Elevated intracranial pressure and pseudotumor cerebri

The development of papilledema requires high cerebrospinal fluid (CSF) pressure in the distal optic nerve sheath, elevation of the pressure in the central retinal vein, and impaired perfusion of the neurons as they traverse the lamina cribrosa. Pseudotumor cerebri (PTC) is a syndrome defined by four criteria: 1) Increased intracranial pressure, 2) normal or small ventricles on neuroimaging, 3) no evidence of an intracranial mass, and 4) normal CSF composition. Elevated intracranial venous pressure is thought by some authors to be the "universal mechanism" of PTC of varying etiologies. The reason obesity predisposes to idiopathic PTC is unclear, but one mechanism proposed is that central obesity raises intra-abdominal pressure, which increases pleural pressure and cardiac filling pressures, which impede venous return from the brain, leading to increased intracranial venous pressure and increased intracranial pressure. Both optic nerve sheath fenestration (ONSF) and lumboperitoneal shunting (LPS) may improve vision and prevent deterioration of vision in patients with PTC. Both procedures have their advantages and disadvantages, but until a prospective, randomized study comparing ONSF with LPS for PTC is performed, the question of which surgical procedure is best for the treatment of PTC remains unanswered.

Ishihara color plates as a test for simultanagnosia

PURPOSE

To alert ophthalmologists to the use of Ishihara color plates in the detection of simultanagnosia.

METHODS

We examined seven patients referred for impaired vision. Evaluation included color plate testing with Ishihara color plates.

RESULTS

All seven patients had simultanagnosia, with marked difficulty in identifying the numbers in Ishihara color plates despite adequate visual acuity and the ability to name all of the colors in the plates correctly. One of these patients was referred with the diagnosis of a cone dystrophy because of her poor performance on the Ishihara test. All of the patients had bilateral occipitoparietal damage or atrophy on magnetic resonance imaging.

CONCLUSIONS

Ophthalmologists must be aware that a poor performance with Ishihara plates may not be attributable to an impairment of color vision but rather to occipitoparietal brain damage associated with simultanagnosia.

Unusual presentations of sellar arachnoid cyst

This report describes two unusual cases of parasellar arachnoid cyst with different neuro-ophthalmologic manifestations and clinical courses: a 33-year-old woman with parasellar arachnoid cyst, manifested by incongruous homonymous hemianopia, and a 64-year-old man with a presumed parasellar arachnoid cyst and bitemporal hemianopia that subsequently decompressed spontaneously. Parasellar arachnoid cyst is uncommon, and the clinical course has been incompletely described in the literature. Optimal treatment of patients with these cysts necessitates better understanding of their signs, symptoms, and clinical course.

Homonymous hemianopsia due to a dural cavernous hemangioma

The clinical and radiographic features of extra-axial cavernous hemangiomas are described, and a case of homonymous visual field loss due to a dural-based occipital cavernous hemangioma is reported. A patient presented with a homonymous hemianopsia due to an enhancing tentorial mass lesion. The preoperative clinical and magnetic resonance imaging features were suggestive of meningioma. The patient underwent gross total resection of the lesion and the final pathologic examination was consistent with cavernous hemangioma. There was complete resolution of the visual field defect after surgery. Extra-axial cavernous hemangiomas differ from intra-axial cavernous hemangiomas in their clinical and radiographic features. The former lesions may mimic meningioma and should be considered in the differential diagnosis of a dural-based mass. Early recognition of the lesion is important because surgical removal of cavernous hemangiomas may be associated with a higher morbidity and mortality rate than meningiomas.

A guide to the evaluation of fourth cranial nerve palsies

PURPOSE To devise a cost-effective guide for the evaluation of fourth nerve palsies (FNP). METHODS A review of the pertinent English language literature was performed to devise a guide for the evaluation (including neuroimaging) of FNP. The authors report a retrospective review of imaging studies performed on 206 patients with FNP. RESULTS The literature was used to develop the imaging guide. In the retrospective chart review of 206 patients from two tertiary care centers, 28 patients (13.6%) underwent a computed tomography scan and/or a magnetic resonance scan. Of these patients, five had associated neurological symptoms (non-isolated), one was traumatic, five were congenital, four were vasculopathic, eleven were non-vasculopathic, and two were progressive. Following the recommendations of the imaging guide, the five isolated congenital FNP and the four isolated vasculopathic FNP would not have undergone neuroimaging studies. The total costs of these neuroimaging studies in these nine patients were 19,000 dollars. Four patients in the retrospective review with associated neurological deficits (non-isolated) should have undergone neuroimaging according to the guide, but did not. CONCLUSIONS Although the evaluation of FNP can be difficult, the decision to order neuroimaging can be improved by using an imaging guide. An imaging guide for the evaluation of FNP may allow more appropriate and cost-effective imaging of these patients. Isolated congenital, old traumatic, or vasculopathic FNP do not require neuroimaging studies. Patients with non-isolated FNP should have directed neuroimaging studies based upon the results of clinical examination.

How lipids interact with an intrinsic membrane protein: the case of the calcium pump

Ca2+-ATPase can be purified from the skeletal muscle of sarcoplasmic reticulum and reconstituted into phospholipid bilayers of defined composition. This allows a detailed study of the interactions between phospholipid molecules and the ATPase, and of the effects of phospholipid structure on the activity of the ATPase. It has been shown that the thickness of the lipid bilayer, its physical phase and the lipid headgroup structure can all be important. The interaction between phospholipids and the ATPase is not structurally specific in that the strength of the phospholipid-ATPase interaction does not depend on headgroup structure or on fatty acyl chain length, but the strength of binding is different for liquid crystalline and gel phase lipid. There are also 'specific' sites for some lipids on the ATPase. There is no unique mechanism explaining the effects of phospholipid on the function of the ATPase; the changes observed with any particular phospholipid follow from a distinct set of changes in the conformational state of the ATPase. The changes in activity are likely to follow from tilting of trans-membrane alpha-helices in the ATPase. In simple model systems it has been shown that the extent to which lipids can distort to match the protein is limited.

Optic disk edema with a macular star

A 13-year-old boy presented with acute loss of vision in his right eye of 2 weeks' duration. He had a high fever and was ill for several days, then improved but suffered recurrent episodes of sweating and a high fever. Ophthalmoscopy of the right eye showed optic disk edema, mild vitreous cells, and minimal exudates in the macula. Bartonella henselae titers were positive. A diagnosis of optic disk edema with a macular star secondary to cat-scratch disease was made. The patient was treated with doxycycline and made a dramatic improvement to visual acuity of 20/30 with a minimal residual relative central scotoma. The optic disk edema and macular star resolved, and the patient was left with mild optic atrophy in the right eye.

Etiology and surgical management of horizontal pontine gaze palsy with ipsilateral esotropia

INTRODUCTION

An esotropia ipsilateral to a horizontal pontine gaze palsy has been infrequently reported. We discuss the etiology and review the surgical management of this ocular motility defect.

METHODS

Four patients with radiographically documented dorsal pontine lesions and persistent horizontal gaze palsy with esotropia ipsilateral to the gaze palsy were treated. In each patient, the esotropia was present in attempted primary gaze, producing symptomatic diplopia. An anomalous face turn was required to attain single binocular vision.

RESULTS

All 4 patients underwent surgical correction to alleviate the anomalous head position and diplopia. Bilateral, asymmetric surgery was required to achieve a long-term successful result. Single binocular vision in the primary position with elimination or marked improvement of the compensatory head posture was initially achieved in all 4 patients. One patient, who had not undergone asymmetric strabismus surgery to reconcile incomitance produced by the esotropia, rapidly developed a residual esotropia.

CONCLUSIONS

Ophthalmologists should recognize that concurrent esotropia may occur in patients with horizontal pontine gaze palsy. Single binocular vision in the primary position, an expanded binocular visual field, and alleviation of a compensatory head position are achievable with strabismus surgery.

Mutational analysis of trans-membrane helices M3, M4, M5 and M7 of the fast-twitch Ca2+-ATPase

Mutational analysis of trans-membrane helices M3, M4, M5 and M7 of the Ca2+-ATPase revealed a novel phenotypic variant, M4 [Y295A (the one-letter symbols are used for amino acid residues throughout)], displaying an increased affinity for Pi and decreased affinity for MgATP, while retaining the ability to translocate Ca2+ ions across the endoplasmic reticulum membrane. The properties of this mutant suggest that the E1-E2 equilibrium is shifted towards E2, and indicate a key role for this aromatic residue (Y295) at the end of trans-membrane helix M4. A mutant containing three amino acid residue substitutions at the end of the seventh trans-membrane helix, M7 (F834A, F835A, T837F), showed a complete loss of ATPase activity and a reduced ability to phosphorylate with Pi, although MgATP-initiated phosphorylation was unaffected. The observation that single mutations in this cluster of residues had no effect on Ca2+ transport suggests that correct anchoring of the helix at the lipid-water interface by these aromatic residues is important in the functioning of the ATPase. Mutation of polar residues in helix M3 did not affect inhibition of the ATPase by thapsigargin, thapsivillosin A or t-butyl hydroquinone, suggesting that hydrogen-bonding partners for the essential -OH groups on these inhibitors lie elsewhere in the ATPase.

Papilloedema, a complication of progressive diaphyseal dysplasia: a series of three case reports

BACKGROUND/AIMS

Progressive diaphyseal dysplasia (PDD) is a rare, autosomal dominant, osteosclerotic dysplasia affecting both endochondrally and intramembranously derived bones. Severely affected patients can develop progressive stenosis of the optic canals and compressive optic neuropathy. Although raised intracranial pressure (ICP) has been described in patients with PDD in whom visual loss has occurred, the elevation of ICP in those patients has been thought to be either non-contributory or only partially responsible for the accompanying visual loss.

METHODS

Three cases were reviewed and the clinical and radiological characteristics are described here.

RESULTS

All three patients had bilateral optic disc swelling with no radiological evidence of either compressive optic neuropathy or thrombosis of the intracranial venous sinuses. The aetiology of the disc swelling was proved to be papilloedema in the first two cases and was probably the dominant cause in the third case.

CONCLUSION

The visual loss documented in at least two of the three patients reported appears to be solely attributable to raised ICP. Normalisation of the ICP has led to an improvement and stabilisation of the visual function in all three patients. Patients with PDD probably require periodic ophthalmic assessments.

Traumatic subluxation of the globe into the maxillary sinus

We report a case of complete traumatic subluxation of the globe into the maxillary sinus as documented by CT. The cornea sustained a mild epithelial abrasion but the globe was otherwise intact without signs of trauma.

Binocular vertical diplopia due to subretinal neovascular membrane

Diplopia is an uncommon finding in patients with subretinal neovascular membranes. We present two patients with binocular diplopia secondary to subretinal neovascular membranes and the foveal displacement syndrome. Subjective diplopia was not improved by prism therapy in either case. In one patient, diplopia was transiently relieved by removal of the choroidal neovascular membrane, but a subsequent subretinal hemorrhage resulted in severe visual loss. In the second patient, diplopia developed following laser therapy for a subretinal neovascular membrane. It is presumed that misalignment of the foveomacular receptor elements between the two eyes produced a central-peripheral fusional mechanism rivalry resulting in binocular diplopia. Ophthalmologists should be aware that a subretinal neovascular membrane may cause binocular diplopia and may mimic neuromuscular strabismus.

Elevation of serum tumor marker CA 15.3 levels as the first manifestation of metastatic breast cancer to the cavernous sinus

We report rising tumor marker levels of CA 15.3 as the presenting manifestation of metastatic breast cancer to the cavernous sinus and orbit. A 39-year-old woman with a history of breast cancer developed increasing levels of tumor marker CA15.3. Ten months later, she developed vision loss in the right eye, diplopia, and right-sided ptosis. A magnetic resonance scan of the head showed a mass involving the right cavernous sinus and superior orbital fissure. Biopsy of the lesion showed metastatic breast cancer. She was treated with surgery and radiotherapy and did well. Ophthalmologists should be aware of the significance of increasing levels of tumor markers, such as CA 15.3, in patients with a history of breast cancer and new neuroophthalmologic signs or symptoms.

Paraneoplastic optic neuropathy and autoantibody production in small-cell carcinoma of the lung

A 59-year-old woman presented with acute-onset, bilateral, painless loss of vision, dysarthria, and ataxia. Ophthalmoscopy showed bilateral optic disc edema. A magnetic resonance scan of the head was normal. Chest radiography showed mediastinal adenopathy. Mediastinoscopy and biopsy identified small-cell carcinoma of the lung. An autoantibody to optic nerve and retina was demonstrated in the patient's serum. An electroretinogram was normal. The patient was diagnosed with a paraneoplastic optic neuropathy and paraneoplastic cerebellar syndrome. After treatment for her lung cancer, the patient remains stable from a visual and neurologic standpoint.

Intracranial Ewing's sarcoma

Three patients with intracranial Ewing's sarcoma had neuro-ophthalmologic manifestations. In one patient, the primary tumor was in the skull and in two, it involved the long bones. Two patients complained of intermittent headache associated with bilateral, transient visual symptoms suggestive of migraine, which prompted imaging that showed occipital metastases. The third patient had an orbital syndrome.

The Baylor survey of Ophthalmology Residency graduates: rationale for reform in residency training

BACKGROUND AND OBJECTIVE

To survey graduates of an ophthalmology residency training program regarding skills necessary for a well-trained ophthalmologist.

METHODS

Two survey instruments were mailed to the graduates of the Baylor College of Medicine Department of Ophthalmology Residency Training Program.

RESULTS

Specific skills were identified that were rated as clinically important and for which training was considered adequate, and, conversely, skills that were rated as less important but for which training was adequate.

CONCLUSION

This survey instrument may allow ophthalmology residency training programs to identify perceived and real deficiencies in the prioritization of changes in curriculum or the skills transfer process.

Efficacy of administering an endothelin-receptor antagonist (SB209670) in ameliorating ischemia-reperfusion injury in lung allografts

The purpose of this study was to determine whether treatment with an endothelin-1 (ET-1)-receptor antagonist could prevent ET-1-mediated ischemia-reperfusion injury and early allograft dysfunction. Eleven dogs were subjected to left lung allotransplantation. Donor lungs were preserved with modified Eurocollins solution and stored at 4 degrees C for 18 to 20 h. Animals received an intravenous infusion of either the ET-receptor antagonist SB209670 (n = 6) (15 microg/kg/min) or saline (control, n = 5), in a blinded fashion. The infusion started 30 min before transplantation and continued for up to 6 h after transplantation. Hemodynamic measurements, blood gas tensions, and plasma samples were obtained with animals functioning solely on the transplanted lung. Open-lung biopsies were obtained for wet-to-dry-weight ratios and histologic and immunohistochemical analyses. Survival at 6 h after transplantation was 40% in the control group and 100% in the treatment group. Pulmonary vascular resistance and lung tissue wet-to-dry-weight ratio were significantly lower in treated animals at 3 and 6 h after transplantation. Histology of the transplanted lungs revealed more intense airway and interstitial inflammatory infiltration and edema in the control group. Arterial and venous plasma ET-1 concentrations increased after transplantation; however, they were significantly higher in the treatment group. Immunohistochemical analysis revealed more intense ET-1 immunostaining in the airways and parenchyma of the treatment group. We conclude that treatment of lung allografts with the mixed endothelin A/endothelin B (ETA/ETB) receptor antagonist SB209670 can ameliorate ischemia-reperfusion injury, resulting in improved graft function and survival after lung transplantation.

Ophthalmoplegia in treated polymyalgia rheumatica and healed giant cell arteritis

Diplopia may be a sign of giant cell arteritis (GCA). Polymyalgia rheumatica (PMR) is a systemic rheumatic inflammatory disease characterized by shoulder and hip girdle pain, and PMR can be associated in some patients with GCA. The authors report diplopia in two patients with treated PMR and biopsy-proven GCA, and review the literature on diplopia in GCA.

Pituitary adenoma in children

Pituitary adenoma is an uncommon intracranial tumor of children. The authors retrospectively reviewed the records of 10 patients younger than 17 years of age with pituitary adenoma. Five patients had visual loss at presentation. Four of these five patients with visual loss and extrasellar tumor extension were adolescents (12-15 years of age). Seven of 10 patients underwent neurosurgery. Of the five patients with visual loss, three patients experienced visual improvement, one patient was unchanged, and one patient did not have follow-up. The visual loss in these patients tended to be more severe and more likely to be associated with optic atrophy than adult patients. Although they are relatively uncommon, ophthalmologists should be aware that pituitary adenomas may occur in children and that these tumors when present in the pubertal period may be more likely to exhibit extrasellar extension or invasiveness.

Optic nerve sheath decompression in pediatric pseudotumor cerebri

The authors report a retrospective review of two cases of optic nerve sheath decompression in children (age younger than 16 years) and review the literature on the procedure. Two children underwent optic nerve sheath decompression. Optic disc edema resolved in both eyes after surgery. Some degree of visual improvement was obtained in one eye of each patient after surgery, but one eye was unchanged in one patient and one eye of the other patient had worsening of visual acuity after surgery. Neither patient suffered any systemic complications from the procedure. Of 12 patients in the literature (including these 2 patients), 66% experienced improved visual acuity following optic nerve sheath decompression, 33% had improvement in visual field, and 17% suffered worsening of visual acuity and visual field after surgery. Although optic nerve sheath decompression is a relatively safe and effective treatment for visual loss due to papilledema in adults, significant complications, including further visual loss, may occur. The experience with this procedure in children is limited, but retrospective data suggest that the safety and efficacy of the procedure may be comparable with that in adult patients.

A novel charcoal-induced model of obliterative bronchiolitis-like lesions: implications of chronic nonspecific airway inflammation in the development of posttransplantation obliterative bronchiolitis

OBJECTIVES

In this study, we describe the development of a nonallogeneic animal model of obliterative bronchiolitis-like lesions. Furthermore, we examined whether chronic rejection alone can lead to the development of obliterative bronchiolitis or whether additional nonspecific airway inflammation is required.

METHODS

Part I: Rats were intratracheally injected with 0.2 ml of activated charcoal or sorbitol solution (carrier for charcoal control). Animals were put to death beginning at 2 weeks up to 20 weeks. Part II: Animals were divided into three groups: group I, underimmunosuppressed Brown Norway to Lewis lung allografts; group II, charcoal-treated underimmunosuppressed allografts; and group III, charcoal-treated rats. Animals were put to death at 3 months after transplantation.

RESULTS

Part I: In charcoal-laden bronchioles, subacute nonspecific airway inflammation was detected at 2 weeks. Slow, subclinical fibroproliferation ensued during the following weeks. Obliterative bronchiolitis-like lesions were observed in 80% of charcoal-treated animals at 12 weeks. Part II: Allografts developed extensive vascular lesions consistent with acute and chronic vascular rejection. Obliterative bronchiolitis-like lesions were scarcely detected. Charcoal-treated allografts demonstrated evidence of diffuse and severe obliterative bronchiolitis-like lesions.

CONCLUSIONS

Transtracheal injection of activated charcoal into native lungs results in slowly progressive airway injury and inflammation leading to obliterative airway lesions. Inadequate immunosuppression primarily results in chronic vascular rejection but not obliterative bronchiolitis. Underimmunosuppressed allografts subjected to nonspecific airway inflammation develop obliterative airway lesions that are more prominent than in native lungs. This suggests that a cofactor to chronic rejection is likely necessary for the development of lung transplant obliterative bronchiolitis.

In vivo CT and MR appearance of prosthetic intraocular lens

PURPOSE

We present the first in vivo CT and MR imaging description of intraocular lenses (IOLs), which are commonly encountered in elderly patients who have undergone cataract surgery.

METHODS

A retrospective review was done of the imaging studies of 20 patients (22 eyes) with IOLs and of three patients (four eyes) with aphakia. CT and MR studies were performed with standard clinical protocols.

RESULTS

Sixteen patients with 18 posterior IOLs underwent six CT and 43 MR studies. Four patients with four anterior IOLs had one CT and eight MR studies. The exact position of the optic portion of the IOL could be optimally determined on CT scans with 1-mm-thick sections and on fat-saturated fast T2-weighted MR orbital coil studies performed on a 1.5-T imager. The haptics could not be distinguished from the ciliary body. Three patients with aphakia had eight MR and two CT studies. Aphakia was difficult to identify if the image thickness was greater than the diameter of the pupil (2.5 to 4.0 mm).

CONCLUSION

The optic portion of an IOL is visible on either high-quality CT or MR studies. However, the haptic portion is not visible on clinical in vivo images.

Cloning and expression of an insect Ca(2+)-ATPase from Heliothis virescens

A complementary DNA for the Tobacco Budworm, Heliothis virescens, sarco(endo)plasmic reticulum-type Ca(2+)-ATPase (HVSERCA) has been cloned and sequenced. cDNA fragments of adult rabbit fast-twitch muscle Ca(2+)-ATPase (SERCA1a) were used as heterologous probes to isolate a partial cDNA clone coding for a protein with high homology to the Ca(2+)-ATPase from Drosophila melanogaster (DRSERCA) and vertebrate ER/SR Ca2+ pumps. The entire cDNA clone contains an ORF encoding a protein of 1000 amino acids which shares the characteristic motifs of a P-type ATPase. HVSERCA shares 89% identity with DRSERCA, 80% identity with the Artemia Ca(2+)-ATPase and 72% identity with avian and mammalian SERCAs. An insect Ca(2+)-ATPase-specific polyclonal antiserum has been raised against a fusion protein containing sequence from the cytoplasmic domain of HVSERCA. Heterologous expression of the insect pump in COS-7 cells has been demonstrated by immunocytochemistry and the reticular pattern of staining is consistent with an ER localisation. However, the expressed enzyme from COS-7 cells does not appear to be active.

Interaction of phosphatidic acid and phosphatidylserine with the Ca2+-ATPase of sarcoplasmic reticulum and the mechanism of inhibition

The sarcoplasmic reticulum of skeletal muscle contains anionic phospholipids as well as the zwitterionic phosphatidylcholine and phosphatidylethanolamine. Here we study the effects of anionic phospholipids on the activity of the Ca2+-ATPase purified from the membrane. Reconstitution of the Ca2+-ATPase into dioleoylphosphatidylserine [di(C18:1)PS] or dioleoylphosphatidic acid [di(C18:1)PA] leads to a decrease in ATPase activity. Measurements of the quenching of the tryptophan fluorescence of the ATPase by brominated phospholipids give a relative binding constant for the anionic lipids compared with dioleoylphosphatidylcholine close to 1 and suggest that phosphatidic acid only binds to the ATPase at the bulk lipid sites around the ATPase. Addition of di(C18:1)PS or di(C18:1)PA to the ATPase in the short-chain dimyristoleoylphosphatidylcholine [di(C14:1)PC] reverse the effects of the short-chain lipid on ATPase activity and on Ca2+ binding, as revealed by the response of tryptophan fluorescence intensity to Ca2+ binding. It is concluded that the lipid headgroup and lipid fatty acyl chains have separate effects on the function of the ATPase. The anionic phospholipids have no significant effect on Ca2+ binding to the ATPase; the level of Ca2+ binding to the ATPase, the affinity of binding and the rate of dissociation of Ca2+ are unchanged by reconstitution into di(C18:1)PA. The major effect of the anionic lipids is a reduction in the maximal level of binding of MgATP. This is attributed to the formation of oligomers of the Ca2+-ATPase, in which only one molecule of the ATPase can bind MgATP dimers in di(C18:1)PS and trimers or tetramers in di(C18:1)PA. The rates of phosphorylation and dephosphorylation for the proportion of the ATPase still able to bind ATP are unaffected by reconstitution. Larger changes were observed in the level of phosphorylation of the ATPase by Pi, which became very low in the anionic phospholipids. The fluorescence response to Mg2+ for the ATPase labelled with 4-(bromomethyl)-6,7-dimethoxycoumarin was also changed in di(C18:1)PS and di(C18:1)PA, so that effects of Mg2+ became comparable with those seen on phosphorylation for the unreconstituted ATPase. The anionic phospholipids could induce a conformational change in the ATPase on binding Mg2+ equivalent to that normally induced by phosphorylation or by binding inhibitors such as thapsigargin.

Hydrophobic mismatch and the incorporation of peptides into lipid bilayers: a possible mechanism for retention in the Golgi

Preferential interaction of trans-membrane alpha-helices whose hydrophobic length matches the hydrophobic thickness of the lipid bilayer could be a mechanism of retention in the Golgi apparatus. We have used fluorescence methods to study the interaction of peptides Ac-K2-G-Lm-W-Ln-K2-A-amide (Pm+n) with bilayers of phosphatidylcholines with chain lengths between C14 and C24. The peptide P22 (m = 10, n = 12) incorporates into all bilayers, but P16 (m = 7, n = 9) does not incorporate into bilayers when the fatty acyl chain length is C24 and only partly incorporates into bilayers where the chain length is C22. The strongest binding is seen when the hydrophobic length of the peptide matches the calculated hydrophobic thickness of the bilayer. It is suggested that a too-thin bilayer can match to a too-long peptide both by stretching of the lipid and by tilting of the peptide. However, a too-thick bilayer can only match a too-thin peptide by compression of the lipid, which becomes energetically unfavorable when the difference between the bilayer thickness and the peptide length exceeds about 10 A. The presence of cholesterol in the bilayer leads to a marked reduction in the incorporation of P16 into bilayers where the chain length is C18. Hydrophobic mismatch could explain retention of proteins with short trans-membrane alpha-helical domains in the Golgi, the effect following largely from the low concentration of cholesterol in the Golgi membrane compared to that in the plasma membrane.

Binocular vertical diplopia

The assessment of a patient with binocular vertical diplopia begins with a thorough history and neuro-ophthalmologic examination. The neuro-ophthalmologic examination includes observation for a compensatory head, face, or chin position; ocular ductions and versions in the nine cardinal positions of gaze; the three-step test; the double Maddox rod test; indirect ophthalmoscopy to observe the location of the fovea in relationship to the optic nerve head to determine cyclodeviation; and the forced ductions test. Binocular vertical diplopia may be due to supranuclear processes, ocular motor nerve dysfunction, neuromuscular junction disease, diseases of eye muscle, mechanical processes causing vertical eye misalignment, and even retinal disease. In this article, the differential diagnosis of these processes is outlined.

Orbital involvement in allergic fungal sinusitis

BACKGROUND

Although allergic fungal sinusitis is a relatively common, noninvasive form of paranasal sinus mycosis, and despite frequent orbital involvement, there have been few reports of this condition in the ophthalmic literature.

METHODS

Two cases of allergic fungal sinusitis having orbital symptoms are described. The current classification, typical presentation, and ideal management of fungal sinusitis are reviewed.

RESULTS

Distinguishing radiologic and pathologic features were present in both patients. Aspergillus flavus was cultured in one case, and Bipolaris spicifera was cultured in the other.

CONCLUSIONS

Allergic fungal sinusitis is a unique subset of sino-orbital disease with highly characteristic clinical, radiologic, and pathologic features. Unlike invasive forms of mycotic disease, allergic fungal sinusitis may be managed adequately with surgical debridement, aeration of the involved sinuses, and systemic and topical corticosteroids.

Complete ophthalmoplegia after zoster ophthalmicus

Complete ophthalmoplegia following herpes zoster ophthalmicus (HZO) is rare. We report three cases of HZO-associated complete ophthalmoplegia and review thirteen additional cases reported in the English language medical literature over the past 30 years. HZO-associated complete ophthalmoplegia occurs mostly in individuals over the age of 50 years and usually occurs within one to two weeks of the development of cutaneous HZO. The prognosis for recovery is good, with-significant improvement typically seen within 2 months and complete or near resolution within 18 months time.

Clinical and magnetic resonance imaging features of Gradenigo syndrome

PURPOSE

To describe the clinical and magnetic resonance imaging findings of a patient with Gradenigo syndrome.

METHODS

A 4 1/2-year-old boy developed Gradenigo syndrome with unilateral facial pain, ophthalmoplegia, and facial weakness secondary to ipsilateral otitis media. The clinical, laboratory, and radiologic findings are discussed.

RESULTS

The patient was treated with antibiotics and had complete resolution of symptoms and signs.

CONCLUSION

Ophthalmologists should be aware of the potential for petrosal involvement of cranial nerves secondary to otitis media and Gradenigo syndrome.

Neuro-ophthalmologic manifestations of adenoid cystic carcinoma

Intracranial adenoid cystic carcinoma is uncommon. We report two unusual cases of intracranial adenoid cystic carcinoma. The first patient presented with a steroid-responsive optic neuropathy from an orbital mass that simulated orbital pseudotumor, and subsequently developed intracranial involvement, presumably by contiguous perineural spread. The second patient presented with proptosis of the left eye, right facial weakness and numbness, and an intracranial mass, presumably from hematogenous metastatic spread.

Acquired supranuclear ocular motor paresis following cardiovascular surgery

Acquired supranuclear ocular motor paresis is a rare disorder characterized by impaired saccadic and smooth pursuit eye movements in one or more directions of gaze. Vestibularly induced eye movements, however, are preserved. Six adult patients developed an acquired supranuclear ocular motor paresis following cardiopulmonary bypass surgery. Neuroimaging studies were normal in two patients and were consistent with small vessel ischemia in four patients. The mean cardiopulmonary bypass time was 132.3 min, and mean circulatory arrest time was 38.7 min; these were not outside established norms for this type of surgery. Patients undergoing cardiopulmonary bypass procedures with deep hypothermia are at risk for acquired supranuclear ocular motor paresis, but the development of this syndrome may not be predictable by duration of circulatory arrest or cardiopulmonary bypass times.

Ocular and orbital complications of intraarterial cisplatin. A case report

Despite advances in neurosurgery, radiation oncology, and chemotherapy, the prognosis for glioblastoma multiforme remains poor, with a median survival time of 11-12 months. Cisplatin (cis-diamminedichlorideplatinum II) is one treatment for glioblastoma multiforme. Higher response rates have been achieved by intraarterial (i.a.) infusion than by systemic infusion of this agent. Cisplatin therapy may cause neurologic complications, and i.a. delivery has been reported to cause ocular toxicity. We report a patient who experienced intraorbital and intraocular toxicity following supraophthalmic i.a. injection of cisplatin.

Presumed tuberculosis presenting as a cavernous sinus syndrome

Cavernous sinus involvement of tuberculosis is rare. We present a 65-year-old woman with extrapulmonary tuberculosis who presented with a cavernous sinus syndrome clinically. A cervical lymph node biopsy revealed non-caseating granulomas but cultures were eventually positive for M. tuberculosis.

Immunohistochemical characterization of inflammatory and proliferative events during chronic rejection in rat lung allografts

BACKGROUND

Chronic rejection is assumed to be the principle cause of airway injury leading to obliterative bronchiolitis (OB) after lung transplantation (Tx). To better understand the contribution of chronic rejection in the development of OB in allografted lungs, we examined the histopathological changes and cytokine expression in inadequately immunosuppressed rat lung allografts.

METHODS

Three groups of rats were studied: group I, control nontransplanted Lewis (Lew) rats (n=5); group II, syngeneic Lew-to-Lew isografts (n=25); and group III, Brown Norway-to-Lew allografts (n=25). Groups II and III received two single doses of cyclosporine on postoperative days 2-3. Transplanted animals were killed (n=5) at monthly intervals from 2 months to 6 months after Tx. Resected lungs were stained with hematoxylin and eosin, Masson's trichrome, and Van Gieson's elastin, and immunostained with antisera to interleukin (IL)-1beta, IL-8, and basic fibroblast growth factor (bFGF). The intensity of immunostaining was graded from 0 to 4 (0=no staining, 4=strong staining).

RESULTS

In groups I and II, normal airways and vessels were observed. Minimal intensity and distribution of immunostaining for all markers were detected in groups I and II. Group III allografts demonstrated acute grade II-III vascular rejection with mild bronchiolar injury and inflammation at 2 months after Tx. At 6 months after Tx, all allografts demonstrated severe and diffuse chronic vascular rejection. Late airway changes consistent with OB were detected in four of five allografts, however, these lesions were expressed infrequently. Immunohistochemical findings revealed moderate to strong expression for IL-8 and bFGF over the airway epithelium, acute and chronic inflammatory cells, and fibroblasts in allografts at 2 months after Tx. Despite focal development of OB at 6 months, intensity and distribution of immunostaining significantly decreased for all three cytokine markers.

CONCLUSIONS

Inadequate immunosuppression of rat lung allografts leads primarily to chronic vascular rejection but fails to induce severe and diffuse development of OB. In this animal model, cytokines IL-1beta, IL-8, and bFGF are likely to play an important role in the early inflammatory phase but not during the late proliferative events of chronic rejection.

A survey on minimally invasive coronary artery bypass grafting

BACKGROUND

There is increasing interest in performing minimally invasive coronary artery bypass grafting. To evaluate the current level of acceptance and utility of this procedure a survey of 162 cardiothoracic surgeons was conducted.

RESULTS

Currently only 16% of surveyed surgeons performed more than 10 minimally invasive coronary artery bypass grafting procedures. Most were less than 55 years old and in private practice. The majority predicted that it will be indicated in less than 25% of coronary artery bypass grafting cases and considered minimally invasive coronary artery bypass grafting a modification of existing techniques rather than investigational. Most believed exposure and stabilization of the coronary arteries on the beating heart to be the most challenging part and expressed concern with quality of the anastomosis.

CONCLUSIONS

We conclude that minimally invasive coronary artery bypass grafting is rapidly gaining acceptance in younger surgeons as techniques are improved. Despite concerns with adequacy of anastomosis the procedure is not considered investigational and follow-up is not rigorous.