Endoscopic and histopathologic reflux-associated mucosal damage in the remnant esophagus following transthoracic esophagectomy for cancer-5-year long-term follow-up

Gastroesophageal reflux is a common problem following esophagectomy and reconstruction with gastric interposition. Despite a routine prescription of proton pump inhibitors, reflux-associated mucosal damage in the remnant esophagus is frequently observed. Purpose of this study is to evaluate mucosal damage in the esophageal remnant during long-term follow-up and to compare the prevalence of this damage between the subgroups of esophageal squamous cell and adenocarcinoma. All patients undergoing transthoracic Ivor-Lewis esophagectomy were prospectively entered in our IRB approved database. All patients underwent a routine check-up program with yearly surveillance endoscopies following esophagectomy. Only patients with a complete follow-up were included into this study. Endoscopic and histopathologic mucosal changes of the remnant esophagus were analyzed in close intervals. A total of 50 patients met the inclusion criteria, consisting of 31 adenocarcinomas (AC) and 19 squamous cell carcinomas (SCC). Mucosal damage was already seen 1 year after surgery in 20 patients macroscopically (43%) and in 21 patients microscopically (45%). At 5-year follow-up the prevalence for macroscopic and microscopic damage was 55% and 60%, respectively. The prevalence of mucosal damage was higher in AC patients than in SCC patients (1y-FU: 51% [AC] vs. 28% [SCC]; 5y-FU: 68% [AC] vs. 35% [SCC], P < 0.05). Newly acquired Barrett's esophagus was seen in 10 patients (20%) with two of those patients (20%) showing histopathologic proof of neoplasia. This study shows a high prevalence of reflux-associated mucosal damage in the remnant esophagus one year out of surgery and only a moderate increase in prevalence in the following years. Mucosal damage was more frequently seen in AC patients and the occurrence of de-novo Barrett's esophagus and de-novo neoplasia was high. Endoscopic surveillance with targeted biopsies seems to be an indispensable tool to follow patients after esophagectomy appropriately.

In vitro effects of 17 beta-oestradiol on the sensitivity of receptors coupled to adenylate cyclase on striatal neurons in primary culture

Pretreatment of intact striatal neurons from the mouse embryo in primary culture with 17 beta-oestradiol (10(-9) M), 24 hours) enhanced the stimulation of adenylate cyclase activity induced by either dopamine (D1 receptors), isoproterenol, serotonin or 2-chloroadenosine (maximal effective concentrations) but suppressed inhibitory responses evoked by agonists of D2-dopaminergic or enkephalin (mu and delta) receptors. Binding studies indicated that some of these effects are (beta 1) or are not (D1 and D2) associated with changes in the number of receptors. Similar effects were partially seen with testosterone but not with 17 alpha-oestradiol, progesterone or dexamethasone and those induced by 17 beta-oestradiol were abolished when cells were exposed to inhibitors of mRNA transcription (alpha-amanitin) or protein synthesis (cycloheximide). Modifications in the properties of Gs or Go,i proteins were postulated because the number of adenylate cyclase catalytic subunits was not affected by 17 beta-oestradiol pretreatment. Results of ADP-ribosylation experiments with cholera toxin or pertussis toxin and of immunoblot experiments with anti-G alpha o and anti-G beta sera led us to suggest that 17 beta-oestradiol induces qualitative modifications in Go,i proteins leading to a stabilization of the associated form of the heterotrimer G alpha o,i beta gamma. In fact, pretreatment with pertussis toxin (which impairs G alpha o,i beta gamma dissociation) mimics the effects of 17 beta-oestradiol on responses of adenylate cyclase to stimulatory and inhibitory agonists.

2-Deoxyglucose and NMDA inhibit protein synthesis in neurons and regulate phosphorylation of elongation factor-2 by distinct mechanisms

Cerebral ischaemia is associated with brain damage and inhibition of neuronal protein synthesis. A deficit in neuronal metabolism and altered excitatory amino acid release may both contribute to those phenomena. In the present study, we demonstrate that both NMDA and metabolic impairment by 2-deoxyglucose or inhibitors of mitochondrial respiration inhibit protein synthesis in cortical neurons through the phosphorylation of eukaryotic elongation factor (eEF-2), without any change in phosphorylation of initiation factor eIF-2alpha. eEF-2 kinase may be activated both by Ca(2+)-independent AMP kinase or by an increase in cytosolic Ca2+. Although NMDA decreases ATP levels in neurons, only the effects of 2-deoxyglucose on protein synthesis and phosphorylation of elongation factor eEF-2 were reversed by Na(+) pyruvate. Protein synthesis inhibition by 2-deoxyglucose was not as a result of a secondary release of glutamate from cortical neurons as it was not prevented by the NMDA receptor antagonist 5-methyl-10,11-dihydro-5H-dibenzo-(a,d)-cyclohepten-5,10-imine hydrogen maleate (MK 801), nor to an increase in cytosolic-free Ca2+. Conversely, 2-deoxyglucose likely activates eEF-2 kinase through a process involving phosphorylation by AMP kinase. In conclusion, we provide evidence that protein synthesis can be inhibited by NMDA and metabolic deprivation by two distinct mechanisms involving, respectively, Ca(2+)-dependent and Ca(2+)-independent eEF-2 phosphorylation.

Advances in the management of lower eyelid retraction

The purpose of this article is to describe the newer surgical techniques and materials available for repair of lower eyelid retraction. The anatomic basis, classification, and prevention of lower eyelid retraction are explored, as well as traditional methods of surgical management. Two case reports involving the successful use of acellular human dermis (AHD) for lower eyelid retraction are presented. Lower eyelid retraction is associated with a variety of etiologies, which mandate that the surgical repair be directed toward correction of the anatomic abnormality in each patient. Each surgical procedure and material used in the repair of eyelid retraction is associated with unique advantages and disadvantages. AHD has found multiple uses in oculoplastics, including reconstruction of the middle and posterior lamellae in eyelid retraction. An understanding of the mechanistic basis of lower eyelid retraction and familiarity with newer techniques and materials enable the oculoplastic surgeon to modify and individualize the operative repair, resulting in better surgical outcomes.

Tarsorrhaphy: clinical experience from a cornea practice

PURPOSE

To evaluate indications, success rate, and complications of tarsorrhaphy in a cohort of cornea and external disease patients.

METHODS

In this study, charts of patients who underwent tarsorrhaphies from January 1, 1995, to September 30, 2000, were retrospectively evaluated. Information reviewed included patient age and sex, indication for tarsorrhaphy, duration of signs and symptoms before tarsorrhaphy, time to epithelial healing after tarsorrhaphy, type of tarsorrhaphy (temporary/permanent), complications, timing of tarsorrhaphy removal, recurrence of signs and symptoms after complete or partial opening of the tarsorrhaphy, number of tarsorrhaphies needed to be replaced or extended, and duration of follow up.

RESULTS

Seventy-seven patients were included in this study. Indications for a tarsorrhaphy were persistent epithelial defects or other ocular surface problems associated with neurotrophic ulcers, penetrating keratoplasty (PK), postinfection, exposure keratopathy, surgery other than PK, dry eye syndrome, radiation keratopathy, ocular cicatricial pemphigoid, Stevens-Johnson syndrome, entropion, and application of tissue adhesive. The epithelial defects in 70 (90.9%) of the 77 eyes completely resolved. Overall, the mean duration of signs and symptoms before tarsorrhaphy was 89.8 +/- 27.8 days, and time-to-healing after tarsorrhaphy was 18.0 +/- 2.0 days. The difference between the duration of the signs and symptoms before tarsorrhaphy and time-to-healing after tarsorrhaphy was statistically significant ( p = 0.01). Of the 77 tarsorrhaphies, 24 (31.2%) were temporary and 53 (68.8%) were permanent. Complications after tarsorrhaphy included trichiasis, adhesion between upper and lower lids after tarsorrhaphy lysis, premature opening of the temporary tarsorrhaphy, pyogenic granuloma, and keloid formation of the eyelid.

CONCLUSION

Tarsorrhaphy is a very effective and safe procedure in the management of nonhealing epithelial defects and other surface problems, with a 90.9% success rate and only minor complications.

Update on orbital trauma

Several advances in orbital trauma are presented. From new techniques in radiologic imaging, the use of endoscopy, and new treatment indications for certain types of fractures. Many of these advances result in decreased morbidity and improved functional results in the treatment of orbital and periorbital trauma.

A new analysis method of single molecule fluorescence using series of photon arrival times: theory and experiment

Up to now, single molecule fluorescence experiments were performed by dividing the time into a set of intervals and to observe the number of fluorescence photons arriving in each interval. It is obvious that the detected photons carry less information than the arrival times of the photons themselves. From the arrival times, one can still calculate the number of photons in any user-defined interval; whereas, when only the number of photons in an interval are recorded, information about their positions in time is lost. Therefore, we present a new analysis method of single molecule fluorescence data based on the positions in time of the detected fluorescence photons. We derive mathematically different statistical characteristics describing the single molecule fluorescence experiment assuming an immobilized molecule. The theory of point processes using the generating functionals formalism is ideally suited for a consistent description, linking the statistical characteristics of the excitation and detected photons to the statistical characteristics of the single motionless molecule. We then use computer-generated data sets mimicking the single molecule fluorescence experiment to explore the parametric estimation of mono- and bi-exponential single molecule impulse response functions (SMIRFs) via the following statistical characteristics: the probability density distributions (pdd) of the single and first photocount time positions in a user-defined detection interval, the probability distribution of the number of photocounts per user-defined detection interval, the time correlation function and the pdd of the time interval between two consecutive photocounts. It is shown that all of the above characteristics ensure a satisfactory recovery of the decay time of mono-exponential SMIRFs for a broad range of excitation intensities and widths of user-defined detection intervals. For bi-exponential SMIRFs, the selection of the experimental conditions is more critical and dependent on the detection procedure. At lower excitation intensities it is advantageous to use the pdds of the single and first photocount time occurrences in the user-defined detection interval. To show the practical usefulness of the new analysis method, series of photon arrival times from immobilized single molecules of DiI and rhodamine 6G were analyzed to estimate triplet lifetimes and intersystem crossing yields.

Triplet states as non-radiative traps in multichromophoric entities: single molecule spectroscopy of an artificial and natural antenna system

Energy transfer in antenna systems, ordered arrays of chromophores, is one of the key steps in the photosynthetic process. The photophysical processes taking place in such multichromophoric systems, even at the single molecule level, are complicated and not yet fully understood. Instead of directly studying individual antenna systems, we have chosen to focus first on systems for which the amount of chromophores and the interactions among the chromophores can be varied in a systematic way. Dendrimers with a controlled number of chromophores at the rim fulfill those requirements perfectly. A detailed photophysical study of a second-generation dendrimer, containing eight peryleneimide chromophores at the rim, was performed 'J. Am. Chem. Soc., 122 (2000) 9278'. One of the most intriguing findings was the presence of collective on/off jumps in the fluorescence intensity traces of the dendrimers. This phenomenon can be explained by assuming a simultaneous presence of both a radiative trap (energetically lowest chromophoric site) and a non-radiative trap (triplet state of one chromophore) within one individual dendrimer. It was shown that an analogue scheme could explain the collective on/off jumps in the fluorescence intensity traces of the photosynthetic pigment B-phycoerythrin (B-PE) (Porphyridium cruentum). The different values of the triplet lifetime that could be recovered for a fluorescence intensity trace of B-PE were correlated with different intensity levels in the trace, suggesting different chromophores acting as a trap as function of time.

Angle-closure glaucoma in association with orbital pseudotumor

PURPOSE

To describe the pathophysiology of angle-closure glaucoma secondary to idiopathic inflammatory orbital pseudotumor.

DESIGN

Retrospective, small noncomparative case series.

PARTICIPANTS

Three patients with angle-closure glaucoma and orbital pseudotumor.

METHODS

The pathophysiology of this entity was investigated using magnetic resonant imaging (MRI) and ultrasound biomicroscopy (UBM).

MAIN OUTCOMES MEASURES

Clinical features, anterior chamber angle configuration, and intraocular pressure.

RESULTS

Angle closure from anterior rotation of the ciliary body caused by choroidal effusions secondary to pseudotumor was demonstrated using MRI and UBM. Two of the three cases resolved after treatment for orbital pseudotumor.

CONCLUSIONS

Idiopathic orbital pseudotumor is a cause of secondary angle-closure glaucoma. The mechanism of angle closure is anterior rotation of the ciliary body secondary to choroidal effusions resulting from the orbital inflammation.

Intramolecular energy hopping and energy trapping in polyphenylene dendrimers with multiple peryleneimide donor chromophores and a terryleneimide acceptor trap chromophore

Intramolecular Förster-type excitation energy transfer (FRET) processes in a series of first-generation polyphenylene dendrimers substituted with spatially well-separated peryleneimide chromophores and a terryleneimide energy-trapping chromophore at the rim were investigated by steady-state and time-resolved fluorescence spectroscopy. Energy-hopping processes among the peryleneimide chromophores are revealed by anisotropy decay times of 50--80 ps consistent with a FRET rate constant of k(hopp) = 4.6 ns(-1). If a terryleneimide chromophore is present at the rim of the dendrimer together with three peryleneimide chromophores, more than 95% of the energy harvested by the peryleneimide chromophores is transferred and trapped in the terryleneimide. The two decay times (tau(1) = 52 ps and tau(2) = 175 ps) found for the peryleneimide emission band are recovered as rise times at the terryleneimide emission band proving that the energy trapping of peryleneimide excitation energy by the terryleneimide acceptor occurs via two different, efficient pathways. Molecular- modeling-based structures tentatively indicate that the rotation of the terryleneimide acceptor group can lead to a much smaller distance to a single donor chromophore, which could explain the occurrence of two energy-trapping rate constants. All energy-transfer processes are quantitatively describable with Förster energy transfer theory, and the influence of the dipole orientation factor in the Förster equation is discussed.

Primary intraepithelial sebaceous gland carcinoma of the palpebral conjunctiva

Sebaceous gland carcinoma usually arises from meibomian or Zeis glands deep within the eyelid, but it can rarely arise within the conjunctival epithelium without a deep component. We describe a woman with a history of chronic blepharoconjunctivitis unresponsive to topical medications. Examination disclosed confluent papillary hypertrophy of the upper palpebral conjunctiva and deposits of white flaky material. Tarsoconjunctival punch biopsy revealed intraepithelial sebaceous gland carcinoma. Management consisted of frozen section-controlled complete tumor excision with removal of the entire posterior lamella of the right upper eyelid, cryotherapy to the margins, and reconstruction. Histopathologic analysis confirmed primary sebaceous gland carcinoma localized to the conjunctival epithelium without involvement of underlying meibomian or Zeis glands or the caruncle. Patients with unexplained chronic unilateral blepharoconjunctivitis or papillary hypertrophy of the palpebral conjunctiva should be considered for biopsy to rule out neoplasia, even when there is no sign of an underlying eyelid mass.

An Experimental Comparison of the Maximum Likelihood Estimation and Nonlinear Least-Squares Fluorescence Lifetime Analysis of Single Molecules

Two procedures based on the weighted least-squares (LS) and the maximum likelihood estimation (MLE) method to confidently analyze single-molecule (SM) fluorescence decays with a total number (N) of 2,500-60,000 counts have been elucidated and experimentally compared by analyzing measured bulk and SM decays. The key observation of this comparison is that the LS systematically underestimates the fluorescence lifetimes by approximately 5%, for the range of 1,000-20,000 events, whereas the MLE method gives stable results over the whole intensity range, even at counts N less than 1,000, where the LS analysis delivers unreasonable values. This difference can be attributed to the different statistics approaches and results from improper weighting of the LS method. As expected from theory, the results of both methods become equivalent above a certain threshold of N detected photons per decay, which is here experimentally determined to be approximately 20,000. In contrast to the bulk lifetime distributions, the SM fluorescence lifetime distributions exhibit standard deviations that are sizably larger than the statistically expected values. This comparison proves the strong influence of the inhomogenuous microenvironment on the photophysical behavior of single molecules embedded in a 10-30-nm thin polymer layer.

Image-guided transorbital roof craniotomy via a suprabrow approach: a surgical series of 72 patients

OBJECTIVE

Many subfrontal and orbitofrontal craniotomy techniques have been developed. We present our results with the transorbital roof craniotomy, a frontal craniotomy that incorporates the orbital roof and is performed via a suprabrow incision. This technique was used in 72 patients, primarily for tumor resection.

METHODS

Charts were retrospectively reviewed for all patients undergoing transorbital procedures. A total of 72 patients underwent 82 transorbital craniotomies from September 1995 to July 1999. The primary indication for the transorbital approach was mass lesion of the orbit, anterior fossa, or parasellar region.

RESULTS

A total of 47 women and 25 men with a mean age of 53 years underwent 82 procedures. The primary pathological finding was meningioma, which occurred in 40 patients (55.6%), followed by craniopharyngioma (6.9%), pituitary macroadenoma (6.9%), schwannoma (5.5%), and hemangioma (5.5%). Simpson Grade I or II resection was achieved in 54% of patients, with Simpson Grade III to V resection achieved in the remaining 46%. Forty-one patients presented with visual loss in 43 cases, with 44.2% experiencing postoperative visual improvement, 46.5% remaining unchanged, and 9.3% worsening. Overall morbidity was 18.4%, with cerebrospinal fluid leak being the most common complication (6.6%). No patients died.

CONCLUSION

The transorbital roof craniotomy is an evolutionary approach that provides excellent exposure to the orbit, anterior fossa, and parasellar region with little significant morbidity and, in our series, no mortality. Although we have used this approach primarily for resection of mass lesions, future directions for this procedure will likely lie in treating vascular lesions and lesions of the interpeduncular fossa.

Ophthalmic plastic applications of acellular dermal allografts

PURPOSE

Clinical problems of contracted conjunctival fornices, superior sulcus defects, and soft tissue contour defects in the periorbital region have not shown good, sustained results with a range of autologous and alloplastic implants. AlloDerm (Lifecell Corp., Woodlands, TX) is an acellular dermal graft processed from human donor tissue. The authors sought to assess the efficacy of AlloDerm as a soft tissue replacement in a variety of oculoplastic applications.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Twenty-three patients.

METHODS

Applications were broadly classified as barrier/scaffolding (i.e., primary and secondary implant coverage, lid spacer graft) and volume augmentation (i.e., superior sulcus and other periorbital soft tissue contour defects). Barrier grafts were applied as single sheets. Stacked sheets or rolled grafts were used for augmentation. Collectively, this material was used in 29 cases with 3 to 16 months' follow-up.

MAIN OUTCOME MEASURES

Clinical evaluation of outcome and complications.

RESULTS

As a soft tissue scaffolding and barrier implant, AlloDerm persisted sufficiently to permit repopulation with native tissue. Rolled/stacked implants demonstrated unpredictable resorption. Upper eyelid grafts seemed to have higher resorption rates than lower eyelid grafts. One case of anophthalmic superior sulcus augmentation required two revision surgeries to provide sufficient volume augmentation. The grafts were well tolerated, with no cases of infection or explanation.

CONCLUSION

Acellular human dermis is an excellent barrier and reconstructive grafting material that provides an alternative to autologous grafts and other alloplastic material, avoids harvesting autologous tissue, possesses excellent handling properties, and is associated with minimal inflammation. Long-term follow-up is required to evaluate persistence.

Pyruvate and lactate protect striatal neurons against N-methyl-D-aspartate-induced neurotoxicity

A sustained release of glutamate contributes to neuronal loss during cerebral ischaemia. Using cultured mouse striatal neurons, we observed that glucose deprivation, which occurs in this pathological process, enhanced the N-Methyl-D-aspartate (NMDA)- or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)-induced neurotoxicity. The end products of glycolysis, lactate and pyruvate, strongly protected neurons from these neurotoxic effects. The neuroprotective effect of pyruvate (which is more prominent in the absence of glucose) was not related to its ability to react with H2O2 by a decarboxylation process. Pyruvate and L-lactate strongly counteracted the deep decrease in the neuronal ATP content induced by NMDA, indicating that they might protect striatal neurons by rescuing cellular energy charge. Addition of MK-801 after the NMDA withdrawal completely protected neurons, suggesting that NMDA neurotoxicity resulted from a delayed NMDA receptor activation probably linked to a delayed release of an endogenous agonist in the extracellular medium. The strong accumulation of extracellular glutamate which was found in both sham and NMDA-treated cultures was markedly decreased by pyruvate. Thus, pyruvate might also exert its protecting activity by decreasing the delayed accumulation of glutamate which seemed to be neurotoxic only after a preexposure of neurons to NMDA.

Removal of orbital apex hemangioma using new transorbital craniotomy through suprabrow approach

PURPOSE

To describe a technique combining the expertise of the oculoplastic orbital surgeon and the neurosurgeon which allows access to the posterior orbit, anterior fossa, cavernous sinus and suprasellar region with minimal brain manipulation.

METHODS

A transorbital craniotomy through a suprabrow incision is performed removing part of the frontal bone and orbital roof as a single piece. This allows wide access with only minimal, if any, brain retraction. The superior, lateral and medial orbit is clearly visualized, as well as the apex of the orbit. The bone flap is replaced at the end of the case with Tantalum plates.

RESULTS

A cavernous hemangioma at the orbital apex was removed without complications. The exposure was superb and allowed identification and preservation of orbital structures.

CONCLUSIONS

Transorbital craniotomy allows for wide access to the posterior orbit and parasellar region and anterior fossa of the brain with minimal brain manipulation. The use of a suprabrow incision results in an excellent cosmetic result. There is minimal postoperative morbidity, which decreases hospitalization time.

Thyroid-related ophthalmology

The classic clinical triad of Graves' disease is hyperthyroidism, diffuse goiter, and exophthalmos. Caring for those undergoing the orbital changes of Graves' ophthalmopathy is often challenging, even as our understanding of the disease progresses. New therapeutic modalities for both Graves' disease and the associated orbitopathy have hastened rehabilitation and improved outcomes, although this disease continues to elude definitive cure.

Balloon catheter dilation for treatment of adults with partial nasolacrimal duct obstruction: a preliminary report

PURPOSE

The purpose of this study is to determine the efficacy and morbidity of balloon catheter dilation for treatment of partial acquired nasolacrimal duct obstruction in adults with epiphora.

METHODS

We performed balloon dacryocystoplasty prospectively on a series of 15 partial nasolacrimal duct obstructions in 13 adults with epiphora. Partial obstruction was diagnosed by a negative Jones-1 test and canalicular irrigation revealing simultaneous reflux through the opposing punctum and drainage into the nose. Balloon dacryocystoplasty was performed under local anesthesia using an antegrade insertion technique. Silicone intubation of the nasolacrimal system was performed immediately after balloon catheter dilation, and the tubes were removed 2 months postoperatively.

RESULTS

Success was measured objectively and subjectively at follow-up examinations 2 months and 6 months after the procedure. At 2 months, 11 (73%) of 15 obstructions were open on irrigation, with subjective success (Munk, grade 0 or grade 1) reported in 13 (87%) of 15 obstructions. At 6 months, 11 (73%) of 15 obstructions were open on irrigation, with subjective success (Munk, grade 0 or grade 1) reported in 9 (60%) of 15 obstructions.

CONCLUSIONS

Balloon dacryocystoplasty may be a satisfactory primary treatment for adults with acquired partial nasolacrimal duct obstruction who exhibit no clinical signs of chronic infection. Additional long-term observations following balloon dacryocystoplasty are required.

Gore-Tex as an orbital implant material

The use of Gore-Tex (W. L. Gore & Associates, Flagstaff, AZ, U.S.A.) spheres as orbital implants is investigated. The left eyes of six New Zealand white rabbits were enucleated and spherical implants made of modified Gore-Tex were implanted. After 6 weeks of follow-up, the implants were harvested. No rabbit developed a postoperative infection and no cases of exposure or extrusion were noted. Histopathologic study revealed varying degrees of acute and chronic inflammation surrounding each implant. There was also evidence of inflammatory infiltration and fibrovascular ingrowth into each implant to a maximum distance of 500 microns. This preliminary study demonstrates that the Gore-Tex implant is well tolerated in vivo, allows cellular ingrowth, and may have a role as a permanent implant.

Enhancement of the cosmetic and functional outcome of enucleation with the conical orbital implant

OBJECTIVE

The authors evaluated a new design of a conical-shaped enucleation implant to help minimize the occurrence of superior sulcus defects and maximize motility of the prosthesis. The implant shape is a modification of a sphere. It has a posterior conical projection paralleling the orbital walls, a superior projection supporting the soft tissues of the upper eyelid sulcus, a flattened anterior surface, and channels for each rectus muscle.

DESIGN

The study design was a consecutive case series from the Oculoplastics and Orbital Service of the Massachusetts Eye and Ear Infirmary. INTERVENTION/PARTICIPANTS: A total of 45 patients (average age, 40 years; range, 13-75 years) had placement of a conical implant (39 primary enucleations, 6 secondary implants) with a minimum of 1 year' follow-up (range, 12-36 months). All of the primary enucleations and two of the secondary procedures had the anterior portion of the implant covered with autologous fascia. Four of the secondary implants were covered with pseudocapsule harvested from the explanted primary implant. Prostheses were fit 6 to 10 weeks after surgery.

MAIN OUTCOME MEASURES

Postoperative appearance of patients was assessed by qualitative appearance of the superior sulcus and prosthetic motility, and subjectively by patients' satisfaction.

RESULTS

A total of 43 patients had minimal or no superior sulcus defect, whereas 2 patients had moderate defects. There were no severe sulcus defects. All patients were satisfied with their appearance and did not seek further surgery to correct any upper sulcus asymmetry. Prosthetic motility with small-angle ductions (<10 degrees) and saccades was good in all cases. There were two cases of conjunctival wound dehiscence. Both occurred within 4 weeks of surgery. One wound dehiscence was sutured, whereas the other healed spontaneously. There were no cases of implant extrusion, migration, or infection.

CONCLUSION

The conical orbital implant provides appropriate reconstitution of orbital volume while minimizing superior sulcus defects with adequate prosthetic motility.

Reduced glucose metabolism enhances the glutamate-evoked release of arachidonic acid from striatal neurons

Glucose deprivation potentiates the glutamate receptor-evoked release of arachidonic acid from cultured mouse striatal neurons. In this study we investigated whether this potentiation would be modified by the end-products of glycolysis. These enhanced responses were completely reversed by the addition of increasing concentrations of either lactate or pyruvate. This reversal was not due to increased osmolarity as substituting sucrose for lactate or pyruvate did not mimic their effects. In contrast, in the presence of glucose, neither lactate nor pyruvate was effective. Furthermore, these monocarboxylic acids rescued neuronal respiration in the absence of glucose. Inhibiting glycolysis with iodoacetate in the presence of glucose reproduced the potentiated glutamate-evoked release of arachidonic acid observed following glucose deprivation and reduced neuronal respiration to the same extent as that observed in the absence of glucose. All of these effects were overcome by the addition of either lactate or pyruvate. The reversal of the potentiated glutamate-evoked release of arachidonic acid by lactate or pyruvate was inhibited by a specific inhibitor of monocarboxylic acid transport, alpha-cyano-4-hydroxycinnamic acid, suggesting that lactate and pyruvate act intracellularly. Therefore, we propose that the enhanced release of arachidonic acid evoked by glutamate during glucose deprivation results from reduced glycolysis and hence from a depletion of lactate or pyruvate.

Lasers in oculoplastic surgery

Applications of laser-assisted surgery in oculoplastics are varied because the enormous scope of the specialty overlaps with ear, nose and throat, dermatology, plastic surgery, and ophthalmology, for example. All of these specialties have applications for lasers that in one fashion or another find their way into our armamentarium. In this article we present the last year's advances in laser applications in oculoplastics. By far, endonasal dacryocystorhinostomies are the most controversial and interest producing. Several articles address different approaches and conclusions. No final determination is available yet as to the effectiveness and ultimate success of this procedure. Dermatologic surgery for lesion removal and for cosmetic surgery also features in this year's review. The use of lasers for tattoo removal was reported in detail in a superb article. Overall there were no major breakthroughs in laser surgery, however, several well-thought-out articles have added to our understanding of this surgical modality.

Oxygen free radicals enhance the nitric oxide-induced covalent NAD(+)-linkage to neuronal glyceraldehyde-3-phosphate dehydrogenase

Nitric oxide (NO) induces a covalent modification of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from various tissues. This phenomenon, which has previously been interpreted as an auto-ADP-ribosylation, is in fact a covalent binding of NAD+ to the enzyme. In the present study, we show that 3-morpholino-sydnonimine (SIN-1) is much more efficient than sodium nitroprusside (SNP) in stimulating the covalent labelling of GAPDH from cultured striatal neurones in the presence of [adenylate-32P]NAD+ (877 +/- 110 and 266 +/- 33% increase in NAD(+)-labelling induced by maximally effective concentrations of SIN-1 and SNP respectively). The difference in the efficacy of both NO-generating compounds could be due to the additional release of superoxide by SIN-1, since superoxide dismutase and the nitrone 5,5'-dimethyl pyrroline-1-oxide markedly inhibited the SIN-1-induced covalent binding of NAD+ to GAPDH. Catalase and selective scavengers of hydroxyl radicals, mannitol and dimethyl sulphoxide, did not alter the SIN-1-induced covalent modification of GAPDH, ruling out the involvement of hydroxyl radicals in this phenomenon. Supporting further a role of oxygen free radicals in the NAD+ linkage to GAPDH, pyrogallol, a superoxide generator, which alone was ineffective, potentiated the SNP-evoked response. The NAD+ linkage to neuronal GAPDH measured in the presence of NO and superoxide probably involves sulphydryl groups, since the radiolabelling of the protein was reversed by exposure to HgCl2 and prevented by pretreatment with the alkylating agent N-ethylmaleimide. Moreover, the NO-induced inhibition of GAPDH activity was enhanced by pyrogallol, which was ineffective alone. In conclusion, the present study indicates that superoxide anions potentiate NO-induced covalent NAD(+)-linkage to GAPDH and enzyme inactivation.

Nicotine protects cultured striatal neurones against N-methyl-D-aspartate receptor-mediated neurotoxicity

The role of cholinergic mechanisms in N-methyl-D-aspartate (NMDA)-mediated neuronal death was investigated using mouse striatal neurones in primary culture. A 30 min exposure of striatal neurones to increasing concentrations of NMDA resulted 24 h later in dramatic neuronal degeneration as assessed by MTT staining, crystal violet incorporation and determination of microtubule-associated protein 2. The NMDA-induced neurodegeneration was strongly inhibited by the co-application of two non-selective cholinergic agonists, acetylcholine or carbachol. This protective effect appears to be mediated by nicotinic receptors since it was insensitive to the muscarinic antagonist atropine but mimicked by nicotine, nornicotine and 1,1-dimethyl-4-phenyl-piperazinium. Moreover, the nicotine-evoked neuroprotection was inhibited by the central nicotinic antagonist hexamethonium. Therefore, this study suggests that cholinergic interneurones play an important role in neuronal survival in the striatum.

Transcription of the rat dopamine-D2-receptor gene from two promoters

Modulation of the expression of the D2-dopamine receptor gene is involved in several pathological and developmental circumstances. The gene and the corresponding promoter regions of the rat D2 receptor were isolated and partly characterized to study its regulation. The rat D2-receptor gene spans at least 50 kb, and possesses eight exons; its organization was compared to those of the other dopamine-receptor genes in a phylogenetic perspective. The gene contains two transcription-start sites: the major one is located about 320 bp upstream from the 3' end of the first exon, and a minor site is 70 bp further upstream. Transient-expression assays with fusion constructs comprising fragments of the D2-promoter region and the luciferase reporter gene confirmed the existence of two independent, TATA-lacking promoters. Both promoters separately induced transcription of the luciferase gene in C6 glioma, primary fibroblasts, GH3 and MMQ pituitary cell lines, among which only the MMQ cells normally express the D2 receptor. Transcription is enhanced by the reunion of the two promoters, and modified by the addition of upstream sequences. Thus the 1-kb promoter region analysed does not contain all the elements necessary to confer tissue-specific expression of the gene, but does carry some positive and negative regulatory elements, which remain to be characterized.

Regulation of the quail tyrosine hydroxylase gene in neural crest cells by cAMP and beta-adrenergic ligands

Expression of tyrosine hydroxylase (TH), the rate-limiting enzyme of catecholamine (CA) synthesis, was studied in quail neural crest (NC) cultures to investigate the role of environmental factors in the development of the adrenergic phenotype. First, the activity of the quail TH gene promoter was analyzed in immortalized quail NC cells by transient transfection assay. We found that chick embryo extract (CEE), which is known to trigger adrenergic differentiation of NC cells in vitro, strongly enhanced reporter gene transcription. A sequence of only 77 nucleotides, including a cAMP-responsive element, was sufficient to elicit this response. Implication of cAMP in the CEE effect was further supported by the fact that CEE produced a stimulation of adenylate cyclase activity that was sensitive to beta-adrenoreceptor antagonists. Moreover, stimulation of TH gene expression by CEE could be reduced by beta-adrenergic antagonists or CA-depleted extract. We have subsequently investigated the possibility that TH expression during differentiation of nontransformed NC cells could also be influenced by CA via the cAMP pathway. In dissociated cultures of 3-day-old quail sclerotomes and of 2-day-old quail trunk NC, differentiation of TH+ cells was induced in the presence of forskolin, an activator of adenylate cyclase, and modulated by beta-adrenoreceptor ligands. In particular, the adrenergic-promoting effect of 10% CEE on trunk NC cultures was inhibited by beta-adrenoreceptor antagonists or by eliminating CA from the extract. In conclusion, these data suggest that CA (through activation of beta-adrenergic receptors and cAMP production) can stimulate the initial expression of TH in cultured NC cells and enhance TH transcription in immortalized NC cells. This supports the notion that exogenous CA, which is present in the early embryo, may promote the differentiation of sympathoadrenal precursors in vivo by stimulating TH gene activity.

D2-dopaminergic agonist quinpirole and 8-bromo-cAMP have opposite effects on Go alpha GTP-binding protein mRNA without changing D2 dopamine receptor mRNA levels in striatal neurones in primary culture

Long-term coordinated regulations (during development or by agonists and second messenger molecules) of the expression of mRNAs encoding D2-dopamine (DA) receptors and D2 receptor-linked Go alpha proteins have been studied by Northern blot analysis in mouse embryonic striatal neurones in primary culture. During the course of the cell culture, the levels of both mRNAs increased, in conjunction with the maturation of the neurones. When the preparation was treated with the D2-DA agonist quinpirole (5-15 hrs, 10(-4) M), which decreases cAMP in these neurones, the levels of Go alpha mRNAs were enhanced whereas that of the D2 mRNA remained unchanged. Conversely, the Go alpha mRNAs, but not the D2 mRNA, decreased when the neurones were exposed to 8-bromo-cAMP (16 hrs, 10(-6) M). It is concluded that, in these experimental conditions where neurones have not yet established their connexions, the longterm regulation of the membrane transmission of D2-DA signal might implicate mainly the Go alpha encoding gene.

Reversal of multidrug resistance by two novel indole derivatives

Two new fused indoles were found to overcome multidrug resistance in P388/Adr cells in vitro. These agents potentiated the cytotoxicity of the antitumor drugs Adriamycin, vinblastine, and vincristine in multidrug-resistant cells with no effect on drug-sensitive parent P388 cells. They significantly increased the ATP-dependent accumulation of [3H]-vinblastine and inhibited efflux of the labeled drug from resistant cells. These compounds also inhibited photoaffinity labeling of P-glycoprotein by [3H]azidopine in P388/Adr cells and membranes isolated from these cells. In addition, the calcium antagonist activity of these compounds was very weak compared with that of verapamil. These data suggest that the compounds reported here may specifically overcome multidrug resistance without the serious hypotensive effects associated with calcium antagonists and that this activity may be independent of their ability to block calcium transport.

High-level expression and purification of mature HIV-1 protease in Escherichia coli under control of the araBAD promoter

A 1.3-kb segment of Escherichia coli DNA containing the regulatory gene, araC, and the promoter of the araBAD operon was amplified by the polymerase chain reaction (PCR) and cloned into pUC18, resulting in plasmid pKB130 that produced the alpha fragment of beta-galactosidase upon addition of L-arabinose (L-ara). A synthetic gene for human immunodeficiency virus (HIV)-1 preprotease was placed downstream of the ara-BAD promoter in pKB130 to create a translational fusion inducible by addition of L-ara. The fusion protein correctly autoprocessed in vivo to yield a mature 99-amino-acid HIV-1 protease, which was found predominantly in inclusion bodies. This material could be refolded to an active form, which was purified to homogeneity. A small fraction of the protease was expressed in vivo as a soluble active form, which allowed the monitoring of expression during fermentation by a rapid and simple whole cell assay employing an HIV-1 protease-specific fluorogenic substrate.

Treatment of intact striatal neurones with cholera toxin or 8-bromoadenosine 3',5'-(cyclic)phosphate decreases the ability of pertussis toxin to ADP-ribosylate the alpha-subunits of inhibitory and other guanine-nucleotide-binding regulatory proteins, Gi and Go. Evidence for two distinct mechanisms

Using primary cultures of striatal neurones from the mouse embryo, we showed that treatment of intact cells with cholera toxin (5 micrograms/ml, 22 h) decreases the subsequent ADP-ribosylation of the alpha subunit of the guanine-nucleotide-binding regulatory protein Go (Go alpha) and the alpha subunit of the inhibitory guanine-nucleotide-binding regulatory protein (Gi alpha) of adenylate cyclase, which is catalyzed in vitro on neuronal membranes by pertussis toxin. The inhibitory effect of cholera toxin could not only be attributed to an increased production of cAMP in neurones. Treatment of cells with 0.1 microM 8-bromoadenosine 3',5'-(cyclic)phosphate (BrcAMP) for 16 h, or with 0.1 mM BrcAMP for 5 min, mimicked the effect of cholera toxin on the ADP-ribosylation of Go alpha and Gi alpha in vitro. However, the two agents seem to act through distinct mechanisms. The protein kinase inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine prevented the action of Br8cAMP but not that of cholera toxin. In addition, measurements of the pI of the Go alpha deduced from immunoblots of two-dimensional gels performed using a specific antibody directed against Go alpha suggest that treatment of neurones with cholera toxin induces ADP-ribosylation of Go alpha in intact cells, while BrcAMP does not.

Botulinum toxin therapy

Botulinum toxin therapy has emerged as a treatment modality for a variety of spastic- or contracture-related muscle diseases. Its safety has been proven for long-term use in the treatment of benign essential blepharospasm, hemifacial spasm, and certain types of strabismus. Recent approval from the Federal Drug Administration should make botulinum toxin available for use in a greater number of patients.

Pretreatment of mouse striatal neurons in primary culture with 17 beta-estradiol enhances the pertussis toxin-catalyzed ADP-ribosylation of G alpha o,i protein subunits

Pretreatment of striatal neurons from mouse embryos in primary culture with 17 beta-estradiol (10(-9) M, 24 h) enhanced the ADP-ribosylation of G alpha o,i proteins catalyzed by pertussis toxin (PTX). As estimated by quantitative ADP-ribosylation of G alpha s with cholera toxin and immunoblot experiments using anti-G alpha o and anti-G beta sera, 17 beta-estradiol pretreatment did not modify the levels of the major GTP-binding protein (G protein) constituent subunits G alpha s, G alpha o, and G beta. Thus, 17 beta-estradiol should induce a qualitative modification of these G proteins, perhaps by stabilizing the association of the heterotrimers G alpha o,i beta gamma, which are the targets of PTX. Such a hypothesis is in agreement with observations indicating that 17 beta-estradiol both suppressed the D2 dopamine- and opiate receptor-induced inhibitions of adenylate cyclase activity and enhanced the positive coupling between biogenic amine receptors (D1 dopamine, beta-adrenergic, and A2 adenosine) and adenylate cyclase. In addition, PTX pretreatment, which is known to uncouple receptors associated with Go,i proteins and thus to impair the dissociation of the heterotrimers G alpha o,i beta gamma, mimicks the effects of the steroid on the responses of adenylate cyclase to inhibitory and stimulatory agonists. Finally, the chemical specificity of the steroids was the same in the ADP-ribosylation as in the adenylate cyclase experiments: Testosterone (10(-9) M) mimicked the effects of 17 beta-estradiol, whereas 17 alpha-estradiol, progesterone, and dexamethasone did not.(ABSTRACT TRUNCATED AT 250 WORDS)

Choroidal detachment, flat anterior chamber, and hypotony as complications of neodymium: YAG laser cyclophotocoagulation

Severe hypotony, flat anterior chamber, and serous choroidal detachment after transscleral neodymium: YAG laser cyclophotocoagulation (Nd:YAG-CPC) for three cases of intractable glaucoma are reported. The three patients had failed previous filtering surgery and were receiving maximal medical therapy. The types of glaucomas treated were two cases of primary open-angle and one chronic-angle closure. The complications were noted between 1 and 2 weeks from the time of treatment. One patient improved spontaneously after 1 week of observation. Another patient required drainage of the choroidal effusion and anterior chamber reformation. The last patient remains under observation with a low intraocular pressure (IOP) and a slowly resolving serous choroidal detachment. Though the incidence of shallow anterior chambers is three cases (0.5%) in this series of 750 Nd:YAG-CPCs, it represents a serious problem that had not been reported previously.

17-beta Oestradiol Pretreatment of Mouse Striatal Neurons in Culture Enhances the Responses of Adenylate Cyclase Sensitive to Biogenic Amines

Embryonic striatal neurons from the mouse grown in primary culture (6 day old culture) were used in order to investigate the effects of 17-beta oestradiol (17-beta E2) on biogenic amine-sensitive adenylate cyclases. Pretreatment (28 h) of intact cells with 17-beta E2 (10-9 M) enhanced cyclic AMP production induced by either dopamine, isoproterenol, serotonin, or 2-chloro-adenosine (maximal effective concentrations). These effects of 17-beta E2 on biogenic amine-sensitive adenylate cyclases occurred after several hours (8 h at least) and were seen in most cases with a concentration as low as 10-11 M (EC50: 10-10 M). They were additive with those induced by phenol red (5.6 microg/l) and chemically specific since 17alpha-oestradiol, 2(OH)17-beta E2, progesterone, and dexamethasone were without effect. In addition, they were not seen in cells which had been pretreated (30 h) with cycloheximide or alpha-amanitin, suggesting an involvement of de novo protein synthesis. Since 17-beta E2 did not influence cyclic AMP production induced by either forskolin or manganese ions, the stimulatory effects of 17-beta E2 pretreatment on biogenic amine-sensitive adenylate cyclases were not linked to an increase in the amount of enzyme catalytic units. 17-beta E2 pretreatment enhanced twofold the number of beta-adrenergic receptors (as estimated by the specific binding of (125I)iodocyanopindolol) but did not, in contrast, affect either the number or the affinity of dopaminergic receptors (as estimated by (125I)SCH 23982 binding). Therefore, the enhancing effects of 17-beta E2 pretreatment on biogenic amine-sensitive adenylate cyclases could be related either to an increased number of coupled receptors or to modifications of the adenylate cyclase transducing system (occurring probably at the G-protein level) or to a combination of the two.

Differential modulation of D1 and D2 dopamine-sensitive adenylate cyclases by 17 beta-estradiol in cultured striatal neurons and anterior pituitary cells

Primary cultures of anterior pituitary cells from female rats and of mouse embryonic striatal neurons were used to study the effects of 17 beta-estradiol on D1- and D2-dopamine (DA)-sensitive adenylate cyclase. 17 beta-Estradiol pretreatment (10(-9) M, 72 h) suppressed the D2-DA-induced inhibition of adenylate cyclase activity in anterior pituitary cells. The steroid (10(-9) M, 24 h) also blocked the D2-DA-evoked response in striatal neurons whereas it enhanced by twofold the D1-DA-induced stimulation of the enzyme activity in these neurons. All these effects of the steroid were dose dependent and specific, as neither 17 alpha-estradiol, dexamethasone, nor progesterone used at the same concentration (10(-9) M) was effective. Furthermore, the modulation of DA-sensitive adenylate cyclases by the steroid required long-term exposure of living cells to 17 beta-estradiol since neither 17 beta-estradiol pretreatment for 4 h nor its addition to broken cells directly into the adenylate cyclase assay induced any alteration in the DA-sensitive adenylate cyclase activity. These results are in agreement with a genomic effect of the steroid. Using both anterior pituitary cells and striatal neurons in culture, 17 beta-estradiol affected neither the total number of DA (D1 and D2) receptors nor the estimated number of adenylate cyclase catalytic units. Therefore, it is suggested that the steroid modifies the coupling process by a mechanism that still has to be elucidated. These results demonstrate an effect of 17 beta-estradiol on DA target cells in both systems.(ABSTRACT TRUNCATED AT 250 WORDS)