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Biomedical subjects

J Mulder

Publications and source records attributed to J Mulder.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cortical cholinergic decline parallels the progression of Borna virus encephalitis.

Borna disease virus (BDV)-induced meningoencephalitis is associated with the dysfunction of the cholinergic system. Temporal development of this cholinergic decline during pre-encephalitic and encephalitic stages of BDV infection remains however elusive. Changes in choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities were therefore determined in the cerebral cortex, hippocampus, striatum, amygdala and cholinergic basal forebrain nuclei (ChBFN) of rats infected with BDV. Immunocytochemistry for ChAT and vesicular acetylcholine transporter (VAChT) was employed to identify morphological consequences of BDV infection on cholinergic neurons. Whereas both ChAT and AChE activities changed only slightly under pre-encephalitic conditions, the encephalitic stage was characterized by a significant decrease of ChAT activity in the cerebral cortex, horizontal diagonal band of Broca (hDBB), hippocampus and amygdala concomitant with a marked reduction of AChE activity in the cerebral cortex, hDBB and hippocampus. The striatum and medial septum remained unaffected. ChAT and VAChT immunocytochemistry revealed prominent axonal degeneration in affected cortical and limbic projection areas of ChBFN. In summary, our data indicate progressive deterioration of forebrain cholinergic systems that parallels the progression of BDV encephalitis.

Acetylcholine↗
PubMed2001

Nitrogen deposition and leaching from two forested catchments in Southwest China--preliminary data and research needs.

Increased nitrogen deposition has resulted in increased nitrogen pools and nitrogen leaching in European and North American forest soils. The development in Asia in general, and China in particular, suggests increased deposition of reduced nitrogen from changes in agricultural practices and of oxidized nitrogen from rapid growth of the transportation sector. Decreased nitrogen retention in forested areas in the future may cause increased NO3- leaching and, thus, acidification and eutrophication in surface waters. The differences in climate, ecosystems, land use, and deposition history make direct application of knowledge from studies in Europe and North America difficult. In Southwest China the potential for nitrogen mobilization from forest soils may be high because of the warm and humid climate, resulting in high decomposition rates of soil organic matter. However, there are very few data available for quantifying the suspected potential for increased nitrogen leaching in forest ecosystems. Here we present data from two forested catchments, dominated by Masson pine (Pinus massoniana), near Guiyang and Chongqing, respectively, in Southwest China. The present nitrogen deposition is moderate, estimated in the range from 10 to 40 kg N ha(-1) year(-1). The C/N ratios of the soils are generally below 15. Nitrate concentrations in soil water are rather variable in space, with highest values of several hundred microequivalents per liter. The turnover rate of nitrogen in the forest ecosystem is quite high compared to the atmospheric deposition rate. At present, nitrate runoff from the catchments is low and intermediate in Guiyang and Chongqing, respectively. More research is needed to improve our ability to predict future nitrogen leaching from subtropical Asian coniferous forests.

Carbon↗
PubMed2001

Decision support for patients with early-stage breast cancer: effects of an interactive breast cancer CDROM on treatment decision, satisfaction, and quality of life.

PURPOSE: To investigate the effects of the Interactive Breast Cancer CDROM as a decision aid for breast cancer patients with a choice between breast conserving therapy (BCT) and mastectomy (MT). PATIENTS AND METHODS: Consecutive patients with stage I and II breast cancer were enrolled. A quasi-experimental, longitudinal, and pretest/posttest design was used. Follow-up was scheduled 3 and 9 months after discharge from the hospital. Control patients (n = 88) received standard care (oral information and brochures). The CDROM was provided to patients in the experimental condition (n = 92) as a supplement to standard procedures. Outcome variables were treatment decision, satisfaction, and quality of life (QoL). RESULTS: No effect on treatment decision was found. CDROM patients expressed more general satisfaction with information at 3 and 9 months (95% confidence interval for the difference (d) between the means (d: 4.1 to 12.5 and 5.7 to 14.2 respectively). CDROM patients were also more satisfied with their treatment decision at 3 and at 9 months (d: 0.1 to 0.4; 0.2 to 0.5). Moreover, at 9 months, CDROM patients were more satisfied with breast cancer-specific information (d: 0.9 to 16.5), the decision-making process (d: 0.1 to 0.4), and communication (d: 0.2 to 11.0). At 3 and 9 months, a positive effect was found on general health (d: 0.2 to 14.5 and 0.3 to 15.0). Moreover, at 9 months, CDROM patients reported better physical functioning (d: 5.1 to 19.8), less pain (d: -17.9 to -4.5), and fewer arm symptoms (d: -14.1 to -0.5). CONCLUSION: The Interactive Breast Cancer CDROM improved decision making in patients with early-stage breast cancer with a choice between BCT and MT, as evaluated in terms of patients' satisfaction and QoL.

Aged↗
PubMed2001

Short-term consequences of N-methyl-D-aspartate excitotoxicity in rat magnocellular nucleus basalis: effects on in vivo labelling of cholinergic neurons.

Cholinergic neurons of the basal forebrain form one of the neuron populations that are susceptible to excitotoxic injury. Whereas neuropharmacological studies have aimed at rescuing cholinergic neurons from acute excitotoxic attacks, the short-term temporal profile of excitotoxic damage to cholinergic nerve cells remains largely elusive. The effects of N-methyl-D-aspartate (NMDA) infusion on cytochemical markers of cholinergic neurons in rat magnocellular nucleus basalis were therefore determined 4, 24 and 48 h post-lesion. Additionally, the influence of excitotoxic damage on the efficacy of in vivo labelling of cholinergic neurons with carbocyanine 3-192IgG was investigated. Carbocyanine 3-192IgG was unilaterally injected in the lateral ventricle. Twenty-four hours later, NMDA (60 nM/microl) was infused in the right magnocellular nucleus basalis, while control lesions were performed contralaterally. Triple immunofluorescence labelling for carbocyanine 3-192IgG, NMDA receptor 2A and B subunits and choline-acetyltransferase (ChAT) was employed to determine temporal changes in NMDA receptor immunoreactivity on cholinergic neurons. The extent of neuronal degeneration was studied by staining with Fluoro-Jade. Moreover, changes in the numbers of ChAT or p75 low-affinity neurotrophin receptor immunoreactive neurons, and the degree of their co-labelling with carbocyanine 3-192IgG were determined in basal forebrain nuclei. The effects of NMDA-induced lesions on cortical projections of cholinergic nucleus basalis neurons were studied by acetylcholinesterase (AChE) histochemistry. Characteristic signs of cellular damage, as indicated by decreased immunoreactivity for NMDA receptors, ChAT and p75 low-affinity neurotrophin receptors, were already detected at the shortest post-lesion interval investigated. Fluoro-Jade at 4 h post-lesion only labelled the core of the excitotoxic lesion. Longer survival led to enhanced Fluoro-Jade staining, and to the decline of ChAT immunoreactivity reaching a maximum 24 h post-surgery. Significant loss of p75 low-affinity neurotrophin receptor immunoreactivity and of cortical AChE-positive projections only became apparent 48 h post-lesion. Carbocyanine 3-192IgG labelling in the ipsilateral basal forebrain exceeded that of the contralateral hemisphere at all time points investigated and progressively declined in the damaged magnocellular nucleus basalis up to 48 h after NMDA infusion. The present study indicates that excitotoxic lesion-induced alteration of cholinergic neuronal markers is a rapid and gradual process reaching its maximum 24 h post-surgery. Furthermore, in vivo labelling of cholinergic neurons may be applied to indicate neuronal survival under pathological conditions, and enable to follow their degeneration process under a variety of experimental conditions.

Acetylcholine↗
PubMed2001

Oral post-lesion administration of 5-HT(1A) receptor agonist repinotan hydrochloride (BAY x 3702) attenuates NMDA-induced delayed neuronal death in rat magnocellular nucleus basalis.

Recent evidence indicates that stimulation of postsynaptic 5-HT(1A) receptors abates excitotoxic neuronal death. Here we investigated whether oral post-lesion administration of the 5-HT(1A) receptor agonist (-)-(R)-2-[4-[[(3,4-dihydro-2H-1-benzopyran-2-yl)methyl]amino]butyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide monohydrochloride (Repinotan HCl) attenuates N-methyl-D-aspartate (NMDA) excitotoxicity (60 nmol/microl) in the rat magnocellular nucleus basalis. Repinotan HCl (1 mg/kg) was administered from day 1, 2, 3, or 6 post-surgery twice daily for five consecutive days. This delayed drug administration protocol was employed to investigate the initiation period during which 5-HT(1A) receptor agonists may significantly influence ongoing neurodegeneration processes. 8-Hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 1 mg/kg) served as reference compound. Twenty-four hours after drug delivery a small open-field test, while on day 14 post-surgery a passive avoidance test was performed. Effects of Repinotan HCl treatment on the survival of cholinergic magnocellular nucleus basalis neurons and their cortical projections were determined by quantitative acetylcholinesterase (AChE) and choline-acetyltransferase (ChAT) histochemistry. Moreover, AChE and ChAT activities were biochemically measured both in the cerebral cortex and in the magnocellular nucleus basalis. Repinotan HCl treatment markedly increased spontaneous activities in the small open-field at any time-point investigated. Improved memory performance was only demonstrated when Repinotan HCl was administered from day 1 post-lesion on wards. Repinotan HCl treatment from day 2 and 3 post-lesion on markedly attenuated both histochemical and neurochemical characteristics of NMDA excitotoxicity on cholinergic magnocellular nucleus basalis neurons and on their cortical projections. Whereas the neuroprotective profile of Repinotan HCl was superior to that of 8-OH-DPAT, oral administration of both 5-HT(1A) receptor agonists yielded largely equivalent behavioral recovery after NMDA infusion in the magnocellular nucleus basalis. In conclusion, the present data indicate the potent neuroprotective action of the 5-HT(1A) receptor agonist Repinotan HCl with a peak efficacy of delayed (2-3 day) post-lesion drug treatment in vivo. Post-lesion treatment with 5-HT(1A) receptor agonists may therefore be of significance in the intervention of neuronal damage associated with acute excitotoxic conditions.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2001

Sternal wound complications after primary isolated myocardial revascularization: the importance of the post-operative variables.

OBJECTIVE: Select pre-, peri-, and post-operative variables, predictive for sternal wound complications (SWC), in a clinical setting. METHODS: We analyzed pre-, peri-, and post-operative data of 3815 patients who underwent a primary isolated bypass grafting. 100 patients (2.6%) had post-operative SWC. Unifactor and multifactor risk analysis, were used for statistical analysis. RESULTS: Unifactor analysis identified age (P=0.05), obesity (P=0.001), lung disease (P=0.001), extracorporeal circulation >100 min (P=0.02), graft choice (P=0.01), post-operative low cardiac output, reoperation, nephrological, pulmonary problems (P<0.001) as risk factors. Multifactor analysis, identified obesity (P=0.005), reoperation (P=0.01), nephrological (P=0.0001), pulmonary problems (P=0.001) and No-IMA-use (P=0.05) as independent predictors. Age <50 years (P=0.04) decreased the risk for SWC. There is, however, an interaction of the graft-use and the pre-operative and post-operative predictors, that can mask the precise effect of the graft-use. CONCLUSION: Reoperation, nephrological and pulmonary problems are strong predictors, obesity and age independent preoperative risk factors for sternal wound complications.

Aged↗
PubMed2001

Effectiveness of an oral health education programme in primary schools in Zimbabwe after 3.5 years.

UNLABELLED: Many medical and dental professionals in African nations believe that school teachers, through attendance of a short workshop, can be trained to provide oral health education. This increases the number of professionals available and is regarded as an important way forward in improving oral health. OBJECTIVES: The current study assesses the effectiveness of an oral health education programme administered by schoolteachers in a district in Zimbabwe over a period of 3.5 years. METHODS: The experimental group consisted of schools that had sent representatives to a regional workshop on oral health held in 1992. The control group was selected at random from schools not having attended the workshop. A total number of 439 boys and 526 girls were examined in 1992. Follow-up evaluations were carried out in 1993, 1994 and 1996. The dependent variables were plaque accumulation and caries increment in grade 2 and grade 4 children of experimental and control schools. RESULTS: ANOVA test with year of evaluation (1992-94), experiment/control school, age and gender as independent variables showed no statistically significant difference in mean plaque scores in longitudinally examined original grade 2 (P>0.20) and grade 4 children (P=0.06) from experimental and control schools. The mean caries increment score in the experimental and control schools was 0.04 and 0.19, respectively. ANOVA test with fluoride levels and gender as independent variables on caries increment in experimental and control schools did not show a statistically significant difference (P=0.06). CONCLUSION: The one-time training of teachers in aspects of oral health was ineffective in lowering plaque levels over a period of 3.5 years. Considering the low caries increment observed over the study period, the effect of the oral health programme on caries levels in the study group was inconclusive.

Analysis of Variance↗
PubMed2001

Validation of a Swiss method of caries prediction in Dutch children.

OBJECTIVE: This study aimed to validate a caries prediction method, the Dentoprog-Method, which was developed on Swiss children. METHOD: A Dutch child population was used for validation. The diagnosis of caries, age of the children and the caries experience were slightly different from the population from which the Dentoprog-Method was developed. With the Dentoprog-Method, Dutch children were ranked in increasing order of high caries risk probability. The measure of prediction was expressed in sensitivity and specificity, which were calculated at 10% risk probability intervals for each class of "high" caries increment and for different forecast periods. ROC curves presenting sensitivity as a function of (100-specificity) were employed to summarize the obtained information. The area under the ROC curve was used as a measure of predictive accuracy. RESULTS: The area under the ROC curves for various caries increment classes of 7.5-year-old and 9.5-year-old Dutch children was in the range of the area under the ROC curves of Swiss children. CONCLUSION: This analysis indicated that the Dentoprog-Method when applied on a sample of Dutch children was robust enough to overcome small differences in caries diagnosis, age and caries experience.

Algorithms↗
PubMed2001

[Three treatment modalities for mandibular overdentures on implants. Clinical and radiological aspects].

The results are presented of 3 treatment modalities for overdentures on implants in the mandible: 2 implants with ball attachment, 2 implants interconnected with a bar and 4 implants interconnected with bars. The patients, in total 110, were at random treated and evaluated 3, 9 and 19 months after insertion of the implants. Six implants were lost out of 283 implants during the osseointegration period. There were hardly any differences found between the groups with respect to the clinical and radiologic parameters. De first group showed less bleeding around the implants after 19 months then the other groups. Around the medial implants there was significantly more bone resorption then around the distal implants and the implants in the other groups. No conclusions can be drawn with respect to the best treatment modality since the period of evaluation is too short and the other parameters like patients' experiences are not included.

Alveolar Bone Loss↗
PubMed2000

Smoking is related to albuminuria and abnormal renal function in nondiabetic persons.

BACKGROUND: Smoking induces albuminuria and accelerates progression to renal failure in persons with diabetes, but little is known about the relation between smoking and renal function in nondiabetic persons. OBJECTIVE: To investigate whether smoking is related to albuminuria and abnormal renal function in nondiabetic persons. DESIGN: Cross-sectional study. SETTING: Groningen, The Netherlands. PARTICIPANTS: 7476 participants in the PREVEND (Prevention of REnal and Vascular ENd stage Disease) Study. MEASUREMENTS: Microalbuminuria and high normal albuminuria were defined as urinary albumin excretion of 30 to 300 mg/24 h and 15 to 30 mg/24 h, respectively. Elevated or decreased glomerular filtration rate (GFR) was defined as a creatinine clearance that exceeded or was less than two times the standard deviation of the mean value in nondiabetic, nonsmoking participants who had an albumin excretion of 0 to 15 mg/24 h, adjusted for age and sex. RESULTS: Current smokers had a higher median albumin excretion than nonsmokers and were more likely to have microalbuminuria and high normal albuminuria with elevated or decreased GFR. After adjustment for several potential confounding factors, persons who smoked 20 or fewer cigarettes/d and persons who smoked more than 20 cigarettes/d, respectively, showed a dose-dependent association between smoking and high normal albuminuria (relative risk, 1.33 [95% CI, 1.10 to 1.61] and 1.98 [CI, 1.49 to 2.64]), microalbuminuria (relative risk, 1.92 [CI, 1.54 to 2.39] and 2.15 [CI, 1.52 to 3.03]), elevated GFR (relative risk, 1. 82 [CI, 1.31 to 2.53] and 1.84 [CI, 1.12 to 3.02]), and decreased GFR (relative risk, 1.53 [CI, 1.04 to 2.24] and 1.83 [CI, 1.05 to 3. 20]), respectively. Quitting smoking was associated only with microalbuminuria. CONCLUSIONS: Smoking is associated with albuminuria and abnormal renal function. However, these associations are less pronounced or absent in former smokers.

Adult↗
PubMed2000

Psychometric properties of the schedules for clinical assessment in neuropsychiatry (SCAN-2.1).

BACKGROUND: The Schedules for Clinical Assessment in Neuropsychiatry (SCAN), the successor of the ninth version of the Present State Examination (PSE-9), is one of the latest instruments developed by the World Health Organisation for the assessment of psychiatric disorders. So far, the psychometric properties have only been established for certain sections of the instrument. The present study is the first to test the psychometric properties of SCAN-2.1 for most of the disorders covered by the SCAN, and was carried out prior to a survey conducted in the Nijmegen Health Area (the Netherlands). METHODS: Interviewers were psychology graduates with little clinical experience. Two designs were used. In one design, pairs of independent live interviews with the same respondent were compared (test-retest situation). In the other, ten videotaped interviews by experts were rated by each of the interviewers (standardized situation), and the outcomes were compared with those of the other interviewers as well as with a reference score. RESULTS: In the test-retest situation the kappa coefficient for diagnostic caseness was qualified as substantial (0.62) and for diagnostic categories and diagnostic groups as moderate to good (0.24 to 0.64). In the standardized situation using videotaped interviews by experts, sensitivity as well as specificity proved to be substantial to almost perfect. The agreement per interviewer with regard to the reference diagnoses ranged from 87% (diagnostic group) to 94% (diagnostic caseness). Agreement on the syndrome level (without duration and interference criteria of DSM-IV) was excellent. CONCLUSIONS: Although the instrument is traditionally used by experienced clinicians, this study shows that less experienced (but well trained) interviewers can apply SCAN reliably. Special attention should be paid to the items without explicit interview questions, as they tend to be more sensitive to neglect than the items with interview questions.

Humans↗
PubMed2000

Precision and accuracy in measuring absence from work as a basis for calculating productivity costs in The Netherlands.

The impact of disease on the ability of a person to perform work should be part of an economic evaluation when a societal viewpoint is used for the analysis. This impact is reflected by calculating productivity costs. Measurement of these costs is often performed retrospectively. The purpose of our study was to study precision and accuracy of a retrospective self-administered questionnaire on sick leave. Employees of a company were asked to indicate the number of days absent from work due to illness during the past 2 weeks, 4 weeks, 2 months, 6 months, and the past 12 months. The percentage of respondents with an absolute difference of a maximum of respectively 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 or more days between reported, and company-registered absence due to illness was determined. Besides this, the proportional difference was calculated. A systematic difference was tested with a signed rank test. Of the reported data, 95% matched the registered data perfectly when the recall period was limited to 2 and 4 weeks. This percentage decreased to 87%, 57%, and 51% for 2 months, 6 months, and 12 months. The weighted mean proportional differences for the recall periods were respectively 32.9, 35.2, 45.3, 34.9, and 113.6%. No systematic positive or negative difference was found between registered and reported sick leave. The results suggest that the recall period for retrospective measurement of sick leave is limited according to the precision level, which seems to be appropriate for the subject and the purpose of the study. We recommend using a recall period of no more than 2 months.

Costs and Cost Analysis↗
PubMed2000

Tissue Doppler imaging in detection of myocardial dysfunction in survivors of childhood cancer treated with anthracyclines.

The applicability of tissue Doppler imaging (TDI) was investigated for estimating cardiac function in long-term survivors of childhood cancer treated with anthracyclines. A total of 63 children (age range 7.8-17.3 y) underwent standard echo Doppler cardiographic studies of blood flow velocities, left ventricular dimensions and fractional shortening, followed by measurements of peak myocardial velocities and direction using the noninvasive tissue Doppler imaging (TDI) technique. All 63 were late survivors (median 7.1 y, range 3.5-13.5 y after end of therapy) who had received mean (+/- SD) cumulative dose of 242 (+/- 141) mg/m(2) of anthracyclines. The control group consisted of 160 healthy subjects (age range 4 to 17.9 y). Standard echo-Doppler anatomical parameters that were found significantly (p < 0.01) different for the study group are: RV wall thickness (decreased); LV diameter (increased); and LV fractional shortening (decreased). Studied hemodynamic parameters were not found to be different between the two groups. Quantitative TDI parameters: peak late diastolic myocardial velocities, as well as transmyocardial systolic and diastolic velocity differences, were significantly lower in late survivors than in the healthy pediatric population (p < 0.01). Qualitative local functional impairment of the movement of the left ventricular walls was detected in 20% of the patients. TDI might become a useful noninvasive method for detecting subclinical myocardial damage in apparently healthy children who received moderate doses of anthracyclines for treatment of childhood malignancy. Prospective studies with TDI for the detection of regional myocardial abnormalities are recommended.

Adolescent↗
PubMed2000

Radiological and clinical results of longterm treatment of rheumatoid arthritis with methotrexate and azathioprine.

OBJECTIVE: To study whether the reported superior effect of methotrexate (MTX) compared to azathioprine (AZA) in retarding radiologic progression after one year in rheumatoid arthritis was sustained at 2 and 4 years. METHODS: All 64 patients enrolled in the original randomized double blind study were invited for an open extension of followup to 4 years including 4-monthly clinical and laboratory assessments and radiographs of hands, wrists, and feet at 2 and 4 years. RESULTS: After 4 years, 18 patients (58%) from the MTX group and 7 patients (21%) from the AZA group continued the initial study drug. During followup more patients (n = 21) switched from AZA to MTX than vice versa (n = 5). In an intention-to-treat analysis improvement of clinical and laboratory variables at 4 years was more pronounced in the MTX group. Mean radiologic scores increased in both treatment groups during followup. According to an intention-to-treat analysis increase in erosion score at one and 2 years in the MTX group was significantly lower than in the AZA group: after one year MTX group 1.8 versus AZA group 5.3 (p = 0.002); after 2 years MTX 3.5 versus AZA 6.5 (p = 0.05). After 4 years there was a trend toward less progression in the MTX group: MTX 6.8 versus AZA 10.8 (p = 0.09). For the total score, progression in the MTX group was less after one and 2 years. After 4 years marked radiologic progression was observed more often in the AZA group. CONCLUSION: Drug continuation after 4 years of followup was better for MTX than for AZA. In an intention-to-treat analysis the beneficial effect of MTX on radiologic progression compared with AZA was sustained after 2 years of followup. Thereafter differences between treatment groups leveled off, probably mainly due to the greater number of switches from AZA to MTX than vice versa.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

[Long-term survival of extensive amalgam restorations].

In cost-effectiveness analysis and contemporary treatment planning strategies, the postponement of placement of cast crowns plays an important role. Extensive Amalgam Restorations (EAR), that involve the rebuilding of cusps and the provision of auxiliary retention, are thought to make this postponement possible. This study reports the long-term survival (100 months) of EAR in a randomized, controlled clinical trial. A total of 300 EAR were placed by 3 operators in molar teeth in which one or more cusps were reconstructed. Five different auxiliary retention methods were used for retention of these restorations. As the purpose of EAR is considered to be twofold (to restore a broken-down molar to acceptably function as an independent restoration and to create a substructure for subsequent crown construction), survival was assessed at different levels. The survival rate of EAR as an independent restoration was 88 +/- 2%. The functional survival rate (as an independent restoration or as a substructure) was 92 +/- 2%. The influence of experimental variables (retention method and operator) and background variables (tooth type, extension of EAR and age of patient) on the survival was analysed using Log Rank and Breslow tests. The analyses revealed that there were no statistically significant influences on the survival rates except for the variable 'age of patient' (p < 0.05). EAR was more prone to failure in the group of older patients than the group of younger ones.

Adult↗
PubMed1999

N-Methyl-D-aspartate receptor antagonist MK-801 and radical scavengers protect cholinergic nucleus basalis neurons against beta-amyloid neurotoxicity.

Previous experimental data indicate the involvement of Ca(2+)-related excitotoxic processes, possibly mediated by N-Methyl-D-Aspartate (NMDA) receptors, in beta-amyloid (beta A) neurotoxicity. On the other hand, other lines of evidence support the view that free radical generation is a critical step in the beta A-induced neurodegenerative cascade. In the present study, therefore, a neuroprotective strategy was applied to explore the contributions of each of these pathways in beta A toxicity. beta A(1-42) was injected into the magnocellular nucleus basalis of rats, while neuroprotection was achieved by either single or combined administration of the NMDA receptor antagonist MK-801 (2.5 mg/kg) and/or a vitamin E and C complex (150 mg/kg). The degree of neurodegeneration was determined by testing the animals in consecutive series of behavioral tasks, including elevated plus maze, passive avoidance learning, small open-field and open-field paradigms, followed by acetylcholinesterase (AChE), choline-acetyltransferase (ChAT), and superoxide dismutase (SOD) biochemistry. beta A injected in the nucleus basalis elicited significant anxiety in the elevated plus maze, derangement of passive avoidance learning, and altered spontaneous behaviors in both open-field tasks. A significant decrease in both AChE and ChAT accompanied by a similar decrement of MnSOD, but not of Cu/ZnSOD provided neurochemical substrates for the behavioral changes. Each of the single drug administrations protected against the neurotoxic events, whereas the combined treatment failed to ameliorate beta A toxicity.

Acetylcholinesterase↗
PubMed1999

Clinical and radiological results of patients treated with three treatment modalities for overdentures on implants of the ITI Dental Implant System. A randomized controlled clinical trial.

In a randomized controlled clinical trial carried out at the Ignatius teaching hospital in Breda, The Netherlands, 110 edentulous patients with severe mandibular bone loss were treated with implants of the ITI Dental Implant System using 3 different treatment strategies: a mandibular overdenture supported by either 2 implants with ball attachments, 2 implants with an interconnecting bar, or by 4 interconnected implants. In this study, results of clinical and radiographic parameters were evaluated and compared over a period of 19 months after implant placement. A total of 283 ITI Dental Implants were placed. Six implants (2%) were lost during the osseointegration period. No further implant losses occurred after that. At the 19 month evaluation mean values and standard deviations for bleeding index were 0.51 +/- 0.5 (bleeding incidence = 70%) and for plaque index they were 0.46 +/- 0.5 (plaque incidence = 45%). The mean values and standard deviations for probing depth and loss of attachment were 2.7 +/- 1.1 mm and 0.26 +/- 0.6 mm respectively. The radiographic evaluation showed a mean bone loss of 1.5 mm +/- 0.26 after 19 months for all the implants. In cases with 4 interconnected implants there was significantly more bone loss around the central 2 implants (2.1 +/- 0.31 mm) in comparison with the lateral 2 (1.4 +/- 0.25 mm). No significant correlations were found between plaque and bleeding indices and bone loss.

Alveolar Bone Loss↗