Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs

Objectives: The aim of the present study was to compare a newly developed biodegradable polylactide/polyglycolide/N‐methyl‐2‐pyrrolidone (PLGA/NMP) membrane with a standard resorbable collagen membrane (RCM) in combination with and without the use of a bone substitute material (deproteinized bovine bone mineral [DBBM]) looking at the proposed tenting effect and bone regeneration. Materials and methods: In five adult German sheepdogs, the mandibular premolars P2, P3, P4, and the molar M1 were bilaterally extracted creating two bony defects on each site. A total of 20 dental implants were inserted and allocated to four different treatment modalities within each dog: PLGA/NMP membrane only (Test 1), PLGA/NMP membrane with DBBM (Test 2), RCM only (negative control), and RCM with DBBM (positive control). A histomorphometric analysis was performed 12 weeks after implantation. For statistical analysis, a Friedman test and subsequently a Wilcoxon signed ranks test were applied. Results: In four out of five PLGA/NMP membrane‐treated defects, the membranes had broken into pieces without the support of DBBM. This led to a worse outcome than in the RCM group. In combination with DBBM, both membranes revealed similar amounts of area of bone regeneration and bone‐to‐implant contact without significant differences. On the level of the third implant thread, the PLGA/NMP membrane induced more horizontal bone formation beyond the graft than the RCM. Conclusion: The newly developed PLGA/NMP membrane performs equally well as the RCM when applied in combination with DBBM. Without bone substitute material, the PLGA/NMP membrane performed worse than the RCM in challenging defects, and therefore, a combination with a bone substitute material is recommended. To cite this article:
Jung RE, Kokovic V, Jurisic M, Yaman D, Subramani K, Weber FE. Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs.
Clin. Oral Impl. Res. 22 , 2011; 802–807
doi: 10.1111/j.1600‐0501.2010.02068.x     

Characterization of dental nociceptive neurons

Selective blockade of nociceptive neurons can be achieved by the delivery of permanently charged sodium channel blockers through the pores of nociceptive ion channels. To assess the feasibility of this application in the dental area, we investigated the electrophysiological and neurochemical characteristics of nociceptive dental primary afferent (DPA) neurons. DPA neurons were identified within trigeminal ganglia labeling with a retrograde fluorescent dye applied to the upper molars of adult rats. Electrophysiological studies revealed that the majority of dental primary afferent neurons showed characteristics of nociceptive neurons, such as sensitivity to capsaicin and the presence of a hump in action potential. Immunohistochemical analysis revealed a large proportion of DPA neurons to be IB(4)-positive and to express TRPV1 and P2X(3). Single-cell RT-PCR revealed mRNA expression of various nociceptive channels, including the temperature-sensitive TRPV1, TRPA1, TRPM8 channels, the extracellular ATP receptor channels P2X(2) and P2X(3), as well as the nociceptor-specific sodium channel, Na(V)1.8. In conclusion, DPA neurons have the electrophysiological characteristics of nociceptors and express several nociceptor-specific ion channels. Analysis of these data may assist in the search for a new route of entry for the delivery of membrane-impermeant local anesthetics.     

Assessing the quality of clinical and administrative data extracted from hospitals: the General Medicine Inpatient Initiative (GEMINI) experience

ObjectiveLarge clinical databases are increasingly used for research and quality improvement. We describe an approach to data quality assessment from the General Medicine Inpatient Initiative (GEMINI), which collects and standardizes administrative and clinical data from hospitals.MethodsThe GEMINI database contained 245 559 patient admissions at 7 hospitals in Ontario, Canada from 2010 to 2017. We performed 7 computational data quality checks and iteratively re-extracted data from hospitals to correct problems. Thereafter, GEMINI data were compared to data that were manually abstracted from the hospital’s electronic medical record for 23 419 selected data points on a sample of 7488 patients.ResultsComputational checks flagged 103 potential data quality issues, which were either corrected or documented to inform future analysis. For example, we identified the inclusion of canceled radiology tests, a time shift of transfusion data, and mistakenly processing the chemical symbol for sodium (“Na”) as a missing value. Manual validation identified 1 important data quality issue that was not detected by computational checks: transfusion dates and times at 1 site were unreliable. Apart from that single issue, across all data tables, GEMINI data had high overall accuracy (ranging from 98%–100%), sensitivity (95%–100%), specificity (99%–100%), positive predictive value (93%–100%), and negative predictive value (99%–100%) compared to the gold standard.Discussion and ConclusionComputational data quality checks with iterative re-extraction facilitated reliable data collection from hospitals but missed 1 critical quality issue. Combining computational and manual approaches may be optimal for assessing the quality of large multisite clinical databases.     

A theoretical framework for cognitive and non-cognitive interventions for older adults: stimulation versus compensation

Background: Recently, interest in cognitive training for older adults has grown significantly, reflecting a need for preserving the quality of life into late adulthood. In spite of increasing interest in cognitive rehabilitation, recent meta-analyses have questioned reported training gains and determined that cognitive gain from cognitive training might be no larger than the gain observed from active controls such as unspecific, non-cognitive activities.

Aims: This paper presents a theoretical framework for clarifying specificity of cognitive training by exploring mechanisms of current cognitive and non-cognitive interventions for older adults. By differentiating compensatory aspects from the components of specific and non-specific stimulation in current training, two related strategies of interventions for age-related cognitive decline, i.e., stimulation versus compensation, are proposed.

Overview: Current interventions for age-related cognitive decline are reviewed in terms of stimulation- and compensation-focused interventions. Stimulation-focused, cognitive and non-cognitive training, with or without specific targets, tend to result in general improvement in attention and sensory or other cognitive functions. Meanwhile, compensation-focused training is likely to be the most effective when the intervention specifically supports the frontally mediating activity in accordance with the direction of indigenous adjustments in the aging brain.

Conclusions: It can be inferred that stimulation-focused training is to ameliorate the adverse effects of neurological aging, whereas compensation-focused cognitive training is primarily to facilitate compensatory adaptation in the brain.     

Twist technique for removal of spinal extradural arachnoid cyst: technical note

Study design

We document a spinal extradual arachnoid cyst treated by twist technique. The cyst is tightly adherent to the neural tissue or the dura, and the communication stalk is little or short.

Objective

To demonstrate the effectiveness of twist technique of closure of the communication stalk for the removal of spinal extradural arachnoid cyst.

Summary of background data

The standard treatment for a spinal extradural arachnoid cyst is complete excision of the cyst, followed by obliteration of the communication stalk and repair of the dural defect. To our knowledge, twist technique of the communication stalk for removal of spinal extradural arachnoid cyst has not been reported.

Methods

A 44-year-old woman presented with a 10-year history of pain and dysesthesia, initially in the posterior neck region and extending gradually to the distal portion of the right upper extremity. Pain and dysesthesia were exaggerated when she was lying down and relieved when standing or walking. She was diagnosed with an extradural arachnid cyst ranging from spinal regions T1 to T3 using MRI. Computerized tomography myelography revealed a mass located posterior to the spinal cord. Pooling of contrast medium was observed in the lesion indicating communication with the subarachnoid space. Laminectomy of the T1–T3 region was performed, preserving the spinous processes and the facet joints. A short communication stalk was found at the proximal root sleeve of right T3. This stalk was closed using twist technique.

Results

The patient experienced marked reduction of pain and dysesthesia after surgery, and the headache and blurred vision completely disappeared. Five days after the operation, she was discharged home in good condition. Postoperative 1 year later, the patient had completely recovered and resumed her normal life.

Conclusions

Twist technique can be seen safe and effective as another surgical option for spinal extradural arachnoid cysts containing a short stalk and dense fibrous adhesion with the dura mater.     

Middle-aged women's awareness of cholesterol as a risk factor: Results from a national survey of Korean Middle-aged Women's Health Awareness (KomWHA) study

Background

Dyslipidemia, a risk factor for cardiovascular disease (CVD), is more prevalent in middle-aged women than in men of the same age in Korea. This study, the first national survey that focused on cholesterol in Korean women, aimed to: (1) assess their awareness and knowledge of cholesterol, (2) evaluate their risk reduction behavior, and (3) examine differences in these variables among geographical regions in Korea.

Methods

A questionnaire survey study was conducted in a randomly selected national sample of 1304 Korean women, aged 40-64 years in 3 geographic regions.

Results

High cholesterol was identified as a cause of CVD by 54.4% of respondents, however, 95.4% did not know their own values. Only 4.1% of respondents were aware of desirable level of total cholesterol. Eight percent of respondents perceived correctly the meaning of high-density lipoprotein cholesterol (HDL-C) as good cholesterol. And 32.9% had cholesterol check at least once a year. No significant regional differences were found in women's awareness and knowledge on cholesterol. No smoking (93.6%), low salt diet (52.5%) and weight management (50.6%) were the most prevalent risk reduction behaviors. Women in the rural area performed less risk reduction behaviors than those in urban area.

Conclusions

Given the low level of awareness and knowledge about cholesterol in these women, nurses need to increase their education about cholesterol and risk reduction behaviors of CVD for middle-aged Korean women, particularly those in rural area. To resolve identified disparities in women's risk reduction behaviors between the rural and urban area, a national-level health policy can result in a successful effort to promote women's awareness of cholesterol and risk reduction behaviors for the cardiovascular health of the public.