Biomedical subjects
Publications and source records attributed to T J Sullivan.
Magnification dacryocystography in 18 patients with chronic infective canaliculitis showed dilatation and irregularity of the affected lacrimal canaliculi, with prominent filling defects in almost all cases. Filling defects are uncommon in other diseases of the canaliculi and serve to confirm the diagnosis.
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PURPOSE: To describe a series of patients with epiphora due to a medial canthal anomaly. This anomaly consists of an anterior displacement of the anterior limb of the medial canthal tendon and a prominent nasal bridge, with lid malposition away from the globe and displacement of the lacrimal puncta out of the tear lake. The authors use the term Centurion syndrome to describe this anomaly. METHODS: The history, results of examination, investigations, and surgical management and outcome of 13 patients with Centurion syndrome were reviewed. Seven patients were recalled for examination to complete patient details. RESULTS: All patients had epiphora since childhood, which worsened at puberty, and all were patent to syringing. Lacrimal scintillography (ten cases) showed a functional block at the inner canthus, with hold up of activity before entry into the sac. Surgery to restore lid globe apposition medially by release of the anterior limb of the medial canthal tendon (eight patients), sometimes combined with dacryocystorhinostomy (four patients), relieved the epiphora. CONCLUSION: There is a group of patients with unexplained epiphora due to a medial canthal anomaly, which the authors have termed Centurion syndrome. It is important to recognize this anomaly, as it can be corrected surgically by medial canthal tendon release or by medial canthal tendon release combined with dacryocystorhinostomy if there is concomitant lacrimal outflow obstruction.
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A 6-month-old female infant with biopsy-proved Hirschsprung's disease had associated sector heterochromia of the irides. The association between sector heterochromia and Hirschsprung's disease has been previously reported and both conditions have been ascribed to neural crest defects. Histologic characteristics of the ocular involvement have not previously been reported, to our knowledge. Histopathologic examination of the globes revealed decreased iris stroma, decreased pigmentation in the anterior stroma, and reduced numbers of pigment-producing cells in the affected areas. Both the ocular and gastrointestinal findings reflect abnormalities in tissues of neural crest origin.
The influence of usual regimens of the H2 blocking drugs, cimetidine, ranitidine, and nizatidine on the steady-state plasma concentrations and pharmacokinetic characteristics of theophylline was studied in seventeen patients with chronic obstructive pulmonary disease (COPD). Patients were dosed to steady-state with an oral, sustained-release formulation of theophylline given in therapeutic doses twice daily for 2 weeks. Over the next 4 weeks, each patient received a week-long regimen of each H2 blocker concomitantly with theophylline, and a week-long regimen of theophylline alone (control). At the end of each of the latter 4 weeks the steady-state pharmacokinetics of theophylline were assessed. Neither ranitidine nor nizatidine treatment altered the steady-state pharmacokinetics of theophylline relative to the control phase (i.e. no H2 blocker treatment). Values for theophylline C(ave), Cssmax, AUC0-12, and CLoral were significantly different during cimetidine treatment compared with all other treatments (ranitidine, nizatidine, and control). Cimetidine increased theophylline Cssmax, AUC0-12 and Cave by approximately 32%, and decreased theophylline oral clearance by approximately 23%. The authors conclude that cimetidine alters the steady-state pharmacokinetics of theophylline in COPD patients, whereas ranitidine and nizatidine are without effect.
Because of the considerable uncertainties associated with modeling complex ecosystem processes, it is essential that every effort be made to test model performance prior to relying on model projections for assessment of future surface water chemical response to environmental perturbation. Unfortunately, long-term chemical data with which to validate model performance are seldom available. The authors present here an evaluation of historical acidification of lake waters in the northeastern United States, and compare historical changes in a set of lakes to hindcasts from the same watershed model (MAGIC) used to estimate future changes in response to acidic deposition. The historical analyses and comparisons with MAGIC model hindcasts and forecasts of acid-base response demonstrate that the acidic and low-ANC lakes in this region are responsive to strong acid inputs. However, the model estimates suggest lakewater chemistry is more responsive to atmospheric inputs of sulfur than do the estimates based on paleolimnological historical analyses. A 'weight-of-evidence approach' that incorporates all available sources of information regarding acid-base response provides a more reasonable estimate of future change than an approach based on model projections alone. The results of these analyses have important implications for predicting future surface water chemical change in response to acidic deposition, establishing critical loads of atmospheric pollutants, and other environmental assessment activities where natural variation often exceeds the trends under investigation (high noise-to-signal ratio). Under these conditions, it is particularly important to evaluate future model projections in light of historical trends data.
A weight-of-evidence approach was used by the US National Acid Precipitation Assessment Program (NAPAP) to assess the sensitivity of chemistry and biology of lakes and streams to hypothesized changes in sulfate deposition over the next 50 years. The analyses focused on projected effects in response to differences in the magnitude and the timing of changes in sulfate deposition in the north-eastern United States, the Mid-Appalachian Highlands, and the Southern Blue Ridge Province. A number of tools was used to provide the weight of evidence that is required to have confidence in an assessment that has many uncertainties because of the complexity of the systems for which the projections of future conditions were made and because of limited historical data. The MAGIC model provided the projections of chemical changes in response to alternative deposition scenarios. Projected chemical conditions were input into biological models that evaluate effects on fish populations. The sensitivity of water chemistry and brook trout resources to the hypothesized changes in deposition was found to be greatest in the Adirondacks and Mid-Atlantic Highlands. Under the hypothesized sulfur deposition reduction scenarios, chemical conditions suitable for fish were projected to improve 20-30 years sooner than with the scenario that assumed no new legislated controls. Other lines of evidence, e.g. other models, field observations, and paleolimnological findings, were used to evaluate uncertainty in the projections. Model parameter/calibration uncertainty for the chemical models and population sampling uncertainty were explicitly quantified. Model structural uncertainties were bracketed using model comparisons, recent measured changes, and paleolimnological reconstructions of historical changes in lake chemistry.
The information reviewed here supports the concept that asthma is potentially curable. Reports of complete, durable remission of asthma can no longer be regarded as fortuitous occurrences, unrepresentative of asthma in general. Systematic studies of anti-inflammatory drug therapy designed to explore possible induction or remission of asthma clearly are warranted. Studies of aggressive anti-inflammatory drug therapy of asthma at the onset, to avoid establishment of chronic asthma, also are desirable. The current goals of therapy of asthma have been revised to include reduction of airway hyperreactivity with topical anti-inflammatory drugs, in addition to relief of current symptoms. This approach may provide valuable resistance to exacerbations in response to antigen exposures, infections, exercise, or irritants. Pathophysiologic mechanisms apparently essential to the establishment and perpetuation of chronic asthma have been identified. These processes may be vulnerable to eradication by combination therapy with existing pharmacologic agents such as cyclosporin A or FK-506 (to suppress cytokine production), gold, methotrexate, and other anti-inflammatory drugs, alone or in combination. Equally important, the vigorous anti-inflammatory therapy may be necessary only long enough to achieve a resolution of the chronic pulmonary inflammation. Systematic studies of the use of these agents to induce partial, or complete, stable remissions of asthma should be performed. In the past, remissions of asthma in children with neoplasia and the other patients presented herein were complete, durable, and welcome, but they were largely unexpected and unpredictable. For the future, there is increasing reason to believe that predictable pharmacologically induced remission of asthma will be feasible.
The authors present a new method for plotting and quantitating the field of binocular single vision (BSV). They modified a Goldmann perimeter to project a fusion target in the form of a cross (+). Unlike previous methods that used a spot, which is a poor fusion target that cannot detect cyclotorsion, the authors' method permits a single tester to plot BSV fields in patients who have any combination of horizontal, vertical, and cyclotorsional diplopia. The BSV fields were plotted in 23 patients with acquired diplopia using both the fusion target and the spot. Scoring was performed using a new scoring template weighted to the functionally important areas around primary and reading positions. Nine patients (39%) had scores for the two targets that differed by more than 10%. The authors' method yields BSV scores that are reproducible and easy to perform and that can be used for preoperative and postoperative assessments, serial monitoring of changes over time, and disability evaluations.
Cryptophthalmos refers to a group of uncommon congenital anomalies of eyelid formation that can occur alone or in combination with multiple congenital anomalies as part of the Fraser syndrome. We present a case of bilateral abortive cryptophthalmos in a child with Fraser syndrome and discuss the problems of surgical management. A brief discussion of isolated and syndromic cryptophthalmos, including normal eyelid development, the pathogenesis of cryptophthalmos, and the management options follows.
Congenital dacryocystocoele occurs when the nasolacrimal drainage apparatus in the newborn has concomitant blocks at the level of the junction of the common canaliculus with the lacrimal sac and at the distal end of the nasolacrimal duct. This results in a typical pink or blue swelling in the region of the medial canthus. Spontaneous resolution is common, although dacryocystitis may supervene. Treatment should be conservative unless dacryocystitis occurs, or intranasal extension coexists. A series of seven consecutive cases is presented and a management plan for the neonate with congenital dacryocystocoele is proposed.
Congenital lacrimal fistulae are developmental anomalies of the lacrimal apparatus that are usually symptomatic, frequently causing epiphora and occasionally causing fistulitis or dacryocystitis. They may be associated with other abnormalities of the lacrimal system or with systemic anomalies. Complete excision alone, or in combination with nasolacrimal intubation and/or dacryocystorhinostomy is recommended for treatment.
Orbital haemangiopericytomas are ideally managed by complete surgical excision in the first instance. This is frequently not achieved, because difficulty in making the diagnosis preoperatively results in incisional biopsy and the highly vascular nature of the tumour makes complete excision difficult. A series of 12 patients with orbital haemangiopericytoma seen over a 23-year period is presented. The following combination of clinical and radiological features is suggestive of haemangiopericytoma. 1. Painless non-axial proptosis with downward displacement of the globe. 2. Intermittent upper lid swelling. 3. A soft, superiorly located mass with poorly defined borders, especially with a blue hue. 4. A superiorly located, rounded or elongated extraconal mass on CT, isodense with brain, with smooth, well-defined borders and moderate to marked enhancement with the injection of intravenous contrast medium. 5. Significant blush in all three phases of carotid angiography, without prominent arteriovenous shunting. Once haemangiopericytoma is suspected, complete surgical excision is recommended.
Congenital corneal anaesthesia is a cause of severe corneal ulceration and scarring in childhood. Although uncommon, it may be underdiagnosed when present as an isolated entity. Measures such as the use of elbow splints and tarsorrhaphy may be necessary to prevent visual loss. In rare instances, the condition may be inherited. A family is presented with autosomal dominant isolated congenital corneal anaesthesia, and the systemic associations and treatment of the condition are reviewed.
Orbital cavernous haemangioma, a common orbital tumour, is usually single and unilateral. We report the first case of histologically confirmed bilateral multiple cavernous haemangiomas of the orbit.
Two siblings with Senior-Loken syndrome are described. The need for a full evaluation of renal function and hearing in children with a retinal dystrophy is emphasised.
Actinomycosis is a very rare cause of orbital abscess usually attributable to direct spread from adjacent structures. A case of actinomycosis of the orbit is presented, which was treated as orbital pseudotumour for 3 months before progression of signs and symptoms, despite high dose steroids, led to the diagnosis being reconsidered.