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Biomedical subjects

S Horner

Publications and source records attributed to S Horner.

At least 19 recordsLinked to original sources
PubMed2005

Detection of bovine viral diarrhoea virus infected cattle--testing tissue samples derived from ear tagging using an Erns capture ELISA.

A new diagnostic approach testing tissue samples derived from cattle ear tagging for bovine viral diarrhoea virus (BVDV) antigen in a commercially available antigen capture enzyme-linked immunosorbent assay (ACE) was developed. To validate this method, 99 positive and 469 negative samples were tested. With those samples the assay yielded a sensitivity of 100% and specificity of >or=99.6%. Serum and ear tissue samples from 11 persistently infected (PI) BVDV calves were tested. While serum samples were negative after intake of colostrum, the ear tissue samples could be detected positive for BVDV all the time. Testing multiple samples derived from the same ear from PI cattle yielded positive results and low variation. Using cattle ear tags combining the ear tag application with sampling of a small ear tissue plug and testing those tissue samples with an ACE could be a reliable and economic way of BVDV testing.

Animals↗
PubMed2000

The association between the diameter of a patent foramen ovale and the risk of embolic cerebrovascular events.

PURPOSE: We sought to determine whether the size of a patent foramen ovale affected the risk of embolic cerebrovascular events of unknown origin. PATIENTS AND METHODS: We ascertained the presence and measured the size of patent foramen ovale using multiplane transesophageal echocardiography in 121 consecutive patients younger than 60 years who had transient ischemic attacks or ischemic strokes and in 123 control subjects. None of the patients had left heart, aortic, or carotid sources of embolism, or echocardiographic signs of elevated left or right atrial pressure. We used multivariate logistic regression to determine whether the size of the patent foramen ovale was an independent risk factor for cerebrovascular events. RESULTS: The mean (+/- SD) diameter of a patent foramen ovale was significantly larger in patients (4 +/- 2 mm) than in control subjects (2 +/- 1 mm, P <0.0001). A patent foramen ovale greater than 4 mm was associated with an increased risk of transient ischemic attacks [odds ratio (OR) = 3.4; 95% confidence interval (CI), 1.0 to 11, P = 0.04], ischemic strokes (OR = 12; 95% CI, 3.3 to 44, P = 0.0001), and, especially, having evidence of two or more strokes (OR = 27; 95% CI, 4.7 to 160, P = 0.0002). CONCLUSION: The diameter of a patent foramen ovale is an independent risk factor for ischemic events, especially recurrent strokes.

Adult↗
PubMed2000

The Bradykinesia Akinesia Incoordination Test (BRAIN TEST), an objective and user-friendly means to evaluate patients with parkinsonism.

The BRAIN TEST, a computerized alternating finger tapping test, was performed on 154 patients with parkinsonism to assess whether the test could be used as an objective tool to evaluate reliably the severity of Parkinson's disease (PD). Patients were instructed to tap two marked computer keyboard keys as fast and as accurately as possible for 60 seconds. The test generates the following variables: (1) kinesia score (KS)--number of keystrokes/min, (2) akinesia time (AT)--cumulative time that keys are depressed, (3) dysmetria score (DS)--a weighted score generated from incorrectly hit keys and corrected for speed, and (4) arrhythmia score (AS)--variance of the time interval between individual keystrokes. Among parkinsonian patients, we found a significant correlation between the four test parameters and PD rating scores of the Hoehn & Yahr, Schwab & England, and Unified PD Rating Scales (KS, AS, and AT p <0.001 and DS p <0.05). When compared with 73 parkinsonian patients 73 age- and sex-matched control subjects showed significantly higher KS and lower AT (p <0.001) as well as lower DS and AS (p = 0.05). The BRAIN TEST is a reliable and practical tool for evaluating the severity of parkinsonism and for distinguishing subjects with parkinsonism from normal control subjects. A version of the BRAIN TEST is available by FTP on the worldwide web (http://www.anaesthetist.com/software/brain.htm).

Adult↗
PubMed1998

Beta-fibrinogen gene polymorphism (C148-->T) is associated with carotid atherosclerosis: results of the Austrian Stroke Prevention Study.

Polymorphisms at the beta-fibrinogen locus have been shown to be associated with plasma concentration of fibrinogen and coronary heart disease. The effect of the genetic heterogeneity of fibrinogen on carotid atherosclerosis has not been determined so far. We examined the influence of the C148 --> T polymorphism on carotid disease in a large cohort of middle-aged to elderly subjects without evidence of neuropsychiatric disease. This polymorphism is located close to the consensus sequence of the interleukin-6 element and may represent a functional sequence variant. The genotype of 399 randomly selected, neurologically asymptomatic individuals, aged 45 to 75 years, was determined by denaturing gradient gel electrophoresis. Carotid atherosclerosis was assessed by color-coded duplex scanning and was graded on a five-point scale ranging from 0 (=normal) to 5 (=complete luminal obstruction). The C/C, C/T, and T/T genotypes were noted in 226 (56.6%), 148 (37.1 %), and 25 (6.3%) individuals, respectively. The T/T genotype group demonstrated higher grades of carotid atherosclerosis than did the C/C and C/T genotypes (P=.003). Logistic regression analysis created a model of independent predictors of carotid atherosclerosis that included apolipoprotein B (odds ratio [OR], 1.17/10 mg/dL), age (OR, 2.46/10 years), lifetime tobacco consumption (OR, 1.03/1000 g), presence of the beta-fibrinogen promoter T/T genotype (OR, 6.17), plasma fibrinogen concentration (OR, 1.05/10 mg/dL), and cardiac disease (OR, 1.80). These data suggest that the beta-fibrinogen promoter T/T148 genotype represents a genetic risk factor for carotid atherosclerosis in the middle-aged to elderly.

Aged↗
PubMed1997

Simultaneous bilateral contrast transcranial doppler monitoring in patients with intracardiac and intrapulmonary shunts.

The prevalence of a right-to-left intracardiac shunt, demonstrated by echocardiography and transcranial Doppler sonography has been shown to be higher in stroke patients than in normal controls. The aim of this study was to assess the sensitivity and specificity of contrast transcranial Doppler sonography in comparison to transesophageal echocardiography in the detection and differentiation of intracardiac and intrapulmonary shunts and to correlate the transcranial Doppler findings with clinical outcome and morphological findings. Forty five consecutive stroke patients with suspected paradoxical embolism were entered into the study. In all 25 patients with middle cerebral artery stroke of the left (56%) or right (44%) territory and echocardiographic demonstrated patent foramen ovale (80%) or intrapulmonary shunt (20%), simultaneous bilateral transcranial Doppler sonography of the middle cerebral arteries was performed after contrast medium injection during rest and valsalva straining under standardized and optimized conditions. Overall sensitivity for the detection of a right-to-left shunt by contrast transcranial Doppler sonography was 97% and overall specificity was 70%. Bilateral appearance of microbubbles, microbubble count and time delay of microbubble appearance significantly increased after valsalva straining. In patients with intracardiac shunts, a significantly higher microbubble count (32 vs. 13 in patients with an intrapulmonary shunt) and a shorter time interval of microbubble appearance (11 vs. 14 s in patients with intrapulmonary shunts) was observed. There was no correlation between the side and numerical distribution of microbubble count and the location and severity of the current clinical symptoms, as well as between microbubble count and presence and hemispherical distribution of brain infarcts. Transcranial Doppler sonography is a highly sensitive method for the detection of right-to-left shunts, whether of cardiac or pulmonary location. However. no correlation was found between the side and number of microbubbles counted and the clinical symptomatology.

Adolescent↗
PubMed1997

[Evaluation of vascular risk factors in patients with Parkinson syndrome].

A vascular etiology of Parkinson's disease (PD) has been long debated. In order to search for an ischemic basis of PD we assessed the clinical symptomatology of a consecutive group of 60 PD patients and compared their frequency of cerebrovascular risk factors, carotid atherosclerosis and ischemic brain lesions with age-matched groups of stroke patients and normals. There were 16 (27%) subjects with PD who also had symptoms of cerebrovascular disease. The frequencies of carotid stenoses, ischemic brain lesions and most of cerebrovascular risk factors seen in the latter group was comparable with those of stroke patients and significantly higher than in the investigational subsets of patients with "pure" PD and normals. Only one (1.6%) individual with PD presented signs suggestive of an ischemic etiology of parkinsonism. These findings suggest that cerebrovascular disease occurs in approximately one fourth of patients with PD, but seldomly is causally related.

Aged↗
PubMed1997

[Prevalence and risk factors in the population of Graz (Austrian Stroke Prevention Study)].

The Austrian Stroke Prevention Study recruited 1960 randomly selected subjects aged 50 to 75 years during a 3-year period of enrollment. The response rate of the study was 32.4%. A telephone interview with 200 randomly selected non-responders yielded no differences to responders regarding the frequency of major vascular risk factors known to the subjects. Besides demographics, the study assessed arterial hypertension, diabetes mellitus, cardiac disease, smoking, a complete lipid status including the apolipoprotein-E genotype, serum fibrinogen and anticardiolipin antibodies as well as various natural antioxidants such as vitamins A, C, E and beta-carotene. Arterial hypertension, diabetes mellitus, cardiac disease and hypercholesterolemia > 200 mg/dl were strikingly common and occurred in 38%, 7.6%, 32% and 76%, respectively. Suboptimal plasma concentrations of vitamin A, E, and beta-carotene were noted in 77.2%, 56.1% and in 53.2% of study participants. The rate of treatment of major risk factors known to the subjects prior to study entry were 60.3% and 70% for arterial hypertension and diabetes mellitus, but only 37.1% and 6.3% for cardiac disease and hypercholesterolemia > 250 mg/dl. Diet was commonly used to treat diabetes but was almost neglected in the treatment of other vascular risk factors. These data provide an orientation on the prevalence of risk factors and the use of primary preventive measures for stroke treatment in our community.

Adult↗
PubMed1995

Advance directives.

Explore the source record for details and available documents.

Advance Directives↗
PubMed1995

Integrative models and responses in cardiac ischemia.

This chapter considers the study of electrophysiological changes during ischemia and incorporates mechanoelectric feedback, i.e., mechanical changes affecting electrophysiology. It considers these interactions in the cell, through multicell systems, the intact heart and the intact organism.

Animals↗
PubMed1995

EEG, CT and neurosonographic findings in patients with postischemic seizures.

Seventy-two patients with postischemic seizures were evaluated with electroencephalography (EEG), computerized tomography (CT) and neurosonography. There were 24% early-onset and 76% late-onset initial seizures. Early-onset seizure was more likely to be simple partial (53%), whereas late-onset seizure was more likely to be primarily generalized (56%). 76% early-onset and 80% late-onset seizures were single. Status epilepticus was more frequent in early-onset that late-onset seizures (p = 0.023). The possibility of recurrence was greater in late-onset than early-onset seizures (p < 0.001). 88% patients had EEG abnormalities, and the most common finding was focal slowing. 75% patients had cerebral infarctions on CT scan, and the majority of them involved cortex. 89% postischemic seizures had carotid lesions which mostly were carotid plaques < 50%. We failed to find these data to be useful in predicting the time of onset of initial seizures after acute ischemic stroke and recurrence.

Adult↗
PubMed1994

Serial transcranial Doppler sonography in ischemic strokes in middle cerebral artery territory.

The changes in middle cerebral artery (MCA) blood flow velocity were serially evaluated in 31 patients with acute ischemic strokes in the MCA territory using transcranial Doppler ultrasound. In patients with a poor clinical prognosis, MCA mean velocity on the infarcted side (MV1) was significantly decreased within 48 hours after onset, compared with that on the opposite side (MV2) (p < 0.01). However, this change was not significant in patients with a good clinical prognosis. As predictors of poor clinical prognosis, an MV1 of 40 cm/sec or less and an asymmetry index of -20% or less showed positive predictive values of 93 and 88%, with sensitivities of 72 and 83% and specificities of 92 and 85%, respectively. An MV1 slower than 20 cm/sec or an asymmetry index below -50% had a 100% positive predictive value and a 100% specificity, but less sensitivity (17 and 44%, respectively). Combining an MV1 of 40 cm/sec or less with an asymmetry index of -20% or less resulted in a 100% positive predictive value and a 100% specificity, with a relatively high sensitivity of 67%. As predictors of good clinical prognosis, an MV1 faster than 40 cm/sec and an asymmetry index above -20% showed positive predictive values of 71 and 79%, with sensitivities of 92 and 85% and specificities of 72 and 83%, respectively. The clinical prognosis based on MV1 seems particularly reliable for MCA territorial and cortical infarctions.

Acute Disease↗
PubMed1994

Assessment of cerebrovascular risk profiles in healthy persons: definition of research goals and the Austrian Stroke Prevention Study (ASPS).

The advent of new laboratory methods and noninvasive imaging modalities has extended the diagnostic possibilities in normal individuals. This article elaborates the new options for the assessment of stroke risk offered by these techniques. In this context we present the Austrian Stroke Prevention Study, which is the first prospective long-term investigation of normals that includes Doppler sonography, magnetic resonance imaging and single photon emission computed tomography. The design, utility and limitations of this study are discussed.

Aged↗
PubMed1994

[Effect of head rotation on the vertebrobasilar system. A transcranial Doppler ultrasound contribution to the physiology].

Examination of the vertebrobasilar system until a short time ago was possible only by invasive and therefore potentially harmful techniques. The results of these studies were also contradictory. The objective of the present study was to determine how blood flow velocity differed in the vertebral arteries during head rotation in normal subjects. The origin of cervical vertigo essentially involves three components that are difficult to distinguish. There are the sensory proprioceptive, vascular and sympathicotonic components. Use of transcranial Doppler sonography (TCD) has now made it possible to measure the flow velocity of the vertebral arteries. In 17 normal probands without vertigo or cervical nystagmus, the mean diameters of the vertebral arteries were measured by means of duplex scanning. TCD was used to determine the mean flow velocities of the vertebral arteries in a median position and after head rotations of 30 degrees and 60 degrees to the left and right. Blood flow velocities in both vertebral arteries were not altered by head rotation. This observation contrasted with that of other publications, which were mainly based on cadaver findings. The results of this study form the basis for further investigations on symptomatic patients with recurring cervical nystagmus and cervical vertigo.

Adult↗
PubMed1994

Recurrent left atrial myxoma.

Based on statistics from the UK, the incidence of myxoma is about 1:1,000,000/year. Three recent cases of recurrent myxoma are reported, one where excision was probably incomplete, one where tumour implantation may have occurred and one where a mesenchymal sarcoma was misinterpreted histologically. The relative importance of these three factors in recurrence of cardiac tumours after surgical excision is discussed.

Adult↗
PubMed1993

Reopening of internal carotid artery occlusions during heparin-induced LDL precipitation (H.E.L.P.) associated with improved haemorheology: report of 2 cases.

As has already been reported, there is a direct relationship between the severity of cerebrovascular insufficiency and elevated plasma fibrinogen levels, as well as whole blood and plasma viscosity, Red Cell Transit Time (RCTT) and cerebral blood flow. By applying heparin-induced extracorporeal LDL < cholesterol, triglycerides, fibrinogen > precipitation (H.E.L.P.), a rapid reduction of fibrinogen has become possible which has proved to be very beneficial for the treatment of acute stroke and multi-infarct disease. The present report demonstrates the impact of H.E.L.P. in connection with Doppler and Duplex sonography: In one patient a complete occlusion at the origin of the right internal carotid artery was revealed by Doppler and Duplex sonography. In a second patient, a complete occlusion of the left internal carotid artery was verified. By applying H.E.L.P. once a week (seven times in patient #1, twelve times in patient #2), a consistent lowering of fibrinogen, whole blood and plasma viscosity, red cell transit time, total cholesterol, low density lipoprotein, lipoprotein (a) and triglycerides was achieved. After H.E.L.P. application, Doppler/Duplex sonography showed complete reopening of the previously occluded vessel in patient #1 and patency of the vessel of patient #2.

Brain Ischemia↗