Parascaris spp. eggs shedding patterns in juvenile horses.

Parascaris spp. infect foals worldwide and foals typically shed eggs in the feces from about three to six months of age, upon which natural immunity is incurred. High levels of anthelmintic resistance of Parascaris spp. are a global concern, and further understanding egg shedding patterns and fecal egg counting (FEC) data variability is of high importance. The aims of this study were to monitor Parascaris spp. egg shedding in untreated foals during 12-23 weeks of age, estimate sources of data variability, and assess precision of two ascarid FEC techniques. Fecal samples were collected weekly from 11 foals born in 2022, from May through November (29 weeks). Six subsamples were extracted from each weekly sample to determine 30 FECs between two techniques: a McMaster technique and an Automated Egg Counting System (AECS). Mixed linear modeling was carried out with age, sex, birth month, seasonality, spring- or summer-born foals, and egg counting technique as explanatory variables. Ascarid FECs were associated with age (p < 0.001), seasonality (p < 0.001), and technique (p < 0.001). The McMaster technique was more precise with a mean coefficient of variation (CV) of 34.57% and a 95% confidence interval (CI) of 30.80%- 38.30% compared to the CV for the AECS, which was 42.22% (CI: 37.70%-46.70%). Seasonality accounted for the highest proportion of variance (PV) of all covariates, but differences in PVs for covariates existed between techniques with foal age and subsample contributing more variance to the McMaster, and individual foal and seasonality contributing more to the AECS. Subsamples and replicate counts accounted for less than 1% of the total data variance. The results highlighted substantial differences in PVs between the two techniques at the subsample (AECS: 57.14%; McMaster: 77.51%) and replicate count levels (AECS: 42.86%; McMaster: 22.49%). While differences in precision were observed between the two FEC techniques, they were negligible in the data set, as the overwhelming majority of the data variability in ascarid FECs was attributed to individual foal, seasonality, and foal age.

Development and Calibration of Pressure-Temperature-Humidity (PTH) Probes for Distributed Atmospheric Monitoring Using Unmanned Aircraft Systems.

Small unmanned aircraft systems (UAS) are increasingly being used for meteorology and atmospheric monitoring. The ease of deployment makes distributed sensing of parameters such as barometric pressure, temperature, and relative humidity in the lower atmospheric boundary layer feasible. However, constraints on payload size and weight, and to a lesser extent power, limit the types of sensors that can be deployed. The objective of this work was to develop a miniature pressure-temperature-humidity (PTH) probe for UAS integration. A set of eight PTH probes were fabricated and calibrated/validated using an environmental chamber. An automated routine was developed to facilitate calibration and validation from a large set of temperature and relative humidity setpoints. Linear regression was used to apply temperature and relative humidity calibrations. Barometric pressure was calibrated using a 1-point method consisting of an offset. The resulting PTH probes were less than 4 g in mass and consumed less than 1 mA when operated from a 5 VDC source. Measurements were transmitted as a formatted string in ASCII format at 1 Hz over a 3.3 V TTL UART. Prior to calibration, measurements between individual PTH probes were significantly different. After calibration, no significant differences in temperature measurements across all PTH probes were observed, and the level of significance between PTH probes was reduced. Actual differences between calibrated PTH probes were likely to be negligible for most UAS-based applications, regardless of significance. RMSE across all calibrated PTH probes for the pressure, temperature, and relative humidity was less than 31 Pa, 0.13 °C, and 0.8% RH, respectively. The resulting calibrated PTH probes will improve the ability to quantify small variations in ambient conditions during coordinated multi-UAS flights.

Misdiagnosis of cerebellar hemorrhage - features of 'pseudo-gastroenteritis' clinical presentations to the ED and primary care.

BACKGROUND: Early-stage cerebellar hemorrhage can present with nausea or vomiting absent other neurological symptoms or signs, potentially leading to an incorrect diagnosis of gastroenteritis. We sought to determine the frequency of gastroenteritis-like presentations and delayed or missed diagnoses among patients with spontaneous cerebellar hemorrhage. METHODS: This is a retrospective, case-control analysis of atraumatic, primary cerebellar hemorrhages derived from a systematic search of surgical pathology and autopsy databases at two large urban, academic medical centers from 1984 to 2006. Hospital visit and clinical symptom data were abstracted from electronic and paper medical records for included patients. Delayed or missed diagnoses were defined as those at least one previous visit for relevant clinical symptoms in the 7 days prior to the correct diagnosis being confirmed. RESULTS: Among 254 records captured by our search filter, we identified 35 cases of pathologically proven primary cerebellar hemorrhage. Four patients (11%) were misdiagnosed initially - three with "gastroenteritis" and one with "hypertension". In this small sample, misdiagnosed patients presented more often with normal mental state (100% vs. 35%, p=0.07) and nausea/vomiting (100% vs. 58%, p=0.22). Although patients deteriorated clinically after the initial misdiagnosis, and potentially dangerous diagnostic tests and treatment strategies were instituted as a result of misdiagnosis, none of the misdiagnosed patients died or suffered major permanent harms due to diagnostic delay. CONCLUSIONS: Our study is limited by the small number of identified cases. Nevertheless, it appears that patients with cerebellar hemorrhages can present with relatively unimpressive clinical findings without obvious neurological manifestations. Such individuals are sometimes misdiagnosed with gastroenteritis or other benign disorders initially, possibly when neurologic examination, particularly gait testing, is omitted or abridged. A careful search for subtle cerebellar signs, including dysarthria, limb ataxia, nystagmus or tandem gait instability, absent in true gastroenteritis cases, could potentially reduce misdiagnosis.

How often is dizziness from primary cardiovascular disease true vertigo? A systematic review.

OBJECTIVES: To assess how frequently cardiovascular dizziness is vertigo. Recent studies suggest providers do not consider cardiovascular causes when a patient reports true vertigo (spinning/motion) as opposed to presyncope (impending faint). It is known that cardiovascular disease causes dizziness, but unknown how often such dizziness is vertiginous, as opposed to presyncopal. DATA SOURCES: Systematic review of observational studies was made: Search--electronic (MEDLINE, EMBASE) and manual (references of eligible articles) search for English-language studies (1972-2007). REVIEW METHODS: Inclusions Studies of >or=5 patients with confirmed cardiovascular causes for dizziness and reporting a proportion with vertigo were included. Two independent reviewers selected studies for inclusion, with differences adjudicated by a third. Study characteristics and dizziness-type proportions were abstracted. Studies were rated on methodology and quality of dizziness definitions. Differences were resolved by consensus. RESULTS: We identified 1,506 citations, examined 125 full manuscripts, and included 5 studies. Principal reasons for exclusion were: abstracts--lack of original data, no cardiovascular diagnosis, or confounding exposure/disease (74%); manuscripts--failure to distinguish vertigo from other dizziness types (78%). In the three studies not using vertigo as an entry criterion (representing 1,659 patients with myocardial infarction, orthostatic hypotension, or syncope), vertigo was present in 63% (95% CI 57-69%) of cardiovascular patients with dizziness and the only dizziness type in 37% (95% CI 31-43%). Limitations include modest study quality and non-uniform definitions for vertigo. CONCLUSIONS: Published data suggest that dizziness from primary cardiovascular disease may often be vertigo. Future research should assess prospectively whether dizziness type is a meaningful predictor for or against a cardiovascular diagnosis.

Visual hemispatial neglect, re-assessed.

Increased computer use in clinical settings offers an opportunity to develop new neuropsychological tests that exploit the control computers have over stimulus dimensions and timing. However, before adopting new tools, empirical validation is necessary. In the current study, our aims were twofold: to describe a computerized adaptive procedure with broad potential for neuropsychological investigations, and to demonstrate its implementation in testing for visual hemispatial neglect. Visual search results from adaptive psychophysical procedures are reported from 12 healthy individuals and 23 individuals with unilateral brain injury. Healthy individuals reveal spatially symmetric performance on adaptive search measures. In patients, psychophysical outcomes (as well as those from standard paper-and-pencil search tasks) reveal visual hemispatial neglect. Consistent with previous empirical studies of hemispatial neglect, lateralized impairments in adaptive conjunction search are greater than in adaptive feature search tasks. Furthermore, those with right hemisphere damage show greater lateralized deficits in conjunction search than do those with left hemisphere damage. We argue that adaptive tests, which automatically adjust to each individual's performance level, are efficient methods for both clinical evaluations and neuropsychological investigations and have the potential to detect subtle deficits even in chronic stages, when flagrant clinical signs have frequently resolved.

Overreliance on symptom quality in diagnosing dizziness: results of a multicenter survey of emergency physicians.

OBJECTIVE: To assess emergency physicians' diagnostic approach to the patient with dizziness, using a multicenter quantitative survey. PARTICIPANTS AND METHODS: We anonymously surveyed attending and resident emergency physicians at 17 academic-affiliated emergency departments with an Internet-based survey (September 1, 2006, to November 3, 2006). The survey respondents ranked the relative importance of symptom quality, timing, triggers, and associated symptoms and indicated their agreement with 20 statements about diagnostic assessment of dizziness (Likert scale). We used logistic regression to assess the impact of "symptom quality ranked first" on odds of agreement with diagnostic statements; we then stratified responses by academic rank. RESULTS: Of the 505 individuals surveyed, 415 responded for an overall response rate of 82%. A total of 93% (95% confidence interval [CI], 90%-95%) agreed that determining type of dizziness is very important, and 64% (95% CI, 60%-69%) ranked symptom quality as the most important diagnostic feature. In a multivariate model, those ranking quality first (particularly resident physicians) more often reported high-risk reasoning that might predispose patients to misdiagnosis (eg, in a patient with persistent, continuous dizziness, who could have a cerebellar stroke, resident physicians reported feeling reassured that a normal head computed tomogram indicates that the patient can safely go home) (odds ratio, 6.74; 95% CI, 2.05-22.19). CONCLUSION: Physicians report taking a quality-of-symptoms approach to the diagnosis of dizziness in patients in the emergency department. Those relying heavily on this approach may be predisposed to high-risk downstream diagnostic reasoning. Other clinical features (eg, timing, triggers, associated symptoms) appear relatively undervalued. Educational initiatives merit consideration.