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Biomedical subjects

J Spiegel

Publications and source records attributed to J Spiegel.

At least 19 recordsLinked to original sources
PubMed2002

[Visual evoked potentials in Creutzfeldt-Jakob disease].

Neuropathological studies show frequent and extensive effects on the visual system in Creutzfeldt-Jakob disease (CJD), but deterioration of vision is not reported by all patients. We examined the function of the visual system by means of visual evoked potentials (VEP). We recorded monocular pattern-reversal VEP in six patients with sporadic CJD 1-13 months after first symptoms occurred. Three patients had normal vision, and in a further three, vision was impaired. All patients had pathological VEP with a delayed P100 component (six eyes) or loss of cortical response (five eyes). The patients with visual impairment vs those without were not different concerning VEP findings. The VEP are already pathological in initial CJD stages and point to an early effect on the visual system in CJD, irrespective of clinical visual deficits.

Aged↗
PubMed2002

A collaborative evidence-based approach to making healthcare a healthier place to work.

It is increasingly well documented that a collaborative problem-solving approach is more effective in addressing workplace health concerns than an adversarial approach. Combining this with strategies based on good evidence is key to success. On this premise, a trial was conducted in British Columbia, beginning in July 1999, based on a collaborative approach in which healthcare workers and managers work together to identify and implement evidence-based initiatives to improve the health and working conditions of healthcare workers.

Benchmarking↗
PubMed2001

The role of androgen ablation in patients with biochemical or local failure after definitive radiation therapy: a survey of practice patterns of urologists and radiation oncologists in the United States.

To identify therapeutic patterns for putative prostate cancer treatment failures and the role played by androgen ablation therapy in these patients, a questionnaire study was undertaken with urologists and radiation oncologists who had attended a brachytherapy forum at the Seattle Prostate Institute (SPI). Hypothetical questions were asked about recommendations the physicians would give to a patient demonstrating biochemical or local failure after external-beam radiation therapy. Most of the physicians queried were in private practice; 53% were radiation oncologists and 47% were urologists. The respondents' recommendations for a hypothetical patient, who was 45 to 65 years of age, with a biopsy-proven local recurrence was treatment with androgen ablation (35% of respondents), radical prostatectomy (25%), interstitial brachytherapy (20%), and observation (19%). In the 65- to 75-year-old patient with a local recurrence, the respondents recommended observation (43%), androgen ablation (35%), interstitial brachytherapy (17%), and radical prostatectomy (4%). In patients receiving androgen ablation for a biochemical failure alone, there was no consensus on whether to use luteinizing hormone-releasing hormone agonist alone, total androgen ablation, orchiectomy, or intermittent androgen ablation. Criteria that prompted physicians to initiate androgen ablation were based on the rate of prostate-specific antigen (PSA) increase (67%), an absolute PSA number (24%), or clinical failure (9%). In the younger patient with a local recurrence, local intervention with radical prostatectomy or interstitial brachytherapy was recommended most often, followed by androgen ablation, then by observation. In the older patient, observation was recommended most often, followed closely by androgen ablation. Overall, there was a lack of consensus on how to deliver androgen ablation. However, there was remarkable agreement between urologists and radiation oncologists on virtually all issues queried.

Age Factors↗
PubMed2000

Clinical evaluation criteria for the assessment of impaired pain sensitivity by thulium-laser evoked potentials.

OBJECTIVES: Cortical potentials evoked by carbon dioxide laser pulses have been applied in clinical practice to study nociceptive pathways for several years. In this study, we evaluate the properties of an infrared laser (thulium-YAG) with a penetration depth in the skin that matches the intracutaneous depth of nociceptors. METHODS: Temperature measurements and modelling showed that the thulium laser generates painful intracutaneous temperatures with less surface heating than the carbon dioxide laser and with no side effects (up to 600 mJ pulse energy). To develop clinical evaluation criteria, laser-evoked potentials (LEPs) were recorded from 3 midline positions (Fz, Cz, Pz) versus linked earlobes in 23 healthy subjects. Within a session, two skin areas were studied twice in a balanced sequence using randomized interstimulus intervals and two intensities in randomized order. RESULTS: After hand and foot stimulation with 540 mJ pulses, all subjects showed reproducible biphasic vertex potential, consisting of a negativity (hand: 210 ms, foot: 250 ms) and a positivity (hand: 330 ms, foot: 380 ms). Mean habituation of the vertex potential amplitude across runs was 25% (hand) or 16% (foot); due to the balanced sequence it did not affect the other comparisons. Following foot stimulation, peak latencies were significantly longer (by 40-50 ms) and amplitudes were significantly smaller than following hand stimulation (22.5+/-6.7 vs. 30.3+/-10.9 microV, mean+/-SD). Using 2. 5 standard deviations from the mean as a cut-off, absolute normative values were determined for peak latencies and amplitudes. In addition, relative normative values were determined for paired comparisons (hand-hand, foot-foot, hand-foot). CONCLUSIONS: The thulium-YAG laser is a useful tool for assessment of impaired pain sensitivity. Representative case reports illustrate that unlike for early SEP components, the most frequent LEP abnormalities were amplitude differences.

Adult↗
PubMed2000

The role of attachment functions in psychotherapy.

The authors propose to clarify concepts of emotional attunement and failures of attunement in early development derived from theoretical and clinical work (Kohut) and infant psychiatry (Stern). Early attunement failures are experienced as shameful by the infant/child, and without repair they form a nidus for later destructive adult interpersonal relationships, "social blindness," and depression. The authors present a case illustrating these ideas. The role of empathic attunement experienced in the unique setting/structure of psychotherapy emerges as the single critical variable for a successful outcome.

Adolescent↗
PubMed1999

Functional MRI of human primary somatosensory and motor cortex during median nerve stimulation.

OBJECTIVES: Somatosensory evoked potential (SEP) studies suggested that some early cortical SEP components may be generated in the primary motor cortex (M1) rather than the primary somatosensory cortex (S1). METHODS: We now used functional magnetic resonance imaging (fMRI) to study activation of S1 and M1 by electrical median nerve stimulation in healthy volunteers. RESULTS: The hand areas of both S1 and M1 showed significant activation (correlation coefficients >0.45) in 7 of 9 subjects (activated volume S1 > M1). For comparison, a sequential finger opposition task significantly activated S1 in 7 and M1 in all 9 subjects (activated volume M1 > S1). CONCLUSIONS: These data show that the electrical stimuli used for SEP recording lead to a functional activation of S1 as well as M1.

Adult↗
PubMed1998

[Polygraphic validation of distraction tasks in clinical differential tremor diagnosis].

In a total of 30 tremor patients (14 with Parkinson's disease, 6 with cerebellar tremor, 4 with essential tremor, 4 with psychogenic tremor, 2 with enhanced physiological tremor), tremor was electromyographically recorded before, during and after contralateral distraction tasks (tapping with the index finger or the tip of the foot, sequential flexion of the 2nd to 5th finger towards the thumb, "keyboarding", and sensory discrimination). 22 of 26 patients with organic tremors spontaneously choose a volitional tapping frequency independent from their tremor frequency. In 4 patients with psychogenic tremor, frequencies of tremor and tapping were locked (n = 3), or tremor disappeared abruptly (n = 1) when contralateral tapping was started. Contralateral "keyboarding" and sensory discrimination revealed no clear differences between organic and psychogenic tremors. Contralateral tapping in further 23 patients (22 with organic tremors and 1 with psychogenic tremor) confirmed these findings. Contralateral tapping appears as the most valid distraction task and may help to differentiate psychogenic from organic tremors.

Adult↗
PubMed1998

Dilatation therapy for dysphagia in patients with upper esophageal sphincter dysfunction--manometric and symptomatic response.

Inability to maintain oral nutrition due to oropharyngeal dysphagia is common in patients with a variety of neurological and neuromuscular disorders and severely affects quality of life. Cricopharyngeal dilatation has been used as empiric therapy in these patients, but little data exist on symptom response and there is no data on the effect on the manometric characteristics of the upper esophageal sphincter (UES) and pharynx. We studied 10 patients with oropharyngeal dysphagia and either elevated upper esophageal sphincter resting pressure, or a high residual pressure or attenuated duration of relaxation on swallowing. Dilatation therapy was performed with an 18-20 mm Savary dilator and manometry was repeated after an average period of 4 weeks. Nine out of 10 patients had improvement in dysphagia and have maintained oral nutrition for a mean follow-up of 13 months. UES residual pressure decreased in nine out of 10 patients and the group median value decreased significantly from 10.8 mmHg pretreatment to 5.7 mmHg after therapy (P < 0.05). UES resting pressure decreased in eight out of 10 patients and the group median value decreased from 82 to 43 mmHg (P < 0.05). Duration of relaxation did not change significantly. Videoradiography was normal in five out of nine responders to therapy. For selected patients with oropharyngeal dysphagia and manometric signs of UES dysfunction, dilatation therapy may give excellent symptomatic relief, apparently by reducing UES resting pressure and/or increasing the duration and completeness of relaxation.

Aged↗
PubMed1998

The vaccinia virus A18R DNA helicase is a postreplicative negative transcription elongation factor.

Loss of vaccinia virus A18R gene function results in an aberrant transcription profile termed promiscuous transcription, defined as transcription within regions of the genome which are normally transcriptionally silent late during infection. Promiscuous transcription results in an increase in the intracellular concentration of double-stranded RNA, which in turn results in activation of the cellular 2-5A pathway and subsequent RNase L-catalyzed degradation of viral and cellular RNAs. One of three hypotheses could account for promiscuous transcription: (i) reactivation of early promoters late during infection, (ii) random transcription initiation, (iii) readthrough transcription from upstream promoters. Transcriptional analysis of several viral genes, presented here, argues strongly against the first two hypotheses. We have tested the readthrough hypothesis by conducting a detailed transcriptional analysis of a region of the vaccinia virus genome which contains three early genes (M1L, M2L, and K1L) positioned directly downstream of the intermediate gene, K2L. The results show that mutation of the A18R gene results in increased readthrough transcription of the M1L gene originating from the K2L intermediate promoter. A18R mutant infection of RNase L knockout mouse fibroblast (KO3) cells does not result in 2-5A pathway activation, yet the virus mutant is defective in late viral gene expression and remains temperature sensitive. These results demonstrate that the A18R gene product is a negative transcription elongation factor for postreplicative viral genes.

Adenosine Triphosphatases↗
PubMed1997

The use of health indicators in environmental assessment.

Environmental assessment (EA) is required in Canadian federal and provincial jurisdictions as part of the process for decision-making on the acceptability of development projects. With increasing recognition of the relationship between environment and health, assessing "health" impact has growing importance. This paper presents the framework that is being developed by the World Health Organization (WHO) for addressing environmental health indicators, reports on the findings of a series of five regional workshops held in 1995-96 to examine the role of health professionals in environmental assessment in Canada, and presents a case study illustrating how human health has been addressed in a prominent EA conduct in northern Saskatchewan. Opportunities for future development of environmental health indicators are considered, with special reference to the potential use of medical data to address these challenges.

Canada↗
PubMed1996

Laser-evoked potentials after painful hand and foot stimulation in humans: evidence for generation of the middle-latency component in the secondary somatosensory cortex.

The vertex potential (N2, P2) of the laser-evoked potential (LEP) is preceded by a small negativity (N1). The role of the secondary somatosensory cortex (SII) in generation of the N1 is established for the upper but not for the lower limb. We therefore investigated the N1 after painful radiant heat stimulation of hand and foot dorsum in 22 subjects. LEPs were recorded from the scalp with midline and temporal electrodes. After hand stimulation N1 was maximal in the contralateral temporal lead (mean peak latency 156 +/- 23 ms). After foot stimulation N1 was maximal in the same lead (200 +/- 22 ms). In the ipsilateral temporal lead, N1 appeared significantly smaller and later. N2 and P2 were maximal in midline electrodes for both stimulus sites. The latency shift between hand and foot stimulation was identical for all three components. These results suggest a contribution of temporo-parietal cortex (e.g. SII) to the N1 generation for stimulation of upper and lower limb.

Adult↗
PubMed1996

Peristomal hidradenitis suppurativa.

Hidradenitis suppurativa is a chronic, suppurative, and cicatricial cutaneous disease with clinical manifestations including inflammatory lesions and nodules, abscesses, and sinus tracts. We describe an unusual case of peristomal lesions that may represent hidradenitis suppurativa. Peristomal hidradenitis suppurativa has not been previously reported. This unusual complication demonstrates the need for a thorough patient history to identify any systemic disease that may contribute to peristomal skin problems.

Crohn Disease↗
PubMed1991

Delayed pharyngoesophageal perforation: a complication of anterior spine surgery.

Stabilization of the cervical spine is often accomplished via an anterior cervical approach. Bone grafts and/or plates and screws are used to achieve stabilization. Injuries to the pharynx and esophagus are known complications in anterior exposure of the cervical spine. These injuries are manifest in the early postoperative period. Reports of late perforations are very rare. We present four cases of delayed injury to the pharynx and esophagus that resulted in abscess or fistula. We postulate that graft displacement with resulting erosion was responsible for these serious complications. Postoperative odynophagia in patients who undergo anterior cervical fusion warrants evaluation of the bone graft location. Early surgical intervention and repair may decrease prolonged morbidity in these patients.

Abscess↗
PubMed1991

An analysis of occupational blood lead trends in Manitoba, 1979 through 1987.

BACKGROUND: While regulations for workplace lead exposure become more strict, their effectiveness in decreasing blood lead concentrations and the method by which this is attained have not been evaluated. METHODS: An analysis was conducted of 10,190 blood lead samples from employees of 10 high-risk workplaces collected in Manitoba, 1979-87, as part of regulated occupational surveillance. RESULTS: A significant decrease in blood lead concentrations was observed overall as well as for each individual company. A 1979 government regulation to reduce blood lead to below 3.38 mumol/L (70 micrograms/dl) was followed by a drop in blood lead concentrations; a 1983 order to reduce blood leads to below 2.90 mumol/L (60 micrograms/dl) was not followed by such a drop. Longitudinal analysis by individual workers suggested that companies were complying by use of administrative control, i.e., removing workers to lower lead areas until blood lead levels had fallen, then returning them to high lead areas. CONCLUSION: Focusing upon blood lead as the sole criterion for compliance is not effective; regulations must specifically require environmental monitoring and controls. Biological surveillance serves as "back-up" to environmental surveillance and this database illustrates the usefulness of a comprehensive centralized surveillance system.

Air Pollutants, Occupational↗
PubMed1990

Mechanization, the labor process, and injury risks in the Canadian meat packing industry.

During the 1980s, Canada's major manufacturing industries experienced considerable financial restructuring and technological transformation, largely in response to recessionary pressures. At the same time, the rate of lost-time injuries in Canadian manufacturing rose steadily. This article explores the relationship between these sets of factors. The meat packing industry has been selected as a case study of the interaction between industrial organization, the labor process, and the risk of workplace injuries. The authors suggest that the following factors have contributed to high and rising injury rates in the meat industry during the 1980s: consolidation into a smaller number of large, highly specialized, and mechanized plants; deteriorating labor relations in the face of falling profits; and an intensified labor process stressing line speedups and a growing risk of repetitive strain injuries. These observations are supported by a detailed analysis of the relationship between the labor process and workplace injuries at one packing plant considered typical for the industry.

Abattoirs↗
PubMed1988

Renal transplant obstruction by B cell lymphoproliferative disorder: case report and review of the literature.

We report a case of renal transplant ureteral obstruction caused by a cyclosporine-associated B cell lymphoproliferative disorder. The interaction of cyclosporine with Epstein-Barr virus infections and the predisposition towards B cell lymphoproliferative disorders are reviewed. The characterization of these tumors by deoxyribonucleic acid hybridization studies and a review of the clinical experience treating these disorders also are presented.

B-Lymphocytes↗