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Biomedical subjects

S A Reid

Publications and source records attributed to S A Reid.

At least 19 recordsLinked to original sources

Primary care physicians' recognition of and attitudes toward domestic violence.

PURPOSE: Physicians fail to identify the majority of domestic violence victims, even though they are often the first and only individuals to whom a victim may present. The present study was designed to assess primary care physicians' recognition of and attitudes toward domestic violence. METHOD: Of the 148 primary care physicians in three midwestern counties, all the women and a random sample of the men were included in the survey, for a total of 83. A seven-page questionnaire was developed that contained items about demographics and practice characteristics, and questions about the following aspects of domestic violence: knowledge, attitudes, importance, and prevalence in practice; attitudes toward responsibility; current practices and protocols used; level of education and domestic violence received; and opinions on how best to distribute information and/or education concerning domestic violence. The questionnaire was mailed in 1994. Follow-up was conducted through phone calls, remailings, and visits to the physicians' offices. Responses were examined using chi-square tests and two-tailed t-tests. RESULTS: The response rate was 63% (52 of 83); 53% of those responding were family physicians and 47% were general internists; 34% were women. Although all of the physicians agreed that finding and treating domestic violence is important, less than half agreed that domestic violence was a significant problem in their patient populations. Almost 96% of the physicians believed that more should be done to educate physicians about domestic violence, and 94% agreed that domestic violence should be included in a doctor's professional medical training; yet nearly half said they would not participate in a domestic violence forum. Even though 41% noted that they had received some type of formal education about domestic violence, 57% felt that their medical education had inadequately prepared them to deal with domestic violence, and less than 25% reported that they had been trained to diagnose domestic violence. The family physicians and the female physicians had received more education about domestic violence and were more comfortable addressing domestic-violence situations. The older physicians were less comfortable addressing domestic violence and were less likely to agree that education about domestic violence should be a part of medical training. CONCLUSION: Interventions by the medical community to increase physician awareness of domestic violence and available treatment resources are necessary, and domestic-violence information should be included in formal medical curricula.

Attitude of Health Personnel

Abnormality of smooth pursuit eye movement initiation: specificity to the schizophrenia spectrum?

Schizophrenia patients have a deficiency of smooth pursuit eye movement initiation. We addressed whether this deficit is specifically related to a predisposition for schizophrenia. Thirty-two relatives of schizophrenia patients, eight schizotypals, 13 psychiatric comparison, and 33 nonpsychiatric subjects were assessed on smooth pursuit initiation. The nonpsychiatric subjects had significantly higher eye accelerations than did subjects in the other three groups, who did not significantly differ. The relatives were subdivided into three groups: (a) those with a schizophrenia spectrum disorder (n = 4) performed similarly to the schizotypals; (b) those with a major depression history (n = 7) were similar to the psychiatric comparison subjects; and (c) those with no psychiatric history differed from the nonpsychiatric subjects only on 30 degrees/s targets. There was also a significant relationship between offspring and parent eye accelerations to 30 degrees/s targets (r = .476). These results suggest that pursuit initiation deficits may be associated with a nonspecific, genetically transmitted neurological abnormality among schizophrenia spectrum disorder subjects.

Adult

STL: a spatio-temporal characterization of focal interictal events.

An innovative method for on-line processing of array ECoG data, the Spatio-Temporal Laplacian, intended for intraoperative epileptic focus localization is presented. This method simultaneously involves the spatial and temporal characteristics of the potential field manifestations peculiar to focal interictal events. A 3-Dimensional (x, y and t) sample space is used to explain and apply the Spatio-Temporal Laplacian (STL) transformation. In particular, a focal interictal event is detected through the coincident spatial and temporal sharpness that it introduces in this sample space. Preliminary results from two subjects are presented and compared with standard bioplar derivation signals, traditionally used in the focus localization task.

Adult

Treatment of epilepsy by stimulation of the vagus nerve.

We treated 14 patients with medically refractory partial seizures by stimulation of the vagus nerve in two single-blind pilot studies. Patients received stimulation through an implantable, programmable NeuroCybernetic Prosthesis, consisting of a pulse generator and a lead-electrode assembly. The mean reduction in seizure frequency after 14 to 35 months of vagal stimulation was 46.6%. Of the 14 patients, five (35.7%) had a 50% or greater reduction in seizure frequency. Two patients, one of whom had had 10 to 100 seizures per day before stimulation, have been seizure-free for over 1 year. Adverse events were primarily limited to initial hoarseness and a tingling sensation at the electrode site in the neck when the device was activated. Most patients tolerated the device and stimulation well. There were no permanent adverse events. Some cases of medically refractory partial seizures are improved by vagal stimulation.

Adolescent

3-D computer animation of electrophysiological responses.

Traditional methods for displaying electrophysiological data, that use time as the axis on a plot, are inadequate for displaying data from simultaneous multi-channel recordings. New methods proposed here plot the instantaneous value of the data on a third axis over a 2-dimensional spatial map of the tissue. The resulting 3-D computer-generated surfaces are animated over time to reveal simultaneous coherent waves of activity over the entire slice. This method was implemented for displaying multi-channel evoked potential data from rat hippocampal and human cortical slices. In rat hippocampal slice, stimulation of the Schaffer collateral-commissural pathway in stratum radiatum (SR) near CA2 elicited evoked extracellular responses along the length of CA1 from the alveus to stratum lacunosum moleculare (SLM). 3-D plotting and subsequent animation of these responses translated differential latencies of activation elicited across the slice into coherent moving patterns. These evoked waves of extracellular activity appeared to propagate along hippocampal laminae and were not readily visible in the individual plots. Human temporal cortical slices were stimulated in the white matter and evoked responses recorded in an array format. Upon plotting and animation, activity was seen to propagate vertically to the pial surface and thereafter move radially away from the stimulation site. Animation of 3-D plots of electrophysiological activity can provide instantaneous visual information on correlated changes in amplitude and latency over an entire brain slice. This means of displaying data can reduce a large number of complex wave forms to simple events and allow the simultaneous visualization of general patterns of activity in a large group of neurons.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Absence of cortical white matter changes in three patients undergoing long-term vigabatrin therapy.

Chronic administration of the experimental antiepileptic drug vigabatrin (gamma-vinyl GABA) to animals has been shown to cause dose-dependent neuropathological changes characterized by a microvacuolation in specific white matter tracts. This finding has led to some concern as to whether similar pathologic changes might occur in patients taking this medication. Here we report on analysis of tissue specimens taken during neurosurgery from three patients undergoing chronic vigabatrin therapy (4 g/day). The first patient, a 34-year-old woman, had taken vigabatrin for 2 years prior to surgery, the second, a 50-year-old man, had taken the drug for 1 year, and a 34-year-old man had taken the drug for 5.3 years. For comparison, similar specimens were taken from three other patients not taking vigabatrin who were undergoing surgery for intractable epilepsy. Specimens from each subject were prepared in an identical manner and examined with light and electron microscopy. All specimens were examined in a blinded fashion. There was some minor nonspecific myelinic splitting seen in both controls and vigabatrin-treated patients but there was no evidence for any drug-induced lesions similar to that seen in experimental animals.

Adult

Epidural lipomatosis in steroid-treated patients.

Epidural lipomatosis is a condition in which excess adipose tissue is deposited circumferentially about the spinal cord in the epidural space. It is most frequently seen in patients on chronic steroid treatment for a variety of medical problems and can present as nonspecific back pain, radiculopathy, or frank spinal cord compression. Diagnosis and treatment have generally relied on multi-level decompressive laminectomy after myelography and computed tomography. The immunocompromised state and the reported postoperative mortality (22%) of these patients, however, suggests that nonoperative therapy may be preferable whenever possible. Five cases of epidural lipomatosis are reported, and previous literature is reviewed for presentation, evaluation, and treatment of this condition.

Adult

Inhibition of hematopoietic progenitor colony growth by a monoclonal antibody against the transferrin receptor: comparison of unconjugated antibody with an immunotoxin containing recombinant ricin A chain.

We studied an immunotoxin consisting of recombinant ricin A chain (rRA) conjugated to 454A12 MoAb, a monoclonal antibody which recognizes an epitope on the human transferrin receptor, and compared the ability of 454A12 MoAb-rRA immunotoxin to inhibit the growth of erythroid burst-forming units (BFU-e) and myeloid colony-forming units (CFU-c) with unconjugated 454A12 MoAb. A significant reduction in BFU-e colony growth was observed at 0.001 microgram/ml of 454A12 MoAb-rRA versus 0.1 microgram/ml of unconjugated 454A12 MoAb (p = 0.005). Comparison of the effects of 454A12 MoAb-rRA and 454A12 MoAb on myeloid colony development gave markedly different results. Unconjugated antibody had no effect on CFU-c colony growth; in contrast, 0.01 microgram/ml of 454A12 MoAb-rRA reduced the number of colonies from 139 per 1 X 10(5) to 75 per 1 X 10(5) cells plated (p = 0.0005). No myeloid progenitor colonies developed at 0.1 microgram/ml of immunotoxin. These observations suggest that 454A12 MoAb-rRA inhibits growth by a potent, ricin A chain-mediated toxic effect on any proliferating cells expressing transferrin receptors, whereas the 454A12 MoAb exerts a selective inhibitory effect primarily on erythroid progenitors by perturbing the transferrin cycle. While growth factor receptors expressed on hematopoietic cells represent promising targets for immunotoxin therapy, our data indicate that an immunotoxin could inhibit cellular proliferation by a different mechanism than the corresponding unconjugated MoAb. Depending on the antibody used, these differences may be important in trials using immunotoxins for in vivo treatment or in vitro purging of malignant hematopoietic cells.

Antibodies, Monoclonal

TDAT--time domain analysis tool for EEG analysis.

An interactive design and analysis tool for displaying and quantifying multiple channels of data is presented. The system allows one to easily visualize multiple data channels and simultaneously observe the effects of filters on the data and to evaluate signal detection algorithms. The software is designed for a workstation environment; it will find application in a variety of applications where one needs to simultaneously visualize multiple data channels. TDAT is being used for the design and evaluation of filters and detection algorithms for electroencephalogram (EEG) waveforms, and it is serving as a prototype of a paperless system to be used by electroencephalographers. This paper describes the general software structure of the system and illustrates many of the system features with examples.

Algorithms

Efficacy and safety of vagus nerve stimulation in patients with complex partial seizures.

A clinical trial of chronic intermittent vagal stimulation in five patients suggests that the procedure may be safe and effective as adjunctive treatment of medically intractable seizures of partial onset. Patients tolerated well the implantation of the neurocybernetic prosthesis and the vagal stimulation without serious physiological or lifestyle changes. Stimulation of the vagus nerve either reduced the seizure frequency or decreased the duration or intensity of seizures. Adverse side effects were limited to a tingling sensation in the throat and hoarseness during stimulation. A major complication was mechanical interruption of the wire-electrode circuitry, with consequent cessation of stimulation. The small number of patients and the relatively short follow-up period make this a pilot study, but the results are promising.

Adult

Vagus nerve stimulation in humans: neurophysiological studies and electrophysiological monitoring.

Evidence from studies of experimental animals indicates that electrical stimulation of the vagus nerve alters behavioral and electrographic seizure activity. We report on effects of electrical stimulation of the vagus nerve in five patients with medically intractable seizures as part of a clinical trial of chronic vagal stimulation for control of epilepsy. The mechanism of action of the vagal antiepileptic effect is unknown, and it is hoped that analysis of electrophysiological effects of vagal nerve stimulation will help elucidate which brain areas are affected. Stimulation of the left vagus nerve in the neck was accomplished with a programmable implanted stimulator. Effects of stimulus amplitude, duration, and rate were studied. Noncephalic reference recording of the vagus-nerve-evoked potential showed some unusual properties: a scalp negative component occurred with latency of 12 ms, very high amplitude (up to 60 microV), and widespread scalp distribution. Field distribution studies indicate that this potential is generated in the neck, in the region of the stimulating electrodes. Muscle paralysis confirms this observation. Stimulation at various frequencies had no noticeable effect on electroencephalographic (EEG) activity regardless of whether the patient was under general anesthesia, awake, or asleep.

Adult

Distribution and physical properties of BCA200, a Mr 200,000 glycoprotein selectively associated with human breast cancer.

Of 122 mouse monoclonal antibodies selective for human breast cancer, 13 immunoprecipitated an acidic glycoprotein from SK-Br-3 and ZR-75-30 human breast cancer cells. The antigen (BCA200) migrates with an apparent molecular weight of 200,000 on reducing and 180,000 on nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting a single polypeptide chain with a folded domain stabilized by a disulfide bond. Cross-blocking and sandwich immunoassays detected at least three distinct antigenic determinants on BCA200. Scatchard experiments measured 1,000,000 to 5,000,000 antigen copies per SK-Br-3 cell. The tissue distribution of BCA200 was studied using two monoclonals to different epitopes. Neither antibody stained any cells in human blood. When frozen sections of 20 normal human tissues were immunoperoxidase stained, the only positive structures were mucinous glands of colon, transitional epithelium of bladder, sweat glands of skin, and acinar epithelium of breast. Antibody 454C11 stained 16 of 21 breast tumor frozen sections and 9 of 12 breast cancer cell lines, while antibody 520C9 stained 5 of 20 breast tumors and 4 of 10 breast cancer lines. Cross-reaction was observed with lung, prostatic, pancreatic, endometrial, and ovarian cancer, but not with lymphoma, melanoma, colon, stomach, bladder, or esophageal cancer. When conjugated to ricin A chain, 10 of 13 antibodies produced immunotoxins selectively cytotoxic to SK-Br-3 breast cancer cells.

Antibodies, Monoclonal

Spontaneous epileptiform discharges in isolated human cortical slices from epileptic patients.

Human epileptic in vitro brain slices were obtained at ablative neurosurgical procedures and examined for spontaneous extracellular field potentials. Electrical events resembling interictal spikes and seizure discharges were observed in tissue from the electrocorticographic epileptic foci, but not in control tissue. It appears that important differences between the epileptic focus and normal tissue are maintained in vitro.

Cerebral Cortex

Toward the ideal electrocorticography array.

Several features desirable in the design of electrocorticography arrays are listed. A new electrocorticography system is described and compared with types that are commercially available. This system offers several advantages over older systems and results in significant saving of time in the operating room.

Cerebral Cortex

NeuroSIG: the computer network of the Congress of Neurological Surgeons.

A sophisticated computer network has been developed specifically for use by the Congress of Neurological Surgeons. This network provides a variety of communication and information features. These include public and private message transmission, teleconferencing, numerous data libraries, programs that may be downloaded and executed on the user's own computer, high resolution color graphics image transmission, an extensive neurosurgical database, and extensive on-line "help" features. The system can be accessed using almost any personal computer and a telephone modem.

Computer Communication Networks

Changes in the mineral density distribution in human bone with age: image analysis using backscattered electrons in the SEM.

We report a study to test the feasibility of studying mineral density distributions in bone using the backscattered electron signal in scanning electron microscopy. Samples were human sixth ribs ranging in age from 8 weeks to 59 years, embedded in polymethylmethacrylate (PMMA), cut, polished, and carbon coated. The proportions of pixels falling in a uniform set of gray level slices of the BSE signal were determined using a microcomputer-based image analysis system interfaced directly to the SEM. The amount of high-density bone gradually increased with age at the expense of low-density bone, and there was an associated compression of the range of the mineral density distribution. Age-related differences were noted between the density distributions in the outer and inner rib cortices. The distribution in the inner cortex in neonates was influenced by the inclusion of densely mineralized endochondral bone and cartilage trabeculae formed at the growth cartilage zone. In adults it appeared that greater bone turnover occurred in the outer cortex, perhaps reflecting a differential mechanical loading across the rib. The technique enabled rapid, unbiased discrimination between the bone of neonates, children, and adults.

Adolescent

Micromorphological characterisation of normal human bone surfaces as a function of age.

Endosteal surfaces of human bone specimens, principally from the sixth rib, from subjects ranging in age from seven weeks to 87 years were studied using the secondary electron imaging mode in the scanning electron microscope. Specimens were examined after the removal of cells only, or after the removal of cells and organic matrix. Morphological differences made it possible to identify the age group to which a specimen belonged. The most obvious of these was the ratio of active to resting bone surfaces, which collagen matrix which was deposited at endosteal surfaces was different in the different age groups. In neonates, collagen was organised as a parallel fibred continuum. It was present in more discrete bundles in adults, although these still branched and anastomosed with one another. The bundles were parallel over limited domains which described large angles with respect to one another. The conformation of resorbed surfaces indicated that the behaviour pattern of osteoclasts changes with age. Shallow gutters, or annular zones around resorption bays were most common in neonates. The elongation ratio of resorption tracks was greatest in infants and juveniles, indicating that osteoclast translocation was greatest during resorption at these ages. The texture of the floors of resorption bays was smooth in specimens from subjects up to 13 years, while in adults the collagen fibre bundle organisation in the resorbed tissue was often visible. This difference may reflect a more equal mineralization in the ground substance and collagen compartments of the bone matrix in children than in adults.

Adolescent