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Biomedical subjects

P Hawrylyshyn

Publications and source records attributed to P Hawrylyshyn.

13 recordsLinked to original sources
PubMed1990

Perinatal factors associated with the respiratory distress syndrome.

Perinatal factors related to the incidence of respiratory distress syndrome were analyzed by the multiple logistic regression statistical method in 263 mothers and their 298 offspring delivered between 24 and 35 weeks' gestation in a 1-year period in a regional referral perinatal center. The risk of respiratory distress syndrome in white infants rose with decreasing gestational age (p less than 0.0001) while prolonged rupture of membranes of greater than 24 hours in the absence of maternal infection (28% of cases) was highly protective (p less than 0.0001). Compared with vaginal delivery, cesarean delivery without labor increased the risk of respiratory distress syndrome (p = 0.03). The administration of tocolytic drugs was unrelated to the incidence of respiratory distress syndrome, but corticosteroid therapy given at least 72 hours before delivery was protective (p = 0.03). Male and female infants were equally at risk for respiratory distress syndrome as were black and white infants, but other races had a lower incidence (p = 0.004). Infants with respiratory distress syndrome were on mechanical ventilators longer than those with other respiratory illnesses.

Adrenal Cortex Hormones↗
PubMed1983

Premature rupture of membranes: the role of C-reactive protein in the prediction of chorioamnionitis.

A group of 52 patients with premature rupture of the membranes (PROM) before 34 weeks' gestation were evaluated prospectively and managed expectantly. Of 42 patients who were delivered of their infants, 26 (61.9%) had significant chorioamnionitis on histopathology, and 18 had positive microbial cultures at delivery. However, only seven patients (16.7%) developed clinical signs of chorioamnionitis. There were no maternal deaths or perinatal deaths attributable to sepsis. Only two infants (less than 5%) had positive blood cultures. All patients were assessed daily for the development of chorioamnionitis. Amniocenteses were not routinely performed. White blood cell counts, band neutrophil counts, and erythrocyte sedimentation rate determinations were found to be unreliable. C-reactive protein determinations were found most reliable with a high sensitivity and specificity. Elevated C-reactive protein levels correlated better with pathologic confirmation of chorioamnionitis than with the clinical febrile morbidity. Clinical implications for the management of PROM are discussed.

Amnion↗
PubMed1983

What happened to VIM thalamotomy for Parkinson's disease?

A prospective review of 75 of 190 parkinsonian patients undergoing unilateral thalamotomy was displayed with a computer graphics technique examining three equal consecutive groups from the pre-, early, and late L-dopa eras. Histograms for average function and scattergrams of individual patient's performance preoperatively and up to 2 years postoperatively were prepared. No ipsilateral effects or consistent iatrogenic deterioration of any function were identified. 2 years after surgery, 82% had no tremor in the contralateral fingers or hand and 7% had almost no tremor; contralateral tremor elsewhere was infrequent. Rigidity and manual dexterity improved less strikingly, the latter only reflecting abolition of tremor; locomotion, speech, facial movement and handwriting did not improve. There was no mortality, but 8% had persistent significant complications. VIM thalamotomy remains the treatment of choice for severe drug-resistant parkinsonian tremor.

Adult↗
PubMed1980

Visual phenomena evoked by electrical stimulation of the human brain stem.

19 visual effects have been elicited out of 9,383 sites during stimulation mapping for physiological localization during stereotactic surgery. It is proposed that three visual pathways can be recognized during subcortical electrical stimulation in man. The optic tract and geniculocalcarine pathway, projecting to area 17, are recognizable by the production of contralateral coloured phosphenes. The tectopulvinar pathway projecting to areas 18 and 19 is recognizable by the eliciting of contralateral or bilateral colourless phosphenes or 'negative' visual effects, the latter presumably reflecting inhibitory collicular influences. Finally, deep responses, consisting of apparent movement of the visual fields, intermingled with 'negative' visual and oculomotor effects, suggest activation of a visual-oculomotor coordinating system.

Brain Mapping↗
PubMed1980

Deafferentation and causalgia.

The concept of deafferentation pain has been developed as an entity distinct from somatic pain which can arise in the course of both cancerous and nonmalignant disease. Its distinctive clinical features and responses to diagnostic and therapeutic manipulations have been reviewed. Evidence is marshalled to show that it results from gradually developing alterations in the central nervous system, which, once established, persist despite removal of the original stimulus. Evidence is presented that the mesencephalic tegmentum may be part of a reticulothalamocortical system undergoing denervation hypersensitivity following deafferentation, whose stimulation by electric impulses, and, presumably, naturally occurring neural inputs, can result in a painful conscious experience reproducing the patient's pain in a manner similar to that whereby stimulation of temporal-parietal association cortex elicits recall of past events.

Anesthetics, Local↗
PubMed1978

Computerized graphic display of physiological data collected during human stereotactic surgery.

An on-line computerized graphic display has been developed for use during stereotactic operations. This depicts in the form of figurine charts and alph-numeric symbols, appropriately oriented on saggital brain diagrams, the results of serial threshold stimulation of the brain. The display facilitates choice of target sites and the data can be stored in a tape library from which search-and-plot programs can be activated for any type or combination of types of response.

Brain↗
PubMed1977

Computerized graphic display of results of subcortical stimulation during stereotactic surgery.

An on-line computer programme is described and illustrated which is capable of displaying graphically in the form of Woolsey-type figurine charts stimulation-induced responses obtained during stereotactic surgery. Not only can these data then be optimally utilized for lesion localization but also the programme includes facilities for a variety of types of analysis of the tape-stored data pooled from all patients studied.

Computers↗
PubMed1976

Computer mapping of brain-stem sensory centers in man.

A computer program is described for use on-line with a two--stage stereotaxic technique in man. It has four capabilities. It transposes coordinates between a brain atlas and a stereotaxic frame, simultaneously adjusting for variations in individual brain dimensions. Corrections for electrode trajectories, and for any irregularities of placement of the stereotaxic frame in the head are also made. It plots an operative template that shows electrode trajectories and the sites from which physiological data are collected appropriately oriented upon a sagittal diagram of the brain. It graphically displays physiological data in the form of a Woolsey-type figurine chart that indicates threshold in milliamperes and, through the use of coded symbols, the quality of response and certain other data. It stores all this data in a tape library together with the locations of any lesions made. This makes it possible to replot any individual patient's operative data at any time. It also permits scanning of the stored protocols from all patients for any particular type of data either by itself or in combination with other data. This retrieved information is plotted on appropriate sagittal brain diagrams corrected for individual variations in brain size. Illustrations of the capabilities of the program are presented particularly with reference to the primary afferent pathways of the upper brain stem.

Afferent Pathways↗
PubMed1975

Decorticate spasticity: a re-examination using quantitative assessment in the primate.

Decorticate spasticity in the squirrel monkey was chosen as a convenient laboratory model of spasticity capable of quantitative assessment upon which to evaluate various currently popular clinical spasmolytic measures. The effects of a wide variety of cortical lesions were studied involving primary and supplementary motor, premotor and parietal cortex unilaterally and bilaterally, measuring muscle tone with the evoked integrated E.M.G. technique. Measurable spasticity resulted only if primary motor cortex was ablated bilaterally usually but not always preferentially involving biceps brachii and quadriceps. Resulting postures were variable offering no justification for the term "decorticate posture". The integrated evoked E.M.G. was proportional to rate of stretch and chiefly phasic in type as in hemiplegic man. Stereotactic dentatectomy resulted in profound ipsilateral reduction in this spasticity, but was without effect in intercollicular or anemic decerebrate cats. The mechanism of the spasticity and of the cerebellar effects are discussed.

Animals↗
PubMedDate not supplied

Sensory organization of the human thalamus.

A computerized program has been developed for on-line display and tape-library storage of stimulation-mapping data collected during stereotactic procedures. Using computer-generated displays of pooled clinical physiological data it has been possible to map through the upper midbrain and thalamus the lemniscal, spinoquintothalamic, auditory, vestibular, visual, extrapyramidal, and motor pathways, as well as the location of the pia. Each system is recognizable by a stereotyped, artificial, somatotopically organized stimulation-induced response that is devoid of modality information and independent of the site and parameters of stimulation.

Auditory Pathways↗