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Biomedical subjects

W E Scott

Publications and source records attributed to W E Scott.

At least 109 records · Page 6Linked to original sources
PubMed1967

Mechanism of fumaric acid accumulation in Rhizopus nigricans.

It is doubtful that the glyoxylate bypass plays a significant role in the accumulation of fumaric acid by fungi, as has been postulated. In high glucose media, which favor fumarate production, isocitrate lyase (threo-D(s) isocitrate glyoxylate lyase), which is the key enzyme of the glyoxylate bypass, is strongly repressed. The specific activity of this enzyme remains low as long as glucose is present in the medium, even though fumarate formation proceeds at a high level. In addition, the activity of isocitrate lyase is inhibited by phosphoenolpyruvate, which would be formed from glucose. Alternatively, evidence is presented that bulk accumulation of fumaric acid under aerobic conditions in high glucose media takes place through a C(3) plus C(1) carbon dioxide fixation. CO(2) fixation was measured by the direct incorporation of NaHC(14)O(3) into fumaric acid, and by demonstrating that the specific radioactivity of fumaric acid formed from uniformly labeled C(14)-glucose was decreased in the presence of nonradioactive carbonate. The extent of decrease in specific radioactivity is in accord with a C(3) plus C(1) CO(2) fixation mechanism.

Carbon Isotopes↗
PubMedDate not supplied

Oblique muscle palsies fixating with the paretic eye.

Palsy of the superior oblique muscle is one of the most commonly occurring entities in strabismus; the clinical characteristics are easily recognizable. Isolated inferior oblique muscle palsy, although anatomically enigmatical, is also known to ophthalmologists. When a patient with an oblique muscle palsy chooses to fixate with the paretic eye, characteristic patterns of motility may be obscured. Patients with superior oblique muscle palsy or isolated inferior oblique muscle palsy who habitually fixate with the paretic eye, may present with limited elevation or depression respectively. In each case, limited motility exists secondary to decreased innervational input to the contralateral antagonist of the paretic muscle, or to a mechanical restriction caused by prolonged contracture of the yoke of the paretic muscle. Inhibitional palsy of the contralateral antagonists and the fallen and rising eye syndromes may present diagnostic dilemmas unless the underlying oblique muscle palsy is recognized. Proper diagnosis may be obtained with three clinical tests; the 3-step test, the comparison of ductions to versions, and forced ductions.

Contracture↗
PubMedDate not supplied

Congenital fourth nerve palsy and occult cranium bifidum.

A 6-year-old girl had paresis of the fourth cranial nerve since infancy. Computed tomography and magnetic resonance imaging revealed occult cranium bifidum with elevation of the straight sinus and tentorium, an abnormal tectal configuration, and a mass in the posterior fossa. Surgical resection revealed that the mass consisted of adipose and fibrous connective tissue. This patient further illustrates that congenital fourth cranial nerve palsy is associated in rare instances with anomalies of the brainstem and adjacent structures.

Brain Neoplasms↗
PubMedDate not supplied

What difference do two days make? The inertia of physicians' sequential prognostic judgments for critically ill patients.

Medical authorities have asserted the importance of observing a patient's clinical course over time. Distinguished committees have suggested that changes over time in physicians' prognostic estimates should influence decisions to transfer patients out of intensive care units (ICUs). This study evaluated how the opportunity to observe patients over time affected physicians' prognostic estimates for a cohort of 269 critically ill patients sequentially admitted to a medical-surgical ICU in a teaching hospital. As soon as possible after admission and again 48 hours later, the authors obtained a quantitative estimate of the probability of survival through hospital discharge from each patient's house officer and primary attending physician, and the critical care attending physician on duty. They independently determined each patient's survival. From this population they analyzed 181 pairs of judgments made by the same house officers, 211 pairs by the same primary attendings, and 172 pairs by the same critical care attendings. The physicians' 48-hour estimates were little changed from their previous estimates for the same patients. The correlation coefficient for the house officers' paired estimates was 0.84 (p less than 0.0001); for the critical care attendings' estimates 0.84 (p less than 0.0001), and for the primary attendings' estimates, 0.90 (p less than 0.0001). Forty-eight hours did not substantially reduce the disagreements present between estimates made by different physicians for the same patient. No group of physicians substantially improved the reliability or the discriminating power of its later estimates. The physicians in the study could not take advantage of sequential clinical information over time. These results point out the need to teach physicians how to better integrate and process sequential clinical data.

Critical Care↗
PubMedDate not supplied

Traumatic simulated Brown's syndrome: a case report.

A case report of a simulated Brown's tendon sheath syndrome is presented which masks as an orbital floor fracture with entrapment. Despite a positive forced traction test, additional diagnostic information such as a normal tomographic exam of the orbital floor, vertical saccadic up gaze velocity measurements consistent with edema and hemorrhage, greater limitation to elevation in adduction than abduction, and tenderness and soft tissue injury in the region of the trochlea, persuaded us to conservatively manage this case. It behooves the ophthalmologist to consider a temporary superior restrictive phenomenon produced by edema prior to any surgical approach to improve elevation of the globe.

Adult↗
PubMedDate not supplied

Surgical treatment of compensatory head position in congenital nystagmus.

Records of 32 patients with congenital nystagmus who underwent surgery for a significant head turn were reviewed to assess the effectiveness of current surgical approaches. Eighteen patients (Group I) had single binocular vision and had bilateral recess/resect procedures either according to Parks' 5-6-7-8 scheme (nine patients) or "augmented" from 10% to 40% for large head turns (nine patients). Fourteen (78%) had a reduction of the turn to 15 degrees or less, six (33%) being 5 degrees or less. One was overcorrected . Fourteen patients had a heterotropia in addition to head turn. Seven (Group II) had bilateral surgery to attempt to correct the head turn and reduce the tropia to less than 10 prism diopters. In three cases (43%) there was both successful treatment of the tropia and reduction of the turn to 15 degrees or less. The tropia was successfully treated in six patients (86%). In seven patients (Group III) monocular recess/resect surgery was done to attempt to correct both abnormalities. In four (57%) the turn was reduced to 15 degrees or less with successful treatment of the tropia at the same time. Five (71%) had a tropia of less than or equal to 10 diopters postoperatively. Overall, the head turns were reduced to 15 degrees or less in 23 (72%) of the 32 patients including 11 (35%) with 5 degrees or less residual turn. Three (9%) were overcorrected at least 10 degrees. The frequency of undercorrections indicates that larger amounts of surgery have to be done, especially for large turns, although ductions will be limited in some gaze positions, at times significantly, to achieve this goal.

Adolescent↗
PubMedDate not supplied

Amblyopia case reports--bilateral hypermetropic ametropic amblyopia.

Six patients are presented with ametropic amblyopia secondary to bilateral hypermetropia. Two patients had a strabismic amblyopia superimposed upon the ametropic amblyopia. All patients had a marked improvement in their visual acuity with the use of constant glass wear only. No associated ocular pathology was identified. It is the authors' belief that these patients are seen occasionally in general ophthalmologic practice. The diagnosis and treatment is straightforward; however, the diagnosis can be perplexing and unnecessary referrals and neuro-ophthalmologic investigation can ensue if this entity is not recognized.

Amblyopia↗
PubMedDate not supplied

Masked bilateral superior oblique palsy: clinical features and diagnosis.

Ninety-two patients treated surgically between 1972 and 1983 were diagnosed initially as having a unilateral superior oblique palsy (SOP). On follow-up, eight (8.7%) developed findings of an SOP of the other eye. Such patients have "masked bilateral" superior oblique palsy. All eight patients had unilateral inferior oblique weakening with or without contralateral inferior rectus recession as the initial surgery. The "unmasking" of the contralateral palsy manifested in seven cases by an overaction of the contralateral inferior oblique muscle and appeared an average of 9.8 weeks (range five days to 11 months) after the first surgery. Their preoperative mean V-shift (7.6 diopters), mean excyclotorsion (5.7 degrees), and mean difference of hyperdeviation on right versus left tilt (19.6 diopters) were not significantly different from the respective values for patients with unilateral SOP (5.0 diopters, 4.3 degrees, 19.0 diopters).

Adult↗
PubMedDate not supplied

Superior oblique tenotomy in the treatment of isolated inferior oblique paresis.

Both tenotomy and tenectomy of the homolateral superior oblique muscle have been advocated as surgical treatment for isolated paresis of the inferior oblique muscle. An iatrogenic superior oblique palsy has been reported to be a frequent complication of superior oblique tenectomy. This complication appears to be less frequent following superior oblique tenotomy. Of 16 consecutive patients with isolated inferior oblique paresis treated by homolateral superior oblique tenotomy and followed an average of 5.0 years (range six months to 11.6 years), only two patients demonstrated a superior oblique palsy postoperatively. Large vertical deviations with spread of comitance, however, required a superior rectus recession of the fellow eye in addition to superior oblique tenotomy.

Adolescent↗
PubMedDate not supplied

Adjustable suture strabismus surgery.

We examined 333 patients between the ages of 11 and 70 years who underwent strabismus surgery with adjustable sutures over a ten-year period. The type of strabismus, the number and amount of adjustments, the postoperative drift, and complications were evaluated. A large percentage of patients required adjustment to obtain the desired postoperative position. The postoperative drift patterns were characteristic for each type of preoperative deviation and were similar to that reported for nonadjustable procedures. Adjustable suture techniques were especially helpful in selected horizontal deviations, vertical deviations, and the more complex strabismus problems. The complications from adjustable suture operations in this series were minimal.

Adolescent↗