Experimental application of tissue adhesives in corneal traumas.

OBJECTIVE: To evaluate intraoperative difficulties of the use of glues for corneal trauma.
 METHODS: Partial or full-thickness perpendicular corneal incisions (3-4 mm straight cuts) near the limbus (perpendicular or parallel to it) were made in 8 albino rabbits and were then sealed with fibrin or cyanoacrylate glue. Follow-up examinations were performed under the surgical microscope. Tissue specimens were also taken for light microscopic evaluation. 
 RESULTS: The cyanoacrylate glue polymerized almost immediately after application on the tissue, limiting the ability of the surgeon to oppose the corneal incisions appropriately. The fibrin glue polymerized more gradually, giving enough time for manipulations to reconstruct the wound properly and for removal of excessive glue, especially when the 2 components were applied separately. Excessive glue and crust formation on the eye surface induced irritation.
 CONCLUSIONS: Fibrin glue for the reconstruction of corneal wounds was easier to use than cyanoacrylate glue and caused less glue crust formation on the corneal surface. The speed of polymerization is an important factor. Excessive glue on the cornea was irritating.

Mucosal changes in chronic hypertrophic rhinitis after surgical turbinate reduction.

Chronic nasal obstruction owed to chronic hypertrophic rhinitis is one of the most common problems encountered in rhinology. Various forms of conservative therapy have been used, but these are often ineffective and surgical reduction techniques have been successfully applied. However, the issue of postoperative histological changes in the nasal mucosa has not been adequately addressed. The aim of the present study was to comparatively evaluate the effect of the methods of submucosal monopolar diathermy, radiofrequency coblation and ultrasounds on the nasal mucosa. Sixty patients with chronic hypertrophic rhinitis of nonallergic etiology underwent different surgical methods of turbinate reduction, divided into two groups: (1) 30 patients underwent tissue volume reduction of the inferior nasal turbinates using ultrasound procedure on the left side and monopolar diathermy on the right; (2) 30 patients underwent radiofrequency coblation technique on the left side and ultrasound reduction on the right. We studied 20 preoperative specimens of the inferior turbinate mucosa taken randomly from both groups of patients, 5 from each side of each group. Normal nasal mucosal specimens taken from ten healthy persons were used as controls. Specimens of the inferior turbinate were taken after 1, 3, and 6 months after surgery, from the same patients. All specimens were examined by electron microscopy. Preoperative observation revealed degeneration of epithelial cells, loss of cilia, disruption of intercellular connections, edema, nasal mucus overproduction and inflammatory infiltration in chorium. Postoperative observations revealed decrease of intercellular edema, reduction of mucus, overproduction of collagen and degeneration of the epithelium to flattened stratified. Only specimens after use of ultrasounds showed islands with normally organized epithelium of columnar ciliated cells. It may be concluded that epithelial changes owed to chronic hypertrophic rhinitis do not significantly improve postoperatively after turbinate tissue volume reduction. Only in several cases operated with ultrasounds, regeneration of epithelium occurs, resulting to anatomical and functional restoration of the nasal physiology.

Ultrastructural changes of the palatal mucosa following application of 4-nitroquinoline-l-oxide (4NQO) in rats subjected to major salivary gland excision.

OBJECTIVE: It has been suggested that saliva exerts a protective role against the carcinogenic effect of various substances in the oral cavity. The objective of this study was to examine the ultrastructural changes of the palatal mucosa caused by the application of 4-nitroquinoline-l-oxide (4NQO) in the presence or absence of saliva. STUDY DESIGN: Wistar-Furth rats subjected and not subjected to total bilateral excision of the major salivary glands were either painted with an aqueous solution of 4NQO or with propylene glycol only (controls). Two animals of each group were humanely killed periodically. The areas of the palatal lesions were immediately sliced and processed for TEM examination. RESULTS: Ultrastructurally, the progressive changes to squamous cell carcinoma were observed in the animals painted with 4NQO. In the desalivated animals group, the ultrastructural alterations appeared earlier than in the group with salivary glands. CONCLUSIONS: Saliva appeared to delay but not hinder tumor induction by 4NQO.

Conjunctival surface changes in patients with Sjogren's syndrome: a transmission electron microscopy study.

PURPOSE: To demonstrate the ultrastructural appearance of the conjunctival surface epithelium in patients with Sjögren's syndrome (SS) compared with normal subjects. METHODS: Conjunctival tissue specimens from seven normal subjects and eight patients with SS were obtained by bulbar conjunctival biopsy and examined by transmission electron microscopy. RESULTS: The average number of microvilli per 8.3 microm epithelial length was significantly lower in the SS group than that in the control group (19.6 +/- 2.5 vs. 28.0 +/- 3.4, P < 0.0001). The microvillus height (0.539 +/- 0.151 microm) and height-width ratio (1.825 +/- 0.549) in the conjunctival epithelium in the SS group were significantly lower than those (height: 0.946 +/- 0.117 microm, P < 0.001; and height-width ratio: 3.717 +/- 0.696, P < 0.0001) in normal individuals. The microvilli in the SS group were wider than those in the control group (P = 0.003). Furthermore, the average number of secretory vesicles (per 8.3 microm epithelial length) in the apical conjunctival epithelial cell was significantly reduced in the SS group (16.4 +/- 6.8 vesicles), compared with the control group (34.7 +/- 1.2 vesicles, P = 0.003). In addition, although the ocular surface glycocalyx (OSG) was always present in control subjects, it was not detectable in all but one of the SS conjunctival specimens. CONCLUSIONS: The ultrastructural morphology of the apical conjunctival epithelium is altered in patients with SS. The findings suggest that an intact OSG may play a key role in the maintenance of a healthy ocular surface, possibly by preventing abrasive influences on the apical epithelial cells.

Detection and typing of human papillomavirus DNA in uterine cervices with coexistent grade I and grade III intraepithelial neoplasia: biologic progression or independent lesions?

OBJECTIVE: To examine the HPV type infection of cervical cone specimens with coexistent CIN1 and CIN3 lesions, in order to define if coexistence of low- and high-grade lesions in the same cervix represent different stages of evolution in a continuing process that is caused by a single viral type or independent lesions induced by different HPV types. STUDY DESIGN: The examined material included 43 cases with coexistent CIN1 and CIN3 in the cone biopsy specimen. Detection and typing of HPV was made by RFLP-PCR. RESULTS: All CIN1 lesions were HPV positive, while three CIN3 lesions were HPV-negative. The proportion of agreement of the HPV type in the two lesions, excluding negative cases (n = 40), was 60% (95% confidence interval: 43.3-75.1). HPV 16 was the most common type in both CIN3 (56.8%) and CIN1 (46.5%). CONCLUSIONS: The so-called morphologic progression of CIN is not always synonymous with biologic progression, since many coexistent CIN lesions are caused by different HPV types, and so represent different cell clones. Clonality of coexistent CIN lesions may be implicated in the evolution of CIN as other recent studies have shown.