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Severe type I plasminogen (PLG) deficiency has been causally linked to a rare chronic inflammatory disease of the mucous membranes that may be life threatening. Here we report clinical manifestations, PLG plasma levels, and molecular genetic status of the PLG gene of 50 patients. The most common clinical manifestations among these patients were ligneous conjunctivitis (80%) and ligneous gingivitis (34%), followed by less common manifestations such as ligneous vaginitis (8%), and involvement of the respiratory tract (16%), the ears (14%), or the gastrointestinal tract (2%). Four patients showed congenital occlusive hydrocephalus, 2 with Dandy-Walker malformation of cerebellum. Venous thrombosis was not observed. In all patients, plasma PLG levels were markedly reduced. In 38 patients, distinct mutations in the PLG gene were identified. The most common genetic alteration was a K19E mutation found in 34% of patients. Transient in vitro expression of PLG mutants R134K, delK212, R216H, P285T, P285A, T319_N320insN, and R776H in transfected COS-7 cells revealed significantly impaired secretion and increased degradation of PLG. These results demonstrate impaired secretion of mutant PLG proteins as a common molecular pathomechanism in type I PLG deficiency. IntroductionPlasminogen (PLG) plays an important role in intra-and extravascular fibrinolysis, wound healing, cell migration, angiogenesis, and embryogenesis. 1 Plg is primarily synthesized by liver tissue. 2 However, other minor sources identified in mice include adrenal gland, kidney, brain, testis, heart, lung, uterus, spleen, thymus, and gut tissue. 3 In humans, the cornea has been described as an extrahepatic site of PLG synthesis. 4 Inherited PLG deficiency in humans can be divided into 2 types: true PLG deficiency (type I, or hypoplasminogenemia) and dysplasminogenemia (type II). In the former, both immunoreactive PLG level and functional activity are reduced, while the latter shows a normal or slightly reduced level of immunoreactive PLG while functional activity is significantly decreased. It has been shown by several authors since 1995 that homozygous or compound-heterozygous type I PLG deficiency is a major cause of a rare inflammatory disease affecting mainly mucous membranes in different body sites. 5,6 The most common clinical manifestation is ligneous conjunctivitis, characterized by development of fibrin-rich, woodlike ("ligneous") pseudomembranous lesions. Involvement of the cornea may result in blindness. Other, less common manifestations are ligneous gingivitis, otitis media, ligneous bronchitis and pneumonia, involvement of the gastrointestinal or female genital tract, juvenile colloid milium of the skin, and congenital occlusive hydrocephalus. 6 In severely affected patients, prognosis is poor and treatment options are few. Worldwide, more than 150 patients with this disease have been reported since 1847, the date of first description. 6,7 From the Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany; For personal use o...

Generalized membranous gingival enlargement due to accumulation of amyloid or fibrin-like material is a rare, destructive and poorly defined disease entity. Some patients also show extraoral manifestations. The lesion is an involvement of periodontal tissues caused by the same process as ligneous conjunctivitis. In this report, 3 new cases, two of whom are siblings, are presented. Defective fibrinolysis and abnormal wound healing seem to be the main pathogenetic mechanism of this unusual disease, which should be evaluated systemically considering other mucosal involvement.

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Hyaline or amyloid-like substances may be seen in several oral lesions. Some of these originate from epithelial cells and some from connective tissue components. In this study, amyloid-like material causing gingival enlargement in three patients, with eyelid involvement in two, was examined using histochemistry, immunohistochemistry and electron microscopy. These accumulations did not share the classical features of amyloid such as green birefringence under polarized light after Congo red staining. Our findings suggest that epithelial degeneration plays an important role in the pathogenesis of these amyloid-like accumulations. These substances may be the result of defective amyloidogenesis and our cases may represent an oral counterpart of ligneous conjunctivitis or colloid milium of the skin.

The aim of this study was to histologically evaluate and compare the effects of the systemic administration of L-thyroxine (TX) and doxycycline (DX) on orthodontically induced root resorption, Twenty-eight male 50- to 60-day-old Wistar rats were used. Seven rats served as the baseline control. Seven animals received TX (20 μg/kg bodyweight/day) and seven DX (1.2 mg/kg bodyweight/day), by means of a mini-osmotic pump implanted subcutaneously. Seven rats were separated as a sham, in order to evaluate the pure effect of the surgical procedure on the animals' health. Tooth movement (TM) was achieved with a continuous force of 50 g by placing Elgiloy coil springs between the right maxillary first molar and incisors for 14 days. The animals were sacrificed and specimens containing the appliance and maxillary tooth-bearing segments were processed for light microscopy. The surface area of root resorption lacunae was measured histomorphometrically using digital photomicrographs. To evaluate the resorptive changes on the molar root surface of each group, scanning electron microscopy (SEM) examinations were also carried out. Statistical evaluation of root resorption percentages was performed using Kruskal-Wallis analysis of variance test. Multiple comparisons were determined by the Student-Newman-Keuls method. The level of significance was set at P < 0.05. Histomorphometric analysis of root resorption, expressed as a percentage, showed that the average relative root resorption affecting the maxillary molars on the TM side was 0.32 ± 0.25 in the TX and 0.26 ± 0.06 in the DX groups and 2.19 ± 0.86 in the control. Statistically significant inhibition of root resorption was determined both in the TX and DX groups (P < 0.001) on the TM side. There was no statistically significant difference in relative root resorption between the TX and DX groups. Systemic administration of TX and DX demonstrated similar effects on root resorption in rats and may have inhibitory effects on orthodontically induced resorptive activity.

Objectives:The purpose of this clinical study was to identify a clinical and histopathological relationship between verrucous hyperplasia, verrucous keratosis, and verrucous carcinoma.Methods:We evaluated 12 patients who had developed oral verrucous carcinoma in the past 10 years in a follow-up study. In this study, the diagnostic criteria included clinical and histopathological features of the lesions. Each lesion was examined by a single oral pathologist.Results:All the patients were diagnosed with verrucous carcinoma following excisional biopsy. One patient was diagnosed with verrucous hyperplasia and another with verrucous keratosis in their initial histological findings. Mandibular, posterior alveolar crest, and retromolar trigone were the most affected sites (41.6%), followed by the buccal mucosa (16.6%), the palate (16.6%), the floor of the mouth (16.6%), and the lip (8.3%). No patients had evidence of recurrence after treatment.Conclusions:Verrucous hyperplasia, verrucous keratosis, and verrucous carcinoma may not be distinguished clinically or may coexist, resulting in diagnostic difficulties. It should be kept in mind that verrucous hyperplasia may also develop from leukoplakic lesions, and it may transform into verrucous carcinoma or squamous-cell carcinoma, acting as a potential precancerous lesion.

Reports on the incidence of odontogenic tumours are infrequent with only a limited number of series having appeared in the literature. In this paper, the results of a multicentre retrospective study on the histologic types and relative frequencies of odontogenic tumours in Turkey are presented. The results indicated that the most frequent histologic type was ameloblastoma (36.5 per cent) and the area at greatest risk for the development of odontogenic tumours was the mandibular molar region. A Table showing the most likely type of tumour by location is also presented.