Matrix metalloproteinase-1 and -8 in gingival crevicular fluid during orthodontic tooth movement: a pilot study during 1 month of follow-up after fixed appliance activation

The role of matrix metalloproteinases (MMPs) in response to mechanical forces in orthodontic tooth movement has only been partially clarified. In the present in vivo pilot study, the presence, levels, and degree of activation of MMP-1 and -8 were measured daily for 1 month in gingival crevicular fluid (GCF) of patients treated with orthodontic fixed appliances. GCF samples were collected from five orthodontic patients and three controls from one upper or lower central incisor or from one upper canine before fixed appliance activation and every 24 hours for 1 month thereafter. The molecular forms and activation degrees of MMP-1 and -8 in GCF were analysed by Western blotting, and MMP-8 levels determined by immunofluorometric assay (IFMA).IFMA revealed, during the study period, on average 12-fold higher levels (56 +/- 50 versus 4.6 +/- 4 microg/l) of MMP-8 in orthodontic GCF than in control GCF. The MMP-8 levels in orthodontic GCF were lower than those detected in gingivitis and periodontitis GCF, but significantly higher than in control GCF. IFMA analysis was confirmed by Western blot analysis showing elevated MMP-8 levels from orthodontic GCF relative to control GCF. Forty-one per cent of total MMP-8 immunoreactivities were high-molecular weight complexes (>100 kDa), 32 per cent in the 75 kDa pro-polymorphonuclear (PMN)-MMP-8 form, 14 per cent in the 60 kDa active-PMN-MMP-8 form, and 13 per cent in the 55 kDa fibroblast-type pro-MMP-8 form. In the GCF of orthodontic patients no MMP-1 immunoreactivities were detected. MMP-8 and -1 levels in the control GCF were low and not detectable.These results demonstrate that in vivo in human GCF, elevation and partial activation of multiple species of PMN- and fibroblast-type MMP-8 reflect periodontal remodelling during orthodontic tooth movement.     

Age of acquisition modulates the amplitude of the P300 component in spoken word recognition

Words acquired earlier in life are easier to process in adulthood than words acquired later; this is known as the age of acquisition (AoA) effect. The goal of this study was to establish whether the P300 component of event-related potentials (ERPs) is sensitive to AoA. Early-acquired words (12.5%), late-acquired words (12.5%) and pseudo-words (75%) were presented in an auditory lexical decision task. The two sets of words were matched for length, word type, concreteness, imageability and, crucially, word frequency. Early-acquired words were recognised faster and more accurately than late-acquired words. In addition, AoA modulated ERP activity in centroparietal electrode sites, with early-acquired words eliciting a larger positivity (P300) than late-acquired words. This is the first study to demonstrate an ERP correlate of AoA effects. An important implication of our findings is that AoA may need to be controlled in ERP studies of lexical processing, especially in designs in which it is likely to be a confound (e.g., studies of lexical category effects).     

Relationship of patients' age to histopathological features of breast tumours in <Emphasis Type="Italic">BRCA1</Emphasis> and <Emphasis Type="Italic">BRCA2</Emphasis>and mutation-negative breast cancer families

Introduction  

Our aim was to evaluate the relationship of patients' age to histopathological features of hereditary breast tumours in a series of breast cancer families not selected for age at diagnosis. In sporadic breast cancer, tumours from premenopausal patients have been shown to differ from those of postmenopausal patients, but this phenomenon has been little studied among familial patients.     

Acute focal bacterial nephritis

Clinical and radiographic characteristics of 12 patients with acute focal bacterial nephritis (AFBN) are presented along with review of the literature. Most patients presented with symptoms of an inflammatory or infectious process. Fever and pyuria were the most frequently encountered clinical characteristics. Imaging modalities that were used to establish a definitive diagnosis of focal bacterial nephritis included ultrasound, computed tomography, and intravenous urography with nephrotomography. Ultrasound was found to be the most effective and least costly method of diagnosis. Misdiagnosis of AFBN as abscess or tumor, which it may stimulate, could lead to inappropriate surgical therapy.     

Intestinal helminths of a landlocked ringed seal (<Emphasis Type="Italic">Phoca hispida saimensis</Emphasis>) population in eastern Finland

A small, landlocked, endangered ringed seal (Phoca hispida saimensis) population lives as a postglacial relict in Lake Saimaa in eastern Finland. In this study, the intestinal metazoans were examined from a total of 61 Saimaa seals found dead from 1981 to 2001. The helminth fauna was very depauperate. Only one acanthocephalan species, Corynosoma magdaleni, has been able to survive during isolation in the freshwater environment. In addition, only two cestode species were found: Diphyllobothrium ditretum and Schistocephalus sp. However, neither of these larvae developed in the ringed seals. As the newborn pups of Saimaa seals are nursed for about 2 months only one of them was infected by C. magdaleni. At 2–5 months the pups harboured worms; however, the mean intensity did not rise distinctively until the seals were adults. C. magdaleni infection increased with increasing age and the abundances were significantly different between the age groups. There was no correlation between the number of parasites and the adult seal body weight; however, seals weighing 36 kg or more carried the majority of the worms. The distribution of the parasites was aggregated; six seals carried 65% (n=1,182) of all worms (total n=1,809) and 26 seals were uninfected. Variation in the number of worms in individual seals may indicate differences in feeding behaviour and in the diet of seals, and/or variation in the immune status of the seals.     

Maternal sex hormones in early pregnancy and asthma among offspring: a case-control study

BACKGROUND: Sex hormones may be associated with the risk of onset of asthma. OBJECTIVE: To study the association between maternal sex hormone concentrations during early pregnancy and the risk of asthma among offspring. METHODS: A case-control study of 129 asthmatic children and 125 control children 5 to 6 years of age. Maternal sera in early pregnancy were obtained from the Finnish Maternal Cohort serum bank. RESULTS: The means of serum progesterone and estradiol and free estradiol in mothers of asthmatic and control children were 81.0 and 82.8 nmol/L (P =.60), 7.87 nmol/L and 7.65 nmol/L (P =.99), and 149.5 pmol/L and 148.0 pmol/L (P =.95), respectively. There were also no differences in the mean concentrations of maternal sex hormones according to the presence of allergic rhinitis or atopic eczema among the children. CONCLUSIONS: The current results do not support an association between maternal sex hormone concentrations during early pregnancy and onset of allergic disease in early childhood.     

Clinical significance of incidental magnetic resonance image abnormalities in mastoid cavity and middle ear in children

OBJECTIVE: Magnetic resonance imaging of the head may reveal incidental findings in paranasal sinuses. The purpose of this study was to discover whether similar changes could be identified in the mastoid cavity and middle ear as well. METHODS: A group of 50 children undergoing magnetic resonance imaging of the head for suspected intracranial pathology were prospectively gathered. Their parents completed a questionnaire concerning each child's medical history connected with acute otitis media. Otoradiologists evaluated the pictures for mastoid cavity and middle ear and paranasal sinus abnormalities. RESULTS: In six (12%) children, magnetic resonance imaging detected abnormalities resembling acute inflammatory changes, although none had had acute otitis media during the preceding last 3 months. Abnormalities detected in the paranasal sinuses were not correlated with abnormalities in the mastoid cavity and middle ear. CONCLUSIONS: High signal intensity in magnetic resonance images from the mastoid cavity and middle ear may be incidental and without any clinical significance. These findings must be interpreted together with knowledge of the child's medical condition and clinical examination of the ears.     

Inhibition of matrix metalloproteinase-14 in osteosarcoma cells by clodronate

BACKGROUND: Bisphosphonates reduce the bone metastasis formation and angiogenesis but the exact molecular mechanisms involved are unclear. Progelatinase A (proMMP-2; 78 KDa) is activated up during the tumor spread and metastasis by a cell surface-associated matrix metalloproteinase (membrane-type matrix metalloproteinase [MT1-MMP] or MMP-14). MATERIAL AND METHODS: We evaluated the effects of a bisphosphonate (clodronate) on MT1-MMP mRNA expression and protein production, catalytic activity and proteolytic activation of proMMP-2 by cultured human MG-63 osteosarcoma cells. RESULTS: Clodronate, at therapeutically attainable noncytotoxic concentrations, dose-dependently inhibited phorbol myristic acetate (PMA)-induced proteolytic activation of proMMP-2 by human MG-63 osteosarcoma cells. Clodronate also downregulated the PMA-induced expression of MT1-MMP mRNA and protein production in human MG-63 osteosarcoma cells, as evidenced by Northern analysis and fluorescent immunohistochemistry. Furthermore, clodronate inhibited directly and dose-dependently MT1-MMP activity, and the MT1-MMP inhibition by clodronate was reduced in the presence of an increased (5 mM) Ca(2+) concentrations when compared to physiological (1 mM) Ca(2+) concentrations. CONCLUSION: We conclude that (1) the extracellular/cell-associated mechanism of bisphosphonate involves inhibition of MT1-MMP catalytic activity eventually by chelation, and that (2) intracellular mechanism involves downregulation of induced MT1-MMP mRNA and protein expression. The inhibition and downregulation of MT1-MMP by clodronate can be related to their ability to reduce MG-63 osteosarcoma cell invasion and spread. These findings may, at least in part, explain at molecular level the antitumor and antibone resorption activities of clodronate observed in clinical studies.