile and adult wolverines (P = 0.2), between male and female wolverines (P = 0.9), and among wolverines classified as having low and high larval intensities overall (P = 0.2). Trichinella T6 was the predominant genotype (63 of 79; 80%), followed by T. nativa (T2) (6 of 79; 8%). Mixed infections of T2 and T6 were observed in 9 of 79 (12%) wolverines. Larval intensity of Trichinella T6 was higher in tongues than diaphragms. No statement can be made for T2 due to insufficient T2 positive samples. In conclusion, tongues are a better site for sampling than diaphragms in future surveys of Trichinella larval intensity in wolverines; however, either tissue is suitable for prevalence studies.

Toward High-Value Care: A Quality Improvement Initiative to Reduce Unnecessary Repeat Complete Blood Counts and Basic Metabolic Panels on a Pediatric Hospitalist Service.

OBJECTIVE: Achieving high-value health care is a goal of health care providers who strive to increase quality and decrease cost. Decreasing laboratory tests is a potential method to increase value. We used quality improvement methodology to decrease the percentage of unnecessary complete blood counts (CBCs) and basic metabolic panels (BMPs) obtained on a pediatric hospital medicine service from 13.5% to <5%. METHODS: A pre- and postintervention design was conducted including all patients admitted to 2 hospital medicine teams between May 2013 and December 2014. Multiple interventions linked to key drivers were tested through rapid plan-do-study-act cycles. Primary and secondary outcome measures, percent reduction of unnecessary CBCs and BMPs, and consecutive day tests were analyzed using statistical process control. Total billed charges, laboratory charges, 7-day readmission rates, and length of stay were compared pre- and postintervention. RESULTS: Primary outcome of unnecessary CBCs and BMPs was reduced from a baseline of 13.5% to 4.5%. Secondary outcome measure of consecutive day testing was reduced from 20.9% to 8.5%. Median laboratory charges decreased significantly ($842 [$256-$1863] vs $800 [$222-$1616], P = .002), with no significant differences in total billed charges, 7-day readmission rates, or length of stay. CONCLUSIONS: Rapid cycle plan-do-study-act methodology, initially focusing on the inclusion of a daily laboratory plan in progress notes, was an effective means to improve laboratory utilization and decrease laboratory charges without adversely affecting other quality measures. Spreading these efforts to different patient populations and laboratory tests could have a demonstrable effect on the value of health care.

HRS/NSA 2014 Survey of Atrial Fibrillation and Stroke: Gaps in Knowledge and Perspective, Opportunities for Improvement.

BACKGROUND: The prevalence of atrial fibrillation (AF) is substantial and increasing. Stroke is common in AF and can have devastating consequences. Oral anticoagulants are effective in reducing stroke risk, but are underutilized. OBJECTIVE: We sought to characterize the impact of stroke on AF patients and their caregivers, gaps in knowledge and perspective between physicians and patients, and barriers to effective communication and optimal anticoagulation use. METHODS: A survey was administered to AF patients with and without history of stroke, caregivers of stroke survivors, and physicians across the range of specialties caring for AF and stroke patients. RESULTS: While AF patients (n = 499) had limited knowledge about stroke, they expressed great desire to learn more and take action to reduce their risk. They were often dissatisfied with the education they had received and desired high-quality written materials. Stroke survivors (n = 251) had poor functional outcomes and often underestimated the burden of caring for them. Caregivers (n = 203) also wished they had received more information about reducing stroke risk before their survivor's event. They commonly felt overwhelmed and socially isolated. Physicians (n = 504) did not prescribe anticoagulants as frequently as recommended by guidelines. Concerns about monitoring anticoagulation and patient compliance were commonly reported barriers. Physicians may underestimate patient willingness to take anticoagulants. CONCLUSION: We identified significant knowledge gaps among patients, caregivers, and physicians in relation to AF and stroke. Furthermore, gaps in perspective often lead to suboptimal communication and decision making. Increased education and better communication between all stakeholders are needed to reduce the impact of stroke in AF.

HRS/NSA 2014 survey of atrial fibrillation and stroke: Gaps in knowledge and perspective, opportunities for improvement.

BACKGROUND: The prevalence of atrial fibrillation (AF) is substantial and increasing. Stroke is common in AF and can have devastating consequences. Oral anticoagulants are effective in reducing stroke risk, but are underutilized. OBJECTIVE: We sought to characterize the impact of stroke on AF patients and their caregivers, gaps in knowledge and perspective between physicians and patients, and barriers to effective communication and optimal anticoagulation use. METHODS: A survey was administered to AF patients with and without history of stroke, caregivers of stroke survivors, and physicians across the range of specialties caring for AF and stroke patients. RESULTS: While AF patients (n = 499) had limited knowledge about stroke, they expressed great desire to learn more and take action to reduce their risk. They were often dissatisfied with the education they had received and desired high-quality written materials. Stroke survivors (n = 251) had poor functional outcomes and often underestimated the burden of caring for them. Caregivers (n = 203) also wished they had received more information about reducing stroke risk before their survivor's event. They commonly felt overwhelmed and socially isolated. Physicians (n = 504) did not prescribe anticoagulants as frequently as recommended by guidelines. Concerns about monitoring anticoagulation and patient compliance were commonly reported barriers. Physicians may underestimate patient willingness to take anticoagulants. CONCLUSION: We identified significant knowledge gaps among patients, caregivers, and physicians in relation to AF and stroke. Furthermore, gaps in perspective often lead to suboptimal communication and decision making. Increased education and better communication between all stakeholders are needed to reduce the impact of stroke in AF.

1,2-selective hydrosilylation of conjugated dienes.

Selective 1,2-hydrosilylation of 1,3-dienes is a challenging problem in transition metal catalysis. Butadiene, specifically, would be a useful substrate because 3-butenylsilane products have promise as superior coupling reagents for hybrid organic/inorganic materials synthesis. We report the first selective 1,2-hydrosilylation of conjugated dienes including butadiene. Hydrosilylation proceeds through a Pt(II/IV) cycle, and selectivity is generated at a hexacoordinate Pt(IV) complex that favors η(2)-diene coordination and prevents π-allyl complex formation.

The heidenhain variant of Creutzfeldt-Jakob disease--a case series.

BACKGROUND: To study the neuro-ophthalmologic characteristics of patients with the visual variant of Creuztfeldt-Jakob disease (CJD) predominantly affecting the occipital and parietal lobes, known as the Heidenhain variant (HvCJD). The initial symptoms and findings may overlap with other posterior cerebral degenerative disorders. We reviewed our experience with HvCJD including clinical course and results of neuroimaging, electroencephalography (EEG), and cerebrospinal fluid (CSF) studies. Neuropathological postmortem findings were reviewed when available to confirm the clinical impression. METHODS: Retrospective study of HvCJD patients examined in the past 15 years at a single tertiary referral university hospital. Rapid rate of visual and neurological deterioration and abnormal diffusion-weighted imaging (DWI) were characteristic for HvCJD. RESULTS: Three patients displayed abnormalities in DWI, EEG, and CSF and had rapid clinical progression, leading to a clinical diagnosis of HvCJD. None underwent diagnostic cerebral biopsy. In 2 patients, the diagnosis of sporadic CJD was confirmed by postmortem neuropathologic, immunohistochemical, and genetic studies. CONCLUSIONS: The gold standard for establishing the diagnosis of HvCJD is based on the characteristic histopathologic findings and molecular confirmation. Concern with potential iatrogenic CJD, related to surgical instrumentation or operating room prion contamination, has limited the availability of confirmatory brain biopsy. Our case series illustrates how the combination of clinical neuroimaging and EEG studies and 14:3:3 protein and other neuronal protein marker levels can lead to the diagnosis of HvCJD. Immunohistochemical analysis and genetic testing at a specialized prion research center will assist in identifying the sporadic variant and genetic forms of CJD.

Performance of commercial ELISA and agglutination test kits for the detection of anti-Toxoplasma gondii antibodies in serum and muscle fluid of swine infected with 100, 300, 500 or 1000 oocysts.

Serum and tissue fluid samples from experimentally infected swine were tested for antibodies to Toxoplasma gondii using both an indirect ELISA and a modified agglutination test (MAT) available commercially in kit form. Ten 8-9 week-old swine were fed meatballs containing 100, 300, 500 or 1000 T. gondii oocysts and three control animals were fed meatballs with no oocysts. Post-inoculation blood samples were collected weekly until euthanasia at 35-63 days post inoculation (DPI). Tissue fluid was obtained from diaphragm, heart and sternomastoideus muscles post-mortem. By 16 DPI, nine of 10 inoculated pigs were detected serologically using ELISA at a pre-test serum dilution of 1:50 and all ten pigs were detected by the MAT at a serum dilution of 1:25. The last pig became positive on ELISA by 21 DPI and the 10 pigs maintained their serological status for the duration of the experiment. Heart muscle was the best overall source of tissue fluid for ELISA and all six pigs inoculated with either 500 or 1000 oocysts were positive using either diaphragm or heart tissue fluid samples. However, 10 of 18 fluid samples from pigs receiving ≤ 300 oocysts were not detected using ELISA, including 5 of 6 from sternomastoideus muscle. The MAT used at a 1:10 pre-test dilution of tissue fluid correctly identified all 10 inoculated pigs regardless of the source muscle. Based on these data, we conclude that either assay would be useful for herd evaluation or surveillance testing using sera, and the MAT would be a good candidate assay for testing tissue fluid for the same purposes.

Neurosyphilis presenting as asymptomatic optic perineuritis.

Introduction. Syphilis is a sexually transmitted disease that is known as "the great imitator" due to its wide variety of clinical presentations, including ocular disorders. There has been an increase in the rate of syphilis in the United States, especially in persons with HIV. We report a case of optic perineuritis in an asymptomatic male secondary to central nervous system (CNS) syphilis. Case Report. A 41-year-old man was found to have bilateral disc edema on a routine exam. Brain MRI was unremarkable, and lumbar puncture revealed a normal opening pressure, with an elevated cerebrospinal fluid white cell count. Orbit MRI showed optic nerve sheath expansion and enhancement, consistent with optic perineuritis. He tested positive for syphilis based on serum RPR and FTA-ABS. Conclusion. Ophthalmologic findings, including disc edema, may be the presenting features of CNS syphilis. Even in asymptomatic persons, perineuritis should be considered early, as diagnosis and treatment are imperative given the progressive nature of the disease.