Toward the quantification of α-synuclein aggregates with digital seed amplification assays

The quantification and characterization of aggregated α-synuclein in clinical samples offer immense potential toward diagnosing, treating, and better understanding neurodegenerative synucleinopathies. Here, we developed digital seed amplification assays to detect single α-synuclein aggregates by partitioning the reaction into microcompartments. Using pre-formed α-synuclein fibrils as reaction seeds, we measured aggregate concentrations as low as 4 pg/mL. To improve our sensitivity, we captured aggregates on antibody-coated magnetic beads before running the amplification reaction. By first characterizing the pre-formed fibrils with transmission electron microscopy and size exclusion chromatography, we determined the specific aggregates targeted by each assay platform. Using brain tissue and cerebrospinal fluid samples collected from patients with Parkinson's Disease and multiple system atrophy, we demonstrated that the assay can detect endogenous pathological α-synuclein aggregates. Furthermore, as another application for these assays, we studied the inhibition of α-synuclein aggregation in the presence of small-molecule inhibitors and used a custom image analysis pipeline to quantify changes in aggregate growth and filament morphology.

Cellular mechanisms of heterogeneity in NF2-mutant schwannoma

Schwannomas are common sporadic tumors and hallmarks of familial neurofibromatosis type 2 (NF2) that develop predominantly on cranial and spinal nerves. Virtually all schwannomas result from inactivation of the NF2 tumor suppressor gene with few, if any, cooperating mutations. Despite their genetic uniformity schwannomas exhibit remarkable clinical and therapeutic heterogeneity, which has impeded successful treatment. How heterogeneity develops in NF2-mutant schwannomas is unknown. We have found that loss of the membrane:cytoskeleton-associated NF2 tumor suppressor, merlin, yields unstable intrinsic polarity and enables Nf2^-/- Schwann cells to adopt distinct programs of ErbB ligand production and polarized signaling, suggesting a self-generated model of schwannoma heterogeneity. We validated the heterogeneous distribution of biomarkers of these programs in human schwannoma and exploited the synchronous development of lesions in a mouse model to establish a quantitative pipeline for studying how schwannoma heterogeneity evolves. Our studies highlight the importance of intrinsic mechanisms of heterogeneity across human cancers.

Medication Dispensing Errors in Community Pharmacies: A Nationwide Study

The available literature concerning medication dispensing errors provides relatively few studies that focus on community-based pharmacies. This paper presents the results of a nationwide, observation-based study of dispensing errors. Although community-based pharmacies were the primary focus, a small number of health-system pharmacies were also included. Investigators collected information concerning the frequency and type of errors and near errors as well as data regarding a number of task and environmental factors previously correlated with dispensing errors. A total of 5,784 prescriptions were inspected, revealing 91 errors (1.57%) and 74 near errors (1.28%). Errors were categorized as either content (41.76%) or labeling (58.24%) errors. Results are consistent with findings in the available literature. In particular, lighting levels, type of inspection system used (e.g., bar code product verification), number of available employees, and the arrangement of drug stock were significantly associated with both types of errors.

Incidence of Intravenous Medication Errors in a Chinese Hospital

OBJECTIVES

The purpose of this study was to explore intravenous (IV) medication errors in a Chinese hospital. The specific objectives were to 1) explore and measure the frequency of IV medication errors by direct observation and identify clues to their causes in Chinese hospital inpatient wards and 2) identify the clinical importance of the errors and find the potential risks in the preparation and administration processes of IV medications.

METHODS

A prospective study was conducted by using the direct observational method to describe IV medication errors on two general surgery patient wards in a large teaching hospital in Beijing, China. A trained observer accompanied nurses during IV preparation rounds to detect medication errors. The difference in mean error rates between total parenteral nutrition (TPN) and non-TPN medications was tested by using the Mann-Whitney U test.

RESULTS

A final total of 589 ordered IV doses plus 4 unordered IV doses as prepared and administered to the patients was observed from August 3, 2010, to August 13, 2010. The overall error rate detected on the study ward was 12.8%. The most frequent errors by category were wrong dose (5.4%), wrong time (3.7%), omission (2.7%), unordered dose (0.7%), and extra dose (0.3%). Excluding wrong time errors, the error rate was 9.1%. Non-TPN medications had significantly higher error rates than did TPN medications including wrong time errors (P = 0.0162).

CONCLUSIONS

A typical inpatient in a Chinese hospital was subject to about one IV error every day. Pharmacists had a very limited role in ensuring the accuracy of IV medication preparation and administration processes.

Effect of barcode technology with electronic medication administration record on medication accuracy rates

PURPOSE

The effect of barcode-assisted medication administration (BCMA) with electronic medication administration record (eMAR) technology on the occurrence of medication administration errors was evaluated.

METHODS

A pretest-posttest nonequivalent comparison group was used to investigate the effect of BCMA-eMAR on the medication administration accuracy rates at two community-based hospitals. Patient care units included three matched pairs in the two hospitals-two medical-surgical, two telemetry, and two rehabilitation units-plus a medical-surgical intensive care unit, an emergency department, and both an inpatient oncology unit and an outpatient oncology service at one of the hospitals. Medication administration accuracy rates were observed and recorded before (phase 1) and approximately 6 and 12 months after (phases 2 and 3, respectively) the implementation of BCMA-eMAR.

RESULTS

The overall accuracy rate at hospital 1 increased significantly from phase 1 (89%) to phase 3 (90%) (p = 0.0015); if wrong-time errors are excluded, the accuracy rate improved from 92% in phase 1 to 96% in phase 3 (p = 0.000008). The overall accuracy rate did not change significantly from phase 1 to phase 3 at hospital 2; when wrong-time errors were excluded from consideration, the accuracy rate improved from 93% in phase 1 to 96% in phase 3 (p = 0.015).

CONCLUSION

Implementation of BCMA-eMAR in two hospitals was associated with significant increases in total medication accuracy rates in most study units and did not introduce new types of error into the medication administration process. Accuracy rates further improved when wrong-time errors were excluded from analysis. The frequency of errors preventable by BCMA-eMAR decreased significantly in both hospitals after implementation of that technology. BCMA-eMAR and direct observation were more effective than voluntary reporting programs at intercepting and recording errors and preventing them from reaching patients.

Geometric probability distribution for modeling of error risk during prescription dispensing

PURPOSE

The relationship between the number of prescriptions dispensed by individual pharmacy staff during a single workday and the probability of committing at least one dispensing error during that same workday period was evaluated using a geometric probability distribution.

SUMMARY

A cross-sectional descriptive study involving 50 pharmacies located in six cities across the United States was conducted. A pharmacist trained to detect dispensing errors recorded the number of prescriptions filled by each pharmacy staff member and noted which prescription represented the staff member's first dispensing error (defined as any deviation from the prescriber's order) made during the observation period. The Kolmogorov-Smirnov tests for discrete distributions revealed that the observed cumulative distribution of dispensing errors could have come from a geometric probability distribution that assumed dispensing error rates of 2-3%. In terms of risk analysis, this study's findings suggest that there can be a quantifiable statistical relationship between a measure of workload and the risk of committing at least one dispensing error. The ability to model dispensing errors using a geometric probability distribution enables the safety and health care practitioner to directly assess dispensing error risk as a function of a pharmacy's accuracy rate and the number of prescriptions a pharmacy staff member should dispense during a work shift.

CONCLUSION

A geometric probability distribution effectively modeled the relationship between the number of prescriptions filled and the occurrence of the first dispensing errors.

Medication errors observed in 36 health care facilities

BACKGROUND

Medication errors are a national concern.

OBJECTIVE

To identify the prevalence of medication errors (doses administered differently than ordered).

DESIGN

A prospective cohort study.

SETTING

Hospitals accredited by the Joint Commission on Accreditation of Healthcare Organizations, nonaccredited hospitals, and skilled nursing facilities in Georgia and Colorado.

PARTICIPANTS

A stratified random sample of 36 institutions. Twenty-six declined, with random replacement. Medication doses given (or omitted) during at least 1 medication pass during a 1- to 4-day period by nurses on high medication-volume nursing units. The target sample was 50 day-shift doses per nursing unit or until all doses for that medication pass were administered.

METHODS

Medication errors were witnessed by observation, and verified by a research pharmacist (E.A.F.). Clinical significance was judged by an expert panel of physicians.

MAIN OUTCOME MEASURE

Medication errors reaching patients.

RESULTS

In the 36 institutions, 19% of the doses (605/3216) were in error. The most frequent errors by category were wrong time (43%), omission (30%), wrong dose (17%), and unauthorized drug (4%). Seven percent of the errors were judged potential adverse drug events. There was no significant difference between error rates in the 3 settings (P =.82) or by size (P =.39). Error rates were higher in Colorado than in Georgia (P =.04)

CONCLUSIONS

Medication errors were common (nearly 1 of every 5 doses in the typical hospital and skilled nursing facility). The percentage of errors rated potentially harmful was 7%, or more than 40 per day in a typical 300-patient facility. The problem of defective medication administration systems, although varied, is widespread.

Comparison of methods for detecting medication errors in 36 hospitals and skilled-nursing facilities

The validity and cost-effectiveness of three methods for detecting medication errors were examined. A stratified random sample of 36 hospitals and skilled-nursing facilities in Colorado and Georgia was selected. Medication administration errors were detected by registered nurses (R.N.s), licensed practical nurses (L.P.N.s), and pharmacy technicians from these facilities using three methods: incident report review, chart review, and direct observation. Each dose evaluated was compared with the prescriber's order. Deviations were considered errors. Efficiency was measured by the time spent evaluating each dose. A pharmacist performed an independent determination of errors to assess the accuracy of each data collector. Clinical significance was judged by a panel of physicians. Observers detected 300 of 457 pharmacist-confirmed errors made on 2556 doses (11.7% error rate) compared with 17 errors detected by chart reviewers (0.7% error rate), and 1 error detected by incident report review (0.04% error rate). All errors detected involved the same 2556 doses. All chart reviewers and 7 of 10 observers achieved at least good comparability with the pharmacist's results. The mean cost of error detection per dose was $4.82 for direct observation and $0.63 for chart review. The technician was the least expensive observer at $2.87 per dose evaluated. R.N.s were the least expensive chart reviewers at $0.50 per dose. Of 457 errors, 35 (8%) were deemed potentially clinically significant; 71% of these were detected by direct observation. Direct observation was more efficient and accurate than reviewing charts and incident reports in detecting medication errors. Pharmacy technicians were more efficient and accurate than R.N.s and L.P.N.s in collecting data about medication errors.

Impact of interruptions and distractions on dispensing errors in an ambulatory care pharmacy

A possible association between interruptions and distractions and the occurrence of dispensing errors was investigated. Fourteen pharmacists and 10 technicians in an ambulatory care pharmacy at a general medical-surgical hospital were tested for distractibility by using the group embedded figures test (GEFT) as well as for visual acuity and hearing. They were videotaped as they filled prescriptions during a 23-day period in 1992. A study investigator compared each filled prescription with the physician's written order, noted details of deviations, verified with the pharmacist any errors that occurred, and asked the pharmacist to correct the error if necessary. Interruptions and distractions were detected and characterized by reviewing the videotapes. None of the study participants had significant hearing or visual impairment. There was a significant association between GEFT scores and error rates. A total of 5072 prescriptions were analyzed, and 164 errors were detected, for an overall error rate of 3.23%. Wrong label information was the most common type of error (80% of errors detected). A total of 2022 interruptions (mean +/- S.D. per half hour per subject, 2.99 +/- 2.70) and 2457 distractions (mean +/- S.D. per half hour per subject, 3.80 +/-3.17) were detected. The error rate for sets of prescriptions with one or more interruptions was 6.65% and for sets during which there were one or more distractions, 6.55%. Interruptions and distractions per half hour were both significantly associated with errors. In an ambulatory care pharmacy, interruptions and distractions over a half-hour period were associated with dispensing errors, a majority of which involved incorrect label information.

Primary angiosarcoma of the ovary: a case report and review of the literature

INTRODUCTION

Gynecological sarcomas are rare and have a poor prognosis. Uterine sarcomas are most common accounting for 4% of all uterine tumors. Ovarian sarcomas are less frequent and are usually carcinosarcomas.

CASE REPORT

A previously healthy 40-year-old G2P2 presented for evaluation of 72 h of right upper quadrant pain and shortness of breath. A malignant right pleural effusion, ascites, and adnexal mass were found. Surgical staging and suboptimal debulking revealed pure angiosarcoma of the ovary Stage IV.

DISCUSSION

There are 12 cases of ovarian angiosarcoma reported in the literature. Ten of these cases presented in advanced stages with survivals of 2-30 months. Various chemotherapy regimens have been tried on these tumors including the most recent recommendation of MAID (mesna, doxorubicin, ifosfamide, and dacarbazine) and prognosis remains poor. Our patient underwent elective right pleurodesis via video-assisted thorascopic surgery under local anesthesia for an early recurrent right pleural effusion and subsequently began MAID chemotherapy.

Papillary and follicular thyroid carcinoma metastatic to the skin: a case report and review of the literature

Cutaneous metastases from thyroid cancers are rare. We report the case of an otherwise asymptomatic 81-year-old woman with an enlarging scalp lesion. Her solitary skin metastasis was the presenting feature of thyroid carcinoma. Routine histopathology of the lesion was notable for an atypical clear cell neoplasm. Immunohistochemistry was positive for thyroglobulin. Subsequent resection of the thyroid gland identified separate foci (< 1 cm) for both papillary and follicular carcinoma. Although such immunohistochemical staining has been used previously, it has never been reported to provide the definitive diagnosis for a solitary cutaneous metastasis from the thyroid. Previous tumors had anatomic features in a clinical context that permitted identification by routine light microscopy. Clear cell features found in the follicular focus of carcinoma in the thyroid suggest that it is the primary. A worldwide literature review reveals that follicular carcinoma has a greater preponderance than papillary carcinoma for cutaneous metastasis and that the majority of skin metastases from either papillary or follicular thyroid cancer are localized to the head and neck.

Observational study of accuracy in compounding i.v. admixtures at five hospitals

Rates of errors in i.v. admixture compounding at five U.S. hospital pharmacies were studied. Pharmacy staff members at five hospitals representing each U.S. geographic region were observed as they compounded sterile products in order to record the medication, dose, base solution, and other details. Intravenous admixtures, antineoplastic preparations, parenteral nutrient solutions, and ready-to-use products were included. Observations took place for five days at each pharmacy. The observers' notes were checked against the labels used to prepare the doses; any deviation was considered an error. The clinical importance of each error was assessed for its potential to affect a patient adversely. The mean error rate for the five hospitals combined was 9% (145 errors for 1679 doses), excluding ready-to-use products. Mean error rates for individual pharmacies ranged from 6% to 10%. Wrong-dose errors were the most common type of error. Parenteral nutrient solutions had the highest error rates-37% for manual preparation and 22% for preparation that was partly automated. Of every 100 errors, 2 were judged to be potentially clinically important. In five U.S. hospital pharmacies, the observed error rate for compounding i.v. admixtures was 9%.

Relationships between ambient sounds and the accuracy of pharmacists' prescription-filling performance

Associations between ambient sounds and accuracy of pharmacists' prescription-filling performance in a pharmacy was studied. Pharmacists were videotaped as they filled prescriptions each workday for 23 days. Each filled prescription was inspected by the investigator. Deviations from the physician's written order were considered errors. Videotape analysis was used to detect unpredictable, predictable, uncontrollable, and controllable sounds. A within-subjects case control study design was employed to determine whether the frequency of ambient sounds was significantly different when prescriptions with errors, compared with those without errors, were filled. Loudness, in terms of equivalent sound levels (Leq) for each half hour, was analyzed for a relationship to dispensing error rate. A mean dispensing error rate of 3.23% was found. Unpredictable sounds, controllable sounds, and noise had a significant effect on pharmacists which resulted in a decreased dispensing error rate. These results suggest that the quality of pharmacists' performance is not adversely affected by ambient sound. As equivalent sound levels increased, the error rate increased to a point, then decreased.

Re-engineering a pharmacy work system and layout to facilitate patient counseling

The development and evaluation of a new work system and facility design for a chain of community pharmacies are described. A new work system was developed to optimize utilization of pharmacist and technician time and allow the pharmacy to increase patient counseling without adding personnel. In the new system, pharmacists would review prescriptions, check technicians' work, and dispense prescriptions, counseling patients as needed; technicians would enter prescriptions into the pharmacy computer and fill them. The existing work system and design were evaluated in June and July of 1992 by observing, classifying, and recording activities of pharmacy personnel three days per week at six pharmacies in the chain. Pharmacy designs that would work with the new work system were created by a university design class after consultation with representatives of the pharmacy chain and the university's college of pharmacy. The pharmacy chain selected one design, and a detailed floor plan and specifications were created. To test how the new design and system would work at each of the six test pharmacies, a computer simulation program was developed and verified by using the data collected on the existing pharmacy operations. Computer simulation showed that, with the new design and system, increasing patient counseling would increase patient waiting time slightly but would not require additional personnel. The layout and work system in a chain of community pharmacies were redesigned to facilitate patient counseling and make the best use of employee time.

Sequential mast cell infiltration and degranulation during experimental carcinogenesis

Mast cell density, distribution, and ultrastructure were studied by light and electron microscopy in hamster buccal pouches undergoing chemically induced carcinogenesis. Epidermoid carcinomas in the pouches were induced by three topical applications per week of 0.5% 7,12-dimethylbenz[a]anthracene (DMBA) in oil using a brush. Four experimental, DMBA-treated and two normal, untreated hamsters were sacrificed after 8, 10, 12, 14, and 16 weeks. After 8 weeks of DMBA treatment, the epithelium showed the pathological signs of dysplasia and hyperkeratosis. In the dermis an increased number of mast cells were evident, some of which showed degranulation. A few mast cells had started to migrate upwards towards the dysplastic epithelium after 10 weeks of DMBA treatment. Rapid degranulation was also apparent in some mast cells. These processes of upward migration and degranulation continued progressively during the 12- and 14-week periods of DMBA application in correlation with the progression of the tumor. By 16 weeks of treatment with the carcinogen, more mast cells had migrated closer to the invasive carcinoma, and many had degranulated. In the connective tissue mast cells were fully packed with many granules, and some mast cells were in proximity to macrophages and eosinophils. Our observations demonstrate that there is a positive correlation between developing carcinomas and mast cell density. Mast cell migration towards the carcinoma and degranulation were also evident.

Effect of estradiol on ultrastructure of granular ducts in submandibular glands of female rats

The effects of estradiol on the granular ducts in submandibular glands of female albino rats were studied. Twenty-five-milligram pellets of 17 beta-estradiol were implanted subcutaneously in the experimental animals, and their glands, as well as controls, were examined after 2, 4, 7, and 10 wk using light and electron microscopy. During the course of the experiment an increasing proportion of the granules in the granular ducts appeared more lightly stained in the experimental animals. In the estradiol-treated rats the granular ducts increased in relative cross-sectional area at a faster rate than in the controls, which exhibited maturation changes. In addition, the average number of granules per granular duct cell decreased significantly in the treated animals. Our results indicate that estradiol caused a change in the cytology of the granular ducts suggesting an alteration in protein synthesis. These results might occur through a change in structural proteins or in other hormones and growth factors which are known to influence the submandibular gland.

Autophagocytosis of melanosomes in cultured embryonic retinal pigment cells

Autophagocytosis not only accounts for the early pigment loss found in proliferating cultured retinal pigment cells, but also occurs in slowly growing and in non-proliferating cells. Both melanosome synthesis and destruction may take place concurrently in cells. Autophagosomes may contain both fully formed melanosomes and also premelanosomes in various stages of formation, are positive for lysosomal enzyme activity, and likely represent secondary lysosomes.

Ultrastructure of normals and castrates and the effects of testosterone and ultraviolet (UVL-B) irradiation on scrotal skin of rats

The ultrastructure of the testosterone dependent epidermal melanocyte system of the scrotal skin of normals and castrates, with and without testosterone replacement therapy, and UVL-B (280-315 nm) radiation in black Long Evans rats is reported. UVL-B increases melanocyte activity, melanosome forming apparatus, (size of Golgi zone and RER, and quantity of cytoplasmic vesicles, dendrites, and stages of melanosomes) in normals and in castrates. Testosterone replacement therapy to castrates is not a prerequisite for stimulation by UVL-B, but it enhances the effects of UVL-B without restoring normalcy as melanosome packaging into complexes predominates. After UVL-B stimulation of normals or castrates, melanocyte dendrites are observed more often. Melanocyte dendrites of skin of castrated rats are observed less often than in normals, but with testosterone replacement therapy, the dendrites become more numerous. Melanosomes donated to keratinocytes are mostly located as singles in normals and as complexes in castrates. After UVL-B, castration, or testosterone replacement therapy, the melanosomes are packaged in keratinocytes in complexes larger than in normals. In the epidermis of long term castrates (9-109 days), non-specific clear cells are observed and Langerhans cells containing melanosomes; we did not observe them in normals. Melanocytes of castrates have a reduced melanosome forming apparatus. The dermis of castrates contains many dermal melanocytes in the superficial dermis with melanosomes in several stages of formation. These cells are not apparent in normals at this location in the dermis. Testosterone replacement therapy and/or UVL-B administered to castrates does not restore the epidermal melanocyte system nor the dermis to precastration ultrastructural appearance; castration has a permanent altering effect as melanosomes are packaged into complexes.