Eosinophilic esophagitis and duodenal food challenge - evaluation through endoscopic confocal laser endomicroscopy

BACKGROUND

Endoscopic confocal laser endomicroscopy (eCLE) is an established technique that allows clinical evaluation of mucosal integrity by fluorescein leaking through the mucosa upon duodenal food challenge (DFC). Analysis of eCLE with DFC in eosinophilic esophagitis (EoE) would be interesting to evaluate epithelial barrier dysfunction also in other regions of the gastrointestinal tract and to characterize potential individual food allergens that trigger the esophageal inflammation.

METHODS

In an observational and proof of concept study we evaluated 9 patients with histologically proven EoE by eCLE and DFC. Severity of symptoms were graduated according to the validated symptom-based EoE activity index. The endoscopic appearance of the esophagus was described according to the Endoscopic Reference Score System (ERERS). Spontaneous and food induced transfer of fluorescein into duodenal lumen were detected 10 minutes following intravenously application of fluorescein and 10 minutes after DFC. Food allergens were yeast, egg, soy, milk, and wheat, respectively. Local application of sodium chloride solution 10 % to the duodenal mucosa before DFC served as a control. Patients responding to DFC received a dietary exclusion therapy according to the results of DFC.

RESULTS

We investigated 9 patients with EoE (8 men, 49.7±13.8, 36-76 years). Symptom-based EoE activity index was 79±27.4, 33-100. In all patients EoE was confirmed by histology with number of esophageal mucosal eosinophilic granulocytes > 15/HPF, (91.4±77.4, 42-263). Mean ERERS score was 4.5±1.3, 3-7. None of the patients was aware of any food intolerance. eCLE revealed one patient with spontaneous transfer of i. v. fluorescein into duodenal lumen before DFC ("leaky gut"). 40 DFC were performed in the remaining 8 patients of whom 5 patients (61 %) responded to DFC. Rank order of fluorescein leakage upon DFC was wheat and milk in 37.5 % each, soy in 25 %, and egg in 12.5 %. The patients were treated by PPI (n=9), esophageal bouginage (n=5) and/or local corticoid therapy (n=3). The 5 patients responding to DFC received an additional food exclusion dietary advice focussed on the results of DFC. All patients reported a reduction of their symptoms. EoE activity indexes of patients with positive DFC were 73.7+28.6, 33-100 before and 22.7+37.9, 0-79 four weeks after food exclusion.

CONCLUSION

The findings of our proof of concept study suggest that eCLE with DFC may be an interesting tool to further evaluate patients with EoE. This technique has the potential to identify patients who may benefit from an additional individual dietary therapy.

[Efficacy of 0.05% cyclosporine A combined with vitamin A palmitate in the treatment of meibomian gland dysfunction-related dry eye]

Objective: To evaluate the efficacy of 0.05% cyclosporine A eye drops combined with vitamin A palmitate eye gel in the treatment of dry eye associated with meibomian gland dysfunction (MGD). Methods: A single-center, prospective, randomized, parallel controlled trial design was used to include patients diagnosed with MGD-associated dry eye. The patients were randomly divided into three groups and administered with medications binocularly for 12 weeks. The CsA+VA group was given 0.05% cyclosporine A eye drops twice a day and vitamin A palmitate eye gel three times a day. The CsA+HA group was given 0.05% cyclosporine A eye drops twice a day and 0.1% sodium hyaluronate eye drops three times a day. The HA group was given 0.1% sodium hyaluronate eye drops 3 times a day. The OSDI score, tear meniscus height, fluorescein tear break-up time, Schirmer Ⅰ test (without anesthesia), tear film lipid layer thickness, meibomian gland morphology and function examination, and corneal fluorescein sodium staining score were evaluated at baseline, 4, 8, and 12 weeks after the initiation of the treatment, respectively. Results: A total of 120 patients with MGD-related dry eye met the enrollment criteria, but 10 patients were lost to follow-up; 110 patients were finally included for observation, including 36 patients in the CsA+VA group, 38 in the CsA+HA group and 36 in the HA group. The OSDI score, tear meniscus height, fluorescein tear break-up time and meibomian gland secretion of the 3 groups were significantly improved. At the 12th week of the treatment, the differences of the CsA+VA group [25.45±15.11, (0.30±0.13) mm, (3.72±1.40) s, (5.03±2.52) points] and the CsA+HA group [26.98±16.89, (0.27±0.10) mm, (4.34±1.76) s, (5.11±2.39) points] from the HA group [24.57±11.26, (0.24±0.06) mm, (3.18±1.11) s, (9.11±3.34) points] were statistically significant (P<0.05). Compared with the CsA+HA group [(68.39±26.66) nm], the tear film lipid layer thickness in the CsA+VA group [(72.61±23.65) nm] was significantly increased (P<0.05). In the CsA+VA group, the meibomian gland secretion characters and discharge capacity among patients with severe abnormalities [(6.28±2.59) and (5.89±2.77) points at the 12th week of treatment], moderate abnormalities [(4.27±2.02) and (4.64±2.02) points at the 12th week of treatment] and mild abnormalities [(2.80±0.84) and (2.60±0.55) points at the 12th week of treatment] were significantly different (P<0.05). Conclusion: 0.05% cyclosporine A combined with vitamin A palmitate can significantly improve the symptoms and signs of patients with MGD-related dry eye, especially the tear film lipid layer thickness and the meibomian gland secretion characters and discharge capacity in severe cases.

Corneal Ulcers in Critically Ill Foals in Intensive Care: Case Series of Standard Treatment and Corneal Cross-Linking

Riboflavin/UV-A corneal cross-linking (CXL) has been applied to treat corneal ulcers in adult horses, but its use in critically ill neonatal foals has not been described. Five cases of hospitalized, critically ill neonatal foals that were in intensive care with corneal ulcers, the ophthalmic treatment, and their outcome up to 1 year are described. A single treatment of CXL phototherapy was performed in three of five foals (five eyes). The application of a riboflavin ophthalmic solution for 20 minutes was followed by the UV-A light irradiation at 30 mW/cm2 for 3 minutes. Topical antibiotic administration was withdrawn after CXL. Two other foals received standard treatment. Descriptions of ocular lesions, fluorescein staining, and photographic documentation were recorded. The visual outcome, corneal transparency, and aesthetics, as well as healing time were evaluated in the follow-up. The frequency of topical medication considerably decreased in cases treated with CXL. Corneal opacity and pain decreased within 3 days following CXL. In the foals treated with CXL, the ulcers healed (fluorescein stain negative) in 24, 28, and 35 days after the onset of clinical signs and 10, 15, and 21, after CXL. No fibrosis or corneal scars were found in the cases treated with CXL. The two standard treatment cases healed after 26 and 36 days respectively. Corneal cross-linking may be an additional or alternative treatment of corneal ulcers in critically ill neonatal foals and may reduce the use of antibiotics.

[Efficacy evaluation of 0.05% cyclosporine A and 0.1% tacrolimus eye drops in the treatment of severe dry eye associated with chronic graft-versus-host disease]

Objective: To evaluate the effectiveness and safety of 0.05% cyclosporine A and 0.1% tacrolimus eye drops in treating severe dry eye associated with chronic graft-versus-host disease (cGVHD). Methods: This non-randomized concurrent control trial enrolled 83 eyes from 83 patients with cGVHD-associated severe dry eye. The treatment had two phases. During the initial shock treatment period (0-3 months), 44 patients received 0.05% cyclosporine A eye drops (4 times/day; group A) and 39 patients received 0.1% tacrolimus eye drops (twice/day; group B) alongside basic treatment. In the maintenance treatment period (3-6 months), both groups used 0.05% cyclosporine A eye drops (twice/day) and sodium hyaluronate. Examinations were conducted at 1, 3, and 6 months after treatment initiation, assessing the Ocular Surface Disease Index (OSDI), corneal fluorescein staining (CFS) score, and fluorescein tear break-up time (BUT) for efficacy. visual acuity and intraocular pressure (IOP) were evaluated for safety, and patients' post-medication irritation symptoms were recorded. Results: The study included 52 males and 31 females, aged (28.57±15.67) years. After 1 month of treatment, the CFS score in group A significantly decreased from 10.0 (6.0, 14.0) to 5.0 (3.0, 8.5) (P<0.001). in group B, the CFS score also significantly decreased from 10.0 (6.0, 15.0) to 6.0 (2.0, 10.0), and the BUT increased from 2.0 (1.0, 2.0) s to 2.0 (1.8, 3.3) s (P<0.001). No significant OSDI decrease was observed in either group. No significant differences were found in OSDI, CFS score, and BUT between the two groups. After 3 months, group A showed significant improvement in OSDI, CFS score, and BUT (P<0.05), while group B only demonstrated significant CFS score decrease (P<0.05). OSDI was significantly lower in group A than group B (P<0.05). No significant differences were noted in CFS score and BUT between groups. After 6 months, OSDI, CFS score, and BUT were 18.9 (9.3, 34.2), 7.0 (3.0, 8.5), and 2.0 (1.0, 3.0) s in group A, and 10.9 (3.6, 35.4), 5.5 (2.8, 10.0), and 2.0 (1.0, 10.0) s in group B. In both groups, CFS scores significantly decreased and BUT increased (P<0.05). Visual acuity improved significantly in group A at 1, 3, and 6 months (P<0.05), while no significant changes were seen in group B. Irritation symptoms were transient and self-resolving in both groups. Conclusions: Both 0.05% cyclosporine A and 0.1% tacrolimus eye drops, when combined with local glucocorticoids, exhibited significant anti-inflammatory effects, effectively and safely treating severe dry eye in cGVHD patients. Although the onset of 0.05% cyclosporine A was slower than 0.1% tacrolimus, it offered more stable long-term effects and better symptom improvement.

Computer-Aided Imaging Analysis of Probe-Based Confocal Laser Endomicroscopy With Molecular Labeling and Gene Expression Identifies Markers of Response to Biological Therapy in IBD Patients: The Endo-Omics Study

BACKGROUND

We aimed to predict response to biologics in inflammatory bowel disease (IBD) using computerized image analysis of probe confocal laser endomicroscopy (pCLE) in vivo and assess the binding of fluorescent-labeled biologics ex vivo. Additionally, we investigated genes predictive of anti-tumor necrosis factor (TNF) response.

METHODS

Twenty-nine patients (15 with Crohn's disease [CD], 14 with ulcerative colitis [UC]) underwent colonoscopy with pCLE before and 12 to 14 weeks after starting anti-TNF or anti-integrin α4β7 therapy. Biopsies were taken for fluorescein isothiocyanate-labeled infliximab and vedolizumab staining and gene expression analysis. Computer-aided quantitative image analysis of pCLE was performed. Differentially expressed genes predictive of response were determined and validated in a public cohort.

RESULTS

In vivo, vessel tortuosity, crypt morphology, and fluorescein leakage predicted response in UC (area under the receiver-operating characteristic curve [AUROC], 0.93; accuracy 85%, positive predictive value [PPV] 89%; negative predictive value [NPV] 75%) and CD (AUROC, 0.79; accuracy 80%; PPV 75%; NPV 83%) patients. Ex vivo, increased binding of labeled biologic at baseline predicted response in UC (UC) (AUROC, 83%; accuracy 77%; PPV 89%; NPV 50%) but not in Crohn's disease (AUROC 58%). A total of 325 differentially expressed genes distinguished responders from nonresponders, 86 of which fell within the most enriched pathways. A panel including ACTN1, CXCL6, LAMA4, EMILIN1, CRIP2, CXCL13, and MAPKAPK2 showed good prediction of anti-TNF response (AUROC >0.7).

CONCLUSIONS

Higher mucosal binding of the drug target is associated with response to therapy in UC. In vivo, mucosal and microvascular changes detected by pCLE are associated with response to biologics in inflammatory bowel disease. Anti-TNF-responsive UC patients have a less inflamed and fibrotic state pretreatment. Chemotactic pathways involving CXCL6 or CXCL13 may be novel targets for therapy in nonresponders.

Effects of the preoperative use of artificial tears combined with recombinant bovine basic fibroblast growth factor on cataract patients complicated with dry eyes

PURPOSE

To assess the effects of the preoperative application of artificial tears combined with recombinant bovine basic fibroblast growth factor on the ocular surface function and inflammatory factor levels after operation in cataract patients complicated with dry eyes.

METHODS

A total of 118 cataract patients (118 eyes) complicated with dry eyes treated from February 2019 to February2020 were assigned to control and observation groups (n=59 eyes/group) using a random number table. One week before the operation, the control group was administered 0.1% sodium hyaluronate eye drops (artificial tears), based on which the observation group received Beifushu eye drops (recombinant bovine basic fibroblast growth factor), both 6 times daily for 1 week. A comparison was made between the scores of clinical symptoms and the indices of ocular surface function, inflammatory factors in tears, and oxidative stress indices before and after the operation. The ocular surface function was evaluated by an ocular surface disease index questionnaire, tear film breakup-time assay, Schirmer's I test, and corneal fluorescein stain test. The inflammatory factors in tears were measured.

RESULTS

No significant differences were noted in the general data and clinical symptom score, ocular surface disease index, tear film breakup-time, Schirmer's I test score, fluorescein stain score, interleukin-6, tumor necrosis factor-alpha, malondialdehyde, superoxide dismutase, lipid peroxide, and total antioxidant capacity before treatment between the 2 groups (p>0.05). After treatment, the clinical symptom score, ocular surface disease index, fluorescein stain score, tumor necrosis factor-alpha, interleukin-6, malondial-dehyde and lipid peroxide declined significantly, and tear film breakup-time, Schirmer's I test score, superoxide dismutase, and total antioxidant capacity increased in both the groups. The improvements in the clinical symptom score as well as in the indices of ocular surface function, inflammatory factors, and oxidative stress were more prominent in the observation group than in the control group (p<0.05).

CONCLUSIONS

Artificial tears combined with recombinant bovine basic fibroblast growth factor before operation. significantly improved the ocular surface function, reduced inflammatory factors in tears, and alleviated dry eye symptoms after operation in cataract patients.

[Infectious keratitis and corneal transplantation in a 15-year-old patient wearing contact lenses]

BACKGROUND

Soft contact lens wearing increases the risk of an infectious keratitis. A patient present with a red painfull eye, in which case a corneal erosion (coloring with fluorescein) was seen by the general practitioner. It is possible that the clinical course worsens in a few days with a corneal perforation as a result. In these cases a timely referral is necessary.

CASE

A fifteen year old soft contact lens wearing girl developed an infectious keratitis. Within a few days she developed a corneal perforation. As a result of an emergency transplantation within 24 hours the patient preserved her globe and her visual acuity recovered.

CONCLUSION

Emergency transplantations usually have a complicated course with a high risk of re-transplantation and long-term pharmacological therapy. Such an emergency transplantation is primarily performed to preserve the globe. In the Netherlands a separate pool of emergency donor transplants is available, so that a transplantation can be performed within 24 hours.

Soft Contact Lens with Embedded Microtubes for Sustained and Self-Adaptive Drug Delivery for Glaucoma Treatment

Because of the physiological and anatomical constraints of the eye, ophthalmic drug delivery is challenging. When applied topically, less than 1% of administered ophthalmic drugs reach the aqueous humor. The delivery of a drug within an efficient therapeutic concentration, to the required site of action, for an extended period of time, is complicated. Herein, a novel type of contact lens device, with embedded microtubes as drug containers, is reported. This device can provide a simple, noninvasive, extended drug release up to 45 days with higher bioavailability and lower risk for adverse effects. Another unique feature of the device is the release of drug triggered by stretching of the contact lens, indicating the possibility for achieving a self-adaptive drug release device for treating glaucoma patients.

C-C chemokine receptor type 4 antagonist Compound 22 ameliorates experimental autoimmune encephalomyelitis

Chemokines and chemokine receptors play important roles in the immune response. We previously reported the pathogenic role of C-C chemokine receptor type 4 (CCR4) in experimental autoimmune encephalomyelitis (EAE). Here, we examined whether CCR4 antagonism modulates the disease course of EAE. Wild-type and CCR4-knockout mice were induced EAE and were administered Compound 22, an antagonist of CCR4. Compound 22 significantly ameliorated the severity of EAE in wild-type mice, but not in the CCR4-knockout mice. Compound 22 inhibited Th1 and Th17 polarization of antigen-induced T-cell responses. Therefore, CCR4 antagonists might be potential therapeutic agents for multiple sclerosis.

Targeting an MMP-9-activated prodrug to multiple myeloma-diseased bone marrow: a proof of principle in the 5T33MM mouse model

Multiple myeloma (MM) is an incurable B-cell cancer characterised by the monoclonal proliferation of tumour cells in the bone marrow (BM). It has been described that matrix metalloproteinases (MMPs) and especially MMP-9 is secreted by MM cells. In this study, we investigated the possibility to exploit MMP-9 activity to activate prodrugs and to target MM cells as a new tumour-specific therapy. Cleavage of the prodrug EV1-FITC by MMP-9 resulted in release of fluorescence which can be used as a measure of prodrug activation. The 5T33MM mouse model was used in this proof-of-principle study. The prodrug was activated in a higher amount by addition to MMP-9-producing 5T33MMvv cells, homogenates from tumour-bearing organs (BM, spleen) and isolated 5T33MM-diseased BM and spleen cells compared to non-MMP-9-producing 5T33MMvt cells and homogenates/cells from non-tumour-bearing organs/mice, as measured by fluorescence release. This fluorescence release could be inhibited by the MMP-2/MMP-9-specific inhibitor, CTT. Activation of the prodrug in the 5T33MM spleen and BM homogenates was confirmed by chromatography. EV1-fluorescein isothiocyanate injection into 5T33MM-diseased animals resulted in a higher fluorescence release by the isolated BM and spleen cells compared to injection into healthy animals. In conclusion, MMP-9 activity can be used to activate prodrugs that target MM.

Photodynamic therapy for wound-healing modulation in pterygium surgery. A clinical pilot study

BACKGROUND

This study was performed to evaluate the safety and efficacy of photodynamic therapy with the carboxyfluorescein ester BCECF-AM as an adjunctive treatment procedure for pterygium surgery to reduce the rate of recurrence.

METHODS

In this nonrandomized prospective clinical trial, 19 eyes with nasally located primary pterygium were examined. All eyes were treated with the bare sclera surgical technique. Seven eyes received in addition treatment with BCECF-AM solution and blue light. All patients were evaluated at least after 1 day, 1 week, 1 month, 3 months, and 1 year. Postoperative fibrovascular growth from the limbus of at least 1 mm was defined as recurrence.

RESULTS

The intraoperative application of BCECF-AM solution did not cause anterior chamber flare or any other significant side effects. The bare sclera surgery rate of recurrence was 0% (zero of 12) after 3 months and 91% (11 of 12) after 1 year. The additional photodynamic therapy treatment had a rate of recurrence of 14.2% (one of seven) after 3 months and 71.4% (five of seven) after 1 year.

CONCLUSIONS

The applied PDT technique seems to be a safe procedure but is associated with a high rate of recurrence. In conclusion, the evaluated PDT treatment procedure, at this point, should not be considered. As we found a high rate of recurrence also in the control group, the bare sclera technique is not effective, even in primary pterygia.

Photodynamic modulation of wound healing in glaucoma filtration surgery

AIM

To report a clinical pilot study investigating photodynamic therapy (PDT) in combination with glaucoma filtration surgery. BCECF-AM was used as the photosensitising substance. The clinical safety and tolerability of BCECF-AM, and its efficacy in controlling postoperative intraocular pressure (IOP) were assessed.

METHODS

Before trabeculectomy (TE), 42 consecutive eyes of 36 glaucoma patients received one subconjunctival injection of 80 micro g BCECF-AM (2,7,-bis- (2-carboxyethyl) -5- (and-6) -carboxy-fluorescein, acetoxymethyl-ester) followed by an intraoperative illumination with blue light (lambda = 450-490 nm) for 8 minutes. Antifibrotic efficacy was established as postoperative IOP reduction of >20% and/or an IOP constantly < 21 mm Hg without antiglaucomatous medication. Follow up of the filtering bleb was documented by slit lamp examination.

RESULTS

Eyes had mean 1.1 preoperative surgical interventions (filtration and non-filtration glaucoma surgery). Mean preoperative IOP was 31.6 (SD 9.7) mm Hg. Patients were followed for mean 496 days (range 3.5-31.8 months). Of the 42 eyes, 25 eyes had an IOP decreased to 15.8 (3.4) mm Hg without medication (complete success: 59.5%; p<0.001; t test). Seven eyes showed good IOP reduction < 21 mm Hg under topical antiglaucomatous medication (qualified success: 16.7%). 10 eyes failed because of scarring within 2-67 weeks (23.8%). Clinical follow up examinations revealed no local toxicity, no uveitis, and no endophthalmitis.

CONCLUSIONS

This method is a new approach in modulating postoperative wound healing in human eyes undergoing glaucoma filtration surgery. The data of the first human eyes combining TE with PDT underline the clinical safety of this method and its possible potential to prolong bleb survival.

Photodynamic therapy to control fibrosis in human glaucomatous eyes after trabeculectomy: a clinical pilot study

OBJECTIVE

To evaluate the safety, tolerability, and clinical effect on intraocular pressure (IOP) of a carboxyfluorescein ester as an adjunctive antifibrotic therapy in human glaucomatous eyes to control postoperative wound healing after trabeculectomy.

METHODS

In 10 human glaucomatous eyes with high IOPs that underwent 1 to 3 previous surgical procedures for glaucoma, 2'7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester was applied 15 minutes prior to trabeculectomy via a subconjunctival injection followed by intraoperative illumination with diffuse blue light (450-490 nm; approximately 51.9 x 10(3) candelas/m(2)) for 8 minutes. Antifibrotic efficacy was established by clinical response, postoperative IOP reduction, slitlamp examination, and filtering bleb site photographs. Success was defined as an IOP less than 21 mm Hg from baseline without the eye receiving any antiglaucomatous medication or an application of antimetabolites.

RESULTS

The mean (SD) IOP on the day before surgery was 37.2 (11.2) mm Hg. The IOP was 16.6 (3.8) mm Hg in 8 successful eyes after a mean (SD) follow-up of 400.1 (38.1) days (P<.001). Two eyes showed scarring at the site of the filtering bleb within 1 month. In 1 eye with pseudoexfoliation glaucoma IOP decreased to 17 mm Hg but needed topical antiglaucomatous medication. Clinical examination revealed none of the following: blebitis, uveitis, endophthalmitis, or toxic damage of the adjacent tissues.

CONCLUSIONS

We report our findings about the first 10 consecutive human glaucomatous eyes treated with a single dose of 80 microg of 2'7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester during trabeculectomy. In contrast to chemotherapeutic agents, cellular photoablation acts only on cells having incorporated 2'7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester and having been exposed to light of an appropriate wavelength. Though safety and efficacy demand a controlled randomized study, our method seems to be an effective therapeutic approach to control postoperative fibrosis in human glaucomatous eyes with a poor surgical prognosis. Multiple factors such as dose of light, means of application, wavelength, irradiation area, total dose of the dye, and multiple dosing may be altered in the future to improve the antifibrotic effect of photodynamic therapy during surgery for glaucoma.

Cellular photoablation to control postoperative fibrosis in filtration surgery: in vitro studies

The purpose of this study was to evaluate the feasibility of cellular photoablation using fluorescence-generated photoreaction products as a method to control postoperative fibrosis in filtration surgery. The fluorescent probe, 2', 7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester (BCECF-AM) is a cell membrane permeable compound rendered membrane-impermeable and fluorescent upon cleavage by intracellular esterases. Human scleral and Tenon's capsule fibroblasts were cultured and used as the target cells. Uptake and retention of the probe were determined with a fluorescence multi-well plate reader. Fibroblasts with or without intracellular probe were irradiated under conditions of fluorescence microscopy with diffuse blue light (450-490 nm, 1.68x10(2)mW m(2-1)). The viability of cells was examined by trypan blue exclusion and crystal violet test. To better mimic a wound healing process the effect of cellular photoablation was verified in artificial lesions produced in cultured monolayers loaded with different concentrations of the probe. Uptake and retention of BCECF-AM is dependent on ambient concentration. When incorporated the probe is lethal to those cells exposed to the appropriate photo-irradiation. Cells exposed to BCECF-AM (for 45 min) at a concentration of approximately 10 microm and irradiated for 1 min resulted in 100% cell death. Cellular photoablation in contrast to chemotherapeutic agents acts only on the targeted cells. This method shall be pursued as an alternative therapy to control postoperative fibrosis in filtration surgery.

Cellular photoablation to control postoperative fibrosis in a rabbit model of filtration surgery

AIM

To evaluate the feasibility of cellular photoablation using fluorescence generated photoreaction products as a method to control postoperative fibrosis.

METHODS

The fluorescent probe, 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester (BCECF-AM) is a cell membrane permeable compound rendered membrane impermeable and fluorescent upon cleavage by intracellular esterases. Rabbits (ChBB:CH; n=20) received a unilateral subconjunctival injection of BCECF-AM (40, 70, 80, or 100 microg) 30 minutes before surgery followed by intraoperative illumination with diffuse blue light (450-490 nm; 51.9 x 10(3) cd/m(2)) for 10 minutes. Controls received either the probe or illumination. Antifibrotic efficacy was established by clinical response and histological examination. Clinical response was assessed by comparing intraocular pressure (IOP) between the treated experimental eye and the fellow eye, which served as control. Success was defined by >20% difference in IOP.

RESULTS

IOP was significantly decreased in all groups within 4 days postoperatively. In control groups IOP rose within 10 days to normal levels. This was similar in the group receiving 40 microg of BCECF-AM. In the other groups (subconjunctival injection of 70-100 microg BCECF-AM) IOP was significantly (p < 0.02) decreased for 2-3 weeks. Clinical and histological examination revealed no toxic damage to adjacent tissues.

CONCLUSIONS

Cellular photoablation in contrast with chemotherapeutic agents acts on cells that have incorporated BCECF-AM and have been exposed to light at the appropriate wavelength. Though safety and reliability demand further studies this method might be an useful therapeutic approach to control postoperative fibrosis in humans undergoing filtration surgery.

Human albumin solders for clinical application during laser tissue welding

BACKGROUND AND OBJECTIVE

Fifty percent human albumin solder significantly improves weld strength when compared to lower concentrations [Wright et al., ASLMS meeting, April, 1995]. We developed a method for preparing 50% human albumin that may be considered compatible for clinical applications.

STUDY DESIGN/MATERIALS AND METHODS

Fifty percent human albumin solder was prepared from 25% commercially available human albumin using a lyophilization technique. Assessment of sterility, viscosity, pH, and peak absorption wavelength were performed.

RESULTS

This report describes the methodology used to prepare a 50% human albumin solder that is compatible with clinical use. Maintenance of the structural integrity of the albumin was confirmed by polyacrylamide gel electrophoresis.

CONCLUSION

This solder preparation can be used alone or with the addition of exogenous chromophores. The final product is sterile, incorporates viral free protocols, maintains high viscosity, and can be applied easily during open or laparoscopic procedures.

Photoinactivation of herpes simplex virus by rose bengal and fluorescein. In vitro and in vivo studies

Rose bengal and fluorescein are photosensitive dyes in widespread use in the evaluation of ocular surface diseases, including herpes simplex virus (HSV) keratitis. These dyes have recently been shown to penetrate living cells, and rose bengal was previously reported to possess antiviral activity. Several experiments reported herein suggest that these dyes do possess the potential for potent antiviral activity against extracellular virus, but only in the presence of light. Rose bengal is substantially more effective in vitro than fluorescein, and the effect is greater with increasing concentration of dye and duration of light exposure. Electron microscopic evaluation of treated virus showed no structural difference from untreated virus, in spite of 4- to 5-log decreases in virus titer. Intracellular virus was found to be markedly resistant to photoinactivation. In a rabbit model of acute primary HSV keratitis, daily application of topical rose bengal followed by light exposure had no therapeutic effect, although an adverse effect on culture sensitivity testing was seen.

Dye-enhanced laser tissue welding

For vascular anastomosis, use of topical photosensitizing dye enhances selective delivery of laser energy to target tissue, thus reducing the amount of collateral thermal injury and threshold power required for welding. For fluorescein isothiocyanate (FITC)--stained rabbit aorta in vitro, the threshold for tissue blanching was 15 seconds of 100 mW exposure of cw argon ion laser compared with 15 seconds at 300 mW for unstained tissue. The threshold power density needed for argon laser welding of abdominal aortotomies in rabbits in vivo was 3.8 W/cm2 with FITC and 7.6 W/cm2 without the dye. However, bursting pressures for the two groups (164 mm Hg with FITC, 147 mm Hg without FITC) were not significantly different. Histology revealed decreased collateral thermal damage in FITC-enhanced welds. Use of photosensitizing dyes for tissue welding is feasible and may allow arterial welding with lower power laser systems and cause less thermal trauma by lowering threshold power levels.

The antiviral effects of rose bengal and fluorescein

We evaluated the antiviral effects of rose bengal and fluorescein sodium. The direct antiviral activity was determined by an in vitro direct neutralization assay. The 50% inhibitory dose was 16 micrograms/mL for rose bengal and 460 micrograms/mL for fluorescein. The in vivo antiviral effects of these drugs were determined in the mouse herpetic keratitis model. Following topical application, rose bengal reduced surface virus titers (swabs) 1 million-fold, and residual ocular virus (eye homogenates) 32-fold, compared with controls. No infectious virus was recovered by swabbing after topical application of rose bengal. Fluorescein had no significant effect on virus replication. Thus, rose bengal, unlike fluorescein, has significant antiviral activity, and the diagnostic use of rose bengal prior to viral culture may preclude a positive result. Also, the use of rose bengal to grade keratitis in the study of new antiviral agents should be discouraged.

[Drug therapy of angiolopathies]

The treatment of angiolopathies is rather difficult, at this time, at least concerning functional angiopathies. It is a fact that protection against cold represents, in all angilopathies, one of the main elements of the treatment besides medications which are essentially vasoactive drugs, myorelaxants or alpha-blockers, and possibly venous tonics. Fluorescein or Sodium fluoresceinate at 5%, administered in slow intra-venous injections, represents one of the best treatment of acrocyanosis, in combination with vitamins A and D, given at the beginning of fall. Other angiolopathies, especially those of organic nature, are represented by allergic vascularitis and will be treated accordingly. In infectious and toxic forms, antibiotics should be prescribed in addition to steroids, preferred in allergic forms, especially granulomatous forms. In conclusion, the treatment of angiolopathies is extremely difficult, and must be particularly adapted to the clinical forms.

Use of mercurochrome in the management of the large exomphalos

The topical application of solutions containing mercury has remained popular in the conservative management of the large exomphalos, despite recent reports of high organ mercury levels occurring in neonates who have died following this type of treatment. There are few reports of mercury poisoning being recognized in survivors. This report records blood and urine mercury levels in four patients with no apparent sequelae after treatment with Mercurochrome and provides guidelines for the safer use of mercurial solutions in the conservative management of exomphalos: one thin application of 1% Mercurochrome be applied to the intact sac; thereafter, Mercurochrome be applied sparingly only to areas that remain moist; blood and urine levels of mercury be monitored routinely; and applications ceased whenever mercury levels exceed the minimum toxic level. Only with this sparing and judicious use of mercurial solutions is the hazard to the infant kept to a minimum.

Pediculosis and the pediatrician

Head lice commonly evoke feelings of disgust, revulsion, anger, and shame among parents and patients. There should, however, be no great cause for such alarm if a physician suspects pediculosis capitis. The recent introduction of several new pediculicidal drugs now allows a choice among four distinct therapeutic agents, which should substantially improve control of isolated cases and epidemics. Physicians must be aware that consumer groups are pressing public health authorities and drug manufacturers to establish proper treatment standards and safety warnings for the use of these agents. In addition, some controversy surrounds the use of lindane in children. This paper reviews the epidemiology and clinical appearance of pediculosis capitis in children, with emphasis on these recent developments. Pubic lice (Phthirus pubis) and body lice (Pediculus humanus corporis), both of which are much less common pediatric infestations, are mentioned only briefly.

[Use of antioxidants to prevent damage during acute ischemia and reperfusion of the kidneys]

Prophylactic injection of the natural antioxidant alpha-tocopherol and synthetic antioxidants ionol, diludin and 6-mercurascan prevented the development of lesions during acute renal ischemia and subsequent reperfusion. Ionol proved more effective on intraperitoneal injection than on intragastric route of administration. It has been demonstrated that antiischemic effect of ionol is related to its ability to exhibit the process of lipid peroxidation.

A new treatment of pthiriasis palpebrarum

Treatment of phthiriasis palebrarum so far is unsatisfactory and prolonged. It was an accidental finding that led us to try various strengths of fluorescein on head lice. It was seen from our study that 20% fluorescein resulted in the lice' instantaneous death. This percentage was used in all our subsequent cases of phthiriasis with excellent results. A new method for the treatment of phthiriasis palpebrarum from the eyelash by a single application of 20% fluorescein is described. This method required no sedation or anesthetic and can be carried out as an outpatient department procedure. It is nontoxic and not irritating. There is no risk of the physician being infested, as the lice and nits are killed instantaneously.

Studies on the therapeutic use of Mercurascar. Part III. Influence of Mercurascan on some metabolic changes in experimental myocardial ischaemia in dogs. Section I: Energetic and ionic metabolism

In experimental studies on dogs, the authors investigated the effect of small does of mercurascan (MSC) on metabolism of the heart muscle damaged by ischaemia. MSC is selectively accumulated and fixed in tissue damaged by ischaemia. MSC was demostrated to inhibit severe disturbances of metabolism in the ischaemic focus. It improves energy metabolism in the damaged tissue by maintaining the concentrations of nucleotides, creatinephosphate and total creatine at a higher level, thereby increasing the energy potential level of the adenylate system. Further, MSC decreases lactate concentration in tissue and reestablishes the disturbed ionic balance. By an hitherto unknown mechanism MSC regulates concentrations of potassium and sodium ions in the ischaemic focus and prevents increased hydration of tissue. Improved metabolic relations in the ischaemic tissue contribute towards normalisation of the heart action.