Blood pressure variability (BPV) is associated with higher cardiovascular morbidity risks; however, its association with cognitive decline remains unclear. We investigated whether higher BPV is ...associated with faster declines in cognitive function in ischemic stroke (IS) patients. Cognitive function was evaluated between April 2010 and August 2015 using the Mini-mental State Examination (MMSE) and Montreal Cognitive Assessment in 1,240 Korean PICASSO participants. Patients for whom baseline and follow-up cognitive test results and at least five valid BP readings were available were included. A restricted maximum likelihood-based Mixed Model for Repeated Measures was used to compare changes in cognitive function over time. Among a total of 746 participants (64.6 ± 10.8 years; 35.9% female). Baseline mean-MMSE score was 24.9 ± 4.7. The median number of BP readings was 11. During a mean follow-up of 2.6 years, mean baseline and last follow-up MMSE scores were 25.4 ± 4.8 vs. 27.8 ± 4.4 (the lowest BPV group) and 23.9 ± 5.2 vs. 23.2 ± 5.9 (the highest BPV group). After adjusting for multiple variables, higher BPV was independently associated with faster cognitive decline over time. However, no significant intergroup difference in cognitive changes associated with mean systolic BP was observed. Further research is needed to elucidate how BPV might affect cognitive function.
The purpose of the present study was to evaluate the mechanical strength and the absorption rate of WE43 material and to develop an absorbable metallic plate and screw for craniofacial application. ...The extruded WE43 plate and screw were evaluated using a LeFort I osteotomy canine model of 10 beagle dogs. Animals were divided into two groups: five dogs in the experimental group and five dogs in the control group. μCT was acquired at 4, 12, and 24 weeks. At 24 weeks after the operation, all animals were sacrificed, and histologic evaluation was performed. Swelling and gas formation were observed in three dogs in the experimental groups at 8 weeks. From 12 weeks, infraorbital fistula and inflammation were observed in three dogs in the experimental group, which gradually decreased and disappeared at 24 weeks. Other two dogs showed less gas formation at 12 weeks. The plates were completely absorbed, and gas formation was not observed at 24 weeks in these two dogs. New bone was well formed around the plates and screws in both groups. Histologic examination showed no specific differences between two groups. The mechanical strength of extruded WE43 was sufficient for mid‐facial application. Plates and screws made with appropriately treated WE43 have the potential to be useful clinically.
In this study, we evaluated the bone regenerative capability of a customizable hydroxyapatite (HA) and tricalcium phosphate (TCP) scaffold using a digital light processing (DLP)-type 3D printing ...system. Twelve healthy adult male beagle dogs were the study subjects. A total of 48 defects were created, with two defects on each side of the mandible in all the dogs. The defect sites in the negative control group (sixteen defects) were left untreated (the NS group), whereas those in the positive control group (sixteen defects) were filled with a particle-type substitute (the PS group). The defect sites in the experimental groups (sixteen defects) were filled with a 3D printed substitute (the 3DS group). Six dogs each were exterminated after healing periods of 4 and 8 weeks. Radiological and histomorphometrical evaluations were then performed. None of the groups showed any specific problems. In radiological evaluation, there was a significant difference in the amount of new bone formation after 4 weeks (
< 0.05) between the PS and 3DS groups. For both of the evaluations, the difference in the total amount of bone after 8 weeks was statistically significant (
< 0.05). There was no statistically significant difference in new bone between the PS and 3DS groups in both evaluations after 8 weeks (
> 0.05). The proposed HA/TCP scaffold without polymers, obtained using the DLP-type 3D printing system, can be applied for bone regeneration. The 3D printing of a HA/TCP scaffold without polymers can be used for fabricating customized bone grafting substitutes.
Introduction
To devise appropriate preventive strategies after stroke, knowledge of the association between post-stroke cognitive impairment (PSCI) and prognosis of stroke patients is important. We ...investigated the association between PSCI and the vascular outcomes in patients with ischemic stroke with best medical care considering their risk factors and adherence to medications.
Methods
Of the 1534 ischemic stroke patients who randomly assigned to aspirin or cilostazol treatment with best medical therapy by the PICASSO (PreventIon of CArdiovascular events in iSchemic Stroke patients with high risk of cerebral hemOrrhage) trial, 1240 with baseline mini-mental state examination (MMSE) scores were analysed retrospectively. The patients were classified into three groups based on MMSE scores. Recurrence of ischemic stroke, stroke of any type and composite of major vascular events were compared among them.
Results
Of the 1240 patients, 376 had MMSE scores of 28–30 (highest tertile), 419 had scores of 24–27 (middle tertile) and 445 had scores of 0–23 (lowest tertile). The average time from stroke onset to MMSE examination was 31.8 days. By trend analysis, lower tertile of MMSE score was significantly associated with recurrent ischemic stroke (
p
= 0.0017), stroke of any type (
p
= 0.0053) and composite vascular outcome (
p
= 0.0122). After adjustment for covariates, PSCI was independently associated with risk of recurrent ischemic stroke (HR 2.40, 95% confidence interval 1.12–5.14).
Conclusions
Cognitive impairment was associated with recurrence of ischemic stroke in high risk patients during adequate medical therapy including antiplatelet therapy. However, the other vascular events were not.
This study evaluated the mechanical properties and bone regeneration ability of 3D-printed pure hydroxyapatite (HA)/tricalcium phosphate (TCP) pure ceramic scaffolds with variable pore architectures. ...A digital light processing (DLP) 3D printer was used to construct block-type scaffolds containing only HA and TCP after the polymer binder was completely removed by heat treatment. The compressive strength and porosity of the blocks with various structures were measured; scaffolds with different pore sizes were implanted in rabbit calvarial models. The animals were observed for eight weeks, and six animals were euthanized in the fourth and eighth weeks. Then, the specimens were evaluated using radiological and histological analyses. Larger scaffold pore sizes resulted in enhanced bone formation after four weeks (
< 0.05). However, in the eighth week, a correlation between pore size and bone formation was not observed (
> 0.05). The findings showed that various pore architectures of HA/TCP scaffolds can be achieved using DLP 3D printing, which can be a valuable tool for optimizing bone-scaffold properties for specific clinical treatments. As the pore size only influenced bone regeneration in the initial stage, further studies are required for pore-size optimization to balance the initial bone regeneration and mechanical strength of the scaffold.
Since severe acute respiratory syndrome-coronavirus-2 variant B.1.1.529 (omicron) was first reported to the World Health Organization on November 24, 2021, the cases of the omicron variant have been ...detected in more than 90 countries over the last month. We investigated the clinical and epidemiological characteristics of the first 40 patients with the omicron variant who had been isolated at the National Medical Center in South Korea during December 4-17, 2021. The median age of the patients was 39.5 years. Twenty-two patients (55%) were women. Seventeen patients (42.5%) were fully vaccinated, and none were reinfected with the omicron. Eighteen (45%) had recent international travel history. Half of the patients (19, 47.5%) were asymptomatic, while the others had mild symptoms. Six patients (15%) showed lung infiltrations on chest image; however, none required supplemental oxygen. These mild clinical features are consistent with recent case reports on the omicron variant from other countries.
Objectives
This study aimed to evaluate the effect of aging on the changes in implant stability over time following implant placement.
Materials and methods
A total of 104 patients in four age ranges ...(group 1: <60 years, group 2: 61–70 years, group 3: 71–80 years, and group 4: >80 years) were included. Bone‐level tapered implants were placed without implementing any bone augmentation procedure. The final torque value displayed on the implant engine during implant insertion was recorded. Cone‐beam computed tomography (CBCT) was performed immediately after surgery to analyze the bone quality around the implant. Implant stability was measured immediately after surgery and 2, 4, and 8 weeks after surgery.
Results
In the CBCT image, higher grayscale values were observed in the order of group 1, group 2, and groups 3/4, with statistical significance (p < .05). There was no significant difference in the insertion torque values between age groups (p ≥ .05). Groups 1 and 2 showed lower implant stability values after 2 and 4 weeks compared to immediately and 8 weeks after surgery (p < .05); however, groups 3 and 4 showed no significant difference between the results measured at different timepoints (p ≥ .05).
Conclusions
Implant treatment in elderly patients is successful showing a settled implant stability over time following implant placement when the implant is appropriately engaged in the alveolar bone in the absence of bone augmentation.
Background: It is not yet clear whether nutritional status is associated with post-stroke cognitive impairment (PSCI). We examined the geriatric nutritional risk index (GNRI) on the domain-specific ...cognitive outcomes 3 months after a stroke. Methods: A total of 344 patients with acute ischemic stroke were included for the analysis. The GNRI was calculated as 1.489 × serum albumin (g/L) + 41.7 × admission weight (kg)/ideal body weight (kg) and was dichotomized according to the prespecified cut-off points for no risk and any risks. The primary outcome was PSCI, defined as having adjusted z-scores of less than −2 standard deviations in at least one cognitive domain: executive/activation, memory, visuospatial and language. Multiple logistic regression and linear regression analyses were performed to investigate the association between the GNRI and cognitive outcomes. Results: Seventy (20.3%) patients developed PSCI 3 months after a stroke. The mean GNRI was 106.1 ± 8.6, and 59 (17.2%) patients had low (<98) GNRI scores. A low GNRI was independently associated with the PSCI after adjusting for age, sex, education, initial stroke severity, stroke mechanism and left hemispheric lesion (odds ratio, 2.04; 95% confidence interval, 1.00–4.14). The GNRI scores were also significantly associated with the z-scores from the mini-mental status examination and the frontal domain (β = 0.04, p-value = 0.03; β = 0.03, p-value = 0.03, respectively). Conclusions: A low GNRI was independently associated with the development of PSCI at 3 months after an ischemic stroke. The GNRI scores were specifically associated with the z-scores of the global cognition and frontal domain cognitive outcomes.
Abstract
This study evaluated the bone regeneration capacity and mechanical properties of block-type hydroxyapatite (HA)/tricalcium phosphate (TCP) scaffolds in response to different concentrations ...of polydeoxyribonucleotide (PDRN) and recombinant human bone morphogenic protein 2 (rhBMP-2). Thirty-two male white rabbits were used as a model of calvarial bone defect and classified into eight groups according to type and concentration of growth factor administered, viz., control group (only HA/TCP scaffold), scaffold + PDRN (0.1, 1, 5, and 10 mg/mL each) and scaffold + rhBMP-2 (0.01, 0.05, and 0.1 mg/mL each). The specimens were evaluated using histomorphometric and radiological analyses. Histomorphometric analyses indicated that the administration of PDRN did not increase bone formation. However, significant increases in bone formation were observed with the administration of rhBMP-2 at 0.05 and 0.10 mg/mL on week 8 compared to the control (
p
< 0.05). Radiological analyses revealed a significant increase in bone formation at week 8 with the administration of PDRN at 5 mg/mL and 10 mg/mL, and rhBMP-2 at 0.05 or 0.10 mg/mL compared to the control (
p
< 0.05). Our findings show that block-type HA/TCP scaffolds possess sufficient mechanical strength and bone regeneration capacity when used with optimal concentrations of growth factors.
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