Resting-State Functional MRI: Everything That Nonexperts Have Always Wanted to Know

Resting-state fMRI was first described by Biswal et al in 1995 and has since then been widely used in both healthy subjects and patients with various neurologic, neurosurgical, and psychiatric disorders. As opposed to paradigm- or task-based functional MR imaging, resting-state fMRI does not require subjects to perform any specific task. The low-frequency oscillations of the resting-state fMRI signal have been shown to relate to the spontaneous neural activity. There are many ways to analyze resting-state fMRI data. In this review article, we will briefly describe a few of these and highlight the advantages and limitations of each. This description is to facilitate the adoption and use of resting-state fMRI in the clinical setting, helping neuroradiologists become familiar with these techniques and applying them for the care of patients with neurologic and psychiatric diseases.

Hip fracture patients who experience a greater fluctuation in RDW during hospital course are at heightened risk for all-cause mortality: a prospective study with 2-year follow-up

This study aims to detect whether there remains valuable prognostic information in fluctuation of red cell distribution width (RDW) in hip fracture patients. Results show that this readily available parameter may provide a more effective strategy for assessment of mortality risk, therefore providing a reference for clinical planning and decision-making.

INTRODUCTION

Prognostic values have been found in the fluctuation of some hematologic parameters. The red cell distribution width (RDW) routinely reported with all complete blood cell counts (CBC) has proven to be associated with poor outcomes in various diseases. However, whether the fluctuation in RDW is predictive of long-term mortality in hip fracture patients treated with surgery remains unknown.

METHODS

One thousand three hundred thirty hip fracture patients who underwent surgery from January 1, 2000 to November 18, 2012 were recruited in this prospective cohort study. Fluctuation in the RDW between admission and discharge was measured, and a Kaplan-Meier (KM) analysis and multivariable Cox regression model were applied to evaluate the relationship between this fluctuation and mortality. Risk factors for a larger fluctuation were detected by using Logistic regression analyses.

RESULTS

In addition to the admission RDW, a high RDW level at the time of discharge was also associated with an increased risk of death, while no significant difference was found in the postoperative RDW. Fluctuation in the RDW between admission and discharge was an independent risk predictor for 2-year mortality (HR 1.45 95%CI 1.06-2.00, p = 0.022). Factors affecting the change in the RDW between admission and discharge included both the demographic characteristics of the patients and clinical interventions.

CONCLUSION

Hip fracture patients who experience a greater fluctuation in RDW during the hospital course are at a heightened risk for 2-year all-cause mortality.

The association between serum uric acid level and the risk of fractures: a systematic review and meta-analysis

Controversy has arisen in regarding the association between serum uric acid (UA) and fracture risk. Therefore, we conducted a systemic review and meta-analysis by pooling estimate of five prospective studies (29,110 participants). Results showed that an increased serum UA level is associated with a lower risk of fracture. Numerous studies have demonstrated that high serum UA is a relevant risk factor for a wide variety of diseases, whereas new understanding in serum uric acid follows recent reports demonstrating a protective role of UA in health status. However, the association between serum UA and fracture remains controversial. Therefore, we conduct a systemic review and meta-analysis to determine whether elevated UA level is a protective factor for fracture among prospective studies. We searched for studies published before May 6, 2016, using PubMed, Embase, and Cochrane databases, without any language restriction. The inclusion criteria were published studies investigating the association between UA and fractures. Two authors independently screened the retrieved articles in accordance to the predefined inclusion criteria. We pooled the study-specific relative risk estimates using a random-effect model for comparison of persons whose UA levels were in the top tertile with those in the bottom tertile. Factors that may predict these associations were evaluated in subgroup analysis and meta-regression. The five included prospective studies included 29,110 participants. In random-effect models that included all five included studies, the summary hazard ratios (HRs) (top vs bottom tertiles) were 079 (95% CI, 0.69 to 0.89), without evidence of heterogeneity (P for heterogeneity = 0.458; I ² = 0%). Similar results were shown when pooling estimate of three higher-quality studies (HR 0.80 95% CI, 0.69 to 0.93). The association between UA and fracture remained in sensitivity and subgroup analyses. An increased serum UA level is shown to be associated with a lower risk of fracture, albeit additional large, high-quality prospective studies or a meta-analysis of individual data are still needed to verify the association.

Characteristics of symptoms experienced by persons with dry eye disease while driving in China

PurposeTo assess the vision-related quality of life and self-reported driving performance of patients with dry eye disease (DED).Patients and methodsThe study was performed in the eye centre of Peking University Third Hospital, China. In total, 87 dry eye patients and 42 controls were enroled, including 49 patients without any treatment (group A), 38 patients treated with artificial tears (group B) and 42 controls without DED (group C). The participants had no eye disease other than DED. Scores of a vision-related quality-of-life questionnaire (Ocular Surface Disease Index (OSDI)), a daily life-related visual function questionnaire and a questionnaire about performance during driving were collected. Data were compared among the groups and analysed.ResultsSignificant differences in all clinical characteristics and OSDI scores were found between DED patients and normal controls (P<0.05). While subjects in group A felt more uncomfortable than those in group B, the functional limitations related to dry eye were significant in all DED patients, especially for daily work and using a computer. DED was correlated with unsafe driving habits and performance, which may increase the risk of dangerous driving (P<0.01). For patients with DED, the rate of accidents and near-accidents was 10.33%, and the rate of missed targets totalled 32.17%.ConclusionsDED can lead to many inconveniences in daily life, including driving. The frequencies of unsafe driving habits and performance were increased in patients with DED.

Unipolar Nonvolatile Resistive Switching in Pt/MgO/Ta/Ru Structures Deposited by Magnetron Sputtering

The recent realization of memristors, nanodevices exhibiting non-volatile resistive switching, has sparked tremendous interest for applications in fields such as nonvolatile memories. Here we report unipolar resistive switching in Pt/MgO/Ta/Ru structures, with an oxide barrier thickness of only 15 nm. No electroforming process was required to achieve resistive switching and an ohmic conduction mechanism is associated with the ON state. We observed an inverse dependence of the ON state resistance on the SET current compliance and average values of 1.61 V and 1.38 V for the SET and RESET voltages, respectively. We show the stability of the switching for over 40 cycles and a clear separation of the ON (10¹ Ω) and OFF (10² Ω) states during at least 10⁴ s.

[Magnetic resonance imaging of dystrophinopathy that mimics adductor enthesopathy]

OBJECTIVE

To report thigh muscle magnetic resonance imaging (MRI) tests of four Chinese patients with dystrophinopathy with edema changes in adductor longus muscles that mimics adductor enthesopathy.

METHODS

Four boys, who were from four unrelated families and aged from 5 to 11 years, were investigated because of the clinical manifestations including myalgia or muscle weakness or the incidental findings of elevated serum creatine kinase levels, and were diagnosed with dystrophinopathy by gene test of Duchenne muscular dystrophy (DMD). Their creatine kinase levels were increased from 4 087 IU/L to 32 700 IU/L (Normal range: 75-175 IU/L). The muscle biopsy of three patients all demonstrated a dystrophic pattern including necrosis, regeneration, hypertrophy, atrophy and connective tissue proliferation, with different proportions of dystrophin-negative muscle fibers. The gene test of DMD showed an out-frame deletion of exons in three of the four patients, involving either exons 45 or exons 49-52 deletion or exon 62 duplication, and c.2665 C>T with nonsense mutation in the other one. Muscle MRI tests of the bilateral thighs were performed with T1 weighed sequence and slow tau inversion recovery sequence. The degree of fatty infiltration changes was scored.

RESULTS

MRI of the thigh muscles showed mild to severe fatty infiltration changes in T1 weighed sequence with the total scores from 2 to 13.The most severe fatty infiltration changes were in the long head of biceps femoris and adductor magnus. Obvious hyperintensities appeared mainly in the adductor longus muscles on slow tau inversion recovery (STIR) images in all the patients without any abnormal signals in the attachment of the ligament, indicating edema changes of the adductor longus muscles which mimiced adductor enthesopathy. Two of the four patients presented with edema changes in the bilateral adductor longus muscles, while the other two were with only unilateral changes. Furthermore, other thigh muscles, including adductor magnus, semitendinosus, sartorius and rectus femoris muscles, could also have mild edema changes in two of the four patients.

CONCLUSION

Dystrophinopathy can manifest as edema changes in the adductor longus muscles in thigh muscle MRI tests, which is a typical lesion in adductor enthesopathy. The adductor longus muscles in the dystrophinopathy patients may be easy to be impaired due to traction injury during sports.

Clinical characteristics and risk factors of postoperative pneumonia after hip fracture surgery: a prospective cohort study

In this study, we attempt to determine the clinical characteristic and risk factors of postoperative pneumonia (POP) after hip fracture surgery in a well-defined hip fracture cohort. We find that intrinsic factors as well as major clinical interventions were all important risk factors of POP.

INTRODUCTION

Postoperative pneumonia (POP) is one of the major complications following hip fractures surgery. However, the risk factors of POP are not well studied in hip fracture cohorts. We attempt to determine the clinical characteristic and risk factors of POP after hip fracture surgery in a well-defined hip fracture cohort.

METHODS

Datasets from a prospective hip fracture cohort study with a 2-year follow-up period, from 2000 to 2011, were reanalyzed for characteristics of POP. Multivariate Cox proportional regression was used to evaluate the association between the incidence of POP and all-cause mortality. Multivariate logistic regression was used to screen for potential risk factors of POP by analyzing demographic factors, comorbidities, major clinical interventions, and hematological parameters.

RESULTS

In 1429 patients who underwent hip surgery, the incidence of POP was 4.9 % (n = 70). All-cause mortality of patients with POP was significantly higher than that of patients without POP at 30 days (hazard ratio (HR) 3.05, 95 % confidence intervals (CI) 1.88-4.94), 1 year (HR 1.87, 95 % CI 1.41-2.48), and 2 years (HR 1.57, 95 % CI 1.23-1.99) postoperatively. Multivariate logistic regression showed that intrinsic factors (advanced age, anemia, diabetes, prior stroke, number of comorbidities, ASA score ≥III, and some laboratory biomarkers) as well as major clinical interventions were all significant risk factors for POP.

CONCLUSION

Intrinsic factors and major clinical interventions were all important risk factors of POP in patients after hip fracture surgery. Targeted preventive measures to mitigate the above risk factors may help in reducing the incidence of POP.

Association between the extent of sigmoid sinus dehiscence and an occurrence of pulsatile tinnitus: a retrospective imaging study

AIM

To assess the extent of sigmoid sinus dehiscence (SSD) on high-resolution computed tomography venography (HRCTV) or high-resolution computed tomography (HRCT) images in pulsatile tinnitus (PT) and non-PT groups to determine whether there is an association between the extent of SSD and occurrence of PT.

MATERIALS AND METHODS

Twenty-eight SSD patients with ipsilateral PT and 28 age- and gender-matched SSD patients without PT who underwent HRCTV or HRCT were enrolled in this study and categorised into two groups: "PT group" and "non-PT group". The extent of SSD in each group was calculated and compared.

RESULTS

The largest transverse diameter and largest vertical diameter of SSD in the PT group were 6.21±1.7 and 6.15±2.19 mm, respectively. The largest transverse diameter and largest vertical diameter of SSD in the non-PT group were 3.06±1.38 and 2.51±1.03 mm, respectively. The extent of SSD was statistically different between the two groups (p<0.001; p<0.001).

CONCLUSIONS

As a cause of PT, SSD can also occur in individuals without PT symptoms. Preliminary findings suggest that there may be a potential correlation between the extent of SSD and an occurrence of PT.

Combination of red cell distribution width and American Society of Anesthesiologists score for hip fracture mortality prediction

The prognostic value of red cell distribution width (RDW) and a combination of RDW and the American Society of Anesthesiologists (ASA) score for long-term hip fracture mortality remains unknown. Our data showed that both RDW and ASA were independent risk predictors. A combination of these two parameters may provide a more powerful strategy for the prediction of hip fracture mortality.

INTRODUCTION

Red cell distribution width (RDW) has recently been suggested as an independent predictor of prognosis in a variety of disorders. The American Society of Anesthesiologists (ASA) system has been widely used to stratify patients for outcome evaluations. However, the prognostic value of RDW and a combination of RDW and the ASA score for long-term hip fracture mortality has yet to be studied.

METHODS

This prospective cohort study included 1402 subjects from 2000 to 2011 with a follow-up study over a 2 year period. Cox proportional hazards models with a bootstrap validation were used to evaluate associations of RDW, ASA, and a combination of both with long-term mortality. The global fit and the area under the receiver operating characteristic (ROC) curve (AUC) for model discrimination were further analyzed.

RESULTS

Both RDW and ASA exhibited as independent risk predictors of 2-year mortality. The population with elevation of either RDW or ASA increased the risk of mortality (bootstrap validated hazard ratio (HR) 1.971 95 % confidence interval (CI) [1.336-3.005] p < 0.01) while those with an increase in both assessments (bootstrap validated HR 2.667 95 % CI [1.526-4.515] p < 0.01) were at the highest risk for mortality. The addition of the combination of ASA and RDW improved the discrimination power of risk prediction models (AUC increased from 0.700 to 0.723, p < 0.05).

CONCLUSION

Both RDW and ASA exhibited as independent risk predictors of 2-year hip fracture mortality. The combination of these two readily available parameters may provide a more powerful and effective strategy for the assessment of all-cause mortality in hip fracture patients.

A prospective evaluation of minimal residual disease as risk stratification for CCLG-ALL-2008 treatment protocol in pediatric B precursor acute lymphoblastic leukemia

OBJECTIVE

The aim of this prospective study was to evaluate the cut-off value of minimal residual disease (MRD) in predicting the efficacy of CCLG-ALL-2008 or CCLG-2008 treatment protocol on pediatric B-precursor ALL (BP-ALL).

PATIENTS AND METHODS

Three hundred and seventy-nine Chinese pediatric BP-ALL were enrolled in this study between Dec 2008 and Sep 2013 in two stratified cohorts. One hundred and fifty-three patients enrolled between Dec 2008 and Oct 2010 as the first cohort, and 196 patients enrolled from Nov 2010 to Sep 2013 as the second cohort. Clinical and biological characteristics and 5 years EFS, RFS, and OS were analyzed.

RESULTS

Patients with E2A-PBX1 showed a favorable treatment response with a lower minimal residual disease (MRD) level (< 10-4) at the time point 1 (TP1, p = 0.039) and the highest proportion of the 5-year EFS, RFS, and OS. A high level of MRD was associated with high WBC counts, increased age, BCR-ABL1 fusion gene, MLL rearrangements and adverse karyotypes. In comparison with the first cohort, the second cohort with the MRD assay incorporated prospectively, the standard risk (SR) and the intermediate risk (IR) patients showed a better RFS, EFS, and OS while the high-risk (HR) patients displayed worse RFS, EFS, and OS than those of the first cohort, respectively. Patients with MRD level at either 10-4 or 10-3 showed a similar OS at TP1 or TP2, and patients with MRD level above 10-2 had the worst OS.

CONCLUSIONS

This study indicated that the levels of MRD to be an adequate guide in risk-adapted treatment under the CCLG-ALL-2008 protocol and can be adapted to the future development of advanced clinical protocols.

HLA-B allele dropout in PCR sequence-specific oligonucleotide probe typing due to intronic polymorphism in the novel B*58:01:01:02 allele

Currently, Luminex technology based on the PCR sequence-specific oligonucleotide (SSO) probe method has been widely used for HLA genotyping in the immunogenetics laboratories. Here, we reported a case with HLA-B allele dropout by Luminex technology. The initial HLA-B result of the Luminex method with a commercial agent kit was inconclusive, and then, the result of PCR-SBT technology indicated the dropout as a HLA-B*58 allele. Subsequently, the full-length sequence of HLA-B allele was determined by TOPO-TA cloning, and a novel allele B*58:01:01:02 was identified in the individual. Compared with HLA-B*58:01:01:01, the novel allele showed some nucleotides difference at 509 C>T, 521 T>G and CCC insertion in position 503 of intron 2. According to the full-length sequence, the new mutations of intron 2 were contributed to HLA-B locus allele dropout in the sample. Our results indicated multiplatform should be used to improve the HLA typing accuracy when a conclusive HLA genotype cannot be determined.

HLA-A, -B and -DRB1 allele and haplotype frequencies of 8333 Chinese Han from the Zhejiang province, China

The distribution of human leucocyte antigen (HLA) allele and haplotype is varied among different ethnic populations. In this study, HLA-A, -B and -DRB1 allele and haplotype frequencies were determined in 8333 volunteer bone marrow donors of Zhejiang Han population using the polymerase chain reaction sequence-based typing. A total of 52 HLA-A, 96 HLA-B and 61 HLA-DRB1 alleles were found. Of these, the top three frequent alleles in HLA-A, HLA-B and HLA-DRB1 loci, respectively, were A*11:01 (24.53%), A*24:02 (17.35%), A*02:01 (11.58%); B*40:01 (15.67%), B*46:01 (11.87%), B*58:01 (9.05%); DRB1*09:01 (17.54%),DRB1*12:02 (9.64%) and DRB1*08:03 (8.65%). A total of 171 A-B-DRB1 haplotypes with a frequency of >0.1% were presented and the five most common haplotypes were A*33:03-B*58:01- DRB1*03:01, A*02:07-B*46:01-DRB1*09:01, A*30:01-B*13:02-DRB1*07:01, A*33:03-B*58:01-RB1*13:02 and A*11:01-B*15:02-DRB1*12:02. The information will be useful for selecting unrelated bone marrow donors and for anthropology studies and pharmacogenomics analysis.

Protective effects of bifidobacteria on intestines in newborn rats with necrotizing enterocolitis and its regulation on TLR2 and TLR4

We established a necrotizing enterocolitis (NEC) rat model and explored the role of bifidobacteria in the intestines of the rats and its regulation on intestinal Toll-like receptors (TLRs). Seventy-five newborn Sprague-Dawley rats were randomly divided into 5 groups (15 rats/group): group A, artificial feeding group (formula-fed); group B, NEC model (LPS + formula-fed); group C, bifidobacterium (LPS + formula-fed + bifidobacterium microcapsules, intragastric administration); group D, artificial feeding + bifidobacterium (formula-fed + bifidobacterium microcapsules gavage); group E, rat breast-feeding group (rat breast-feeding). After 3 days of feeding, rats were placed in incubators, fasted for 12 h, and killed by decapitation. The ileocecal proximal segment ileum was fixed and sliced; pathological examination was conducted, and TLR2, TLR4, and nuclear factor-kB p65 protein expression in the intestinal tissue was detected by immunohistochemistry. There was a statistically significant difference in pathological scores between groups C and B (H = 21.789, P = 0.000), and the former was lower than the latter. TLR2, TLR4, and nuclear factor-kB p65 expression in intestinal tissue was determined in groups A-E. There were statistically significant differences between groups C and B (P = 0.001; P = 0.000; P = 0.000). Bifidobacteria had a protective effect on the intestines of newborn rats with NEC, which showed reduced NEC and intestinal damage severity. This observation may be related to the reduced levels of TLR2, TLR4, and nuclear factor-kB P65 observed during the inflammatory response.

Superior semicircular canal dehiscence in relation to the superior petrosal sinus: a potential cause of pulsatile tinnitus

AIM

To examine the association between superior semicircular canal dehiscence (SSCD) and pulsatile tinnitus (PT).

MATERIALS AND METHODS

Two SSCD groups included 408 unilateral persistent PT patients, and 511 controls undergoing head and neck dual-phase contrast-enhanced computed tomography (DP-CECT) for reasons other than PT. The prevalence of type I (no the superior petrosal sinus running through the dehiscence) and type II (superior semicircular canal dehiscence in relation to the superior petrosal sinus) SSCD was analysed using chi-square test.

RESULTS

SSCD was identified in 5.1% (21/408) of PT ears, significantly different from 2% (8/408) of non-PT ears and 0.7% (7/1022) of controls. There was no significant difference in SSCD prevalence between non-PT ears in the PT group and controls. In the PT group, 15/21 ears were type II SSCD; 6/21 ears were type I. Fifteen combined non-PT and control ears with SSCD included two type II and 13 type I SSCD. The prevalence of type II SSCD in PT ears was significantly higher than that of non-PT ears in both groups, and the prevalence of type I SSCD in PT ears was similar to that of non-PT ears in both groups.

CONCLUSION

Compared with type I SSCD, there may be a causal relationship between type II SSCD and PT.

Magnetic mediation effect of a C impurity in a Mn-doped Zn₁₂O₁₂ nanocluster: a case of multiple exchange interactions

The stability and exchange interaction mechanism of a doped Zn12O12 cluster with Mn and C atoms were investigated by first-principles calculations. For the Mn-doped Zn12O12 cluster, it is identified that a superexchange interaction deriving the hybridization between the Mn 3d(2/x)-2/y and O 2p(xy) orbitals dominates the Mn(↑)-Mn(↓) antiferromagnetic coupling, although a direct exchange interaction deriving the Mn-Mn bonding is also found. In order to turn the Mn spin state in the Mn-doped Zn12O12 cluster, C doping is undertaken to change the magnetic interactions of these impurities. It is proved that the C incorporation into the Mn-doped Zn12O12 cluster destroys the short-ranged antiferromagnetic coupling, where multiple exchange interactions take over, including the direct exchange interaction and the kinetic p-d exchange interaction partially due to the geometric distortion and surface effect with dangling bonds (sp(2)-like hybrids). It is concluded that the kinetic p-d exchange interaction plays a dominant role in Mn/C-doped Zn12O12 clusters.

A novel 3D-printed device for localization and extraction of trabeculae from human femoral heads: a comparison with traditional visual extraction

In this study, we propose a novel method for accurate trabeculae extraction from human femoral heads using 3D-printing techniques and compare spatial deviation errors between this novel method and the conventional method. We found that spatial deviation errors, which indicate inaccuracy and unreliability, were significantly higher with the conventional method.

INTRODUCTION

Assessment of structural and mechanical properties of local bone is important in the study of pathological changes associated with musculoskeletal degenerative diseases. However, the widely used visual extraction method (VIS) for trabecular columns showed large deviations from veridicality, referred to as spatial deviation errors (SDE). Here, we propose a novel method for accurately locating and trephining trabeculae using a 3D-printed (3DP) positioning device and also evaluate the SDE of the VIS.

METHODS

Twenty femoral heads were obtained from osteoporotic patients, and the trabecular columns were extracted from the principal compressive trabeculae by VIS (n = 10) or the 3DP (n = 10) method. Morphological, structural, and mechanical properties were compared between both groups along with the recorded errors in spatial deviation.

RESULTS

Compared with the 3DP group, the average angle of central axis deflection in the VIS group was significantly greater; SDE in the VIS group was 26.1, 8.8, 4.1, 9.8, 7.2, 8.1, and 10.1 % greater for bone mineral density, bone volume/tissue volume ratio, trabecular thickness, trabecular number, Young's modulus, yield strength, and ultimate strength.

CONCLUSION

In this study, a high degree of SDE was demonstrated in the VIS, which indicates that the conventional technique is unreliable. Additionally, accurate sample fabrication and credible quantitative analysis of local trabeculae among individuals can be achieved with the aid of computed tomography and the 3DP device, thus providing a more objective method for researching musculoskeletal degenerative diseases and possibly a better clinical understanding of these disorders.