Identification and treatment of Strongyloides stercoralis infection in a Boston Terrier dog from south-eastern Australia

Strongyloides stercoralis, the causative agent of strongyloidiasis, is a potentially zoonotic intestinal nematode endemic to northern Australia. Strongyloidiasis is typically observed in immunocompromised hosts and is characterised by gastrointestinal signs, respiratory symptoms and a failure to thrive. In immunocompromised hosts, hyperinfection syndrome and disseminated infections can prove life-threatening. A 24-month-old Boston Terrier dog was referred for investigation of chronic small and large intestinal watery hematochezic diarrhoea, emaciation and hematemesis. Small intestinal histology identified a nematode despite consecutive negative faecal flotations. A real-time polymerase chain reaction and Baermann test subsequently confirmed infection with S. stercoralis. The dog had received an oral parasiticide comprising milbemycin oxime and afoxolaner every month for the 11 months prior to this diagnosis. Despite fenbendazole being reported as successful in the treatment of canine strongyloidiasis, a course of fenbendazole failed to clear the infection. Eradication of S. stercoralis infection was confirmed after the administration of off-label ivermectin fortnightly for 12 doses. Attention should be paid to this nematode as the failure of routine copromicroscopic methods to diagnose S. stercoralis infections can result in misdiagnosis, mistreatment and progression of the disease. Off-label ivermectin may be an alternative to fenbendazole for the treatment of Strongyloides spp. infection in dogs.

Outcomes of patients with active cancers and pre-existing cardiovascular diseases infected with SARS-CoV-2

OBJECTIVE

To determine the impact of acute SARS-CoV-2 infection on patient with concomitant active cancer and CVD.

METHODS

The researchers extracted and analyzed data from the National COVID Cohort Collaborative (N3C) database between January 1, 2020, and July 22, 2022. They included only patients with acute SARS-CoV-2 infection, defined as a positive test by PCR 21 days before and 5 days after the day of index hospitalization. Active cancers were defined as last cancer drug administered within 30 days of index admission. The "Cardioonc" group consisted of patients with CVD and active cancers. The cohort was divided into four groups: (1) CVD (-), (2) CVD ( +), (3) Cardioonc (-), and (4) Cardioonc ( +), where (-) or ( +) denotes acute SARS-CoV-2 infection status. The primary outcome of the study was major adverse cardiovascular events (MACE), including acute stroke, acute heart failure, myocardial infarction, or all-cause mortality. The researchers analyzed the outcomes by different phases of the pandemic and performed competing-risk analysis for other MACE components and death as a competing event.

RESULTS

The study analyzed 418,306 patients, of which 74%, 10%, 15.7%, and 0.3% had CVD (-), CVD ( +), Cardioonc (-), and Cardioonc ( +), respectively. The Cardioonc ( +) group had the highest MACE events in all four phases of the pandemic. Compared to CVD (-), the Cardioonc ( +) group had an odds ratio of 1.66 for MACE. However, during the Omicron era, there was a statistically significant increased risk for MACE in the Cardioonc ( +) group compared to CVD (-). Competing risk analysis showed that all-cause mortality was significantly higher in the Cardioonc ( +) group and limited other MACE events from occurring. When the researchers identified specific cancer types, patients with colon cancer had higher MACE.

CONCLUSION

In conclusion, the study found that patients with both CVD and active cancer suffered relatively worse outcomes when they had acute SARS-CoV-2 infection during early and alpha surges in the United States. These findings highlight the need for improved management strategies and further research to better understand the impact of the virus on vulnerable populations during the COVID-19 pandemic.

Gastrointestinal Bleed After Total Pancreatectomy With Islet Autotransplant

OBJECTIVE

Gastrointestinal bleeding (GIB) is an uncommon complication after abdominal surgery. Given the unique risks in the total pancreatectomy with islet autotransplant (TPIAT) population, we aimed to describe this population's incidence of postoperative GIB.

METHODS

Prospectively collected data on patients who underwent a TPIAT from 2001 to 2018 at the University of Minnesota were reviewed for postoperative GIB. Each GIB patient was matched to a control patient and compared for medical, medication, and social history and for clinical outcomes.

RESULTS

Sixty-eight patients developed a GIB (12.4%) at median time after surgery of 17 months. Etiologies included the following: anastomotic ulcer (35%), Clostridium difficile (4%), gastric or duodenal ulcers (9%), esophagitis/gastritis (10%), hemorrhoids (3%), inflammatory bowel disease (4%), Mallory-Weiss tears (1%), and unknown (29%). During diagnostic workup, 87% had an endoscopic procedure and 3% underwent imaging. Seven patients required an operation (10%), 1 required an open embolization (1%), and 13 required endoscopic treatments (19%). Patients with a GIB were more likely to die (15% vs 5%, P = 0.055).

CONCLUSIONS

Twelve percent of patients developed a GIB after TPIAT. One third of those had an undefined etiology despite endoscopy. The need for intervention was high (30%).

Propensity score adjusted comparison of three-factor versus four-factor prothrombin complex concentrate for emergent warfarin reversal: a retrospective cohort study

BACKGROUND

Prothrombin Complex Concentrates (PCC) are prescribed for emergent warfarin reversal (EWR). The comparative effectiveness and safety among PCC products are not fully understood.

METHODS

Patients in an academic level one trauma center who received PCC3 or PCC4 for EWR were identified. Patient characteristics, PCC dose and time of dose, pre- and post-INR and time of measurement, fresh frozen plasma and vitamin K doses, and patient outcomes were collected. Patients whose pre-PCC International Normalized Ratio (INR) was > 6 h before PCC dose or the pre-post PCC INR was > 12 h were excluded. The primary outcome was achieving an INR ≤ 1.5 post PCC. Secondary outcomes were the change in INR over time, post PCC INR, thromboembolic events (TE), and death during hospital stay. Logistic regression modelled the primary outcome with and without a propensity score adjustment accounting for age, sex, actual body weight, dose, initial INR value, and time between INR measurements. Data are reported as median (IQR) or n (%) with p < 0.05 considered significant.

RESULTS

Eighty patients were included (PCC3 = 57, PCC4 = 23). More PCC4 patients achieved goal INR (87.0% vs. 31.6%, odds ratio (OR) = 14.4, 95% CI: 3.80-54.93, p < 0.001). This result remained true after adjusting for possible confounders (AOR = 10.7, 95% CI: 2.17-51.24, p < 0.001). The post-PCC INR was lower in the PCC4 group (1.3 (1.3-1.5) vs. 1.7 (1.5-2.0)). The INR change was greater for PCC4 (2.3 (1.3-3.3) vs. 1.1 (0.6-2.0), p = 0.003). Death during hospital stay (p = 0.52) and TE (p = 1.00) were not significantly different.

CONCLUSIONS

PCC4 was associated with a higher achievement of goal INR than PCC3. This relationship was observed in the unadjusted and propensity score adjusted results.

Tracked Patient Encounters During Advanced Pharmacy Practice Experiences and Skill Self-assessment Using Entrustable Professional Activities

Objective. To determine if the number of patient encounters during advanced pharmacy practice experiences (APPEs) relates to student self-assessment of patient care skills using entrustable professional activities (EPAs). Methods. During 12-week acute care/institutional (AC/INST) APPEs, 15-week combined community pharmacy and ambulatory care (CPAC) APPEs, and three 5-week AC/INST or CPAC elective APPEs, fourth-year pharmacy students completed patient tracking surveys. Students documented the number of encounters, type of care provided, primary and secondary diagnoses, and special dosing/population considerations. Students completed self-assessment surveys for 12 EPAs. Students rated their ability to perform each EPA using a four-point scale (1=still developing this skill; 4=can do this independently) at the start and after each APPE semester. Results. Data were collected from May 2016 through April 2017. During this time, 165 students completed APPEs. Students reported 79,717 encounters. There was no significant correlation found between total number of encounters and EPA scores. The baseline EPA mean score was 3.1 and semester 3 EPA mean score was 3.7. The mean student-reported EPA scores did increase over time, some more quickly than others. Conclusion. Tracking student patient encounters provided insight into the quantity and variety of patients and conditions seen and level of care provided by students during APPEs. Mean scores on EPAs increased over time with increased exposure to patients. Patient tracking can be used to inform the curriculum by identifying potential gaps in both didactic and experiential education.

Meta-Analytic and Economic Approaches for Evaluation of Pesticide Impact on Sclerotinia Stem Rot Control and Soybean Yield in the North Central United States

As complete host resistance in soybean has not been achieved, Sclerotinia stem rot (SSR) caused by Sclerotinia sclerotiorum continues to be of major economic concern for farmers. Thus, chemical control remains a prevalent disease management strategy. Pesticide evaluations were conducted in Illinois, Iowa, Michigan, Minnesota, New Jersey, and Wisconsin from 2009 to 2016, for a total of 25 site-years (n = 2,057 plot-level data points). These studies were used in network meta-analyses to evaluate the impact of 10 popular pesticide active ingredients, and seven common application timings on SSR control and yield benefit, compared with not treating with a pesticide. Boscalid and picoxystrobin frequently offered the best reductions in disease severity and best yield benefit (P < 0.0001). Pesticide applications (one- or two-spray programs) made during the bloom period provided significant reductions in disease severity index (DIX) (P < 0.0001) and led to significant yield benefits (P = 0.0009). Data from these studies were also used in nonlinear regression analyses to determine the effect of DIX on soybean yield. A three-parameter logistic model was found to best describe soybean yield loss (pseudo-R2 = 0.309). In modern soybean cultivars, yield loss due to SSR does not occur until 20 to 25% DIX, and considerable yield loss (-697 kg ha-1 or -10 bu acre-1) is observed at 68% DIX. Further analyses identified several pesticides and programs that resulted in greater than 60% probability for return on investment under high disease levels.

Validating Sclerotinia sclerotiorum Apothecial Models to Predict Sclerotinia Stem Rot in Soybean (Glycine max) Fields

In soybean, Sclerotinia sclerotiorum apothecia are the sources of primary inoculum (ascospores) critical for Sclerotinia stem rot (SSR) development. We recently developed logistic regression models to predict the presence of apothecia in irrigated and nonirrigated soybean fields. In 2017, small-plot trials were established to validate two weather-based models (one for irrigated fields and one for nonirrigated fields) to predict SSR development. Additionally, apothecial scouting and disease monitoring were conducted in 60 commercial fields in three states between 2016 and 2017 to evaluate model accuracy across the growing region. Site-specific air temperature, relative humidity, and wind speed data were obtained through the Integrated Pest Information Platform for Extension and Education (iPiPE) and Dark Sky weather networks. Across all locations, iPiPE-driven model predictions during the soybean flowering period (R1 to R4 growth stages) explained end-of-season disease observations with an accuracy of 81.8% using a probability action threshold of 35%. Dark Sky data, incorporating bias corrections for weather variables, explained end-of-season disease observations with 87.9% accuracy (in 2017 commercial locations in Wisconsin) using a 40% probability threshold. Overall, these validations indicate that these two weather-based apothecial models, using either weather data source, provide disease risk predictions that both reduce unnecessary chemical application and accurately advise applications at critical times.

Weather-Based Models for Assessing the Risk of Sclerotinia sclerotiorum Apothecial Presence in Soybean (Glycine max) Fields

Sclerotinia stem rot (SSR) epidemics in soybean, caused by Sclerotinia sclerotiorum, are currently responsible for annual yield reductions in the United States of up to 1 million metric tons. In-season disease management is largely dependent on chemical control but its efficiency and cost-effectiveness depends on both the chemistry used and the risk of apothecia formation, germination, and further dispersal of ascospores during susceptible soybean growth stages. Hence, accurate prediction of the S. sclerotiorum apothecial risk during the soybean flowering period could enable farmers to improve in-season SSR management. From 2014 to 2016, apothecial presence or absence was monitored in three irrigated (n = 1,505 plot-level observations) and six nonirrigated (n = 2,361 plot-level observations) field trials located in Iowa (n = 156), Michigan (n = 1,400), and Wisconsin (n = 2,310), for a total of 3,866 plot-level observations. Hourly air temperature, relative humidity, dew point, wind speed, leaf wetness, and rainfall were also monitored continuously, throughout the season, at each location using high-resolution gridded weather data. Logistic regression models were developed for irrigated and nonirrigated conditions using apothecial presence as a binary response variable. Agronomic variables (row width) and weather-related variables (defined as 30-day moving averages, prior to apothecial presence) were tested for their predictive ability. In irrigated soybean fields, apothecial presence was best explained by row width (r = -0.41, P < 0.0001), 30-day moving averages of daily maximum air temperature (r = 0.27, P < 0.0001), and daily maximum relative humidity (r = 0.16, P < 0.05). In nonirrigated fields, apothecial presence was best explained by using moving averages of daily maximum air temperature (r = -0.30, P < 0.0001) and wind speed (r = -0.27, P < 0.0001). These models correctly predicted (overall accuracy of 67 to 70%) apothecial presence during the soybean flowering period for four independent datasets (n = 1,102 plot-level observations or 30 daily mean observations).

Supporting quality in experiential education through enhanced faculty engagement

INTRODUCTION

There are ongoing assessment and improvement activities related to strategies to improve the quality of education in the complex and resource-intensive area of experiential education (EE). One undescribed approach for design and delivery of EE programs for schools and colleges, with reliance on volunteer preceptors, is to utilize clinical practice faculty in formal partnerships with EE leadership to enhance curriculum and assessment.

COMMENTARY AND IMPLICATIONS

Clinical practice faculty, who possess practice setting expertise, can serve as course directors for advanced pharmacy practice experience (APPE) rotations. In this role, they can collaborate with EE faculty and staff to create more course-specific expectations, learning objectives, and criteria for APPE rotation experiences. This model could increase consistency for students and preceptors, using an approach that is analogous to content experts serving as course directors in didactic curriculum. This commentary explores the potential of this strategy to increase quality and consistency in EE.

Adherence to treatment guidelines: the association between stroke risk stratified comparing CHADS2 and CHA2DS2-VASc score levels and warfarin prescription for adult patients with atrial fibrillation

Background

Ischemic stroke is a risk associated with atrial fibrillation (AF) and is estimated to occur five times more often in afflicted patients than in those without AF. Anti-thrombotic therapy is recommended for the prevention of ischemic stroke. Risk stratification tools, such as the CHADS₂, and more recently the CHA₂DS₂-VASc, for predicting stroke in patients with AF have been developed to determine the level of stroke risk and assist clinicians in the selection of antithrombotic therapy. Warfarin, for stroke prevention in AF, is the most commonly prescribed anticoagulant in North America. The purpose of this study was to examine the utility of using the CHADS₂ score levels (low and high) in contrast to the CHA₂DS₂-VASc when examining the outcome of warfarin prescriptions for adult patients with AF. The CHA₂DS₂-VASc tool was not widely used in 2010, when the data analyzed were collected. It has only been since 2014 that CHA₂DS₂-VASc criteria has been recommended to guide anticoagulant treatment in updated AF treatment guidelines.

Methods

Bivariate and multivariate data analysis strategies were used to analyze 2010 National Ambulatory Care Survey (NAMCS) data. NAMCS is designed to collect data on the use and provision of ambulatory care services nationwide. The study population for this research was US adults with a diagnosis of AF. Warfarin prescription was the dependent variable for this study. The study population was 7,669,844 AF patients.

Results

Bivariate analysis revealed that of those AF patients with a high CHADS₂ score, 25.1% had received a warfarin prescription and 18.8 for those with a high CHA₂DS₂-VASc score. Logistic regression analysis yielded that patients with AF had higher odds of having a warfarin prescription if they had a high CHADS₂ score, were Caucasian, lived in a zip code where < 20% of the population had a university education, and lived in a zip code where < 10% of the population were living in households with incomes below the federal poverty level. Further, the analysis yielded that patients with AF had lesser odds of having a warfarin prescription if they were ≥ 65 years of age, female, or had health insurance.

Conclusions

Overall, warfarin appears to be under-prescribed for patients with AF regardless of the risk stratification system used. Based on the key findings of our study opportunities for interventions are present to improve guideline adherence in alignment with risk stratification for stroke prevention. Interprofessional health care teams can provide improved medical management of stroke prevention for patients with AF. These interprofessional health care teams should be constituted of primary care providers (physicians, physician assistants, and nurse practitioners), nurses (RN, LPN), and pharmacists (PharmD, RPh).

Team science as interprofessional collaborative research practice: a systematic review of the science of team science literature

The National Institute of Health's concept of team science is a means of addressing complex clinical problems by applying conceptual and methodological approaches from multiple disciplines and health professions. The ultimate goal is the improved quality of care of patients with an emphasis on better population health outcomes. Collaborative research practice occurs when researchers from >1 health-related profession engage in scientific inquiry to jointly create and disseminate new knowledge to clinical and research health professionals in order to provide the highest quality of patient care to improve population health outcomes. Training of clinicians and researchers is necessary to produce clinically relevant evidence upon which to base patient care for disease management and empirically guided team-based patient care. In this study, we hypothesized that team science is an example of effective and impactful interprofessional collaborative research practice. To assess this hypothesis, we examined the contemporary literature on the science of team science (SciTS) produced in the past 10 years (2005–2015) and related the SciTS to the overall field of interprofessional collaborative practice, of which collaborative research practice is a subset. A modified preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach was employed to analyze the SciTS literature in light of the general question: Is team science an example of interprofessional collaborative research practice? After completing a systematic review of the SciTS literature, the posed hypothesis was accepted, concluding that team science is a dimension of interprofessional collaborative practice.

A strategy for monitoring and evaluating massive open online courses

We argue that the complex, innovative and adaptive nature of Massive Open Online Course (MOOC) initiatives poses particular challenges to monitoring and evaluation, in that any evaluation strategy will need to follow a systems approach. This article aims to guide organizations implementing MOOCs through a series of steps to assist them in developing a strategy to monitor, improve, and judge the merit of their initiatives. We describe how we operationalise our strategy by first defining the different layers of interacting agents in a given MOOC system. We then tailor our approach to these different layers. Specifically, a two-pronged approach was developed, where we suggest that individual projects be assessed through performance monitoring; assessment criteria for which would be defined at the outset to include coverage, participation, quality and student achievement. In contrast, the success of an overall initiative should be considered within a more adaptive, emergent evaluation inquiry framework. We present the inquiry framework we developed for MOOC initiatives, and show how this framework might be used to develop evaluation questions and an assessment methodology. We also define the more fixed indicators and measures for project performance monitoring. Our strategy is described as it was developed to inform the evaluation of a MOOC initiative at the University of Cape Town (UCT), South Africa.

Entrustable Professional Activities for Pharmacy Practice

The profession of pharmacy is facing a shifting health system context that holds both opportunity and risk. If the profession of pharmacy is to advance, pharmacists must be recognized as a consistent member of the health care team in all clinical settings, contributing at the fullest extent of licensure and education. One part of achieving this broad goal is to implement a new way of defining and assessing pharmacy practice skills, such as entrustable professional activities (EPA). Assessment of professional tasks and practice activities with EPAs has been successfully implemented in medical education for assessing trainee preparation for practice. This EPA model is being applied to pharmacy education to develop an assessment framework across the advanced pharmacy practice experience (APPE) curriculum. The APPE course directors, practice faculty members, and the Office of Experiential Education collaboratively defined a set of universal EPAs critical for pharmacists in any practice setting and would be assessed in all practice experience types.

Evaluation of diamide insecticides co-applied with other agrochemicals at various times to manage Ostrinia nubilalis in processing snap bean

BACKGROUND

Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. In a 2 year small-plot study, O. nubilalis control was evaluated by applying cyantraniliprole (diamide) and bifenthrin (pyrethroid) insecticides at one of three phenological stages (bud, bloom and pod formation) of snap bean development. Co-application of these insecticides with either herbicides or fungicides was also examined as a way to reduce the total number of sprays during a season.

RESULTS

Cyantraniliprole applications timed either during bloom or during pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co-applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest.

CONCLUSION

Diamides are an alternative to pyrethroids for the management of O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season.

Non-weight-based enoxaparin dosing subtherapeutic in trauma patients

BACKGROUND

We report our experience dosing and monitoring enoxaparin with anti-factor Xa activity (anti-FXaA) levels for venous thromboembolism prophylaxis in trauma patients (TP).

MATERIALS AND METHODS

TP receiving standard, non-weight-based dosed enoxaparin administered every 12 h for venous thromboembolism prophylaxis with peak anti-FXaA levels measured were prospectively monitored and evaluated and those whose first anti-FXaA levels ≥ or <0.2 IU/mL were compared. Anti-FXaA levels and enoxaparin dose (mg/kg actual body weight) were evaluated for correlation.

RESULTS

Of the fifty-one TP included, initial anti-FXaA levels were <0.2 IU/mL in 37 (72.5%) whose dose was lower than those within target range (0.38 [0.32-0.42] mg/kg versus 0.45 [0.39-0.48] mg/kg, P = 0.003). Thirty-seven TP achieved anti-FXaA level ≥0.2 IU/mL (23 requiring dose increases) at a dose of 0.49 [0.44-0.54] mg/kg. Correlation between dose and anti-FXaA levels for the initial 51 anti-FXaA levels (r = 0.360, P = 0.009) and for all 103 anti-XaA levels (r = 0.556, P < 0.001) was noted.

CONCLUSIONS

Non-weight-based enoxaparin dosing did not achieve target anti-FXaA levels in most TP. Higher anti-FXaA levels correlated with larger weight-based enoxaparin doses. Weight-based enoxaparin dosing (i.e., 0.5 mg/kg subcutaneously every 12 h) would better achieve target anti-FXaA levels.

Comparison of 3-Factor Prothrombin Complex Concentrate and Low-Dose Recombinant Factor VIIa for Warfarin Reversal

Introduction

Prothrombin complex concentrate (PCC) and recombinant Factor VIIa (rFVIIa) have been used for emergent reversal of warfarin anticoagulation. Few clinical studies have compared these agents in warfarin reversal. We compared warfarin reversal in patients who received either 3 factor PCC (PCC3) or low-dose rFVIIa (LDrFVIIa) for reversal of warfarin anticoagulation.

Methods

Data were collected from medical charts of patients who received at least one dose of PCC3 (20 units/kg) or LDrFVIIa (1000 or 1200 mcg) for emergent warfarin reversal from August 2007 to October 2011. The primary end-points were achievement of an INR 1.5 or less for efficacy and thromboembolic events for safety.

Results

Seventy-four PCC3 and 32 LDrFVIIa patients were analyzed. Baseline demographics, reason for warfarin reversal, and initial INR were equivalent. There was no difference in the use of vitamin K or fresh frozen plasma. More LDrFVIIa patients achieved an INR of 1.5 or less (71.9% vs. 33.8%, p =0.001). The follow-up INR was lower after LDrFVIIa (1.25 vs. 1.75, p < 0.05) and the percent change in INR was larger after LDrFVIIa (54.1% vs. 38.8%, p = 0.002). There was no difference in the number of thromboembolic events (2 LDrFVIIa vs. 5 PCC3, p = 1.00), mortality, length of hospital stay, or cost.

Conclusions

Based on achieving a goal INR of 1.5 or less, LDrFVIIa was more likely than PCC3 to reverse warfarin anticoagulation. Thromboembolic events were equivalent in patients receiving PCC3 and LDrFVIIa.

Prothrombin complex concentrate versus standard therapies for INR reversal in trauma patients receiving warfarin

BACKGROUND

Prothrombin complex concentrate (PCC) is recommended as a therapy to be considered for the reversal of warfarin's effects. Few published data are available on the use of PCC for this indication in traumatically injured patients.

OBJECTIVE

To determine whether the addition of PCC to standard approaches to warfarin reversal more rapidly corrects the international normalized ratio (INR) in injured patients.

METHODS

A retrospective analysis was performed in trauma patients who were on warfarin preinjury from January 2007 to September 2009 at North Memorial Medical Center. Data were collected from medical records and the trauma registry. Patients were separated based on whether or not they received PCC. The groups were compared on the basis of demographics, units of fresh frozen plasma (FFP), vitamin K use, units of PCC, number of patients achieving an INR of 1.5 or less, time to an INR of 1.5 or less, mortality, intensive care unit (ICU) and hospital length of stay, and the incidence of thromboembolic events during hospitalization.

RESULTS

Thirty-one patients were included in the analysis; 13 patients who received a total mean (SD) dose of 2281 (1053) units (25.6 [12.2] units/kg) of PCC (Profilnine SD) were compared to 18 patients who did not receive PCC. There was no significant difference between groups in FFP units received or the number of patients who received vitamin K. Most patients in both groups achieved an INR of 1.5 or less (92% PCC vs 89% no PCC). However, the mean time to achieve an INR of 1.5 or less was 16:59 (20:53) hours in the PCC group versus 30:03 (23:10) hours in the no PCC group (p = 0.048). There were 3 deaths in the PCC group and no deaths in the no PCC group (p = 0.06). ICU and hospital length of stay and number of thromboembolic events did not differ significantly between the 2 groups.

CONCLUSIONS

PCC, when added to FFP and vitamin K, resulted in a more rapid time to reversal of the INR.

What to do when warfarin therapy goes too far

Warfarin is certainly a lifesaver--but it can also lead to potentially fatal hypocoagulability. Here we recommend best reversal options based on the type of bleed. For patients with an elevated international normalized ratio (INR) with mild or no bleeding, withhold the warfarin and recheck INR in 1 to 2 days; if INR >5, add oral vitamin K supplementation. For major bleeding and elevated INR, hospital admission, vitamin K, fresh frozen plasma, and frequent monitoring are needed. Emergent situations call for hospitalization, clotting factor replacement, and vitamin K administered by slow intravenous infusion.

Safety and Effectiveness of a Modification of Diet in Renal Disease Equation-Based Potassium Replacement Protocol

Background:

No data exist regarding the safety and effectiveness of a potassium replacement protocol for hospitalized patients when potassium replacement dosing regimens (KRDRs) are adjusted to Modification of Diet in Renal Disease estimation of glomerular filtration rate (MDRD GFR).

Objective:

To evaluate the effectiveness and safety of a potassium replacement protocol in which KRDRs are prescribed based on MDRD GFR and serum potassium deficiency (Kdef).

Methods:

Patients prescribed the potassium replacement order set were identified in a retrospective fashion. Serum potassium, prescriber-defined goal serum potassium, and MDRD GFR data were collected for patients who received protocol KRDRs. The KRDR to be administered is selected based on Kdef (goal serum potassium minus measured serum potassium) of 0.1–0.2, 0.3–0.5, or more than 0.5 mEq/L and the patients’ MDRD GFR of greater than 70, 40–70, or less than 40 mL/min/1.73 m2 (any patient undergoing dialysis is included in the <40 mL/min/1.73 m2 group). Efficacy was evaluated by determining the change in serum potassium level (AK) following potassium replacement, the number of KRDRs needed to achieve goal serum potassium, and the milliequivalents of potassium needed to achieve goal serum potassium levels. Safety was assessed by the incidence of serum potassium values greater than 5.0 mEq/L following replacement.

Results:

One hundred forty-nine patients were evaluated. There were 184 protocol initiations and 257 KRDRs administered to achieve goal serum potassium levels. The AK was 0.50 ± 0.40 mEq/L (mean ± SD) following KRDR. The AK was similar between MDRD GFR groups. One hundred thirty six (73.9%) protocol initiations required 1 KRDR, and 168 (91.3%) protocol initiations required 1 or 2 KRDRs to achieve goal serum potassium. Patients whose MDRD GFR was 40–70 mL/min/1.73 m2 were less likely to achieve goal serum potassium value after 1 KRDR (58.2% vs 79.6% >70 group and 84.6% <40 group). This was true regardless of the patient's goal serum potassium. One (0.54%) serum potassium greater than 5.0 mEq/L occurred following a KRDR,

Conclusions:

Our potassium replacement protocol based on MDRD GFR and Kdef effectively corrects hypokalemia. Fewer protocol initiations achieved goal serum potassium levels in the group with MDRD GFR 40–70 mL/min/1.73 m2. Hyperkalemia rarely occurred following KRDR.

Acute renal failure and intravenous immune globulin: occurs with sucrose-stabilized, but not with D-sorbitol-stabilized, formulation

OBJECTIVE

To report 2 cases of acute renal failure (ARF) following administration of sucrose-stabilized intravenous immune globulin (IVIG), one of which did not recur following subsequent doses of d-sorbitol-stabilized formulation, and review the relevant literature.

CASE SUMMARIES

A 44-year-old white man awaiting heart transplantation developed ARF requiring hemodialysis following administration of sucrose-stabilized IVIG for high alloreactivity to population human leukocyte antigens. Following a return of renal function to baseline, subsequent doses of d-sorbitol-stabilized IVIG were administered without incident. A 90-year-old white man developed ARF after administration of sucrose-stabilized IVIG for monoclonal gammopathy. Renal function returned to baseline, and no subsequent IVIG doses were administered. An objective causality assessment revealed that sucrose-stabilized IVIG was the probable cause of the adverse drug event for both cases.

DISCUSSION

Several case reports of ARF secondary to IVIG have been published. Recent publications note that sucrose-stabilized IVIG products have a disproportionately high rate of ARF occurrence (approximately 88%) versus non-sucrose-stabilized formulations. Recent market data for IVIG products indicate that sucrose-stabilized products account for approximately 40% of the total IVIG market. When administered intravenously, sucrose is excreted unchanged in the urine. ARF has been reported in patients receiving large doses of intravenous sucrose.

CONCLUSIONS

ARF secondary to IVIG may be more likely to occur with sucrose-stabilized formulations. Before prescribing IVIG, clinicians should consider other nephrotoxic medications, preexisting renal function, age, diabetes mellitus, and rate of infusion. In patients at risk, it may be best to avoid sucrose-stabilized formulations.

Pancreatitis associated with valproic acid: a review of the literature

Black box warnings for valproic acid caution clinicians of the potential for fatal hepatotoxicity and teratogenicity. Since 1979, case reports of pancreatitis induced by valproic acid have been published in the medical literature. As a result, pancreatitis was added to the black box warnings for valproic acid. We performed searches of MEDLINE and International Pharmaceutical Abstracts and found valproic acid-induced pancreatitis in 45 patients from 31 published articles. Demographics, clinical characteristics, and outcomes of these patients are summarized. Recommendations for monitoring the potential for pancreatitis to develop in patients receiving valproic acid therapy are described, as are potential mechanisms for inducement of pancreatitis by valproic acid.

Unilateral diaphragmatic paralysis following bronchial artery embolization for hemoptysis

Bronchial artery embolization is an effective treatment for patients with hemoptysis. Serious complications are rare, but may occur if the arterial supply to other structures is compromised. We present a case of unilateral diaphragmatic paralysis following bronchial artery embolization in a patient with cystic fibrosis. We believe that the diaphragmatic paralysis was due to the inadvertent obstruction of the left pericardiacophrenic artery during the embolization procedure, with compromise of the phrenic nerve blood supply. This resulted in a significant loss of lung function in our patient, who did not recover despite the subsequent return of diaphragmatic function.

Glycoproteins of trabecular meshwork, cornea and sclera

PURPOSE

To analyse high-molecular-weight matrix glycoproteins in trabecular meshwork, cornea and sclera using SDS/PAGE and immuno- and lectin blotting.

METHOD

Extracts of normal trabecular meshwork (TM), cornea and sclera were analysed under reducing conditions on SDS/ PAGE. Western blots were stained for total protein, and major high-molecular-weight components were identified by immunoblotting with antibodies to fibronectin (FN) and type VI collagen. Lectin blotting with PSA, MPA and DSA identified some of the glycoprotein glycans.

RESULTS

FN antibody bound to the 240 kDa band in TM, cornea and sclera. Type VI collagen antibody bound more strongly to one band and less so to two other bands at approximately 200 kDA in normal TM and to a ladder of bands in cornea and sclera. PSA and DSA bound at 240, 200 and 140 kDa in TM, cornea and sclera. MPA bound at 240, 200 and 140 kDa in TM and at 240, 200 and approximately 120 kDA in cornea and sclera.

CONCLUSIONS

FN is a component of the band at 240 kDA in TM, cornea and sclera. Normal TM was found to contain relatively more of one of the isoforms of the alpha 3 (VI) chain whilst cornea and sclera contained all the alpha 3 (VI) isoforms. Complex N-linked bi/tri-antennary glycans were localised in FN and the alpha 1, alpha 2 and alpha 3 (VI) chains in TM, cornea and sclera. O-linked glycans (identified by MPA binding) were located in FN and alpha 3 (VI) chains of TM, cornea and sclera.

Health promotion and managed care: surveys of California's health plans and population

INTRODUCTION

The purpose was to examine whether health-promotion programs offered by California health plans are a serious attempt to improve health status or a marketing device used in an increasingly competitive marketplace. The research examined differences in the coverage, availability, utilization, and evaluation of health-promotion programs in California health plans.

METHODS

A mail survey was done of the 35 HMOs (86% response) and 18 health insurance carriers (83% response) licensed to sell comprehensive health insurance in California in 1996 (some plans sell both HMO and PPO/indemnity products). The final sample included 30 commercial HMOs and 20 PPO and indemnity plans. The 1996 California Behavioral Risk Factor Survey (BRFS) of 4,000 adults was used to estimate population participation rates in health-promotion programs.

RESULTS

California's HMOs in 1996 offered more comprehensive preventive benefits and health-promotion programs compared to PPO and indemnity plans. HMOs relied on a more comprehensive set of health-education methods to communicate health information to members and were more likely to open their programs to the public. HMOs are also more likely to have developed relationships with community-based and public health providers. Participation in health-promotion programs is low (2%-3%), regardless of plan type, and most health plans limit evaluations to assessment of member satisfaction and utilization. Only 35%-45% of HMOs, and no PPO/indemnity plans, assess the impact of health-promotion programs on health risks and behaviors, health status, or health care costs.

CONCLUSION

For the majority of California's PPO and indemnity plans, health promotion is not an integral part of their business. For the majority of HMOs, health-promotion programs are offered primarily as a marketing vehicle. However, a substantial minority of HMOs offer health-promotion programs to achieve other organizational goals of health improvement and cost control.

Considerations for using ketoconazole in solid organ transplant recipients receiving cyclosporine immunosuppression

Drug interactions involving cyclosporine following transplantation are a challenging issue for the transplant clinician. This is especially true when ketoconazole is the second agent used in conjunction with cyclosporine. Because both agents are metabolized by the cytochrome P-450 IIIA4 enzyme system, cyclosporine levels rise dramatically in the presence of ketoconazole. Many other agents interact with ketoconazole, either by competitive enzyme inhibition in the liver and gastrointestinal tract, or by reducing the absorption of ketoconazole by agents that increase the pH of the gastrointestinal tract. Despite the potential cost savings when using ketoconazole to reduce cyclosporine doses, adverse effects associated with ketoconazole put patients at risk when using this combination. Close monitoring of cyclosporine levels is imperative when adding ketoconazole to cyclosporine, and once the dosage adjustments are complete, the addition of a third drug that interacts with either cyclosporine or ketoconazole could result in an unexpected rejection episode or toxic cyclosporine side effect.

Glycans of the trabecular meshwork in primary open angle glaucoma

AIMS

Glycan expression was compared in glaucomatous trabecular meshwork (TM) and normal TM in order to determine any differences which may reflect pathological changes underlying primary open angle glaucoma (POAG).

METHODS

Resin embedded TM from trabeculectomy specimens from 15 eyes with POAG and from 12 eyes with normal anterior segments were probed with a panel of biotinylated lectins and an avidin-peroxidase revealing system at the light microscope level. Statistical analyses were performed on the comparative staining results.

RESULTS

The lectins ConA and ePHA showed strong staining in all areas of both glaucomatous and normal TM; ePHA staining of Schlemm's canal (SC) from POAG TM was significantly less than that from normal TM (ePHA-SC p = 0.04). The lectins PSA, LCA, and SNA bound moderately strongly to SC endothelium and weakly to the endothelium of the corneoscleral meshwork (CSM); glaucomatous SC endothelial binding was significantly less than that of normal SC endothelium for PSA and LCA (PSA-SC p = 0.002, LCA-SC p = 0.002). STA and DSA showed moderately strong binding while WGA, ECA, AHA, and MPA bound weakly throughout the TM; for DSA and MPA this staining was significantly greater in POAG than in normal TM (DSA-SC p = 0.001, DSA-CSM p = 0.002, MPA-SC p = 0.01, MPA-CSM p = 0.02). Jac stained strongly throughout the TM and showed no significant difference in POAG compared with normal TM (Jac-SC p = 0.6, Jac-CSM p = 1). 1PHA, SBA, DBA, CTA, UEA-1 and LTA did not bind to glaucomatous TM or normal TM. There were no age-related changes seen.

CONCLUSIONS

The expression of some complex and hybrid, bisected and non-bisected N-linked glycans is significantly diminished in glaucomatous TM compared with normal TM. Some glycans with multiple N-acetylglucosamine residues and O-linked glycans with terminal and subterminal galactosyl groups are significantly increased in POAG TM. Glycan expression does not change significantly with age in POAG or normal TM.

Glycoconjugates of the human trabecular meshwork: a lectin histochemical study

Twelve specimens of resin-embedded human trabecular meshwork were probed with a panel of 21 biotinylated lectins, using an avidin-biotin peroxidase revealing system, in order to determine the normal pattern of saccharide expression in this tissue. High-mannose, intermediate and hybrid N-linked glycans, and complex N-linked bisected and non-bisected bi/tri-antennate glycans, as shown by the binding of Canavalia ensiformis (ConA), Pisum sativum (PSA), Lens culinaris (LCA) agglutinins and Phaseolus vulgaris erythroagglutinin (ePHA), were strongly expressed by the canal of Schlemm endothelium and juxtacanalicular tissue, but less so by the corneoscleal meshwork. Highly branced complex glycans were not found, as there was no binding by Phaseolus vulgaris leukoagglutinin (IPHA). Sialyl residues, especially those alpha 2,6-linked as demonstrated by strong Sambucus nigra (SNA) lectin staining, were also abundant in this area. N-acetyllactosamine sequences and some O-linked glycans were present in the trabecular meshwork, as shown by Solanum tuberosum (STA), Datura stramonium (DSA), and Jacalin (Jac) lectin binding, while fucose residues were not detected by Tetragonolobus purpureas (LTA) or Ulex europaeus-1 (UEA-1) agglutinins. These results indicate similarities with renal glomerular and vascular endothelium, although the lack of binding with UEA-1 agglutinin suggests differences which may relate to the specialized function of the trabecular meshwork. This study provides a baseline for comparative analysis of the glycans of human trabecular meshwork in pathological conditions such as primary open-angle glaucoma.

Localisation of alpha(2,3) and alpha(2,6) linked terminal sialic acid groups in human trabecular meshwork

Sialic acid specific lectins were used to localise isomers of sialyl glycosides in human trabecular meshwork (TM) at the ultrastructural level. A lectin immunogold method demonstrated that sialic groups were concentrated on the endothelial surface of Schlemm's canal (SC) and in the adjacent juxta-canalicular tissue (JCT). One sialyl glycoside, alpha(2,6) linked N-acetyl neuraminic acid, was present mainly on the luminal aspect of the SC endothelium and in the cytoplasm of the JCT cells. Another, alpha(2,3) linked N-acetyl neuraminic acid, was localised predominantly to the extracellular fibrillar material of the JCT. The existence of a topographical segregation of these two sialyl glycosides within the TM supports the view that highly charged anionic molecules may be of significance in regulating aqueous outflow.

Dietary manganese deficiency decreases rat hepatic arginase activity

This study was designed to quantify the effect of dietary manganese deficiency on rat hepatic Mn concentration and arginase activity. Weanling male Sprague-Dawley rats were randomly assigned to two groups of nine rats each and fed L-amino acid diets with 0 or 48 micrograms Mn/g diet for 21 d. After 21 d, hepatic Mn concentration (mumol/g liver dry wt, mean +/- SEM) was 0.130 +/- 0.005 for the control group but was lower (P < 0.01) in the Mn-deficient group (0.040 +/- 0.003). There were no differences in the hepatic concentrations of any other measured mineral. Hepatic arginase activity [mmol ornithine/(g hepatic protein.min)] was 1.55 +/- 0.22 in the control group and was lower (P < 0.01) in the Mn-deficient group (1.12 +/- 0.26). Plasma ammonia concentration was 301 +/- 6 mumol/L in the control group and was higher (P < 0.01) in the Mn-deficient group (480 +/- 8 mumol/L). In contrast, plasma urea concentration was higher (P < 0.01) in the control group (350 +/- 10 mumol/L) than in the Mn-deficient group (267 +/- 7 mumol/L). There were no differences in plasma concentrations of arginine or other amino acids between the control and the Mn-deficient groups. Our results demonstrate for the first time that dietary Mn deficiency results in altered plasma concentrations of ammonia and urea in association with decreased hepatic Mn concentration and arginase activity in young growing rats.

Effect of excision of occipital lobe tissue on about the 70th day of gestation on the growth and development of the sheep's brain

A unilateral occipital excision was performed on 14 fetal lambs at about the 70th day of gestation, and the brains were examined postnatally for gross morphological and histologic changes. Three operated brains revealed a posterior shift of the principal transverse sulcus in the ipsilateral hemisphere. This sulcus is remote from the area of excision, which was usually represented by a cystic cavity. Histologic examination showed that the dorsal lateral geniculate body was reduced in size in all but three of the operated brains. In two brains with the changed gyral pattern there was also a reduction in the size of the white fiber tracts of the frontal lobe. No evidence of neural regeneration was found in any of the brains. The implications of these findings from the point of view of possible neurosurgical intervention in the fetus are considered.

Occipital lobectomies in foetal lambs

Foetal lambs undergoing unilateral occipital lobectomy have been investigated post-natally with computed tomographic (CT) scans, visual evoked potentials (VEP) recording and histological examination of their brains. Only the lambs operated at about 100th day of gestation have so far had their investigations completed, however, the results in all the lambs suggests that the foetal brain responds to an occipital lobectomy in essentially the same way as the post-natal brain. To date no evidence of regeneration has been found in any of the brains. It seems reasonable to conclude that if the foetal brain responds to lobectomy in the same manner to the post-natal brain, then its response to disease is likely to be similar. If this is so it can be argued that remediable foetal central nervous system abnormalities should be treated as soon as possible, if necessary in utero.

The changing dynamics of graduate medical education. Implications for decision-making

Cost-containment pressures and changes in traditional patient-care patterns are altering the process of graduate medical education. A thorough understanding of this process is a prerequisite to implementing changes that preserve the function of graduate medical education. This report describes the structure of the graduate medical education system and analyzes possible responses to the changes that are affecting it. The decision-making process within academic health centers is described, including an assessment of the roles of hospital directors, deans and faculty, as well as external regulatory agencies such as residency review committees, medical specialty boards and state licensing agencies. The activities of these participants are analyzed within the framework of the teaching hospital's service and education functions, and potential conflicts are described and illustrated by recent examples. Understanding the complex structure and functions of graduate medical education is a first step toward responding effectively to a changing environment.

The outcome of unilateral occipital lobectomy in 12 foetal lambs in about the 100th day of gestation: a preliminary report

In this study occipital lobectomies were carried out on 12 foetal lambs on about the 100th day of gestation. Three lambs were born alive and had computed tomographic (CT) scans performed on the 13th or 18th day of life. One lamb was found to have hydrocephalus due to ventriculitis. All three lambs had low attenuation areas on their CT scans suggesting that scarring rather than regeneration of the cerebral tissues had taken place. There was no evidence that accelerated bone healing of the skull had occurred. It is speculated that the lack of regeneration cerebral tissues and poor bone healing may have been due to the procedure being performed at a comparatively late stage of gestation.

Response of the fetal rat brain to trauma during the 17th to 21st days of gestation

Ultrasonography has made it possible to diagnose abnormalities of the human central nervous system early in pregnancy. However, more needs to be known about the response of the fetal brain before the mother and fetus are subjected to the risks of complex neurosurgical procedures. This study investigated the effects of trauma on fetal rat brains during a period equivalent to the early part of the second trimester of human pregnancy. Trauma inflicted on the fetal rat brains caused haemorrhage and necrosis of the cerebral hemisphere, which was not followed by significant regeneration of neural tissue. This preliminary study suggests that it cannot be assumed that the fetal brain will regenerate itself after injury, and that this should be considered when making plans for operative procedures on the central nervous system in utero.

Comparison of scanning electron and light microscopic appearances of sequential changes taking place in the ischemic cortex of the rat brain

The right middle cerebral territory of rat brains was made ischemic (a) for periods varying from 30 minutes to 24 hours, and at the end of each of the times the animals were killed and their brains were fixed, or (b) for 30 minutes, and the animals were allowed to survive for between 1 week and 9 months before they were killed and their brains were fixed. The ischemic areas were examined by light and scanning electron microscopy and the findings of the two methods of examination were compared. Scanning electron microscopy allowed the tissues to be studied at a wider range of magnification than was possible with the light microscope. Scanning electron microscopy also provided a three-dimensional view of the structures so that their relationship to one another could be examined. However, because it is generally not possible to stain material for examination by scanning electron microscopy, it was sometimes difficult to identify positively the individual structures. Nevertheless, this study has shown that scanning electron microscopy provides a valuable new way of investigating the ischemic brain and is likely to prove useful in other studies in the future.

Which hospital services are most overused? Results from a medical audit

When we assessed the extent of unnecessary ordering of clinical services by medical house staff at a large university hospital, 21% of services were judged to be unwarranted. Most overordered were nuclear medicine services, followed by laboratory tests. Because of their large volume, clinical laboratory services accounted for 78% of all unwarranted orders. Unwarranted use of hospital services is substantial and variable among physicians and services. This study confirms the value of medical record reviews for documenting the need for and guiding the course of hospital cost-containment programs.

Effect of early revascularization on the ischaemic rat brain

Rat brains made regionally ischaemic by manipulation of the large vessels in the neck were revascularized up to 4 hours later. Mortality rates, patterns of ink staining and the water content of the brains were studied. Scanning and transmission electron microscopy was carried out. The results showed that whilst revascularization did not reperfuse areas of the brain that had been subjected to very low levels of perfusion, it did reperfuse other areas with higher perfusion and, in so doing, prevented the extension of the ischaemic process into them.

Lessons for teaching cost containment

Increasing financial restrictions on hospitals by the federal government and changing physician reimbursement procedures make it more important to control the use of medical care resources by physicians. A prospective controlled study was made of an educational program for the medical and surgical house staffs and for medical students designed to reduce unneeded orders for low cost, high volume ancillary and nursing services. The program was comprised of six mutually reinforcing components: lectures, medical record audits and reviews, group feedback in the form of cost summaries containing information on unnecessary ordering, hospital price booklets, current patient bills, and pertinent journal articles. Operating at a time of retrospective hospital cost reimbursement, the program achieved only modest reductions in the residents' and students' use of hospital services and no substantive effect upon hospital costs. However, the program participants accepted the program enthusiastically. Several factors crucial to such educational cost containment programs were identified. The authors believe that experience with the program has valuable lessons for other hospitals initiating cost-control efforts.

Some scanning electron microscopic studies of the surface of coronal sections cut from the rat brain

The cut surfaces of coronal sections of the rat cerebral hemispheres have been examined with the scanning electron microscope. Under low magnification the structures of the brain are easily identified. Using the focusing power of the microscope and the ability to tilt the specimen in its column, under higher magnification the neurones, glial cells, cell processes, bundles of myelinated axons and the cerebral blood vessels can be examined in great detail. This method of study should prove of value in the future for the investigation of brains which have been subjected to experimental procedures and those affected by disease.

The failure of physician education as a cost containment strategy. Report of a prospective controlled trial at a university hospital

To test the hypothesis that physician education is an effective strategy to reduce total hospital costs, we evaluated three educational interventions at a large university hospital. This prospective controlled study spanned two academic years and involved 1,663 patients and 226 house staff. In the first year, weekly lectures on cost containment (medicine and surgery) and audit with feedback (medicine only) both failed to produce a significant change in total hospital charges. The "dose" of the intervention was increased on medicine in the second year by combining the lecture and audit strategies. Again, total charges did not change significantly. While decreased use occurred for certain selected services, the impact was not great enough to affect total hospital charges significantly. We conclude that, in the absence of other cost containing incentives, physician education alone is not an effective hospital cost containment strategy.

Ischemia and revascularization of the middle cerebral territory of the rat brain by manipulation of the blood vessels in the neck

Ischemia of the middle cerebral territory in the rat brain has been produced by anastomosing the right common carotid artery to the right jugular vein, and occluding the left internal and common carotid arteries. Revascularization is performed by ligating the right common carotid artery distal to the arteriovenous anastomosis and removing the clips from the left carotid arteries. The majority of the rats made ischemic deteriorated progressively and died if revascularization was not carried out, but only 10% of them died if the operation was performed within one hour, although the rate rose to 90% if the operation was delayed for 4 hours.

Ventricular ependyma of normal and hydrocephalic subjects: a scanning electronmicroscopic study

Recent scanning electronmicroscopic studies of the ependymal surfaces of the lateral, third and fourth ventricles of a variety of animals have shown that most areas are covered by numerous cilia. In this paper, the density of the ciliary population in each of the ventricles is illustrated with material taken from human and rat brains. The authors' examination of Hy3 mice with hydrocephalus, and a number of other reports of examinations of animals with genetic and artificially induced hydrocephalus, have shown that the cilia are lost only from the ependymal surfaces covering those parts of the ventricular wall which are stretched and thinned by the raised intraventricular pressure. Thus the loss of the cilia is most probably the result of the hydrocephalus, and not its cause. Theories concerning the functions of the cilia are reviewed, and a new one accounting for why they are present in such large numbers is suggested. It is proposed that the cilia, together with the ventricular system and the cerebrospinal fluid, provide a cooling system for the brain.

The influence of systemic aspirin on rat small diameter vein grafts: a scanning electron microscopic study

Small diameter vein grafts have been shown previously to have a poor patency rate unmedicated rats. Oral aspirin administered to male and female rats for one week pre-operatively reduced the number of platelets laid down on the luminal surface of their grafts, and resulted in a greater number of grafts remaining patent up to one hour after the blood flow through them had been established. The patency rate of grafts examined one to 17 weeks after operation was significantly better in female rats than in males given aspirin pre- and post-operatively. The different effect of aspirin in preventing thrombosis of the vein grafts of the two sexes makes its clinical usefulness for this purpose suspect.