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Biomedical subjects

J Goodwin

Publications and source records attributed to J Goodwin.

At least 37 records · Page 2Linked to original sources
PubMed1995

Mathematical modeling of dendritic growth in vitro.

The dendritic branching pattern of cultured hippocampal neurons was analyzed to obtain mathematical parameters that fit the time-dependent growth of dendrites under limited extrinsic influence. Cultured neurons were stained with a non-toxic carbocyanine dye (diO) and pyramidal-shaped neurons that were physically separated from one another were analyzed at post-plating days 1, 2, 3, 4, 6 and 7. The geometric branching pattern of the dendrites was analyzed using a mathematical model that incorporates random effects in the form of a Galton-Watson branching process where splitting of one branch is statistically independent of the splitting of all other branches, and deterministic effects in the form of a parameter that measures the extent to which dense patterns (clusters) or sparse patterns (elongated trees) are formed. The geometric branching pattern of the dendrites was analyzed using a mathematical model that incorporates random and deterministic effects. The model parameters were estimated via the method of maximum likelihood. The data suggest that in vitro basal dendrites grow according to a purely random branching process without pronounced dense or sparse patterns, while apical dendrites tend to form elongated trees with fewer secondary bifurcations. This trend is quantified, and it depends on the culture conditions in which the neurons are grown. The quantitative assessment of various influences on dendritic growth patterns are discussed.

Animals↗
PubMed1995

Lightning and electrical injuries: neuro-ophthalmologic aspects.

Lightning and electrical injuries have widespread manifestations involving almost all organ systems of the body, including the central nervous system (CNS) and the eye. This article considers the neuro-ophthalmologic effects of lightning and electrical injury.

Animals↗
PubMed1995

Circadian body temperatures and the effects of a cold stress in elderly and young subjects.

To determine whether there is a decrement in normal resting body temperature with age, 11 healthy elderly and 11 young adults were studied together for 48 h in warm (21 degrees C) ambient conditions. The resting levels and daytime rhythms of urine and oral temperature were similar, but night-time body temperature fell to a lower value in the young. There were time-of-day effects of increasing skin temperature and metabolic rate in both groups with resting levels higher in the young. After 6 h in cold (6 degrees C) conditions, core (urine) temperature fell by 0.4 degrees C in the elderly subjects but was maintained in the young, and the rise in blood pressure in the elderly exceeded that in the young. Self-reported arousal, however, increased equally in both groups in the cold.

Adult↗
PubMed1993

Pattern visual evoked potentials in cases of ambiguous acuity loss.

Thirty patients were referred to our visual evoked potential laboratory with complaints of profound acuity loss in one or both eyes. However, the objective ophthalmologic findings were normal, including pupillary reaction, and anterior segment and fundus examinations. Transient visual evoked potentials to a 2.3-c/deg sinusoidal grating pattern were found to be present in 26 of these 30 patients. Visual evoked potentials may be used as a measure of afferent pathway integrity.

Adolescent↗
PubMed1993

Cerebrospinal fluid diversion procedures in pseudotumor cerebri.

We reviewed the efficacy of CSF diversion for pseudotumor cerebri (PTC) in patients from six different institutions. Thirty-seven patients underwent a total of 73 lumboperitoneal shunts and nine ventricular shunts. Only 14 patients remained "cured" after a single surgical procedure. The average time between shunt insertion and shunt replacement was 9 months, although 64% of shunts lasted less than 6 months. Shunt failure (55%) and low-pressure headaches (21%) were the most common causes for reoperation. The vision of most patients improved (13) or stabilized (13) postoperatively. However, three who had initially improved subsequently lost vision. Six had a postoperative decrease in vision. Two patients improved in one eye but worsened postoperatively in the other. Four lost vision despite apparently adequate shunt function. Shunt failure with relapse of PTC occurred as late as 7 years after insertion. CSF diversion procedures have a significant failure rate as well as a high frequency of side effects.

Cerebrospinal Fluid Shunts↗
PubMed1993

Accutracker II (version 30/23) ambulatory blood pressure monitor: clinical validation using the British Hypertension Society and Association for the Advancement of Medical Instrumentation standards.

OBJECTIVE: To assess the Accutracker II (version 30/23) ambulatory blood pressure monitor by nationally agreed protocols in order to resolve previous conflicting assessments, and to examine the feasibility of combining these protocols into one study. DESIGN: The protocols of the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS) were used simultaneously. SUBJECTS: Five normotensive subjects were used to assess interobserver variation; 30 subjects took part in the field evaluation and 85 in the laboratory evaluation. The latter subjects were selected to cover a wide range of blood pressures and differences in arm circumference. OUTCOME MEASUREMENTS: Classification of device accuracy according to the criteria of the BHS and AAMI protocols. RESULTS: Among 255 observations the mean +/- SD difference between blood pressure measurements by the Accutracker II and the observers was -2.2 +/- 0.8/-3.5 +/- 0.9 mmHg. There was a small but statistically significant difference between one device and the other two, but all three fulfilled the BHS criteria of 95% of measurements falling within 3 mmHg before and after use. In 30 24-h recordings > 80% of the programmed inflations produced valid recordings. Editing criteria accounted for the majority (55%) of invalid readings; weak Korotkoff sounds, imperfect electrocardiogram signals or movement artefact accounted for the remainder. CONCLUSIONS: Version 30/23 of the Accutracker II fulfilled the AAMI criteria; using the BHS system, it was graded A for systolic and C for diastolic blood pressure. Although both protocols were readily combined into one study, they do not assess exactly the same aspects of blood pressure measurement. Previous conflicting evaluations could be due to differences in applying the protocols or may result from modifications in production models. Posture may affect the rating given by the BHS protocol. Until there is general international agreement on the method used to validate ambulatory blood pressure monitors, simultaneous use of both the BHS and AAMI protocols is recommended. In future assessments or investigational use of any similar instruments the model used should be described precisely.

Adolescent↗
PubMed1991

The epidemiology of skin tears in the institutionalized elderly.

While skin tears are a common occurrence in the institutionalized elderly population, nothing has been written about this problem. We retrospectively studied all incident reports during a 1-year period at a large, urban, long-term-care facility to identify residents with skin tears. The overall incidence of skin tears was 0.92 per patient per year. The incidence rate for females, but not for males, increased significantly with age (P = 0.012). The mean length of the skin tear was 1.9 cm +/- 1.4 (mean +/- SD). Eighty percent occurred in the upper extremities, with the most frequent location being the forearm. Almost half of the skin tears reported had an unknown cause. Wheelchairs and accidentally bumping into an object each accounted for a quarter of the skin tears where the cause was known. Transfers and falls contributed to a lesser extent. Impaired mental status was no more likely to be present in residents experiencing a skin tear than in all nursing home residents. Twenty-four of the 147 residents with skin tears had four or more tears, accounting for 40% of all skin tears reported. Ninety-seven percent of the episodes resulted in no attending physicians' orders other than the standing orders. Future studies should be designed to determine if there are adverse consequences of skin tears and to suggest programs to reduce their occurrence.

Aged↗
PubMed1990

Cephalic blood flow correlates of induced headaches.

The purpose of this study was to examine the cephalic blood flow patterns of subjects with frequent headaches during a headache induction procedure. Thirty-six subjects with muscle-contraction, migraine, or mixed headache symptoms were exposed to a 1-hr stressor designed to induce a headache while multiple cephalic blood volume pulse amplitude (BVPA) was measured. Thirty subjects reported a headache during the procedure, and the procedure was associated with significant changes in several cephalic BVPA measures. Between-group differences were found for several cephalic BVPA sites and there were significant correlations between induced headache activity and cephalic BVPA measures for most subjects. The results support causal roles for psychosocial stressors and cephalic blood flow in muscle-contraction and migraine headache.

Adult↗
PubMed1990

Vascular lesions in the central nervous system in sickle cell disease (neuropathology).

The incidence of serious neurologic complications in sickle cell disease ranges from 6% to 30% in various series. Our experience indicates that the incidence in adults is approximately 15%. The clinical and neuropathologic correlations at autopsy in 20 sickle cell disease patients are discussed in this paper. Some patients had massive infarcts and/or hemorrhages in the cerebral hemispheres as the terminal event. In some, both infarction and hemorrhage occurred simultaneously; others had thrombosis of major branches of the circle of Willis and in the internal carotid artery on one or both sides. Prominent large arterial occlusive disease in the terminal intracranial portions of the internal carotid arteries and proximal segments of their main branches was frequently observed. The pathology of the brain showed diffuse chronic gliotic scars of microinfarcts in the deep white matter and cerebral gray matter, even when no past neurologic history was recorded. We hypothesize that the vague, nonspecific complaints, including chronic alteration of intellectual and emotional function, of some sickle cell disease patients prior to their death, may constitute the clinical counterpart of disseminated microscopic lesions resulting from small-vessel disease. The pathogenesis of vaso-occlusive disease includes altered cerebral blood flow, platelet response to endothelial injury, and sickled erythrocyte adhesion to endothelium.

Adolescent↗
PubMed1989

Multiple electrodes for detecting spikes in partial complex seizures.

The contribution of various electroencephalographic electrodes in detecting spikes from patients with seizures of suspected anterior temporal origin was prospectively studied with a standard protocol. The following electrodes were studied: International Standard 10-20 positions F7-8 and A1-2, sphenoidal (SP), nasopharyngeal (NP), anterior temporal (T1-2), mandibular notch surface (MNS), and mandibular notch subdermal (MNSD). Twenty patients were recorded of whom 16 demonstrated anterior temporal spikes. There was no difference in the number of spikes detected by SP, MNS, MNSD, or T1-2 electrodes (p less than 0.05); however these electrodes detected significantly more spikes than NP, F7-8, or A1-2. The SP electrode recorded spikes of highest amplitude (p less than 0.05). We conclude that for patients suspected of having seizures of anterior temporal origin, (1) a substantial number of spikes will be missed if only the International Standard electrode system is employed; (2) in comparison to SP electrodes the non-invasive and easily applied MNS or T1-2 electrodes will detect almost all spikes and should be used in outpatient EEG recordings; (3) NP electrodes provide no information that cannot be obtained by more reliable and better tolerated electrodes.

Adolescent↗
PubMed1989

Psychiatrists choosing psychoanalytic training at mid-career.

At one institute 48 percent of physician candidates doing class-work are over 40. This percentage has increased over the past decade, perhaps reflecting new economic constraints and the increased proportion of women candidates. A review of the first training analysis, Freud's, and conversations with some present day candidates indicate that choosing training at mid-career can address specific adult developmental issues, including the "race against time," needs for increased structuring of family life and of creative work and shifts from physical to intellectual play and from being a mentee to mentorship.

Adult↗
PubMed1989

New laws about sexual misconduct by therapists: knowledge and attitudes among Wisconsin psychiatrists.

As many as 7% of psychiatrists admit to having sexual intercourse with patients, despite ethical prohibitions going back to the Hippocratic Oath. Emotional damage, reported by 85% to 90% of involved patients, forms part of the justification for this prohibition. Since 1986, therapist sexual misconduct has been a felony in Wisconsin. Under this law, definitions of sexual exploitation include sexual contact as well as sexual intercourse, and non-psychiatric physicians may be defined as "therapists." In May 1988, Wisconsin legislation became effective requiring therapists to report sexual exploitation revealed in treatment. A 1987 survey of 175 members of the Wisconsin Psychiatric Association showed that a majority favored passage of such a law. More than 40% of surveyed psychiatrists have had experience with such cases, and more than half were willing to provide consultation in this area.

Attitude of Health Personnel↗