Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Adipose-derived mesenchymal stem cells cultured in serum-free medium attenuate acute contrast-induced nephropathy by exerting anti-apoptotic effects

BACKGROUND

Contrast-induced nephropathy (CIN) is a major clinical problem associated with acute kidney injury during hospitalization. However, effective treatments for CIN are currently lacking. Mesenchymal stem cells (MSCs) have protective effects against kidney injury by suppressing inflammation and fibrosis. We previously showed that MSCs cultured in serum-free medium (SF-MSCs) enhance their anti-inflammatory and anti-fibrotic effects. However, whether SF-MSCs potentiate their anti-apoptotic effects is unknown. Here, we investigated the effects of SF-MSCs on a CIN mouse model.

METHODS

To create CIN model mice, we removed right kidney at first. One week later, the left renal artery was clamped for 30 min to cause ischemia-reperfusion injury, and mice were injected with iohexol. Then the kidney received 10 Gy of irradiation, and MSCs or SF-MSCs were injected immediately. At 24 h post-injection, mice were sacrificed, and their blood and kidneys were collected to evaluate renal function, DNA damage, and apoptosis. In addition, apoptosis was induced in HEK-293 cells by irradiation and cells were treated with conditioned medium from MSCs or SF-MSCs.

RESULTS

Treatment of CIN model mice with SF-MSCs markedly improved renal function compared with MSCs treatment. Cleaved caspase-3 levels and TUNEL-positive cell numbers were strongly suppressed in CIN model mice treated with SF-MSCs compared with the findings in those treated with MSCs. γH2AX levels, a chromosome damage marker, were reduced by MSCs and further reduced by SF-MSCs. In addition, cleaved caspase-3 in irradiated HEK-293 cells was more strongly suppressed by conditioned medium from SF-MSCs than by that from MSCs. Secretion of epidermal growth factor (EGF) was enhanced by culturing MSCs in serum-free medium. Knockdown of EGF by siRNA attenuated the inhibitory effects of SF-MSCs on CIN-induced renal dysfunction and tubular apoptosis.

CONCLUSIONS

These findings strongly suggest that SF-MSCs improve CIN in model mice by exerting anti-apoptotic effects in a paracrine manner. Thus, SF-MSCs represent a potential novel therapy for CIN.

Peripheral T cell profiling reveals downregulated exhaustion marker and increased diversity in lymphedema post-lymphatic venous anastomosis

Lymphedema is a progressive condition accompanying cellulitis and angiosarcoma, suggesting its association with immune dysfunction. Lymphatic venous anastomosis (LVA) can provide relief from cellulitis and angiosarcoma. However, the immune status of peripheral T cells during lymphedema and post-LVA remains poorly understood. Using peripheral blood T cells from lymphedema, post-LVA, and healthy controls (HCs), we compared the profile of T cell subsets and T cell receptor (TCR) diversity. PD-1⁺ Tim-3 ⁺ expression was downregulated in post-LVA compared with lymphedema. IFN-γ levels in CD4⁺PD-1⁺ T cells and IL-17A levels in CD4⁺ T cells were downregulated in post-LVA compared with lymphedema. TCR diversity was decreased in lymphedema compared with HCs; such TCR skewing was drastically improved in post-LVA. T cells in lymphedema were associated with exhaustion, inflammation, and diminished diversity, which were relieved post-LVA. The results provide insights into the peripheral T cell population in lymphedema and highlight the immune modulatory importance of LVA.

Endothelial Function Is Preserved in Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy

Heart failure (HF) is associated with endothelial dysfunction. Vascular function per se plays an important role in cardiac function, whether it is a cause or consequence. However, there is no information on vascular function in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM). The purpose of this study was to evaluate vascular function in patients with ATTRwt-CM. We measured flow-mediated vasodilation (FMD) as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function and brachial artery intima-media thickness (bIMT) and brachial-ankle pulse wave velocity (baPWV) as indices of arterial stiffness in 22 patients with ATTRwt-CM and in 22 one-by-one matched control patients using vascular function confounding factors. FMD was significantly greater in patients with ATTRwt-CM than in the controls (5.4 ± 3.4% versus 3.5 ± 2.4%, p = 0.038) and the N-terminal pro-brain natriuretic peptide (NT-proBNP) level was significantly greater in patients with ATTRwt-CM than in the controls (2202 ± 1478 versus 470 ± 677 pg/mL, p < 0.001). There were no significant differences in NID, bIMT or baPWV between the two groups. There was a significant relationship between NT-proBNP and FMD in patients with ATTRwt-CM (r = 0.485, p = 0.022). NT-proBNP showed no significant relationships with NID, bIMT or baPWV. Conclusions: Endothelial function was preserved in patients with ATTRwt-CM. Patients with ATTRwt-CM may have compensatory effects with respect to endothelial function through elevation of BNP.

Effect of exposure to radiation caused by an atomic bomb on endothelial function in atomic bomb survivors

Background

The purpose of this study was to evaluate the effects of exposure to radiation caused by an atomic bomb in atomic bomb survivors on vascular function and vascular structure and to evaluate the relationships of radiation dose from the atomic bomb with vascular function and vascular structure in atomic bomb survivors.

Methods

Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) as indices of vascular function, brachial-ankle pulse wave velocity (baPWV) as an index of vascular function and vascular structure, and brachial artery intima-media thickness (IMT) as an index of vascular structure were measured in 131 atomic bomb survivors and 1,153 control subjects who were not exposed to the atomic bomb. Ten of the 131 atomic bomb survivors with estimated radiation dose in a cohort study of Atomic Bomb Survivors in Hiroshima were enrolled in the study to evaluate the relationships of radiation dose from the atomic bomb with vascular function and vascular structure.

Results

There was no significant difference in FMD, NID, baPWV, or brachial artery IMT between control subjects and atomic bomb survivors. After adjustment of confounding factors, there was still no significant difference in FMD, NID, baPWV, or brachial artery IMT between control subjects and atomic bomb survivors. Radiation dose from the atomic bomb was negatively correlated with FMD (ρ = -0.73, P = 0.02), whereas radiation dose was not correlated with NID, baPWV or brachial artery IMT.

Conclusion

There were no significant differences in vascular function and vascular structure between control subjects and atomic bomb survivors. Radiation dose from the atomic bomb might be negatively correlated with endothelial function.

Correlation between Lymphatic Surgery Outcome and Lymphatic Image-Staging or Clinical Severity in Patients with Lymphedema

Lymphoscintigraphy and indocyanine green (ICG) lymphography reveal the severity of extremity lymphedema. Lower extremity lymphedema (LEL) index and NECST classification are related to the clinical severity of lymphedema. We aimed to investigate the correlation between lymphatic surgery, lymphatic imaging, and clinical severity in patients with lymphedema. Thirty-five patients with lower-extremity lymphedema who underwent lymphatic venous anastomosis (LVA) were evaluated. Ten of the thirty-five patients underwent multi-surgery (additional vascularized lymphatic transfer and/or liposuction). We investigated the correlation between the LEL index, NECST classification, lymphoscintigraphy staging, ICG lymphography staging, and rate of improvement (RI: [preoperative LEL index − postoperative LEL index]/[preoperative LEL index] × 100). The LEL index in 35 patients after LVA and all procedures decreased significantly compared to that of preoperative (272.4 vs. 256.2 vs. 243.5, p < 0.05). RI after LVA and all procedures showed positive correlations with the preoperative LEL index; however, there was no correlation with any other lymphatic image or clinical severity. LVA can reduce lymphedema circumference at any stage. Additional surgery improved the circumference. Hence, LVA as the first line of treatment, and vascularized lymphatic transfer and liposuction as additional procedures, should be considered as the standard treatment for lymphedema.

Absence of the Anterior Communicating Artery on Selective MRA is Associated with New Ischemic Lesions on MRI after Carotid Revascularization

BACKGROUND AND PURPOSE

ICA-selective MRA using a pencil beam presaturation pulse can accurately visualize anterior communicating artery flow. We evaluated the impact of anterior communicating artery flow on the perioperative hemodynamic status and new ischemic lesions after carotid revascularization.

MATERIALS AND METHODS

Eighty-three patients with carotid artery stenosis were included. We assessed anterior communicating artery flow using ICA-selective MRA. The preoperative hemodynamic status was measured using SPECT. We also measured the change in regional cerebral oxygen saturation after temporary ICA occlusion. New ischemic lesions were evaluated by DWI on the day after treatment.

RESULTS

Anterior communicating artery flow was detected in 61 patients, but it was not detected in 22 patients. Preoperative cerebrovascular reactivity was significantly higher in patients with (versus without) anterior communicating artery flow with a mean peak systolic velocity of ≥200 cm/s (39.6% [SD, 23.8%] versus 25.2% [SD, 16.4%]; P = .030). The decrease in mean regional cerebral oxygen saturation was significantly greater in patients without (versus with) anterior communicating artery flow (8.5% [SD, 5.6%] versus 3.7% [SD, 3.8%]; P = .002). New ischemic lesions after the procedure were observed in 23 patients. The multivariate logistic regression analysis revealed that anterior communicating artery flow (OR, 0.07; 95% CI, 0.012-0.45; P = .005) was associated with new ischemic lesions.

CONCLUSIONS

The absence of anterior communicating artery flow influenced the perioperative hemodynamic status in patients with carotid stenosis and was associated with an increased incidence of new ischemic lesions after carotid revascularization.

Bone-destructive osseous arteriovenous fistula at the jugular bulb mimicking a glomus jugular tumor

BACKGROUND

Some reports have described intraosseous arteriovenous fistulas showing osteolytic changes, but an osseous arteriovenous fistula (AVF) at the jugular bulb showing extensive bone destruction is a very rare disease.

CASE DESCRIPTION

A 60-year-old man presented with pulsatile tinnitus and right facial nerve palsy. Radiological imaging showed a large homogenously enhanced osteolytic lesion at the right jugular foramen. A cerebral angiogram showed a high-flow vascular lesion of the jugular bulb associated with retrograde sinus reflux, resulting in venous congestion of the deep venous system. These findings led us to misdiagnose this lesion as a glomus jugular tumor. However, combined arterial and venous angiography after transarterial embolization revealed the precise angioarchitecture, and we finally diagnosed this lesion as a high-flow osseous AVF at the jugular bulb. We performed transvenous embolization using a triple catheter technique. The lesion was successfully obliterated, and the 6-months angiogram showed no recurrence.

CONCLUSION

A rare case of high flow osseous AVF at the jugular bulb associated with osteolytic changes in the surrounding bony structure is reported. Although many hypervascular lesions at the jugular bulb are glomus tumors, bone destructive osseous AVF at the jugular bulb should be considered.

DWI for Monitoring the Acute Response of Malignant Gliomas to Photodynamic Therapy

BACKGROUND AND PURPOSE

Photodynamic therapy is a novel treatment that provides effective local control, but little is known about photodynamic therapy-induced changes on MR imaging. The aim of this study was to assess the utility of DWI and ADC in monitoring the response of malignant gliomas to photodynamic therapy.

MATERIALS AND METHODS

Time-dependent changes in DWI and ADC values after photodynamic therapy were analyzed in a group that received photodynamic therapy in comparison with a group that did not.

RESULTS

Twenty-four patients were enrolled (photodynamic therapy, n = 14; non-photodynamic therapy, n = 10). In all patients who received photodynamic therapy, linear high signals on DWI in the irradiated area were detected adjacent to the resection cavity and were 5-7 mm in depth from 1 day posttreatment and disappeared in about 30 days without any neurologic deterioration. The non-photodynamic therapy group did not show this change. The photodynamic therapy group had significantly lower ADC values from 1 day posttreatment (P < .001), which increased steadily and disappeared by 30 days. There was no decline or time-dependent change in ADC values in the non-photodynamic therapy group.

CONCLUSIONS

The acute response of malignant gliomas to photodynamic therapy was detected as linear high signals on DWI and as a decrease in ADC values. These findings were asymptomatic and transient. Although the photodynamic therapy-induced acute response on MR imaging disappeared after approximately 30 days, it may be helpful for confirming the photodynamic therapy-irradiated area.

Localization of Parotid Gland Tumors in Relation to the Intraparotid Facial Nerve on 3D Double-Echo Steady-State with Water Excitation Sequence

BACKGROUND AND PURPOSE

Reliable preoperative facial nerve mapping may help avoid or minimize facial nerve injury during parotid tumor resection. The purpose of this study was to investigate the diagnostic performance of the 3D double-echo steady-state with water excitation sequence in localizing parotid gland tumors through direct visualization of the intraparotid facial nerve in comparison with indirect methods of estimating the facial nerve location.

MATERIALS AND METHODS

We retrospectively reviewed 91 parotid gland tumors in 90 patients who underwent surgical resection and preoperative MR imaging, including the 3D double-echo steady-state with water excitation sequence. The tumor locations were categorized as deep or superficial on the basis of direct and 3 indirect methods: the facial nerve line, retromandibular vein, and Utrecht line. Surgical localization was considered the criterion standard. The diagnostic performance for localizing deep lobe lesions using direct and indirect methods was calculated and compared using the McNemar test.

RESULTS

Surgical localization confirmed 75 superficial lesions and 16 deep lesions. The interobserver variability of the 3D double-echo steady-state with water excitation sequence was excellent (κ = 0.870). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for localizing deep lobe lesions using the 3D double-echo steady-state with water excitation method were 97.8%, 87.5%, 100%, 100%, and 97.4%, respectively. These findings were significantly higher than the facial nerve line in sensitivity, the retromandibular vein in sensitivity, and the Utrecht line in accuracy and specificity (P < .05). Overall, the direct method was the most accurate, sensitive, and specific in localizing parotid gland tumors.

CONCLUSIONS

We can achieve higher diagnostic performance in localizing parotid gland tumors by directly visualizing the intraparotid facial nerve using the 3D double-echo steady-state with water excitation sequence compared with indirect methods.

Etiology-Specific Mineralization Patterns in Patients with Labyrinthitis Ossificans

BACKGROUND AND PURPOSE

Our aim was to identify whether specific patterns of ossification in labyrinthitis ossificans are associated with the known risk factors. Labyrinthitis ossificans has been described as sequela of prior temporal bone trauma, prior infection, and other disorders including sickle cell disease. Specific patterns of mineralization in the membranous labyrinth associated with these risk factors has not been previously described.

MATERIALS AND METHODS

This was a retrospective study evaluating temporal bone CT scans at our institution from November 2005 to May 2018 in patients with labyrinthitis ossificans. Membranous labyrinthine structures evaluated for ossification included the following: basal, middle, and apical cochlear turns; lateral, posterior, and superior semicircular canals; and the vestibule for both ears in all patients. These structures were assigned a severity score, 0-4, based on degree of mineralization. Clinical records were reviewed for potential labyrinthitis ossificans risk factors. Basic descriptive statistics and a mixed model were used to correlate the degree and patterns of ossification with clinical history.

RESULTS

Forty-four patients (58 ears) with labyrinthitis ossificans were identified and evaluated. The most common risk factors were chronic otomastoiditis (n = 18), temporal bone surgery (n = 9), temporal bone trauma (n = 6), sickle cell disease (n = 5), and meningitis (n = 4). For all etiologies, the semicircular canals were most severely affected, and the vestibule was the least. In patients with prior temporal bone surgery, significantly greater mineralization was seen in the basal turn of the cochlea (P = .027), the vestibule (P = .001), and semicircular canals (P < .001-.008). No significant pattern was identified in patients with meningitis, sickle cell disease, or trauma.

CONCLUSIONS

Significant patterns of mineralization in labyrinthitis ossificans were observed in patients with prior temporal bone surgery. For all etiologies, the semicircular canals were most severely affected. No significant mineralization pattern was observed in patients with chronic otomastoiditis, meningitis, sickle cell disease, or prior temporal bone trauma.

Low body mass index is a risk factor for hyperkalaemia associated with angiotensin converting enzyme inhibitors and angiotensin II receptor blockers treatments

WHAT IS KNOWN AND OBJECTIVE

Angiotensin converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) represent the cornerstones of hypertension and congestive heart failure treatment. Risk factors for hyperkalaemia associated with ACEI and ARB are chronic kidney disease and concomitant medications which increase serum potassium level. Body mass index (BMI) also affects pharmacokinetics of ACEI and ARB and potassium disposition. We evaluated the relationship between BMI and hyperkalaemia associated with ACEI and ARB treatments.

METHODS

Study design is a retrospective case-control analysis. Patients who had been prescribed ACEI or ARB between June 2015 and June 2017 at Tokyo Women's Medical University, Medical Center East, were included. Patient clinical background was collected from medical records. Hyperkalaemia was defined as serum potassium above 5.5 meq/L. The concomitant use of ACEI and ARB, aldosterone antagonists, direct renin inhibitor, sulfamethoxazole-trimethoprim and non-steroidal anti-inflammatory drugs (NSAIDs) was regarded as hyperkalaemia-inducing medications. The relationship between BMI and hyperkalaemia associated with ACEI and ARB treatments was assessed using multivariable logistic regression analysis.

RESULTS AND DISCUSSION

The study included 2987 patients aged 70.1 ± 12.9 years, 61.0% were men, and BMI was 23.8 ± 4.4 kg/m² . The incidence of hyperkalaemia was 7.8%. Multivariable logistic regression analysis revealed that age >65 years, low BMI, diabetes, history of treatment for hyperkalaemia, serum sodium <135 meq/L, eGFR <30 mL/min/1.73m² and the concomitant use of hyperkalaemia-inducing medications were independent risk factors for hyperkalaemia associated with ACEI and ARB.

WHAT IS NEW AND CONCLUSION

This study demonstrated that BMI provides useful information for the identification of potential risk for hyperkalaemia associated with ACEI and ARB treatments.

High-pressure synthesis of L10 MnAl with near-stoichiometric composition

L10 MnAl, which is a nonequilibrium ferromagnetic phase, is fabricated successfully with various compositions via high-pressure synthesis. The L10 phase is observed at pressures higher than 5 GPa, indicating that the volume effect is crucial for the stabilization of this phase. The employed synthesis route does not require a Mn-rich ε-phase, which has conventionally been used as the precursor compound. This allows for the synthesis of the L10 phase with a near-stoichiometric composition. In addition to variations in the composition in terms of the Mn/Al ratio, the axial ratio (c/a) as well as the ordering parameter (S) are modified systematically, with the maximum c/a and S values corresponding to the stoichiometric composition. With this structural change, the highest coercive force is also observed at the stoichiometric composition.

Different X-linked KDM5C mutations in affected male siblings: is maternal reversion error involved?

Genetic reversion is the phenomenon of spontaneous gene correction by which gene function is partially or completely rescued. However, it is unknown whether this mechanism always correctly repairs mutations, or is prone to error. We investigated a family of three boys with intellectual disability, and among them we identified two different mutations in KDM5C, located at Xp11.22, using whole-exome sequencing. Two affected boys have c.633delG and the other has c.631delC. We also confirmed de novo germline (c.631delC) and low-prevalence somatic (c.633delG) mutations in their mother. The two mutations are present on the same maternal haplotype, suggesting that a postzygotic somatic mutation or a reversion error occurred at an early embryonic stage in the mother, leading to switched KDM5C mutations in the affected siblings. This event is extremely unlikely to arise spontaneously (with an estimated probability of 0.39-7.5 × 10(-28) ), thus a possible reversion error is proposed here to explain this event. This study provides evidence for reversion error as a novel mechanism for the generation of somatic mutations in human diseases.

Bone-Subtracted Spinal CT Angiography Using Nonrigid Registration for Better Visualization of Arterial Feeders in Spinal Arteriovenous Fistulas

BACKGROUND AND PURPOSE

Pretreatment diagnosis for the location of shunts and arterial feeders of spinal arteriovenous fistulas is crucial. This study aimed to evaluate the utility of subtracted CT angiography imaging by using nonrigid registration (R-CTA) in patients with spinal arteriovenous fistulas compared with conventional CTA imaging.

MATERIALS AND METHODS

The records of 15 consecutive subjects (mean age, 65 years; 2 women) who had undergone CTA and digital subtraction angiography for clinically suspected spinal arteriovenous fistula were reviewed. From CTA images obtained at the arterial and late arterial phases, warped images of the late arterial phase were obtained by using nonrigid registration that was adjusted to the arterial phase images. R-CTA images were then obtained by subtracting the warped images from the arterial phase images. The accuracies of using nonrigid registration and conventional spinal CTA and the time required for detecting arterial feeders in spinal arteriovenous fistulas were analyzed for each patient with DSA results as a standard reference. The difference between R-CTA and conventional spinal CTA was assessed by the Welch test and the McNemar χ(2) test.

RESULTS

R-CTA had a higher accuracy compared with conventional spinal CTA (80% versus 47%, P = .025). The time for interpretation was reduced in R-CTA compared with conventional spinal CTA (45.1 versus 97.1 seconds, P = .002).

CONCLUSIONS

Our subtracted CTA imaging by using nonrigid registration detects feeders of spinal arteriovenous fistulas more accurately and quickly than conventional CTA.

MR relaxometry for the facial ageing assessment: the preliminary study of the age dependency in the MR relaxometry parameters within the facial soft tissue

OBJECTIVES

To investigate the location-specific tissue properties and age-related changes of the facial fat and facial muscles using quantitative MRI (qMRI) analysis of longitudinal magnetization (T1) and transverse magnetization (T2) values.

METHODS

38 subjects (20 males and 18 females, 0.5-87 years old) were imaged with a mixed turbo-spin echo sequence at 1.5 T. T1 and T2 measurements were obtained within regions of interest in six facial fat regions including the buccal fat and subcutaneous cheek fat, four eyelid fat regions (lateral upper, medial upper, lateral lower and medial lower) and five facial muscles including the orbicularis oculi, orbicularis oris, buccinator, zygomaticus major and masseter muscles bilaterally.

RESULTS

Within the zygomaticus major muscle, age-associated T1 decreases in females and T1 increases in males were observed in later life with an increase in T2 values with age. The orbicularis oculi muscles showed lower T1 and higher T2 values compared to the masseter, orbicularis oris and buccinator muscles, which demonstrated small age-related changes. The dramatic age-related changes were also observed in the eyelid fat regions, particularly within the lower eyelid fat; negative correlations with age in T1 values (p<0.0001 for age) and prominent positive correlation in T2 values in male subjects (p<0.0001 for male×age). Age-related changes were not observed in T2 values within the subcutaneous cheek fat.

CONCLUSIONS

This study demonstrates proof of concept using T1 and T2 values to assess age-related changes of the facial soft tissues, demonstrating tissue-specific qMRI measurements and non-uniform ageing patterns within different regions of facial soft tissues.

Visualization of the Peripheral Branches of the Mandibular Division of the Trigeminal Nerve on 3D Double-Echo Steady-State with Water Excitation Sequence

BACKGROUND AND PURPOSE

Although visualization of the extracranial branches of the cranial nerves has improved with advances in MR imaging, only limited studies have assessed the detection of extracranial branches of the mandibular nerve (V3). We investigated the detectability of the branches of V3 on a 3D double-echo steady-state with water excitation sequence.

MATERIALS AND METHODS

We retrospectively evaluated the detectability of the 6 branches of the V3, the masseteric, buccal, auriculotemporal, lingual, inferior alveolar, and mylohyoid nerves, by using a 5-point scale (4, excellent; 3, good; 2, fair; 1, poor; and 0, none) in 86 consecutive patients who underwent MR imaging with the 3D double-echo steady-state with water excitation sequence. Weighted κ analysis was used to calculate interobserver variability among the 3 readers.

RESULTS

The detection of the lingual and inferior alveolar nerves was the most successful, with excellent average scores of 3.80 and 3.99, respectively. The detection of the masseteric, the buccal, and the auriculotemporal nerves was good, with average scores of 3.31, 2.67, and 3.11, respectively. The mylohyoid nerve was difficult to detect with poor average scores of 0.62. All nerves had excellent interobserver variability across the 3 readers (average weighted κ value, 0.95-1.00).

CONCLUSIONS

The 3D double-echo steady-state with water excitation sequence demonstrated excellent visualization of the extracranial branches of V3 in most patients. The 3D double-echo steady-state with water excitation sequence has the potential for diagnosing V3 pathologies and preoperatively identifying peripheral cranial nerves to prevent surgical complications.

Using Texture Analysis to Determine Human Papillomavirus Status of Oropharyngeal Squamous Cell Carcinomas on CT

BACKGROUND AND PURPOSE

Human papillomavirus-associated oropharyngeal squamous cell carcinoma is increasing in prevalence and typically occurs in younger patients than human papillomavirus-negative squamous cell carcinoma. While imaging features of human papillomavirus-positive versus human papillomavirus-negative squamous cell carcinoma nodal metastases have been described, characteristics distinguishing human papillomavirus-positive from human papillomavirus-negative primary squamous cell carcinomas have not been well established. The purpose of this project was to evaluate the use of texture features to distinguish human papillomavirus-positive and human papillomavirus-negative primary oropharyngeal squamous cell carcinoma.

MATERIALS AND METHODS

Following institutional review board approval, 40 patients with primary oropharyngeal squamous cell carcinoma and known human papillomavirus status who underwent contrast-enhanced CT between December 2009 and October 2013 were included in this study. Segmentation of the primary lesion was manually performed with a semiautomated graphical-user interface. Following segmentation, an in-house-developed texture analysis program extracted 42 texture features from each segmented volume. A t test was used to evaluate differences in texture parameters between human papillomavirus-positive and human papillomavirus-negative squamous cell carcinomas.

RESULTS

Of the 40 included patients, 29 had human papillomavirus-positive oropharyngeal squamous cell carcinoma and 11 had human papillomavirus-negative oropharyngeal squamous cell carcinoma. Significant differences were seen in the histogram parameters median (P = .006) and entropy (P = .016) and squamous cell carcinoma entropy (P = .043).

CONCLUSIONS

There are statistically significant differences in some texture features between human papillomavirus-positive and human papillomavirus-negative oropharyngeal tumors. Texture analysis may be considered an adjunct to the evaluation of human papillomavirus status and characterization of squamous cell carcinoma.

A quantitative and humane tail bleeding assay for efficacy evaluation of antihaemophilic factors in haemophilia A mice

The tail bleeding model using haemophilic mice has been used as one of the standard assays for efficacy evaluation of novel antihaemophilic therapies at the preclinical level. A number of different configurations and endpoints have been proposed in the literature for this model, hindering interlaboratory comparisons. A particular configuration, known as the tail bleeding survival assay (TBS), adopted by several groups, involves measuring the ability of conscious haemophilic mice to survive exsanguination following tail transection. Major limitations to this configuration include ethical constraints and impaired quantitative determinations. The aim of this study was to standardize and validate a quantitative haemostatic assay for evaluation of antihaemophilic therapies employing an alternative to TBS, which involves a more humane endpoint associated with stable clot formation. Haemophilic mice were treated with vehicle or different doses of two antihaemophilic reference products licensed in Brazil. The haemostatic response was evaluated by our quantitative tail bleeding haemostatic assay (qTBA) over a period of 120 min and then quantified by dose-response modelling. We demonstrate that our qTBA method allows a direct relationship between the number of animals which achieved full haemostatic response and the dosage of both antihaemophilic factors evaluated over 120 min. In addition, the method sensitivity is suitable to demonstrate the conversion from a severe to a moderate haemophilia phenotype. Our proposed qTBA is easy to implement and constitutes an alternative and more ethical endpoint, which could be effectively used as a surrogate to the commonly employed survival endpoint, allowing quantitative haemostatic response evaluation associated with stable clot formation.

Effect of articulatory rehabilitation after oral cancer surgery on higher brain activation

The present study aimed to verify the importance of postoperative articulatory rehabilitation in patients with oral cancer and to clarify the neurological changes underlying articulatory functional recovery. A longitudinal assessment of oral function and accompanying brain activity was performed using non-invasive functional magnetic resonance imaging (fMRI). We assessed 13 patients with cancers of the tongue and oral floor before and after ablative surgery. Articulatory function was assessed preoperatively and postoperatively using a conversation intelligibility test and the Assessment of Motor Speech for Dysarthria test. Patients also performed a verbal task during fMRI scans. The assessments were then repeated after the patients had undergone 4-6 months of articulatory rehabilitation therapy. Compared to pretreatment levels, articulatory rehabilitation resulted in a significant increase in activation in the supplementary motor cortex, thalamus, and cingulate cortex. The present study offers a quantitative assessment of the effects of speech rehabilitation by investigating changes in brain activation sites.

Clinical significance of trochlear calcifications in the orbit

BACKGROUND AND PURPOSE

Trochlear calcification is frequently seen on CT scans that include the orbits, but prior studies linking this finding to diabetes mellitus were based on selected populations by using relatively thick sections. We assessed the relationship between trochlear calcification and diabetes mellitus and other chronic medical conditions in an unrestricted population by using thin-section CT.

MATERIALS AND METHODS

Noncontrast head CT studies performed consecutively on 1000 patients between January and February 2011 were retrospectively reviewed for the presence of trochlear calcifications. Axial 1.25-mm-thick images acquired by 64-detector row CT were reviewed. Medical records were reviewed for chronic medical conditions, including diabetes mellitus, chronic kidney disease, alcoholism, autoimmune conditions, endocrine disorders, serum calcium and alkaline phosphatase levels, and HIV status. Motion-limited studies and patients with limited clinical data were excluded. Statistical analyses were performed by using the Fisher exact test.

RESULTS

Thirty-two patients were excluded from analysis. Of the remaining 968 patients, 128 had trochlear calcification (13%). No significant association was observed between diabetes mellitus and trochlear calcifications in patients of any age (P = .40). There was no significant correlation between trochlear calcifications and chronic kidney disease, alcoholism, endocrine disorders, or HIV infection. Statistically significant associations among trochlear calcification, autoimmune conditions, and elevated alkaline phosphatase levels were observed (P < .0001 and P < .0001, respectively).

CONCLUSIONS

On the basis of a large unrestricted population with thin-section CT imaging of the orbit, no significant association was observed between trochlear calcifications and diabetes mellitus. A statistically significant association was observed between trochlear calcification and autoimmune disease and elevated alkaline phosphatase levels.

Effect of local anesthesia on trigeminal somatosensory-evoked magnetic fields

For objective neurophysiological evaluation of the function of the trigeminal system, magnetoencephalography- based TSEF (trigeminal somatosensory-evoked field) assessment would be valuable in providing spatial and temporal profiles of cortical responses. However, this necessitates knowledge of how TSEF varies with trigeminal nerve dysfunctions. We introduced a conduction block of the trigeminal nerve using local anesthesia (lidocaine) to temporally mimic nerve dysfunctions, and monitored TSEF changes. Following an electrical stimulation of the lower lip, a magnetic response with peak latency of approximately 20 ms was identified in all participants. Dipole for the peak was estimated on the post-central gyrus in the participant's own magnetic resonance image. After normalization to Montreal Neurological Institute (MNI) space and inter-participant data integration, the summary equivalent current dipole localization among participants remained in the post-central gyrus, suggesting validity of the use of MNI space. Partial anesthesia of the lower lip led to a loss of the waveform characteristics of TSEF for electrical stimulation to the trigeminal nerve. We verified that the 20-ms latency cortical response of TSEF components localized at the primary sensory cortex can serve as a robust neurofunctional marker of experimental trigeminal nerve dysfunction.

A preliminary prediction model with MR plaque imaging to estimate risk for new ischemic brain lesions on diffusion-weighted imaging after endarterectomy or stenting in patients with carotid stenosis

BACKGROUND AND PURPOSE

Findings on MR imaging of carotid plaques correlate with histologic findings and may be useful in identifying vulnerable plaques. The objective of this study was to show how MR imaging findings and clinical factors could be used to construct a preliminary model and a nomogram for predicting the risk of new ischemic lesions on DWI following CEA or CAS.

MATERIALS AND METHODS

One hundred four patients with carotid stenosis undergoing treatment (63 CEA, 41 CAS) were prospectively enrolled (mean age, 71.7 ± 7.0 years; 11 women). T1-SIR and T2-SIR of carotid plaque were measured on MR imaging. Associations among carotid MR imaging findings, treatment procedures, degree of stenosis, cardiovascular risk factors, and occurrence of new ischemic lesions on DWI 1 day after treatment were studied by multivariate logistic regression.

RESULTS

One stroke occurred after CAS (2.4%), and none after CEA. New DWI lesions after treatment were observed in 25 patients (24%). Our preliminary prediction model demonstrated that T1-SIR (OR [per 0.5 increase], 3.99; 95% CI, 2.18-7.31; P < .0001) and CAS (OR, 2.06; 95% CI, 1.01-4.24; P = .048 compared with CEA) were positively associated with new DWI lesions on posttreatment DWI scans. T2-SIR (OR [per 0.5 increase], 0.74; 95% CI, 0.55-0.98; P = .037) was negatively associated. The C-index of this model was 0.79 (95% CI, 0.69-0.89), which indicated some utility in predicting the response.

CONCLUSIONS

Our preliminary prediction model and nomogram may provide an individualized risk estimate of new ischemic lesions after CEA or CAS and useful information for decision-making regarding treatment strategy.

Determination of the magnetic ground state in the martensite phase of Ni-Mn-Z (Z = In, Sn and Sb) off-stoichiometric Heusler alloys by nonlinear AC susceptibility

DC and AC magnetic measurements were carried out to clarify the difference in the magnetic ground state depending on the kinds of Z element used in the martensite phase in Ni-Mn-Z (Z = In, Sn and Sb) off-stoichiometric Heusler alloys. Magnetic field cooling effects were observed in the DC thermomagnetization curves in the low temperature regions, and a frequency dependence on AC susceptibility was also observed in both real and imaginary parts of the susceptibility. Negative divergence was clearly observed in nonlinear AC susceptibility only for the Ni(50)Mn(40)Sb(10) alloy, suggesting that the magnetic feature of its ground state is the spin-glass state. The magnetic ground state of the martensite phase in these alloys would relate to the magnetic configuration of the Mn atoms in the ferromagnetic austenite phase.

Clinical application of arterial spin-labeling MR imaging in patients with carotid stenosis: quantitative comparative study with single-photon emission CT

BACKGROUND AND PURPOSE

Arterial spin-labeling is an emerging technique for noninvasive measurement of cerebral perfusion, but concerns remain regarding the reliability of CBF quantification and clinical applications. Recently, an ASL implementation called QUASAR was proposed, and it was shown to have good reproducibility of CBF assessment in healthy volunteers. This study aimed to determine the utility of QUASAR for CBF assessment in patients with cerebrovascular diseases.

MATERIALS AND METHODS

Twenty patients with carotid stenosis underwent CBF quantification by ASL (QUASAR) within 3 days of performance of (123)I-iodoamphetamine-SPECT. CVR to acetazolamide also was assessed by ASL and SPECT. In surgically treated patients, the respective scans before and after the procedures were compared.

RESULTS

Regional CBF and CVR values measured by ASL were significantly correlated and agreed with those measured by SPECT (r(s) = 0.92 and 0.88, respectively). A Bland-Altman plot demonstrated good agreement between 2 methods in terms of CBF quantification. Furthermore, ASL could detect pathologic states such as hypoperfusion, impaired vasoreactivity, and postoperative hyperperfusion, equivalent to SPECT. However, ASL tended to overestimate CBF values especially in high-perfusion regions.

CONCLUSIONS

ASL perfusion MR imaging is clinically applicable and can be an alternative method for CBF assessment in patients with cerebrovascular diseases.

[Subscapular elastofibroma]

Elastofibroma is a tumor that is localized mainly at the subscapular region. We report 2 cases of subscapular elastofibromas. Case 1, 75-year-old woman was seen at the hospital because of a left dorsal tumor. Computed tomography (CT) scan revealed the tumor of 6 cm in diameter in the inferior angle of left scapula. The patient underwent excision of the tumor. Case 2, 90-year-old man underwent excision a tumor of 5 cm in diameter in the inferior angle of right scapula simultaneously with the operation of right lung cancer. Histological examinations showed increased elastic fiber with elastica van Gieson staining. These specimens confirmed the diagnosis of elastofibroma There have been no signs of recurrence after surgery.

Stress-assisted large magnetic-field-induced strain in single-variant Co-Ni-Ga ferromagnetic shape memory alloy

The magnetic anisotropy and the magnetic-field-induced strain (MFIS) in a single-variant Co(47.5)Ni(22.5)Ga(30.0) ferromagnetic shape memory alloy (FSMA) have been investigated. From the magnetization curves for the single crystal, the hard c-axis was confirmed, and the uniaxial magnetic anisotropy constant K(u) at 300 K was evaluated to be -1.07 × 10(6) erg cm(-3) for the single-variant Co(47.5)Ni(22.5)Ga(30.0) martensite phase. The magnitude of compressive shear stress for the variant rearrangement was estimated to be 6.0-7.5 MPa from the stress-strain curves. An assisted stress τ(assist) of 6.0 MPa was applied before applying a magnetic field, and then a magnetic stress τ(mag) of 0.3 MPa was added. As a result, a large MFIS of about 7.6 % was obtained at room temperature in the martensite phase of the single-variant Co(47.5)Ni(22.5)Ga(30.0).

Magnetic anisotropy in Ni-Fe-Ga-Co ferromagnetic shape memory alloys in the single-variant state

The effects of the addition of Co on the magnetic anisotropy in Ni(55-x)Fe(18)Ga(27)Co(x) (x = 1-6) single-variant ferromagnetic shape memory alloys have been investigated. By the addition of Co from 1 to 6 at.%, the Curie temperature T(C) is increased from 318 to 405 K, keeping the martensitic transformation temperatures above room temperature. As a result, the value of the uniaxial magnetic anisotropy constant |K(u)| at 300 K increases with increasing x of the Co concentration and the martensite phase of Ni(49)Fe(18)Ga(27)Co(6) exhibits a relatively high value of |K(u)| = 1.15 × 10(5) J m(-3) at 300 K. With increasing Co concentration, on the other hand, the c axis changes from the magnetic easy axis to the hard axis at 4.2 K, that is, the sign of K(u) is reversed from positive to negative between 2 and 3 at.% Co. Furthermore, K(u) in Ni(53)Fe(18)Ga(27)Co(2) is positive below 100 K and negative above 100 K up to T(C), reducing the magnetic anisotropy around 200 K. From the present results, it is evident that the magnetic anisotropy of Ni(55-x)Fe(18)Ga(27)Co(x) (x = 1-6) single-variant ferromagnetic shape memory alloys is very sensitive to Co concentration and also temperature.

Improvement in respiratory function by percutaneous vertebroplasty

BACKGROUND

Percutaneous vertebroplasty (PVP) improves back pain and corrects spinal misalignment to some extent, and thus may improve respiratory function.

PURPOSE

To retrospectively investigate changes in respiratory function after PVP.

MATERIAL AND METHODS

41 patients (mean age 72.0 years, range 59-86 years; 39 women, two men) who had undergone PVP for vertebral compression fractures (37 thoracic vertebral bodies [Th6-Th12] and 50 lumbar vertebral bodies [L1-L5]) caused by osteoporosis visited our hospital for follow-up consultation between January and June 2005. At this follow-up consultation, respiratory function testing, including percent forced vital capacity (FVC%) and percent forced expiratory volume in 1 s (FEV(1)%), was performed. We retrospectively compared these values with those taken before PVP using a Wilcoxon signed-rank test.

RESULTS

FVC% was 85.2+/-30.3% before PVP and 91.5+/-16.8% at follow-up (mean 10 months after PVP), which represented a significant difference (P<0.003). No significant difference in FEV(1)% was detected. Regarding the number of treatment levels, that is, single vertebroplasty versus multiple vertebroplasty, no significant difference in improvement of FVC% was confirmed (P=0.1). FVC% was abnormally low (<or=79%) before PVP in 16 patients and improved to within normal range postoperatively in six of these patients (38%).

CONCLUSION

PVP improves preoperatively decreased lung function, but this improvement takes time.