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Biomedical subjects

G Rubin

Publications and source records attributed to G Rubin.

At least 55 records · Page 3Linked to original sources
PubMed1998

Relation between cerebral blood flow and neurologic deficit resolution in acute ischemic stroke.

BACKGROUND AND OBJECTIVE: Early intervention remains the key to acute ischemic stroke therapy. Many patients whose deficits would later resolve without intervention are exposed to the risks of stroke treatment without benefit. The purpose of this study was to determine whether patients with transient deficits could be distinguished from patients with evolving strokes on the basis of acute cerebral blood flow (CBF) measurements before any clinical distinction could be made. METHODS: Fifty-three patients who presented with acute hemispheric stroke symptoms and who underwent xenon-enhanced CT (XeCT) CBF studies within 8 hours of onset of symptoms (and before any clinical improvement) were studied. RESULTS: Eight patients (15%) had a complete resolution of their symptoms within 24 hours (not related to treatment). All eight patients with deficits that resolved had normal CBF in the symptomatic vascular territories (mean time to XeCT = 3 hours, 51 min). Mean CBF in the regions of interest of the symptomatic vascular territories of patients who had deficits that resolved was 35.4 +/- 8.1 mL x 100 g(-1) x min(-1) compared with 17.3 +/- 9.3 mL x 100 g(-1) x min(-1) of patients with evolving strokes (p = 0.00058). CONCLUSIONS: Patients with ischemic neurologic deficits that will later resolve can be acutely distinguished from patients with evolving cortical infarctions using XeCT CBF measurements. CBF measurements may assist in the triage of patients for acute stroke therapy by selecting patients with a favorable prognosis and may not benefit from therapy but would still be exposed to the potential risks and expense of treatment.

Acute Disease↗
PubMed1997

Adrenosensitivity of injured afferent neurons does not require the presence of postganglionic sympathetic terminals.

Nerve injury sometimes triggers neuropathic pain states that are exacerbated by sympathetic efferent activity. A classic example is causalgia. The mechanism of coupling between sympathetic efferent activity and the afferent discharge responsible for pain sensation is a subject of controversy. Some authors hold to the 'direct coupling hypothesis' which proposes that noradrenaline (NA), released from sympathetic varicosities, acts directly on alpha-adrenoreceptors located in the membrane of injured primary afferents. Others believe that coupling is indirect; that the effects of NA are mediated by additional, non-adrenergic, chemical substances and their receptors (the 'indirect coupling hypothesis'). For example, it has been proposed that in inflamed skin NA acts back on the sympathetic endings which, secondarily, release a prostanoid mediator which sensitizes afferent endings. We report that the responsiveness of injured afferent axons to systemically applied NA persists, and in fact increases in prevalence, in rats that underwent prior chemical or surgical sympathectomy. The observation of adrenosensitivity in injured afferents in the absence of sympathetic postganglionic endings is consistent with the direct coupling hypothesis, which associates adrenosensitivity with the injured afferent axon. It is not consistent with the indirect coupling hypothesis which requires the presence of sympathetic endings as a source for NA-evoked prostanoid release.

Adrenergic alpha-Agonists↗
PubMed1996

Development of a scale to measure the social and psychological effects of severe dental anxiety: social attributes of the Dental Anxiety Scale.

This paper describes the development of a scale designed to measure the extent to which severe dental anxiety or phobia affects patients' social wellbeing outside of the dental setting. Items initially selected on the basis of clinical experience were administered to two groups: 78 patients seeking help for severe anxiety and 88 patients attending the general clinic of a dental hospital. Items on the scale discriminated between these two groups and also between patients who were reluctant to attend even when experiencing symptoms and those who attend more regularly. Although the scale correlated moderately well with Corah's Dental Anxiety Scale, factor analysis indicated that its items assess the effects of severe anxiety on the two domains of psychological reactions and social inhibition as they occur as indirect effects of dental care. The scale could be included in assessments designed to measure the social and psychological effects of severe dental anxiety.

Adult↗
PubMed1996

Short communication: Prospective assessment of a new graduated hookwire for the localization of impalpable breast lesions.

The benefits of the addition of site specific variable graduations to a conventional mammographic localizing wire were assessed in a prospective multidistrict study. Six surgeons and five radiologists localized lesions in 31 patients in three District General Hospitals. The advantages of the graduated wire were shown to be greater ease and accuracy of radiological localization with easier surgical excision and a smaller resected breast specimen.

Biopsy↗
PubMed1995

The Peter Principle in orthopedics.

Original orthopedic devices that were developed, tested, and found useful, were subsequently modified and seemingly "improved" to a point of diminished usefulness--a manifestation of the Peter Principle applied to orthopedics. The authors describe seven examples: (1) the talar-tilt inversion apparatus; (2) the patellar-tendon-bearing, below-knee amputation prosthesis; (3) the patellar-tendon-bearing orthosis; (4) the Veterans Administration Prosthetic Center's lumbosacral orthosis; (5) the partial-foot prosthesis; (6) the ankle-foot orthosis; and (7) the occipito-zygomatic cervical orthosis.

Artificial Limbs↗
PubMed1994

Meningiomas of the anterior cranial fossa floor. Review of 67 cases.

The authors report 67 cases of meningioma of the anterior cranial fossa floor treated surgically between 1978 and 1992. The olfactory groove and tuberculum sellae were the most frequent locations. Mean duration of the clinical history was 30 months. Seventy-three percent of the tumors were large (> 4 cm). All patients were examined with computed tomography and 18 with magnetic resonance imaging as well. Complete removal was performed in 56 cases (84%); in the remaining 11 (16%), partial removal was performed because of encasement of the carotid artery, cavernous sinus, or optic nerves by the tumour. Mortality was 9%. Results at follow-up of the 61 survivors were good in 56 (84%), fair in four (6%), and poor in one (1%). The clinical results were correlated to tumor location and dimension. After review of the literature, the management of these difficult tumours and the preferred surgical technique are discussed. The authors stress the importance of early diagnosis for improving the surgical results.

Adolescent↗
PubMed1994

The effects of alternative smoking policies on indoor air quality in 27 office buildings.

The effect of alternative smoking policies, which prohibited or restricted smoking, on indoor air quality was studied in 27 air-conditioned office buildings. Carbon monoxide, carbon dioxide, respirable particulates, formaldehyde, ultraviolet particulate matter (u.v.PM), nicotine, air temperature, relative humidity and illumination were measured at eight sample sites in each building. Smoking policy had no effect on carbon monoxide, carbon dioxide, relative humidity, formaldehyde, air temperature or illumination for open office areas. It did have an effect on levels of respirable suspended particulates, ultraviolet particulate matter and nicotine.

Air Conditioning↗
PubMed1994

Legionnaires' disease outbreak, Fairfield 1992: public health aspects.

An investigation of an outbreak of Legionnaires' disease in 1992 in Fairfield, a municipality of Sydney, was carried out to determine the source of the outbreak. Cases of Legionnaires' disease with onset of symptoms between 11 and 20 April 1992 were included. Definite cases were individuals with a history consistent with Legionnaires' disease, confirmed by direct fluorescent antibody testing plus serology or culture. There were two control groups: patients admitted to the same hospital as the cases, matched for age and sex, and patients admitted to hospital with a presumptive diagnosis of legionnaires' disease, in whom the diagnosis was subsequently excluded. There were 26 definite cases with onset of symptoms between 11 and 20 April 1992. Six (23 per cent) died. Twenty-two cases (85 per cent) reported visiting the Fairfield business district during the ten days prior to the onset of symptoms. They were 20 times more likely to have visited Fairfield than were matched controls. Matching of Legionella pneumophila serogroup 1 from environmental and clinical samples was achieved by cytogenetic fingerprinting. Fourteen cases were linked to a single environmental sample. The epidemiological findings were consistent with a point source of Legionella in the Fairfield business district. It is most likely that the exposure occurred on 10 April 1992.

Adult↗
PubMed1994

Enhancement of anti-Shigella lipopolysaccharide (LPS) response by addition of the cholera toxin B subunit to oral and intranasal proteosome-Shigella flexneri 2a LPS vaccines.

Addition of the cholera toxin B subunit to oral and intranasal proteosome-Shigella flexneri 2a lipopolysaccharide vaccines improved their immunogenicities. Enhancement of anti-O-Shigella immunoglobulin A levels was most evident in lung lavages following oral immunization and in lung and intestinal fluids when suboptimal doses were used with either immunization route.

Administration, Intranasal↗
PubMed1993

Epilepsy in chronic subdural haematoma.

We studied retrospectively 143 adult patients treated in our department from 1979 to 1991 for chronic subdural haematoma (SDH) in order to identify the incidence of seizures and the necessity for prophylactic anticonvulsant treatment. Furthermore, after review of the literature, we selected an additional 879 cases for comparison. Results indicated a low incidence of epilepsy. Before surgery 5.6% of patients in our series and 4.3% in the literature had epilepsy, whereas after surgery, the frequencies were 3% and 1.8%, respectively. According to our data, antiepileptic drugs need not be administered prophylactically in patients with chronic SDH. But the situation is different for alcoholic patients, because they have a major risk of epilepsy.

Adolescent↗
PubMed1993

Joint laxity and its association with hip dysplasia in Labrador retrievers.

A study was done to determine whether radiographic-distraction measurement of coxofemoral joint (hip) laxity at 4 and 8 months of age can serve as a predictor of hip dysplasia in older Labrador Retrievers. The method of Smith, Biery, and Gregor was used for radiologic examination of hips and for evaluation of radiographs. Mean (+/- SEM) distraction laxity (ie, distraction index) for 10 adult disease-free dogs was 0.29 +/- 0.05, whereas a group of 8 dogs with dysplastic hips had mean distraction index of 0.60 +/- 0.10 (P < 0.05). Mean distraction index at 4 months of age for 11 pups of 4 litters from matings between dogs with normal hips was 0.39 +/- 0.07, and was 0.54 +/- 0.04 for 31 pups of 7 litters from matings between dogs with hip dysplasia. The distraction index and, thus, joint laxity at that age was significantly (P = 0.0351) different for the 2 groups. The distraction index at 4 months correlated positively with the distraction index at a later age at necropsy (r = 0.43; P = 0.0289). Distraction index < 0.4 at 4 months of age predicted normal hips in 88% of cases and distraction index > or = 0.4 predicted hip dysplasia in 57% of the dogs. Logistic regression modeling indicated that the odds of a hip being normal decreased with increasing distraction index, and thus, with increasing joint laxity. The logistic regression models provided a reasonable mathematical description of the data. Based on the logistic model of the data, distraction indexes between 0.4 and 0.7 at either 4 or 8 months of age were not associated strongly enough with evidence of disease to be clinically reliable in predicting, on an individual basis, the outcome for dysplastic hip conformation when dogs were older. Index > 0.7 was associated with high probability for developing dysplastic joints and distraction index < 0.4 predicted normal hips with high probability.

Animals↗
PubMed1992

Using mark-recapture methodology to estimate the size of a population at risk for sexually transmitted diseases.

To study the spread of sexually transmitted diseases (STDs) using social/sexual mixing models, one must have quantitative information about sexual mixing. An unavoidable complication in gathering such information by survey is that members of the surveyed population will almost certainly have sexual contacts outside that population. The number of these outsiders may be substantial and, hence, important for the modelling process. In this paper, we develop a mark-recapture model for estimating the size of the population at risk for contracting a STD due to direct sexual contact with a specified population targeted by a survey. This mark-recapture methodology provides a reliable method of estimating the number of outsiders. Because not everyone in the targeted population may be sexually active, the size of the sexually active subset, used as the number marked in our tag-recapture formulation, must be estimated, which introduces extra variability. We derive an estimator of the variance of the estimated total number at risk that accounts for this extra variability and an expression for the bias of that estimator. We extend the methodology to stratified surveys and illustrate its use with data collected from a population of university undergraduates to estimate sexual mixing parameters of a deterministic model of the spread of STDs.

Analysis of Variance↗