Family History of MI, Smoking, and Risk of Periodontal Disease.

Periodontal disease (PD) shares common risk factors with cardiovascular disease. Our hypothesis was that having a family history of myocardial infarction (FamHxMI) may be a novel risk factor for PD. Risk assessment based on FamHxMI, conditional on smoking status, was examined given the strong influence of smoking on PD. Exploratory analysis with inflammatory biomarkers and genetic determinants was conducted to understand potential mechanistic links. The Women's Genome Health Study (WGHS) is a prospective cohort of US female health care professionals who provided blood samples at baseline in the Women's Health Study, a 2 × 2 factorial clinical trial investigating vitamin E and aspirin in the prevention of cardiovascular disease and cancer. PD was ascertained via self-report over 12 y of follow-up. Prevalence (3,442 cases), incidence (1,365 cases), and survival analysis of PD were investigated for associations of FamHxMI as well as in strata of FamHxMI by smoking. Kruskal-Wallis, chi-square tests, multivariate regression, and Cox proportional hazard models were used for the analyses. In the WGHS, women with FamHxMI showed higher risk of ever having PD. A particularly high-risk group of having both FamHxMI and smoking at baseline was highlighted in the prevalence and risk of developing PD. PD risk increased according to the following strata: no FamHxMI and nonsmokers (reference), FamHxMI and nonsmokers (hazard ratio [HR] = 1.2, 95% CI = 1.0 to 1.5), smokers without FamHxMI (HR = 1.3, 95% CI = 1.2 to 1.5), and smokers with FamHxMI (HR = 1.5, 95% CI = 1.2 to 1.8). An independent analysis by the dental Atherosclerosis Risk in Communities study ( N = 5,552) identified more severe periodontitis cases among participants in the high-risk group (smokers with FamHxMI). Further examination of interactions among inflammatory biomarkers or genetic exploration with FamHxMI did not explain the risk increase of PD associated with FamHxMI in the WGHS. Future efforts based on an integrative-omics approach may facilitate validation of these findings and suggest a mechanistic link between PD and FamHxMI.

[Evolution of functional capacity, assessed with the Egen Klassifikation scale, in the Spanish population with spinal muscular atrophy or Duchenne muscular dystrophy. A three year longitudinal study]. / Evolucion de la capacidad funcional valorada con la escala Egen Klassifikation en personas afectas de atrofia muscular espinal o distrofia muscular de Duchenne de la poblacion española: estudio longitudinal de tres años.

INTRODUCTION: Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are two neuromuscular diseases which evolve with a progressive loss of muscle strength and, therefore, the loss of functional capacity. The valuation measurement scales are used to understand better and to quantify this involution as well as making treatment to anticipate problems and improve the quality of life of people suffering from these diseases. AIM: To study the changes in the functional capacity of a group of patients with SMA and DMD, over a period of three years. PATIENTS AND METHODS: Nineteen individuals of the Spanish population affected with SMA and DMD, which were assessed with the Egen Klassifikation scale twice, with a time interval of three years. RESULTS: The results show a decrease in the functional capacity of these persons during this time period, with a significant difference in the total amount of the scale (p = 0.003). All scale items showed lower valuations after three years, reaching statistical significance during the assessment, containing the ability to move his hands and coughing. CONCLUSION: The functional capacity of patients with SMA and DMD decreases significantly within three years.

TITLE: Evolucion de la capacidad funcional valorada con la escala Egen Klassifikation en personas afectas de atrofia muscular espinal o distrofia muscular de Duchenne de la poblacion española: estudio longitudinal de tres años.Introduccion. La atrofia muscular espinal (AME) y la distrofia muscular de Duchenne (DMD) son dos enfermedades neuromusculares que evolucionan con perdida progresiva de la fuerza muscular y, en consecuencia, perdida de la capacidad funcional. La valoracion con escalas de medicion permite conocer mejor y cuantificar esta involucion, asi como tomar decisiones terapeuticas para anticiparse a los problemas y mejorar la calidad de vida de las personas afectas de estas patologias. Objetivo. Estudiar los cambios de la capacidad funcional de un grupo de pacientes con AME y DMD en un periodo de tres años. Pacientes y metodos. Diecinueve personas de la poblacion española afectas de AME o DMD, a las que se valoro con la escala Egen Klassifikation en dos ocasiones, en un periodo de tres años. Resultados. Los resultados obtenidos reflejan una disminucion de la capacidad funcional de estas personas durante este periodo de tiempo, con una diferencia significativa en la suma total de la escala (p = 0,003). Todos los items de la escala tuvieron valoraciones inferiores despues de tres años, y se llego a la significacion estadistica en la valoracion de la capacidad de mover las manos y de toser. Conclusion. La capacidad funcional de los pacientes con AME y DMD disminuye de forma significativa en tres años.

Fatigue in patients with spinal muscular atrophy type II and congenital myopathies: evaluation of the fatigue severity scale.

PURPOSE: The aim of this study was to evaluate whether the fatigue severity scale (FSS) is an appropriate instrument to assess fatigue in patients with spinal muscular atrophy type II (SMA II) and congenital myopathies (CM). METHODS: FSS and visual analog scale (VAS) were administered to 33 SMA II- and 72 CM patients. The psychometric properties of the FSS were evaluated by means of classical test theories for each of the disease groups. If abnormal fatigue was present in the disease group, the construct of fatigue was evaluated by means of focus group interviews. RESULTS: Fatigue was rare in SMA II patients, but very frequent in patients with CM. The cut-off score designating abnormal fatigue (FSS score ≥ 4) was exceeded by 10% of the SMA II patients in contrast to 76% of the CM patients, of whom 52% suffered from severe fatigue (FSS score ≥ 5). Focus group interviews demonstrated that fatigue had an adverse effect on motor function, level of energy, social relations, and identity, four themes that could be captured by the FSS. The FSS and VAS were strongly correlated in SMA II patients, but only moderately in CM patients. The psychometric properties indicated that the original FSS with nine items measures more than one construct of fatigue, eliminating the first two items improved scale properties. CONCLUSION: This study demonstrates that fatigue is characteristic in patients with CM, but not in patients with SMA II, in whom fatigue does not seem to impact daily life. While fatigue in CM and SMA II can be captured by FSS, omitting the first two items of the scale will improve its properties and content validity, along with comprehension of the scale itself.

Change in muscle strength over time in spinal muscular atrophy types II and III. A long-term follow-up study.

Whether muscle strength deteriorates with time in spinal muscular atrophy (SMA) types II and III is still debated. We present a long-term follow-up study on muscle strength in 30 patients with SMA types II and III. Median follow-up time was 17 years. Median number of assessments was four. All patients were assessed by Manual Muscle Testing (MMT), Brooke upper limb scale and EK scale. There was a difference in muscle strength of the upper limbs from first to last assessment in SMA II (p<0.0001) and SMA III patients (p<0.02). In SMA II patients, the rate of yearly decline in strength (% MRC score) was 0.22 units (p<0.03). The decline was independent of the grade of muscle strength at entry. In SMA II patients the decline in muscle strength was reflected in a loss upper limb function as measured by Brooke upper limb scale (p<0.0001) and motor function as measured by EK scale (p<0.0001), a loss of great importance to the patients' need for practical assistance. This study demonstrates loss of muscle strength over time in SMA II and III patients. Because of the very slow deterioration, it takes years to detect this change, which has to be taken into account in future treatment trials.

Physical characteristics and applicability of standard assessment methods in a total population of spinal muscular atrophy type II patients.

The aims of this study were to evaluate muscle strength, functional abilities, contractures and Forced Vital Capacity in a population of 54 spinal muscular atrophy (SMA) type II patients between the ages of 5 and 70, and to evaluate the applicability of conventional assessment methods. The patients were evaluated by means of functional scales, muscles tests, joint motion measurement and Forced Vital Capacity test. There was a significant score difference in functional tests and muscle tests as well as in the sum of contractures between younger individuals (or= 21years). The functional scales were not sensitive enough to differentiate among the most impaired persons. A reduced Manual Muscle Test score of the upper limbs was found to differentiate more precisely among individuals than a total score derived from testing 38 muscle groups. There is a need for clinical tools that can evaluate patients with SMA type II of all ages and with severely reduced functional abilities.

Co-purified gelatinases alter the stability and biological activities of human plasma fibronectin preparations.

BACKGROUND AND OBJECTIVE: Fibronectin (FN) is an important cell adhesion molecule that is used widely to characterize cell behavior. Preparations of FN purified from human plasma by gelatin-Sepharose affinity chromatography typically also contain gelatin-binding gelatinases that may cleave FN, reduce its stability and alter its biological activities. Available methods for separating gelatinases from FN are resource demanding. Therefore, our objective was to devise a time- and cost-efficient protocol for purification of gelatinase-free FN. MATERIAL AND METHODS: Experiments tested the elution profiles for FN and gelatinases from gelatin-Sepharose using a concentration range (1-7%) of dimethyl sulfoxide (DMSO) and 4 m urea as eluants. Subsequently, we explored the sequential application of those eluants for differential elution of gelatinases and FN using a single affinity column. Finally, experiments characterized the stability of purified FN with or without contaminating gelatinases, as well as the effects of FN degradation on cell attachment and migration. RESULTS: Assay optimization demonstrated that pre-elution with 3% DMSO efficiently eliminated gelatinases but not FN from gelatin-Sepharose, whereas subsequent elution with 4 m urea released FN. Sequential elutions with DMSO and urea produced gelatinase-free FN, which was more stable than FN eluted by urea only. Fibronectin degradation did not affect human gingival fibroblast attachment, but increased cell migration significantly. CONCLUSION: The present experiments devised a time- and cost-efficient protocol for eliminating gelatinases during purification of human plasma FN. Gelatinase-free FN preparations had greater stability, which may be essential for experiments because FN fragments have altered biological activities compared with intact FN.

The Duchenne muscular dystrophy population in Denmark, 1977-2001: prevalence, incidence and survival in relation to the introduction of ventilator use.

Mechanical ventilation of patients with Duchenne muscular dystrophy continues to be a subject of study. The purpose was to estimate prevalence, incidence, mortality and use of mechanical ventilation in the total Duchenne muscular dystrophy population in Denmark between 1977 and 2001 and further, to reconstruct the introduction of mechanical ventilation to assess the role of the patient organization. Study objects were collected from five sources and verifiable cases identified. Negotiations between health authorities and the patient organization constituted main empirical data for the reconstruction. While overall incidence remained stable at 2.0 per 10(5), prevalence rose from 3.1 to 5.5 per 10(5), mortality fell from 4.7 to 2.6 per 100 years at risk and prevalence of Duchenne muscular dystrophy ventilator users rose from 0.9 to 43.4 per 100. We conclude that survival of Duchenne muscular dystrophy patients has increased and ventilator use is probably a main reason. The patient organization exercised a key role but acted upon preconditions created by other players.

Amelogenin is a cell adhesion protein.

Amelogenin, the major protein component of tooth enamel, is shown to be a cell adhesion protein. Since it had been shown that an amelogenin-containing preparation, Emdogain, possessed cell-adhesive activity, we tested the hypothesis that amelogenin was responsible for cell-adhesive activity. Recombinant amelogenin was found to promote adhesion at less than 15 micro g/60-mm plate and requires divalent cations for activity. While we found that amelogenin does not bind to collagen or heparin under physiological conditions, it was demonstrated previously that amelogenin does bind to hydroxyapatite. The cell-adhesive activity of amelogenin may play a role in development and may provide a partial explanation for the therapeutic effects of Emdogain in periodontal regeneration.

Validity of the EK scale: a functional assessment of non-ambulatory individuals with Duchenne muscular dystrophy or spinal muscular atrophy.

BACKGROUND AND PURPOSE: The EK scale comprises ten categories (EK 1-10), each contributing to an overall picture of function in the non-ambulatory stage of Duchenne muscular dystrophy (DMD). The purpose of the present study was to investigate content and construct validity of the EK scale as a tool to discriminate between levels of functional ability in individuals with DMD or spinal muscular atrophy (SMA) who were non-ambulatory. METHOD: Data from a sample of 56 subjects with DMD and 38 with SMA, who were non-ambulatory, were obtained from four separate studies. The relationship of functional ability by use of the EK scale and (1) muscle strength, (2) contractures, (3) forced vital capacity and (4) years of wheelchair dependency were assessed. All items of the EK scale were used except the one representing severe hypoventilation. RESULTS: Regression analyses showed that the EK sum was the most significant explanatory variable (p < 0.05) of all variables measured to explain muscle strength in both DMD and SMA subjects. The individual categories of EK (1-10) all contributed as significant explanatory variables (p < 0.05) to the other variables measured. CONCLUSIONS: The categories and items of the EK scale were relevant and valid as means of discriminating between levels of functional performance in the population studied which was evidence of content and construct validity.

Fracture risk in patients with muscular dystrophy and spinal muscular atrophy.

We aimed at studying fracture risk in patients with Duchenne's muscular dystrophy (DMD), Becker's muscular dystrophy (BEMD), and spinal muscular atrophy type II and III (SMA II and III). A self-administered questionnaire was mailed to 293 patients with DMD, BEMD, SMA II or SMA III of which 229 returned the questionnaire. Each respondent was compared with an age- and gender-matched control subject. The mean age was 23.9 +/- 15.9 years for the patients and 23.3 +/- 16.5 years for the controls. There were significantly more fractures among patients than controls after the diagnosis was made (RR = 1.9), but not before. The patients had more fractures of the femurs, lower legs, and upper arms than the controls. Low energy fractures were more frequent in patients than controls (9% vs 0%). Many fractures in the femurs (40%), lower legs (35%), and feet and toes (44%) led to a permanent loss of function. Loss of ambulation was the major risk factor for fractures. In conclusion, fracture risk is increased in neuromuscular disease.

Longitudinal data analysis: an application to construction of a natural history profile of Duchenne muscular dystrophy.

A 30-month prospective study of 27 Scandinavian boys with confirmed diagnosis of Duchenne muscular dystrophy was carried out to construct profiles of the natural history of the disease. Assessments which included measures of voluntary muscle strength and function were done at 3 monthly intervals except for the first and second which were separated by 1 month. Recently developed statistical methods for analysis of longitudinal data with repeated observations on the same individual were used avoiding the problem of induced serial correlations. This allowed for the construction of both reference and prediction profiles for the variables %MRC, motor ability, walking time for 10 m and the sum of myometry of seven muscle groups.

Proteolytic events of wound-healing--coordinated interactions among matrix metalloproteinases (MMPs), integrins, and extracellular matrix molecules.

During wound-healing, cells are required to migrate rapidly into the wound site via a proteolytically generated pathway in the provisional matrix, to produce new extracellular matrix, and, subsequently, to remodel the newly formed tissue matrix during the maturation phase. Two classes of molecules cooperate closely to achieve this goal, namely, the matrix adhesion and signaling receptors, the integrins, and matrix-degrading and -processing enzymes, the matrix metalloproteinases (MMPs). There is now substantial experimental evidence that blocking key molecules of either group will prevent or seriously delay wound-healing. It has been known for some time now that cell adhesion by means of the integrins regulates the expression of MMPs. In addition, certain MMPs can bind to integrins or other receptors on the cell surface involved in enzyme activation, thereby providing a mechanism for localized matrix degradation. By proteolytically modifying the existing matrix molecules, the MMPs can then induce changes in cell behavior and function from a state of rest to migration. During wound repair, the expression of integrins and MMPs is simultaneously up-regulated. This review will focus on those aspects of the extensive knowledge of fibroblast and keratinocyte MMPs and integrins in biological processes that relate to wound-healing.

A randomized comparative study of two methods for controlling Tendo Achilles contracture in Duchenne muscular dystrophy.

A 30-month prospective randomized study of 27 Scandinavian boys with confirmed diagnosis of Duchenne muscular dystrophy was done to compare the effect of passive stretching combined with the use of night splints (group A) or passive stretching (group B) on the evolution of Tendo Achilles contractures. Assessments were based on the methodology of Scott et al. (Muscle Nerve 1982;5:291-301)Analysis of the pattern and mechanism of dropout was done to eliminate bias between the two groups. Logistic regression showed that Tendo Achilles contracture was the most important variable (P=0.0020) for dropout. Methods of statistical analysis for longitudinal data avoiding induced serial correlations were used in the analysis. The expected annual change in Tendo Achilles contracture was found to be 23% less in group A than in group B after equalization for total muscle strength (%MRC).

Clinical validation of a new subtraction radiography technique for periodontal bone loss detection.

BACKGROUND: Diagnostic subtraction radiography (DSR) is a new digital radiographic image subtraction method designed to enhance detection of crestal or periapical bone density changes and to help evaluate caries progression in teeth. In this clinical study, the performance of the DSR method was evaluated for its ability to detect periodontal bone loss and was compared with that of conventional evaluation of radiographs and the standardized cephalostat-guided image acquisition and subtraction technique (LRA) which served as the "gold standard." METHODS: In each of 25 subjects with alveolar crestal bone loss created by periodontal surgery, one set of DSR radiographs and one set of LRA radiographs were obtained before and after the surgery. Subtraction images were then generated by both the proprietary DSR and the LRA techniques. Four viewers evaluated the paired film sets and both subtraction image sets using a 5 point confidence scale to determine the presence or absence of crestal bone loss. Receiver operating characteristics (ROC) statistical procedures were applied to analyze the diagnostic accuracy and statistical differences between the three imaging modalities. RESULTS: The DSR subtraction viewing generated an ROC area of 0.882. For 2 of the viewers this represented a statistically significant gain (P <0.05) over the conventional viewing of the radiographs which had an average ROC area of 0.730. In comparison, the LRA method achieved an area of 0.954. The differences between the LRA and the DSR subtraction methods were not statistically significant, but the statistical power for claiming equality was low ranging from 0.2 to 0.6. CONCLUSIONS: The use of the DSR technique in clinical radiographic image acquisition and subsequent subtraction analysis clearly enhanced the accuracy of alveolar crestal bone loss detection when compared to conventional film viewing. Because this methodology is less resource demanding than LRA and the film exposure techniques and computer-based image analysis skills may be acquired with only a few hours of training, the DSR has potential in clinical practice.

The involvement of the fibronectin type II-like modules of human gelatinase A in cell surface localization and activation.

Recombinant collagen-binding domain (rCBD) comprising the three fibronectin type II-like modules of human gelatinase A was found to compete the zymogen form of this matrix metalloproteinase from the cell surface of normal human fibroblasts in culture. Upon concanavalin A treatment of cells, the induced cellular activation of gelatinase A was markedly elevated in the presence of the rCBD. Therefore, the mechanistic aspects of gelatinase A binding to cells by this domain were further studied using cell attachment assays. Fibroblasts attached to rCBD-coated microplate wells in a manner that was inhibited by soluble rCBD, blocking antibodies to the beta1-integrin subunit but not the alpha2-integrin subunit, and bacterial collagenase treatment. Addition of soluble collagen rescued the attachment of collagenase-treated cells to the rCBD. As a probe on ligand blots of octyl-beta-D-thioglucopyranoside-solubilized cell membrane extracts, the rCBD bound 140- and 160-kDa protein bands. Their identities were likely procollagen chains being both bacterial collagenase-sensitive and also converted upon pepsin digestion to 112- and 126-kDa bands that co-migrated with collagen alpha1(I) and alpha2(I) chains. A rCBD mutant protein (Lys263 --> Ala) with reduced collagen affinity showed less cell attachment, whereas a heparin-binding deficient mutant (Lys357 --> Ala), heparinase treatment, or heparin addition did not alter attachment. Thus, a cell-binding mechanism for gelatinase A is revealed that does not involve the hemopexin COOH domain. Instead, an attachment complex comprising gelatinase A-native type I collagen-beta1-integrin forms as a result of interactions involving the collagen-binding domain of the enzyme. Moreover, this distinct pool of cell collagen-bound proenzyme appears recalcitrant to cellular activation.

Specific, high affinity binding of tissue inhibitor of metalloproteinases-4 (TIMP-4) to the COOH-terminal hemopexin-like domain of human gelatinase A. TIMP-4 binds progelatinase A and the COOH-terminal domain in a similar manner to TIMP-2.

The binding properties of the newly described tissue inhibitor of metalloproteinases-4 (TIMP-4) to progelatinase A and to the COOH-terminal hemopexin-like domain (C domain) of the enzyme were examined. We present evidence for the first time of a specific, high affinity interaction between TIMP-4 and the C domain of human gelatinase A and show that TIMP-4 binds both progelatinase A and the C domain in a similar manner to that of TIMP-2. Saturable binding of recombinant C domain to TIMP-4 and to TIMP-2 but not to TIMP-1 was demonstrated using a microwell protein binding assay. The recombinant collagen binding domain of gelatinase A, comprised of the three fibronectin type II-like repeats, did not bind to TIMP-4, indicating that binding is mediated selectively by the C domain. Binding to TIMP-4 was of high affinity with an apparent Kd of 1.7 x 10(-7) M but slightly weaker than that to TIMP-2 (apparent Kd of 0.66 x 10(-7) M). Affinity chromatography confirmed the TIMP-4-C domain interaction and also showed that the complex could not be disrupted by 1 M NaCl or 10% dimethyl sulfoxide, thereby further demonstrating the tight binding. To verify the biological significance of this interaction, binding of full-length progelatinase A to TIMP-4 was investigated. TIMP-4 and TIMP-2 but not TIMP-1 bound specifically to purified TIMP-2-free human recombinant full-length progelatinase A and to full-length rat proenzyme from the conditioned culture medium of ROS 17/2.8 cells. Preincubation of the C domain with TIMP-2 was found to reduce subsequent binding to TIMP-4 in a concentration-dependent manner. Competition between TIMP-2 and TIMP-4 for a common or overlapping binding sites on the gelatinase A C domain may occur; alternatively TIMP-2 may prevent the binding of TIMP-4 by steric hindrance or induction of a conformational change in the C domain. We propose that the binding of progelatinase A to TIMP-4 represents a third TIMP-progelatinase interaction in addition to that of progelatinase A with TIMP-2 and progelatinase B with TIMP-1 described previously. This new phenomenon may be of important physiological significance in modulating the cell surface activation of progelatinase A.

Indicators of need for mechanical ventilation in Duchenne muscular dystrophy and spinal muscular atrophy.

STUDY OBJECTIVES: The purpose was to investigate a possible relationship between different parameters of physical function, spirometric measurements, and the approaching need for mechanical ventilation. DESIGN: A nonrandomized, prospective, descriptive study of 11 patients with spinal muscular atrophy type II (SMA-II) and 14 patients with Duchenne muscular dystrophy (DMD). At a home visit, the anthropometric indices of age, height, and weight were recorded, the degree of disability was scored, and measurement of the strength of eight muscle groups and spirometry was performed. The interdependence of the variables was analyzed and the intergroup differences evaluated. Eighteen months later, it was found that one of the authors (B.J.), who was blind to the results of the first examination had instituted home mechanical ventilation on seven of the patients. The data were analyzed retrospectively for their predictive value as indicators of approaching ventilator dependency. RESULTS: The seven patients who needed mechanical ventilation were the patients with DMD with the highest disability score (Egen Klassifikation [EK] sum > 20) and the smallest values for FVC < 1.2 L (FVC% < 30). We found a significant correlation (p = 0.002) between FVC% and the EK sum at the first examination and between the FVC% and the time until treatment with mechanical ventilation was instituted (p = 0.023). Although 7 of the 11 patients with SMA type II had FVC below 1.2 L and some of them had an EK sum score higher (indicating more disability) than some patients with DMD who needed mechanical ventilation, none of them required mechanical ventilation. CONCLUSION: In this investigation, a combination of EK sum and FVC% provided a better indication of the approaching need for mechanical ventilation in the patients with DMD than the variables separately.

Diagnosis and management of vertical root fractures.

Vertical root fractures constitute a significant management problem for dentists. The diagnosis of root fractures is difficult because several of their signs and symptoms are shared with other common dental or oral pathologies. However, reaching an accurate diagnosis is crucial to establishing the prognosis for a fractured tooth and selecting the appropriate treatment. This review describes current knowledge of the causes, diagnosis, and management of vertical root fractures, with special attention to the periodontal aspects of this condition.

Extracellular matrix binding properties of recombinant fibronectin type II-like modules of human 72-kDa gelatinase/type IV collagenase. High affinity binding to native type I collagen but not native type IV collagen.

72-kDa gelatinase/type IV collagenase is an important matrix metalloproteinase in the degradation of basement membranes and denatured collagens (gelatin). These proteolytic processes are required for pathologic tissue destruction and physiologic tissue remodeling. To investigate the molecular determinants of substrate specificity of this enzyme, a 21-kDa domain of 72-kDa gelatinase, consisting of three tandem fibronectin type II-like modules, was expressed in Escherichia coli. Similar to full-length 72-kDa gelatinase and the type II modules in fibronectin, the recombinant (r) fibronectin-like domain of this proteinase bound denatured type I collagen with an apparent Kd in the micromolar range. This domain, designated the collagen-binding domain (rCBD123), possesses at least two collagen-binding sites that can each be simultaneously occupied. rCBD123 also avidly bound elastin and denatured types IV and V collagens, but neither native types IV and V collagens nor fibronectin, all of which are substrates of the enzyme. Although 72-kDa gelatinase is involved in basement membrane degradation, rCBD123 also did not bind reconstituted basement membrane, laminin, or SPARC. Native type I collagen, which is not degraded by 72-kDa gelatinase, competed with gelatin for a shared binding site on rCBD123. rCBD123 also displaced full-length 72-kDa gelatinase bound to native type I collagen, further demonstrating that the collagen binding properties of the recombinant domain closely mimicked those of the full-length enzyme. Since rCBD123 showed reduced binding to pepsin-cleaved type I collagen, either or both of the collagen telopeptide ends contain recognition sites for the 72-kDa gelatinase fibronectin-like domain. This was confirmed by the avid binding of rCBD123 to the alpha 1(I) collagen cyanogen bromide fragment CB2 from the NH2-terminal telopeptide. rCBD123 also bound alpha 1(I)-CB7, which encompasses the fibronectin-binding site, and to alpha 1(I)-CB8, a fragment not bound by fibronectin. Thus, type I collagen contains multiple binding sites for rCBD123 which are partially masked by the triple helical conformation of native collagen and fully exposed upon unfolding of the triple helix. The potential of the fibronectin-like collagen binding domain of 72-kDa gelatinase to bind extracellular matrix proteins may facilitate enzyme localization in connective tissue matrices.

Root resorptions in a patient with hemifacial atrophy.

Hemifacial atrophy (Parry-Romberg syndrome) is a rare but well-recognized condition. The developmental effects on facial and oral structures have been well documented in the literature. However, the etiology of hemifacial atrophy remains unknown. Previous reported alterations in tooth growth and development include delayed tooth eruption, abnormal root morphology, and malocclusion but not root resorption. This report presents the orofacial changes from hemifacial atrophy in a 22-yr-old woman and describes the occurrence of root resorptions in two regions affected by this condition. The concurrent presence of root resorptions in both the maxilla and mandible in the regions showing the most severe dental malformations points to root resorption as an additional complication of hemifacial atrophy.