Matrix metalloproteinases (MMPs) are thought to play important roles during enamel and dentin biomineralization. Previously, membrane type-1 matrix metalloproteinase (MT1-MMP) was localized to the plasma membranes of ameloblasts and odontoblasts of the developing tooth. The best-characterized function of MT1-MMP is to initiate the activation of gelatinase A (MMP-2). Thus, we hypothesized that gelatinase A may also be expressed by developing tooth tissues. A full-length porcine gelatinase A mRNA was isolated by RT-PCR homology cloning of an enamel-organ-specific cDNA library. Northern blot and in situ hybridization analyses demonstrated gelatinase A expression in developing tooth tissues. Immunohistochemical analysis localized gelatinase A close to the plasma membrane of these tissues. Furthermore, recombinant gelatinase A was demonstrated to cleave recombinant amelogenin into several fragments of differing molecular masses. Thus, gelatinase A is expressed by developing tooth tissues along with its activator MT1-MMP and may, therefore, play an important role during tooth development.
Despite good internal consistency of the questionnaire and the recognized validity of the test, people's perception of their masticatory efficiency does not reflect objective efficiency as measured using a clinical test.
protein C and protein S levels in 127 consecutive young adults with ischemic stroke. Acta Neurol Scand 1998: 98: 124-127. 0 Munksgaard 1998.I
Objectives -The aim of our study was to evaluate the prevalence of antithrombin, protein C and protein S deficiencies in consecutive ischemic stroke patients under 45. Material and methods -We studied 127 consecutive patients with a mean age of 34.4 years admitted for an ischemic stroke, over a 2-year period, after exclusion of those with arterial dissection. Antithrombin, protein C and protein S levels were measured in all patients at the acute stage of the ischemic stroke and measurements were repeated in case of abnormality. Results -We found abnormal levels in 9 patients. Seven had an acquired cause of deficiency (pregnancy, oestrogen, acute inflammation). Two had no obvious acquired cause of deficiency but further controls were normal. Conclusions -Hereditary deficiencies of coagulation inhibitors are rare in ischemic stroke patients under 45 and their systematic
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