Involvement of free-space optics in Raman distributed temperature sensing.

This Letter demonstrates the successful use of free-space optics (FSO) as a transition channel for an air segment in transmitting Raman backscattering signals for distributed temperature sensing (DTS). A barrier-free air segment link shaped by an FSO is part of the Raman-based DTS (RDTS) fiber optic transmission route. For this plan, the FSO enables delivery of the RDTS's pulse with the low-loss transmission over the air segment while also returning to the RDTS the varied Raman backscattered signals from the probing temperature variations for signal interpretation. The difference between various temperatures sensed and the referential air temperature remains nearly the same before and after passing the FSO. The viability of this technology provides a crucial basis for tackling the high expense of installing and repairing DTS cables and the challenges associated with doing so owing to topographical restrictions.

Susceptibility to Colorectal Cancer Based on HSD17B4 rs721673 and rs721675 Polymorphisms and Alcohol Intake among Taiwan Biobank Participants: A Retrospective Case Control Study Using the Nationwide Claims Data.

Colorectal cancer (CRC) is a major public health issue, and there are limited studies on the association between 17ß-hydroxysteroid dehydrogenase type 4 (HSD17B4) polymorphism and CRC. We used two national databases from Taiwan to examine whether HSD17B4 rs721673, rs721675, and alcohol intake were independently and interactively correlated with CRC development. We linked the Taiwan Biobank (TWB) participants' health and lifestyle information and genotypic data from 2012 to 2018 to the National Health Insurance Database (NHIRD) to confirm their medical records. We performed a genome-wide association study (GWAS) using data from 145 new incident CRC cases and matched 1316 healthy, non-CRC individuals. We calculated the odds ratios (OR) and 95% confidence intervals (CI) for CRC based on multiple logistic regression analyses. HSD17B4 rs721673 and rs721675 on chromosome 5 were significantly and positively correlated with CRC (rs721673 A > G, aOR = 2.62, p = 2.90 × 10-8; rs721675 A > T, aOR = 2.61, p = 1.01 × 10-6). Within the high-risk genotypes, significantly higher ORs were observed among the alcohol intake group. Our results demonstrated that the rs721673 and rs721675 risk genotypes of HSD17B4 might increase the risk of CRC development in Taiwanese adults, especially those with alcohol consumption habits.

Emergent use of tube tip in pharynx technique in "cannot intubate cannot oxygenate" situation: A case report.

BACKGROUND: A "cannot intubate, cannot oxygenate (CICO)" situation is a life-threatening condition that requires emergent management to establish a route for oxygenation to prevent oxygen desaturation. In this paper, we describe airway management in a patient with an extended parotid tumor that invaded the airways during CICO using the endotracheal tube tip in the pharynx (TTIP) technique. CASE SUMMARY: A 43-year-old man was diagnosed with parotid tumor for > 10 years. Computed tomography and nasopharyngeal fiberoptic examination revealed a substantial mass from the right parotid region with a deep extension through the lateral pharyngeal region to the retropharyngeal region and obliteration of the nasopharynx to the oropharynx. Tumor excision was arranged. However, we encountered CICO during anesthesia induction. An endotracheal tube was used as an emergency supraglottic airway device (TTIP) to ventilate the patient in a CICO situation where other tools such as laryngeal mask airway or mask ventilation were not suitable for this complicated and difficult airway. The patient did not experience desaturation despite sudden loss of definite airway. During tracheostomy, the pulse oximetry remained 100% with our technique of ventilating the patient. The arterial blood gas analysis revealed PaCO2 35.7 mmHg and PaO2 242.5 mmHg upon 50% oxygenation afterward. CONCLUSION: Using an endotracheal tube as a supraglottic airway device, patients may have increased survival without experiencing life-threatening desaturation.

Human Papillomavirus and Risk of Colorectal Cancer: An Analysis of Nationwide Claims Data.

Background and Objectives: Although human papillomavirus (HPV) is a major etiology of cervical and anogenital cancers, whether it is associated with colorectal carcinogenesis is yet undetermined. Materials and Methods: The longitudinal association of HPV infection with colorectal cancer (CRC) was evaluated using 2000-2013 data from a nationwide Taiwanese claims database. In this retrospective cohort study, 358 patients with primary HPV diagnoses (HPV-infected cohort) and 1432 patients without such a diagnosis (HPV-uninfected cohort) were recruited between 2000 and 2006. Both cohorts were followed up to identify CRC incidences from 2006 to 2013. Hazard ratios (HRs) and their 95% confidence intervals (CIs) derived from Cox proportional hazards models were used to estimate the association between HPV and CRC risk. Results: The HPV-infected cohort had a significantly higher cumulative incidence of CRC than the HPV-uninfected cohort. The presence of HPV was associated with an increased risk of CRC (adjusted HR, 1.63; 95% CI, 1.02-3.62). Furthermore, the significant HPV-CRC risk association was evident in both sexes. Conclusions: This population-based cohort study reveals longitudinal evidence that HPV is associated with an increased risk of CRC. Further studies are required to verify the role of HPV in colorectal carcinogenesis.

Cation Valences and Multiferroic Properties of EuTiO3 Co-Doped with Ba and Transition Metals of Co/Ni.

Eu1-xBaxTi1-yMyO3 (M = Co or Ni) was sintered at 1400 °C under a reduction atmosphere. X-ray photoelectron spectroscopy revealed the mixed valences of Eu2+/Eu3+ and Ti4+/Ti3+ in EuTiO3 and Eu0.7Ba0.3TiO3, as well as some oxygen vacancies required to keep the charge neutrality. The co-doping of Co2+/Ni2+ in Eu0.7Ba0.3TiO3 resulted in the disappearance of oxygen vacancies, as a result of a reduction in Ti3+ numbers and an increase in Eu3+ numbers. On the other hand, Ba2+ doping led to an increased lattice parameter due to its larger ionic size than Eu2+, whereas the Co2+/Ni2+ co-doping resulted in smaller lattice parameters because of the combined effects of ionic size and variation in the oxygen-vacancy numbers. Eu0.7Ba0.3TiO3 exhibited a clear ferroelectricity, which persisted in the Co2+/Ni2+ co-doped samples until the doping levels of y = 0.05 and 0.10, respectively. Eu0.7Ba0.3TiO3 remained to be antiferromagnetic with a reduced transition temperature of 3.1 K, but co-doping of Co2+/Ni2+ turned the samples from antiferromagnetic to ferromagnetic with transition temperatures of 2.98 K and 2.72 K, respectively. The cause for such a transition could not be explained by the larger lattice volume, oxygen vacancies and mixed valences of Eu2+/Eu3+, which were proposed in previous works. Instead, it was more likely to arise from a large asymmetric distortion of the Eu-O polyhedron introduced by the aliovalent doping, which promotes the admixture of Eu 5d and 4f states.

Association between serum uric acid levels and colonic diverticulosis in terms of sex.

BACKGROUND: The association between elevated serum uric acid (UA) levels and the risk of developing colonic diverticulosis has not yet been investigated. Thus, this cross-sectional study aimed to examine this correlation in individuals from Taiwan. METHODS: From Jan. 1, 2010, to Dec. 31, 2016., approximately 5,605 patients (aged >20 years) from Tri-Service General Hospital who met the inclusion criteria according to colonoscopy and laboratory test findings were included in this research. The correlation between serum UA levels and colonic diverticulosis was investigated via regression analyses. RESULTS: Participants with elevated serum UA levels were at a higher risk of colonic diverticulosis. The area under the curve for serum UA levels was significantly higher in women than in men (0.651 [95% confidence interval: 0.596-0.707] vs. 0.55 [0.507-0.593]). There were specific trends in female-specific indicators for colonic diverticulosis across increasing quartiles of serum UA levels. CONCLUSIONS: Patients with elevated serum UA levels should be cautious regarding the development of colonic diverticulosis disorder in female. Moreover, prospective studies may provide additional information on the relationship between elevated serum UA levels and colonic diverticulosis.

The Combination of Sleep Disorders and Depression Significantly Increases Cancer Risk: A Nationwide Large-Scale Population-Based Study.

Introduction: Sleep disorders, depression, and cancer have become increasingly prevalent worldwide. However, it is unknown whether coexistence of sleep disorders and depression influences the risk of cancer development. Therefore, we conducted a nationwide population-based study to examine this association among patients in Taiwan. Materials and Methods: A total of 105,071 individuals diagnosed with cancer and 420,284 age- and sex-matched patients without a diagnosis of cancer between 2000 and 2015 were identified from Taiwan's National Health Insurance Research Database. The underlying chronic diseases of patients that may developed cancer were gathered and studied as the predictor. A multivariate Cox proportional odds model was used to estimate the crude and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) to estimate the interaction effect between sleep disorders and depression on the risk of cancer. Results: After adjusting for age, sex, comorbidities, and other covariates, the cancer group was associated with increased exposure to sleep disorders than the non-cancer group (aOR = 1.440, 95% CI = 1.392−1.489, p < 0.001). In addition, patients with both sleep disorders and depression were at an even higher risk for cancer than the general population (aOR = 6.857, p < 0.001). Conclusions: This retrospective cohort study shows that patients with both sleep disorders and depression are at a higher risk of cancer. Clinically, a meticulous cancer risk evaluation is recommended for patients with both sleep disorders and depression.

The potential role of herbal extract Wedelolactone for treating particle-induced osteolysis: an in vivo study.

BACKGROUND: Osteolysis is one of the most prevalent clinical complications affecting people who undergo total joint replacement (TJR). Wedelolactone (WDL) is a coumestan compound derived from the Wedelia chinensis plant and has been demonstrated to exhibit anti-inflammatory properties. This study aimed to investigate the oral administration of WDL as a potential treatment for particle-induced osteolysis using a well-established mice calvarial disease model. METHODS: Thirty-two C57BL/6 J mice were randomized into four groups: Sham, vehicle, osteolysis group with oral WDL treatment for 4 weeks (WDL 4w), and osteolysis group treated for 8 weeks (WDL 8w). Micro-CT was used to quantitatively analyze the bone mineral density (BMD), bone volume/tissue volume (BV/TV) and trabecular bone thickness (Tb.Th). Osteoclast numbers were also measured from histological slides by two investigators who were blind to the treatment used. RESULTS: The results from micro-CT observation showed that BMD in the WDL 8w group improved significantly over the vehicle group (p < 0.05), but there was no significant difference between WDL 4w and 8w for BV/TV and Tb.Th. Osteoclast numbers in the WDL 4w group were also lower than the vehicle group (p < 0.05), but the difference between WDL 8w and 4w groups was not significant. CONCLUSIONS: Particle-induced osteolysis is an inevitable long-term complication after TJR. The results of this animal study indicate that an oral administration of WDL can help reduce the severity of osteolysis without adverse effects.

Evaluation of graphene-derived bone scaffold exposure to the calvarial bone_in-vitro and in-vivo studies.

Graphene is a novel material which has recently been gaining great interest in the biomedical fields. Our previous study observed that graphene-derived particles help induce bone formation in a murine calvarial model. Here, we further developed a blended graphene-contained polycaprolactone (PCL/G) filament for application in a 3D-printed bone scaffold. Since implants are expected to be for long-term usage, in vitro cell culture and in vivo scaffold implants were evaluated in a critical-size bone defect calvarial model for over 60 weeks. Graphene greatly improved the mechanical strength by 30.2% compared to pure PCL. The fabricated PCL/G scaffolds also showed fine cell viability. In animal model, an abnormal electroencephalogram power spectrum and early signs of aging, such as hair graying and hair loss, were found in the group with a PCL/G scaffold compared to pure PCL scaffold. Neither of the abnormal symptoms caused death of all animals in both groups. The long-term use of graphene-derived biomaterials for in-vivo implants seems to be safe. But the comprehensive biosafety still needs further evaluation.

Profiles of Hospitalized Patients with Angiographic Coronary Heart Disease in Taiwan during 2014-2016: Report of a Tertiary Hospital.

BACKGROUND: The Taiwan Society of Cardiology (TSOC) has established multicenter registries for coronary artery disease (CAD) to investigate clinical characteristics, management and risks for mortality. However, the impacts of newly-emerged evidence-based therapies, including the use of drug-eluting stents (DESs), on patients with CAD in Taiwan remain unclear. METHODS: The Tri-Service General Hospital-Coronary Heart Disease (TSGH-CHD) registry is a single-center, prospective, longitudinal registry in Taiwan containing data from 2014-2016. Individuals who were admitted for coronary angiography were enrolled. Patient profiles, management and in-hospital outcome data were collected. RESULTS: We included 3352 patients: 2349 with stable angina and 1003 with acute coronary syndrome (ACS). In the stable angina group, both patients receiving stenting and those receiving medical treatment had a 0.7% mortality rate; DESs were used in 70.4% of the patients receiving stenting. In the ACS group, the patients receiving stenting and those receiving medical treatment had a 4.9% and 10.7% mortality rate, respectively; DESs were used in 63.1% of the patients receiving stenting. In the 2008-2010 Taiwan ACS registry, DESs were used in only 28% of all stenting procedures, and the estimated hospital mortality rate was 1.8%. Multivariate analysis indicated that older age, prior stroke, and cardiogenic shock on admission were associated with an increased risk of in-hospital mortality in the ACS group. CONCLUSIONS: Compared with the Taiwan ACS cohort, the TSGH-CHD registry revealed increased DES use and increased disease complexity and severity after 2010. Although unlikely to significantly improve survival, interventionists seemed to perform high-risk procedures for complex CAD more often in the new DES era.

Preservation of superior rectal artery in laparoscopically assisted subtotal colectomy with ileorectal anastomosis for slow transit constipation.

BACKGROUND: Slow transit constipation (STC) has traditionally been considered as a functional disorder. However, evidence is accumulating that suggests that most of the motility alterations in STC might be of a neuropathic etiology. If the patient does not meet the diagnosis of pelvic outlet obstruction and poorly response to conservative treatment, surgical intervention with subtotal colectomy may be effective. The most unwanted complication of the procedure is anastomotic leakage, however, preservation of the superior rectal artery (SRA) may reduce its incidence. AIM: To evaluate the preservation of the SRA in laparoscopically assisted subtotal colectomy with ileorectal anastomosis in STC patients. METHODS: This was a single-center retrospective observational study. STC was diagnosed after a series of examinations which included a colonic transit test, anal manometry, a balloon expulsion test, and a barium enema. Eligible patients underwent laparoscopically assisted total colectomy with ileorectal anastomosis and were examined between January 2016 and January 2018. The operation time, blood loss, time to first flatus, length of hospital days, and incidence of minor or major complications were recorded. RESULTS: A total of 32 patients (mean age, 42.6 years) who had received laparoscopic assisted subtotal colectomy with ileorectal artery anastomosis and preservation of the SRA. All patients were diagnosed with STC after a series of examinations. The mean operative time was 151 min and the mean blood loss was 119 mL. The mean day of first time to flatus was 3.0 d, and the mean hospital stay was 10.6 d. There were no any patients conversions to laparotomy. Post-operative minor complications including 1 wound infection and 1 case of ileus. There was no surgical mortality. No anastomosis leakage was noted in any of the patients. CONCLUSION: Laparoscopically assisted subtotal colectomy with ileorectal anastomosis and preservation of the SRA can significantly improve bowel function with careful patient selection. Sparing the SRA may protect against anastomosis leakage.

Risk of Colorectal Cancer in Patients With Attention-Deficit Hyperactivity Disorder: A Nationwide, Population-Based Cohort Study.

Background: The association between attention-deficit hypersensitivity disorder (ADHD) and the risk of developing colorectal cancer (CRC) is, as yet, to be investigated, and thus, we have conducted this nationwide, cohort study to examine the association in patients from Taiwan. Methods: In this study, 798 individuals with newly diagnosed ADHD and 2,394 (1:3) age-, gender-, and index year- matched controls without ADHD were enrolled, between 2000 and 2013, from the Longitudinal Health Insurance Database, a subset of the National Health Insurance Research Database in Taiwan. The cumulative incidence of CRC was assessed in each cohort by the Kaplan-Meier method. The multivariate Cox proportional hazards model was used to estimate the crude, and the adjusted hazards ratios (HRs) with 95% confidence intervals (CIs), was conducted to estimate the association between ADHD and CRC. Results: The Kaplan-Meier analysis revealed that the cumulative incidence of CRC was significantly higher in patients with ADHD than in those without it (log rank test, p < 0.001). After adjustments for age, gender, comorbidities, and other covariates, the ADHD group was associated with an increased risk of CRC in comparison to the non-ADHD group (adjusted HR = 3.458, 95% CI = 1.640-7.293, p < 0.001). In addition, the usage of methylphenidate was not associated with the risk of developing CRC in patients with ADHD. Conclusion: This retrospective cohort study depicts the evidence that ADHD was associated with the increased risk of CRC. Further studies are needed to confirm the association and the underlying mechanisms.

Sex Differences in the Mortality Risk of Elderly Patients with Systolic Heart Failure in Taiwan.

BACKGROUND: Sex differences in heart failure mortality might be affected by age, race, and treatment response. Many large studies in Western countries have shown conflicting results, however few studies have been conducted in Asian patients. OBJECTIVES: We prospectively investigated the mortality risk in a multicenter cohort of 1,093 male and 416 female heart failure patients with reduced ejection fraction (HFrEF) hospitalized for worsening symptoms in Taiwan between 2013 and 2015. METHODS: Kaplan-Meier curve and Cox proportional regression analyses were used to determine the one-year mortality risk by sex. RESULTS: There were no significant differences in major adverse cardiovascular events, re-admission rate, and mortality between sexes in the overall cohort and the young subgroup during one-year of follow-up. In the elderly subgroup, the overall and cardiac mortality rate of the male patients were higher than those of the female patients (p = 0.035, p = 0.049, respectively). We found that the prognostic effect of old age on overall mortality rate appeared to be stronger in the male patients (p < 0.0001) than in the female patients (p = 0.69) in Cox regression analysis and Kaplan-Meier survival curves. Male sex was a risk factor for all-cause mortality in the elderly (hazard ratio: 1.50, 95% confidence interval 1.02-2.25) independently of systolic blood pressure, diabetes mellitus, hemoglobin concentration, kidney function, and medications. CONCLUSIONS: In the Taiwan HFrEF registry, the highest mortality risk was observed in male patients aged 65 years or more. Clinicians need to pay more attention to these patients.

Risk of colorectal cancer in patients with alcoholism: A nationwide, population-based nested case-control study.

BACKGROUND: Colorectal cancer (CRC) is regarded as a multifactorial disease and shares many risk factors with alcoholism. However, the association between alcoholism and CRC remains controversial. OBJECTIVES: In this study, we aimed to evaluate the association between alcoholism and risk of CRC. METHODS: We performed a large-scale, population-based nested case-control study using the Longitudinal Health Insurance Database 2013, derived from Taiwan's National Health Insurance Research Database, and collected data from 2000 to 2013. There were 49,095 diagnosed cases of CRC defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification. Each case was matched with three controls by sex, age, index date of CRC, and annual medical visits; a total of 147,285 controls were identified. Multiple risk factors of CRC in alcoholism cases were investigated using unconditional multiple logistic regression analysis. RESULTS: Among 49,095 cases of CRC, alcoholism was associated with a significantly higher risk of CRC (adjusted odds ratio (OR), 1.631; 95% CI, 1.565-1.699) in multivariate logistic regression, after adjusting other CRC risk factors, and in stratified analysis with multivariate logistic regression. In addition, there was a time-dependent relationship between alcoholism duration and CRC risk in >1 year, > 2 years, >5 years, and > 11 years groups (adjusted ORs, 1.875, 2.050, 2.662 and 2.670; 95% CI, 1.788-1.967, 1.948-2.158, 2.498-2.835, and 2.511-2.989 respectively). CONCLUSION: An association between alcoholism and risk of CRC was found in this study. Furthermore, patients with longer alcoholism history showed higher likelihood of developing CRC, which indicates a time-dependent relationship between alcoholism exposure and CRC. Further research on colorectal tumorigenesis is needed.

In vitro and in vivo Biological Responses to Graphene and Graphene Oxide: A Murine Calvarial Animal Study.

BACKGROUND: Graphene and its derivatives have recently gained popularity in the biomedical field. Previous studies have confirmed that both the mechanical strength and wear resistance of graphene-containing polyethylene have been greatly improved. Therefore, it is being considered as an alternative for artificial joint replacement liners. Based on the literature, the wear debris generated from the traditional polymers used for orthopedic liners could lead to particle-induced osteolysis and, consequently, failure of joint replacement. However, the biological response of this novel graphene-based polymer is still unclear. Therefore, the current study aimed to investigate the in vitro and in vivo biological effects of graphene and graphene oxide (GO) particles on bone. MATERIALS AND METHODS: The biological responses of graphene and GO particles were tested via in vitro and murine calvarial in vivo models. In the in vitro model, murine macrophage cells were mixed with particles and hydrogel and printed into two differently designed scaffolds; the induced proinflammatory cytokines were then tested. In the murine in vivo model, the particle size distribution was measured via SEM, and these particles were then administrated in the calvarial area, referring to our established model. A micro-CT and histological analysis were performed to examine the biological effects of the particles on bone health. The data were analyzed via the one-way analysis of variance to determine the differences between the groups. RESULTS: Both graphene and GO induced significantly higher TNF-α and IL-6 secretion compared with the control in the three-dimensional in vitro model. In the murine calvarial in vivo test, the graphene and GO particles increased the bone mass compared with the sham groups in the micro-CT analysis. Bone formation was also observed in the histological analysis. CONCLUSION: In these in vivo and in vitro studies, the graphene and GO wear debris did not seem to induce harmful biological response effect to bone. Bone formation around the skull was observed in the calvarial model instead. Graphene-containing biomaterials could be a suitable new material for application in orthopedic prostheses due to their benefit of eliminating the risk of particle-induce osteolysis.

Increased incidence of colorectal cancer with obstructive sleep apnea: a nationwide population-based cohort study.

BACKGROUND: Epidemiological studies on the obstructive sleep apnea (OSA) and cancer relationship in humans are inconsistent. Furthermore, there are limited prospective studies on the association between OSA and the risk of colorectal cancer (CRC). This retrospective cohort study examined the longitudinal relationship between OSA and CRC in a nationwide population-based cohort. METHODS: We identified 4180 individuals newly diagnosed with OSA (the exposed cohort) and randomly selected 16,720 age- and sex-matched subjects without OSA (the nonexposed cohort) between 2000 and 2008 from Taiwan's National Health Insurance Research Database (NHIRD). The Kaplan-Meier method was used for calculating the cumulative incidence of CRC in each cohort. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and the accompanying 95% confidence intervals (CIs) for the association between OSA and CRC. RESULTS: After adjusting for potential confounders, patients with OSA were associated with a significantly higher risk of CRC than those without OSA (adjusted HR, 1.80; 95% CI, 1.28-2.52). The cumulative incidence of CRC was significantly higher in the OSA cohort than in the comparison cohort (log-rank test, p < 0.001). Furthermore, the association between OSA and CRC appeared to be enhanced with increasing frequency of OSA medical visits (adjusted HR [95% CI] was 1.61 [0.97-2.66] and 1.86 [1.26-2.75] for one visit and two or more visits, respectively). CONCLUSION: This population-based cohort study demonstrated that OSA was associated with an increased risk of CRC. Further large-scale prospective studies are needed to confirm our results.

Association between mild anemia and physical fitness in a military male cohort: The CHIEF study.

Anemia defined as reduced hemoglobin levels of red blood cells may carry less oxygen to skeletal muscle and impair physical performance. Previous studies have shown that exercise intolerance was related to moderate or severe anemia, however, the relationship to mild anemia was unknown. We investigated the cross-sectional association of mild anemia defined as a hemoglobin level of 10.0-13.9 g/dL with physical fitness in 3,666 military young males in Taiwan in 2014. Aerobic fitness was evaluated by 3000-meter run test, and anaerobic fitness was evaluated by 2-minute sit-ups and 2-minute push-ups, respectively. Multiple logistic regressions for the best 10% and the worst 10% performers were used to determine the relationship. There were 343 mild anemic males in whom 47.8% were microcytic anemia and 3,323 non-anemic males for the analysis. The multiple logistic regression shows that as compared with non-anemic males, mild anemic males were more likely to be the worst 10% performers in the 3000-meter run test (odds ratios (OR) and 95% confidence intervals: 1.47, 1.01-2.14) after adjusting for age, service specialty, body mass index, waist size, mean blood pressure, unhealthy behaviors, lipid profiles, and exercise frequency. On the contrary, mild anemic males had higher possibility to be the best 10% performers in the 2-minute push-ups test (OR: 1.48, 1.08-2.04). However, there was no association between mild anemia and 2-minute sit-ups. Our findings suggest that unspecified mild anemia might be associated with lower cardiorespiratory fitness but not with anaerobic fitness in physically active military males.

Preclinical alveolar ridge preservation using small-sized particles of bone replacement graft in combination with a gelatin cryogel scaffold.

BACKGROUND: Particulate anorganic bovine bone matrix (ABBM) is extensively used for alveolar ridge preservation (ARP). This study evaluates the potential of ABBM/gelatin cryogel scaffold of regular (250 to 1,000 µm) and small (50 to 100 µm) particles for ARP. METHODS: ABBM was either condensed in a gypsum ring to simulate filling of ABBM in a defect or incorporated into a gelatin cryogel scaffold to disperse ABBM. Condensed regular-sized or small-sized ABBM (rABBM or sABBM) (± bone morphogenetic protein [BMP]-2) were subcutaneously implanted in rats to evaluate biocompatibility and osteogenic potential. Experimental extraction sockets were surgically created on the maxillary ridges of rats and were unfilled (control), filled with rABBM/gelatin, or sABBM/gelatin cryogel scaffold. The socket fill and dimensional changes of the ridge were evaluated by microcomputed tomography imaging and histology. RESULTS: Condensed sABBM showed acceptable biocompatibility but significantly lower interparticle distance (IPD) and porosity (P < 0.001) compared with rABBM, whereas rABBM/gelatin and sABBM/gelatin cryogel scaffold showed similar IPD and porosity. Osteogenesis took place in rABBM/gelatin and sABBM/gelatin-treated extraction sockets showed osteogenesis at 8 weeks and had increased ridge width and reduced ridge discrepancy compared with the control sites. sABBM/gelatin scaffold significantly increased socket fill and reduced ridge discrepancy at 4 weeks, increased ridge width at 8 weeks, and reduced buccal ridge height resorption at both 4 and 8 weeks (P < 0.05 for all). CONCLUSIONS: Osteoconductivity was suppressed in condensed sABBM, even after adding BMP-2. By dispersing sABBM in a gelatin cryogel scaffold, sABBM/gelatin showed a greater potential in promoting socket fill, reducing buccal ridge atrophy, and providing equivalent ridge stability compared with rABBM/gelatin.

PDGF-metronidazole-encapsulated nanofibrous functional layers on collagen membrane promote alveolar ridge regeneration.

This study aimed to develop a functionally graded membrane (FGM) to prevent infection and promote tissue regeneration. Poly(l-lactide-co-d,l-lactide) encapsulating platelet-derived growth factor (PDLLA-PDGF) or metronidazole (PDLLA-MTZ) was electrospun to form a nanofibrous layer on the inner or outer surface of a clinically available collagen membrane, respectively. The membrane was characterized for the morphology, molecule release profile, in vitro and in vivo biocompatibility, and preclinical efficiency for alveolar ridge regeneration. The PDLLA-MTZ and PDLLA-PDGF nanofibers were 800-900 nm in diameter, and the thicknesses of the functional layers were 20-30 µm, with sustained molecule release over 28 days. All of the membranes tested were compatible with cell survival in vitro and showed good tissue integration with minimal fibrous capsule formation or inflammation. Cell proliferation was especially prominent on the PDLLA-PDGF layer in vivo. On the alveolar ridge, all FGMs reduced wound dehiscence compared with the control collagen membrane, and the FGM with PDLLA-PDGF promoted osteogenesis significantly. In conclusion, the FGMs with PDLLA-PDGF and PDLLA-MTZ showed high biocompatibility and facilitated wound healing compared with conventional membrane, and the FGM with PDLLA-PDGF enhanced alveolar ridge regeneration in vivo. The design represents a beneficial modification, which may be easily adapted for future clinical use.