Enamel Matrix Derivative and Systemic Antibiotics as Adjuncts to Non-Surgical Periodontal Treatment: Biologic Response

BACKGROUND

Short-term clinical observations suggest an anti-inflammatory effect of enamel matrix derivative (EMD). The purpose of this study was to evaluate the anti-inflammatory capacity of EMD, used as an adjunct to non-surgical periodontal treatment of deep lesions in chronic periodontitis patients, by monitoring inflammatory markers in gingival crevicular fluid (GCF).

METHODS

Sixteen subjects were randomly assigned to treatment with EMD or placebo in contralateral dentition areas. Half of the subjects received 250 mg metronidazole and 375 mg amoxicillin three times a day for 7 days; the other half received a placebo. GCF samples were collected from one interproximal lesion in each of the contralateral quadrants before treatment and after 10 days and 2, 6, and 12 months. Total protein content was determined according to the Bradford method. Myeloid-related protein (MRP) 8/14 and interleukin (IL)-1beta were analyzed quantitatively by enzyme-linked immunosorbent assay (ELISA), and elastase activity was determined using a low molecular weight fluorogenic substrate.

RESULTS

No significant differences were observed between sites treated with or without EMD for any biochemical parameter. Two months after treatment, subjects treated with antibiotics exhibited less clinical signs of inflammation. Furthermore, these subjects had lower MRP 8/14 levels only at day 10 compared to those receiving the placebo. For total protein, IL-1beta, and elastase, no statistically significant differences were noted for subjects with or without antibiotic therapy at any time point.

CONCLUSIONS

Improved healing of the soft tissues has been noted clinically in non-surgically treated sites in subjects treated with antibiotics. The expression of inflammatory mediators in GCF corroborated this finding only in part. EMD did not seem to further affect the expression of inflammatory mediators.

The influence of jaw innervation on the dental maturation pattern in the mandible

OBJECTIVES

To explore the relationship between mandibular dental maturation and the pattern of jaw innervation.

SETTING AND SAMPLE POPULATION

The sample included 365 panoramic radiographs taken in the period 1965-1969 in a Danish municipality.

DESIGN

For assessing dental maturity, the seven left mandibular teeth (M2, M1, P2, P1, C, I2, I1) were given a dental maturity score according to a method introduced by Demirjian. Spearman correlation coefficients between the maturity score of an index tooth (one of each teeth) and the maturity score of the 6 other teeth was calculated and illustrated.

RESULTS

All the correlation coefficients were larger than 0.5 indicating a rather high level of association between the development of mandibular teeth in the same individual. Thus, associations between the pattern of dental maturation and jaw innervation were not obvious.

CONCLUSION

When the correlation between the dental maturity stages was analysed, no significant relation was found between dental maturation and jaw innervation in the mandible. This is interesting considering the results presented in a recent study, which showed that the clinical observed tooth eruption was closely related to the pattern of jaw innervation. Those authors suggested that the factors influencing the eruption might be associated with jaw innervation. In our study, the stepwise dental maturation process, however, is not equally associated with jaw innervation.

Perinatal risk factors of adverse outcome in very preterm children: a role of initial treatment of respiratory insufficiency?

AIM

To investigate risk factors of adverse outcome in a cohort of very preterm children treated mainly with nasal continuous positive airway pressure (CPAP) during the neonatal course.

METHODS

In Denmark, preterm children are treated with nasal CPAP as a first approach to respiratory support. A national prospective study of all infants with a birthweight below 1000 g or a gestational age below 28 wk born in 1994-1995 was initiated to evaluate this approach. Of the 269 surviving children 164 (61%) were not treated with mechanical ventilation in the neonatal period. A follow-up of the children at 5 y of age was conducted. Data from the neonatal period and the 5-y follow-up were analysed.

RESULTS

In multivariate analyses including 250 children, a severely abnormal neonatal brain ultrasound scan was predictive of cerebral palsy (OR = 19.9, CI 95%: 6.1-64.8) and intellectual disability (OR = 6.2, CI 95%: 2.3-16.5). A high Clinical Risk Index for Babies (CRIB) score (OR = 2.4, CI 95%: 1.1-5.5) and chronic lung disease (OR = 2.8, CI 95%: 1.2-6.9) were predictive of intellectual disability. In univariate analyses mechanical ventilation was associated with cerebral palsy (OR=4.3, CI 95%: 1.7-10.8) and intellectual disability (OR = 2.2, CI 95%: 1.2-4.2), but the associations became insignificant in multivariate analyses including chronic lung disease and a severely abnormal ultrasound scan.

CONCLUSION

The associations between neonatal risk factors and adverse outcome in our cohort were very similar to those found in other cohorts with another initial treatment of respiratory insufficiency. We found no significant adverse effects of mechanical ventilation beyond what could be explained by associations with chronic lung disease and IVH 3-4/PVL.

Environmental effects of agri-environmental schemes in Western Europe

Agri-environmental schemes (AES) have been introduced as part of European Union's (EU) Common Agricultural Policy and are now an important part of this. A methodological approach to analyse the policy effects of AES is outlined, in which we distinguish between performance effects (on agricultural practices) and outcome effects (environmental impact). The performance effects are further approached including measurement of improvement and protection effects based on 12 indicators on changes/maintenance of land use and agricultural management. Data from personal interviews of participating and non-participating farmers in AES measures in nine EU Member States and Switzerland were used to analyse policy effects, including single indicator effects on agricultural practices as well as combined effects at the agreement level. Significant effects were found for mineral N-fertiliser use, stocking density reduction, maintenance of a minimum livestock density and pesticides. For AES agreements regulating grassland management, fertiliser use and pesticides, clear indications of combined improvement and protection effects were found. In addition clear improvement effects of agreements regulating fertiliser and pesticides use on mainly arable lands were revealed. It is concluded that the approach presented including the 12 selected indicators has proven to be operational.

Mechanical stability of custom and anatomical femoral stems: an experimental study in human femora

In this study we have compared the mechanical stability of custom (n=8) and anatomical (n=8) uncemented femoral components, following insertion into human cadaveric femurs, during simulated single leg stance and stair climbing. In the custom group two specimens were excluded from the study due to detachment of the greater trochanter during cyclical loading. As a consequence of their mechanical behaviour both types of stems could be divided into subgroups of "unstable" and "stable" implants. In the course of one thousand loading cycles three anatomical stems and one custom stem migrated more than 1 mm, which was interpreted as mechanical loosening. This difference in rate of mechanical loosening was not significant. However, the majority of the stems were remarkably stable and showed micromotion of less than 18 m and migration of less than 35 m at the proximal implant-bone interface. The corresponding figures for the tip of the stems were 243 m and 170 m, respectively. During torsional loading the custom stems showed less rotatory motion than the anatomical stem (p<0.05). There were no significant differences in the magnitude of cyclical micromotion or migration for the two types of femoral stems. (Hip International 2002; 12: 263-73).

Changes in proximal femoral strain after insertion of uncemented standard and customised femoral stems. An experimental study in human femora

We have compared the changes in the pattern of the principal strains in the proximal femur after insertion of eight uncemented anatomical stems and eight customised stems in human cadaver femora. During testing we aimed to reproduce the physiological loads on the proximal femur and to simulate single-leg stance and stair-climbing. The strains in the intact femora were measured and there were no significant differences in principal tensile and compressive strains in the left and right femora of each pair. The two types of femoral stem were then inserted randomly into the left or right femora and the cortical strains were again measured. Both induced significant stress shielding in the proximal part of the metaphysis, but the deviation from the physiological strains was most pronounced after insertion of the anatomical stems. The principal compressive strain at the calcar was reduced by 90% for the anatomical stems and 67% for the customised stems. Medially, at the level of the lesser trochanter, the corresponding figures were 59% and 21%. The anatomical stems induced more stress concentration on the anterior aspect of the femur than did the customised stems. They also increased the hoop strains in the proximomedial femur. Our study shows a consistently more physiological pattern of strain in the proximal femur after insertion of customised stems compared with standard, anatomical stems.

Changes in proximal femoral strain after insertion of uncemented standard and customised femoral stems

We have compared the changes in the pattern of the principal strains in the proximal femur after insertion of eight uncemented anatomical stems and eight customised stems in human cadaver femora. During testing we aimed to reproduce the physiological loads on the proximal femur and to simulate single-leg stance and stair-climbing.

The strains in the intact femora were measured and there were no significant differences in principal tensile and compressive strains in the left and right femora of each pair. The two types of femoral stem were then inserted randomly into the left or right femora and the cortical strains were again measured. Both induced significant stress shielding in the proximal part of the metaphysis, but the deviation from the physiological strains was most pronounced after insertion of the anatomical stems.

The principal compressive strain at the calcar was reduced by 90% for the anatomical stems and 67% for the customised stems. Medially, at the level of the lesser trochanter, the corresponding figures were 59% and 21%. The anatomical stems induced more stress concentration on the anterior aspect of the femur than did the customised stems. They also increased the hoop strains in the proximomedial femur. Our study shows a consistently more physiological pattern of strain in the proximal femur after insertion of customised stems compared with standard, anatomical stems.

Aromatic quinolinecarboxamides as selective, orally active antibody production inhibitors for prevention of acute xenograft rejection

The prevention of xenograft rejection is substantially dependent on inhibiting antibodies (Ab) produced by B-cells independently of T-cell signals (TI-1). Due to their ubiquitous biochemical mechanisms of action, the immunosuppressants currently employed not only fail to discriminate between B- and T-cells but also have a narrow therapeutic window and, thus, their prolonged use in complex immunosuppressive regimens is problematic. By capitalizing on the target enzyme-bound (DHODH) structure 1b of one of these compounds, leflunomide, and modulating part of its multiple mechanisms of action to gain selectivity, the quinoline-8-carboxamide 3 was designed as a potentially weak enzyme inhibitor but effective immunosuppressant. Compound 3 fulfilled the mechanistic criteria set and had 10-fold B-cell over T-cell selectivity. Its pyridyl analogue 4 was found to be a highly potent and selective B-cell immunosuppressant with a 75-fold selectivity for B- over T-cells (as judged by the MLR data) and no general cytotoxicity at concentrations up to 160-fold higher than those required to inhibit B-cells. In the mouse, 4 effectively blocked TI-1 Ab production and suppressed Ab-mediated xenograft rejection in a xenotransplantation model under a once-daily dosing regimen, with efficacy down to 0.3 mg/kg/day po. These are the first data demonstrating the feasibility of the development of drugs specific for impeding Ab production.

A prospective clinical study evaluating the safety and effectiveness of narrow-diameter threaded implants in the anterior region of the maxilla

The aim of the present study of single-tooth implants was to compare the success rate and marginal bone resorption of a narrow-diameter self-tapping implant placed in less available bone volume with the standard-diameter self-tapping implant placed in a well-dimensioned alveolar process. A new abutment technique and a different permanent abutment design were also evaluated. Fifty-five patients were included in the study; 27 patients received 28 standard-diameter (3.75-mm) implants, and 28 patients received 32 narrow-diameter (3.25-mm) implants replacing either a central or a lateral incisor in the maxilla. In an attempt to create an ideal emergence profile and to regenerate papillae, individual acrylic resin tooth-shaped temporary abutments were fabricated, based on impressions made immediately following implant placement, and connected to the implant after 6 months. A minimum of 2 months were then allowed before definitive restorative procedures were performed. Impressions were always made at the implant level. Follow-up examinations were performed at 6 months after loading and 1, 2, and 3 years after loading. Two narrow-diameter implants were lost after 6 months, but no other failures were subsequently observed in any of the groups after that. In both groups, marginal bone loss followed the same pattern and was recorded radiographically to be a mean of 0.4 mm from the first to the last examination.

Development of ARI case management at primary and secondary level in southern Vietnam

In southern Vietnam it is not uncommon that children under 5 years of age die from pneumonia. Reduction of severity and mortality has to rely on proper case management by mothers and health workers on both grass root level and referral level. The responsibility of training of clinical skills of ARI case management in the southern provinces of Vietnam has been delegated to Pediatric Hospital N1 (PHN1) Ho Chi Minh City (HCMC) by Ministry of Health. A pilot project was carried out by the Danish-Vietnamese Study Group. The immediate objects were: to provide basic epidemiological information about ARI in southern Vietnam, to develop training modules and case management intervention modules at primary and secondary level in order to enable mothers, village workers, health post staff and district hospital emergency department staff to treat moderate and severe pneumonia and acute bronchitis in accordance with the WHO management guide for ARI and to evaluate the effect of those modules after implementation in a limited number of communes. The modules were developed at PHN1. Ten commune health stations were carefully selected. The purpose of the project and the conditions for taking part had been explained to the health workers. The doctors and other commune health workers from the 10 commune health stations and doctors from the connected district hospitals attended the training courses at PHN1, HCMC and also at the belonging provincial hospitals. Essential equipment was provided and a pharmacy with essential drugs established. The registered health statistics was collected yearly during on site visits. The local doctors and commune health workers gave seminars for mothers in the villages of the 10 project communes. The mothers' knowledge, attitude and practice (KAP) was tested in interviews before and two months after the seminars had taken place. The spread of KAP was measured by random interviews of mothers six month later. In the interviews information on social conditions was obtained. The mothers' KAP had risen by 25% two months after attending the seminars. A further increase of KAP by 5-10% within the untrained group appeared in a survey 4-6 months later. It was not possible to obtain reliable statistics on morbidity or mortality of ARI in the project area.

Fc receptor mediated endocytosis of small soluble immunoglobulin G immune complexes in Kupffer and endothelial cells from rat liver

Soluble circulating immunoglobulin G immune complexes are mainly eliminated by the liver, predominantly by uptake in the Kupffer cells, but also the liver endothelial cells seem to be of importance. In the present study we have followed the intracellular turnover of immune complexes after Fc(gamma) receptor mediated endocytosis in cultured rat liver endothelial cells and Kupffer cells by means of isopycnic centrifugation, DAB cross-linking and morphological techniques. For the biochemical experiments the antigen, dinitrophenylated bovine serum albumin (BSA), was labeled with radioiodinated tyramine cellobiose that cannot cross biological membranes and therefore traps labeled degradation products at the site of formation. The endocytic pathway followed by immune complexes was compared with that followed by scavenger receptor ligands, such as formaldehyde treated BSA and dinitrophenylated BSA, and the mannose receptor ligand ovalbumin. Both Kupffer cells and liver endothelial cells took up and degraded the immune complexes, but there was a clear delay in the degradation of immune complexes as compared to degradation of ligands taken up via scavenger receptors. The kinetics of the endocytosis of scavenger receptor ligand was unaffected by simultaneous uptake of immune complexes. Experiments using both biochemical and morphological techniques indicated that the delayed degradation was due to a late arrival of the immune complexes at the lysosomes, which partly was explained by retroendocytosis of immune complexes. Electron microscopy studies revealed that the immune complexes were retained in the early endosomes that remained accessible to other endocytic markers such as ovalbumin. In addition, the immune complexes were seen in multivesicular compartments apparently devoid of other endocytic markers. Finally, the immune complexes were degraded in the same lysosomes as the ligands of scavenger receptors. Thus, immune complexes seem to follow an endocytic pathway that is kinetically or maybe morphologically different from that followed by scavenger and mannose receptor ligands.

[Quality assessment of resuscitation]

The object of the study was to evaluate the availability of paediatricians for resuscitation of newborns and the quality of resuscitation. During the period 1.9.95-15.1.96 a prospective registration was made of the initial treatment of all newborns where a paediatrician was involved. It was noted whether the doctor was present when needed. A comparison with the written guidelines was made. The paediatrician was called to 27% of the 1461 babies born during that period. In 93% of the deliveries with maternal risk factors the pediatrician was called before the delivery and was present at the delivery in 89% of the cases. The resuscitation was optimal in 60%, less satisfactory in 38% and unsatisfactory in 2% of the cases. Intensified training and supervision of doctors dealing with resuscitation of newborns and strengthening of the staff on duty is recommended.

Cervical lymph node metastases from unknown primary tumours. Results from a national survey by the Danish Society for Head and Neck Oncology

BACKGROUND AND PURPOSE

The management of patients with cervical lymph node metastases from unknown primary tumours is a major challenge in oncology. This study presents data collected from all five oncology centres in Denmark.

MATERIAL AND METHODS

Of the 352 consecutive patients with squamous cell or undifferentiated tumours seen from 1975 to 1995, a total of 277 (79%) were treated with radical intent. The general treatment policy at all centres during the entire study period has been to treat all suitable candidates with radiotherapy to both sides of the neck and include elective irradiation of the mucosal sites in nasopharynx, and larynx, hypopharynx and larynx (81%). Irradiation of the ipsilateral neck only was done in 26 patients (10%). Radical surgery was the only treatment in 23 N1-N2 patients (9%).

RESULTS

The 5-year estimates of neck control, disease-specific survival and overall survival for radically treated patients were 51, 48 and 36%, respectively. The emergence of the occult primary was observed in 66 patients (19%). About half of the emerging primaries were within the head and neck region with oropharynx, hypopharynx and oral cavity being the most common sites. Emerging primaries outside the head and neck region were primarily located in the lung (19 patients) and oesophagus (five patients). The frequency of emerging primary in the head and neck was significantly higher in patients treated with surgery alone, the actuarial risks at 5-year being 54+/-1% (no RT) vs. 15+/-3% (with RT), P<0.0001. The most important factor for neck control was nodal stage (5-year estimates 69% (N1), 58% (N2) and 30% (N3)). Other important parameters for neck control and disease-specific survival included haemoglobin, gender and overall treatment time. Patients treated with ipsilateral radiotherapy had a relative risk of recurrence in the head and neck region of 1.9 compared with patients treated to both neck and mucosa. At 5 years, the estimated control rates were 27% (ipsilateral) and 51% (bilateral; P=0.05). The 5-year disease-specific survival estimates were 28 and 45%, respectively (P=0.10).

CONCLUSIONS

This study has confirmed that patients with neck node metastases from occult head and neck cancer have clinical features and prognosis similar to other head and neck malignancies. Extensive irradiation to both sides of the neck and the mucosa in the entire pharyngeal axis and larynx resulted in significantly less loco-regional failures compared with patients treated with ipsilateral techniques, but only a trend towards better survival. A prospective randomized trial is required to determine the optimal strategy in terms of locoregional control, survival and morbidity.

The prenatal cranial base complex and hand in Turner syndrome

From early childhood, Turner syndrome patients have a flattened cranial base, maxillary retrognathism, and short hands. There are, however, no studies that show when these genotype-determined abnormalities occur prenatally. The purpose of the present study was to measure craniofacial profile and hand radiographs of second trimester foetuses with Turner syndrome and compare the results with similar measurements from normal foetuses. The subjects consisted of 12 Turner syndrome foetuses, gestational age (GA) varying between 15 and 24 weeks, and crown-rump length (CRL) between 108 and 220 mm. The mid-sagittal block of each cranium was analysed as part of the requested brain analysis (pituitary gland analysis). This block and the right hand from seven foetuses were radiographed, and the skeletal maturity of the cranial base complex, i.e. the cranial base and the maxilla, was evaluated from the profile radiographs. Shape and size measurements in the cranial base were performed, and compared with normal values according to cranial maturity and to CRL. The cranial base angle in Turner syndrome was greater and the maxillary prognathism was reduced compared with the normal group. The dimensions in the cranial complex and in the hand showed that the bone lengths and distances in relation to CRL were generally smaller compared with normal foetuses. This investigation showed that the abnormal shape of the cranial base complex and the short hands in Turner syndrome are present prenatally.

Human gingival crevicular fluid contains MRP8 (S100A8) and MRP14 (S100A9), two calcium-binding proteins of the S100 family

Human gingival crevicular fluid contains unidentified proteins which might play a role as markers in periodontal diseases. Therefore, low-molecular-weight proteins found in human gingival crevicular fluid (GCF), but absent from serum, were identified in the present study by means of two-dimensional electrophoresis (2-D PAGE) analysis. GCF, serum, and whole saliva were collected from periodontitis and healthy subjects, as well as from edentulous and newborn subjects. Protein samples were separated by two-dimensional polyacrylamide gel electrophoresis, stained with silver, and compared with reference protein maps in the SWISS-2D PAGE database. In GCF and saliva from periodontitis patients and healthy subjects, four dominant low-molecular-mass (from 8 to 14 kDa) acidic spots were observed. They were not found in serum and were less visible in saliva from edentulous and newborn subjects. From N-terminal amino acid sequencing, the two 2-D protein spots of 8 kDa and isoelectric points between 6.5 and 7.0 were both identified as protein MRP8 (SI00A8), a member of the S100 family of calcium-binding proteins. Using peptide mass fingerprinting and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), we identified the other two protein spots, with mass of 14 kDa and isoelectric points between 5.5 and 6.0, as protein MRP14 (S100A9), also belonging to the S100 family. The presence of MRP8 and MRP14 in GCF was confirmed by Western blot, with monoclonal antibodies. The two polypeptides, MRP8 and MRP14, identified in GCF represent the major difference between the 2-D PAGE patterns of serum and GCF, and we hypothesize that they may play an important role in the gingival sulcus and could represent possible markers for periodontal diseases.

Overexpression of a C-terminal fragment of presenilin 1 delays anti-Fas induced apoptosis in Jurkat cells

Most cases of early onset familial Alzheimer's disease (FAD) involve mutations in presenilins (PS1 and PS2) genes. The C-terminal portion of PS2 is a homologue with an apoptosis-linked gene (ALG-3). To characterise the role of PS1 in apoptosis, we overexpressed the corresponding C-terminal fragment of PS1 (PS1-f) under the control of the tetracycline-responsive transactivator in Jurkat cells. The tight regulation of the expression of the 11 kDa PS1-f peptide was verified. A 50% inhibition of anti-Fas induced apoptosis was observed upon PS1-f transient overexpression compared to the repressed state. Stable transfectants selectively overexpressing PS1-f revealed a transient protective effect of 30% after apoptosis induction.

[Long-term results of treatment of overweight in self-help groups]

The long-term results achieved by people trying to lose weight by participating in organised self-help groups have previously been reported as quite satisfactory. Our objective was to explore whether a change of diet and treatment policy produced a change of outcome. We report the results of a survey among 1,340 earlier participants in self-help groups, randomly sampled from the files of group leaders all over Norway. 657 (49%) responded; the mean follow-up time since first group participation was three years. The survey results was supplemented by information from the group leaders' files. The participants had on average kept 62% of their initial weight-loss. 39% of the participants had kept their initial weight-loss or had gone further down in weight. The result is among the best reported in the literature. Even if all participants who did not respond had regained all initial weight-loss, 16% of the total sample would in fact have kept their weight-loss. Exercise and adherence to nutrition advice in the groups were factors pointing to positive long-term results.