Accuracy of cardiovascular magnetic resonance in myocarditis: comparison of MR and histological findings in an animal model.

BACKGROUND: Because endomyocardial biopsy has low sensitivity of about 20%, it can be performed near to myocardium that presented as late gadolinium enhancement (LGE) in cardiovascular magnetic resonance (CMR). However the important issue of comparing topography of CMR and histological findings has not yet been investigated. Thus the current study was performed using an animal model of myocarditis. RESULTS: In 10 male Lewis rats experimental autoimmune myocarditis was induced, 10 rats served as control. On day 21 animals were examined by CMR to compare topographic distribution of LGE to histological inflammation. Sensitivity, specificity, positive and negative predictive values for LGE in diagnosing myocarditis were determined for each segment of myocardium. Latter diagnostic values varied widely depending on topographic distribution of LGE and inflammation as well as on the used CMR sequence. Sensitivity of LGE was up to 76% (left lateral myocardium) and positive predictive values were up to 85% (left lateral myocardium), whereas sensitivity and positive predictive value dropped to 0-33% (left inferior myocardium). CONCLUSIONS: Topographic distribution of LGE and histological inflammation seem to influence sensitivity, specificity, positive and negative predictive values. Nevertheless, positive predictive value for LGE of up to 85% indicates that endomyocardial biopsy should be performed "MR-guided". LGE seems to have greater sensitivity than endomyocardial biopsy for the diagnosis of myocarditis.

Acute myocarditis in a rat model: late gadolinium enhancement with histopathological correlation.

The aim of the current study was to use an established animal model of autoimmune myocarditis and to judge the ability of cardiovascular MRI (CMR) in quantitatively measuring the extent of myocardial involvement compared with histopathological measurement of severity and extent. Experimental autoimmune myocarditis (EAM) was induced in 10 male Lewis rats. On day 21, all animals were investigated by CMR to measure the extent of late gadolinium enhancement (LGE). Subsequently, histopathological evaluation of the entire heart was performed. All animals of the experimental group fulfilled histopathological criteria of myocarditis, revealing necrosis in seven of eight cases. At reduced heart rate, area of LGE correlated highly with histologically proven area of myocarditis (r = 0.80-0.87, p < 0.05). LGE was mainly located in the anterior (range 50-62.5%) and lateral (range 62.5-75%) left ventricular wall and septum (range 25-50%) with a midwall to subepicardial accentuation. The LGE pattern found by CMR can be regarded as suggestive of EAM. With cellular necrosis being the main mechanism for LGE we were able to show high correlations between CMR examination results and histopathologically proven areas of myocarditis. Thus we think the current animal model can provide the opportunity for further fundamental research into myocarditis.

Corneal femtosecond laser keratotomy results in isolated stromal injury and favorable wound-healing response.

PURPOSE: To examine the corneal repair response after intrastromal femtosecond (fs) laser keratotomy. METHODS: Twelve rabbits underwent monocular intrastromal keratotomy performed with an fs laser at a preoperatively determined corneal depth of 160 to 200 microm. The fs laser-induced corneal repair response was compared with that of nonoperated control eyes and eyes treated with photorefractive keratectomy (PRK). Follow-up examinations were performed 1, 3, 7, and 28 days after surgery. Corneas were evaluated using slit lamp, in vivo confocal microscopy, and light microscopy. The extracellular matrix components fibronectin and tenascin were located using immunofluorescence staining. Anti-Thy-1 and anti-alpha-SMA antibodies and phalloidin were used to identify repair fibroblasts. Cell proliferation and nuclear DNA fragmentation were detected using an anti-Ki-67 antibody and the TUNEL assay, respectively. RESULTS: Intrastromal fs keratotomy resulted in a hypocellular stromal scar discernible as a narrow band of increased reflectivity on slit lamp examination. Deposition of fibronectin and tenascin as well as death and subsequent proliferation of keratocytes were observed. No differentiation of keratocytes into Thy-1- or alpha-SMA-positive fibroblasts could be detected. In contrast, after PRK, which causes epithelial and stromal wounding, all markers for repair fibroblasts were found in subepithelial stromal layers. On slit lamp examination, a fibrotic scar and a corneal haze were revealed. CONCLUSIONS: Isolated stromal injury using an fs laser avoids epithelial injury and is associated with a favorable wound-healing response preserving corneal transparency. Thus, fs laser keratotomy is a highly selective laser treatment that can be useful for the treatment of refractive errors.

Correlation between clinical in vivo confocal microscopic and ex vivo histopathologic findings of Salzmann nodular degeneration.

PURPOSE: To report clinical, in vivo confocal microscopy and ex vivo histopathologic findings of Salzmann nodular degeneration (SND). METHODS: A 48-year-old woman with symptoms of ocular irritation and decreased visual acuity caused by SND in both eyes was treated by corneal scraping and phototherapeutic keratectomy (PTK). Slit-lamp biomicroscopy, in vivo confocal microscopy, ex vivo light microscopy, immunohistology, and corneal topography were performed. RESULTS: In vivo confocal microscopy showed an irregular network of highly reflective structures representing activated keratocytes, which could be seen by light microscopy and characterized immunohistologically as myofibroblasts. Unstructured areas with increased reflectivity correlated with irregularly arranged collagen fibers and hyaline deposits in the nodulus. Epithelial cells in vivo appeared atypically shaped and elongated. These observations were consistent with decreased thickness of the epithelium over the nodules showed by histopathology. Treatment led to a dramatic reduction of hyperopia. Two months after surgery, uncorrected visual acuity (UCVA) in the right eye was 20/32 and 20/20 with a refraction of -0.75 -0.75/0 degrees. UCVA in the left eye was 20/40 and 20/20 with a refraction of +0.50 -1.75/165 degrees. Corneal topography showed regular astigmatism. CONCLUSION: In vivo confocal microscopy confirmed the clinicopathologic findings of Salzmann's nodular degeneration. Observations by in vivo confocal microscopy were consistent with the histopathologic descriptions of SND.

Corneal trephination with the femtosecond laser.

PURPOSE: To evaluate the feasibility and cut quality of corneal trephination in human donor corneal tissue with the femtosecond laser. METHODS: Twelve human corneoscleral discs were inserted in an artificial anterior chamber. After corneal thickness measurement and tonometry, the cornea was mounted on a femtosecond laser (FEMTEC; 20/10 Perfect Vision, Heidelberg, Germany) through a contact lens (patient interface). Trephination was performed with diameters of 7.0, 7.5, 8.0, and 8.5 mm in 3 corneas each. The corneal button was removed from the corneoscleral disc in 2 of the 3 corneas in each case. The cut was not manipulated in the remaining corneas to enable histologic detection of possible tissue bridges. The cut edges were macroscopically and light-microscopically examined for quality. RESULTS: Corneal buttons and corneoscleral discs could be separated by blunt dissection in all cases. Tissue bridges were more common in thicker edematous corneas than in thinner ones. Both the macro- and microscopic examination disclosed smooth rectilinear cut margins with a perpendicular cut edge. CONCLUSION: This feasibility study shows that the femtosecond laser enables sufficient trephination of human donor corneas.

Prostatic sarcoma of the Ewing family in a 33-year-old male - A case report and review of the literature.

Ewing sarcoma is the second most common primary bone tumor seen in children and adolescents, typically presenting between 10 and 20 years of age. Extraosseous sarcomas of the Ewing family in adults are rare. We report a manifestation of this tumor entity in the periprostatic tissue of a 33-year-old male and discuss our treatment approach. Transrectal biopsy is a feasible and simple diagnostic tool for unclear pelvic masses. Multi-modal therapy and central registries are needed to gain knowledge of rare pelvic tumors like Ewing sarcoma.

Top-hat shaped corneal trephination for penetrating keratoplasty using the femtosecond laser: a histomorphological study.

PURPOSE: To evaluate a novel technique for penetrating keratoplasty (PK) with the use of a new software algorithm for the femtosecond laser, designed to create penetrating cuts in a top hat configuration. DESIGN: Consecutive histomorphological case series. PATIENTS AND METHODS: Twelve eyes of 12 patients underwent penetrating keratoplasty by means of a 60-kHz femtosecond laser (IntraLase, Irvine, California) with a software specifically developed for corneal surgery. Of the 12 patients, the reason for keratoplasty was keratoconus in 4 patients, bullous keratopathy in 6 patients, keratotorus in 1 patient, and status post chemical burn in 1 patient. A new software was used to create penetrating cuts in a top-hat-shaped configuration. In all cases, cutting parameters were identical in all donor and corresponding host corneas: 7.0 mm diameter of the anterior side cut, 8.5-8.7 mm diameter of the posterior side cut, and a depth of 300 microm for the lamellar cut. In all cases, a complete penetrating cut with the laser in the host cornea was not intended intraoperatively. Complete penetration was performed subsequently and manually with a diamond knife because of logistic conditions. Trephined corneoscleral rings and button corneas were analyzed macroscopically and histologically to determine cut quality. RESULTS: All procedures were performed without any complications. With application of appropriate combinations of pulse energy and spacing, trephination took less than 200 seconds. Macroscopic examination and histology of donor and recipient specimens showed a straight, smooth cut with perpendicular edges in all donor buttons. No corneal edema and no visible damage to the keratocyte nuclei were found. At the region of manual dissection, a small stromal tissue-tag was present in parts of the circumference in all donor buttons. No evidence of any cut complication was noted. CONCLUSIONS: Top-hat-shaped penetrating keratoplasty using the IntraLase femtosecond laser enables a quick and sufficient trephination of both human donor and host corneas. It creates favorable histomorphological results with regard to cut quality of the donor and host corneas.