Post-treatment course of acute lipodermatosclerosis

OBJECTIVES

We aimed to clarify whether acute lipodermatosclerosis (LDS) progress to chronic LDS without continued compression therapy.

METHODS

Between April 2015 and November 2021, 30 patients with acute/subacute LDS, which was diagnosed clinically by presence of isolated, poorly demarcated, tender erythema, and induration limited to the lower leg(s), visited our clinic and were able to be followed up for longer than a year. We reviewed their treatment results and the post-treatment courses.

RESULTS

In all cases, the symptoms in the acute phase subsided with compression bandages. After the discontinuation of compression therapy, 18 legs (56%) progressed to chronic LDS, and 14 legs (44%) did not. In the legs without progression, subcutaneous tissue in the affected leg was thicker compared with that in the contralateral leg (median 19.1 mm vs. 13.4 mm, p < 0.05) on the initial visit. In the legs with progression, the difference in subcutaneous tissue thickness between the affected and unaffected legs was not significant (10.0 mm vs. 7.6 mm).

CONCLUSIONS

Our findings suggest that in legs which later progress to chronic LDS, subcutaneous tissue contraction due to panniculitis is already present during the acute phase; therefore, long-term compression therapy is unlikely to improve the prognosis.

VGF nerve growth factor inducible has the potential to protect pancreatic β-cells

VGF nerve growth factor inducible (VGF) is a secreted polypeptide involved in metabolic regulation. VGF derived peptides have been reported to regulate insulin secretion in the plasma of patients with type 2 diabetes and model mice. However, the protective effects of VGF on pancreatic β-cells in diabetic model are not well understood. In this study, we aimed to elucidate the β-cell protective effect of VGF on a streptozotocin (STZ)-induced diabetic model using VGF overexpressing mice and also examined the therapeutic effect by a small molecule, SUN N8075 which is an inducer of VGF. VGF overexpressing mice improved blood glucose levels and maintained β-cell mass, compared to WT mice on STZ-induced diabetic model. In addition, VGF-overexpressing mice showed better glucose tolerance than WT mice. In culture, AQEE-30, a VGF derived peptide, suppressed STZ-induced β-cell death in vitro and attenuated the decrease in the phosphorylation of Akt and GSK3β. Furthermore, SUN N8075 suppressed the blood glucose levels and increased VGF expression in the pancreatic islet. SUN N8075 also protected STZ-induced β-cell death in vitro. These findings indicate that VGF plays a hypoglycaemic role in response to blood glucose levels in diabetes and protecting β-cells from STZ-induced cell death. Therefore, VGF and its inducer have the therapeutic potential by preserving β-cells in diabetes.

Gli1+-PDL Cells Contribute to Alveolar Bone Homeostasis and Regeneration

The periodontal ligament (PDL) contains mesenchymal stem cells (MSCs) that can differentiate into osteoblasts, cementoblasts, and fibroblasts. Nevertheless, the distribution and characteristics of these cells remain uncertain. Gli1, an essential hedgehog signaling transcription factor, functions in undifferentiated cells during embryogenesis. Therefore, in the present study, the differentiation ability of Gli1⁺ cells was examined using Gli1-CreERT2/ROSA26-loxP-stop-loxP-tdTomato (iGli1/Tomato) mice. In 4-wk-old iGli1/Tomato mice, Gli1/Tomato⁺ cells were only slightly detected in the PDL, around endomucin-expressing blood vessels. These cells had proliferated over time, localizing in the PDL as well as on the bone and cementum surfaces at day 28. However, in 8-wk-old iGli1/Tomato mice, Gli1/Tomato⁺ cells were quiescent, as most cells were not immunoreactive for Ki-67. These cells in 8-wk-old mice exhibited high colony-forming unit fibroblast activity and were capable of osteogenic, chondrogenic, and adipogenic differentiation in vitro. In addition, after transplantation of teeth of iGli1/Tomato mice into the hypodermis of wild-type mice, Tomato fluorescence indicating the progeny of Gli1⁺ cells was detected in the osteoblasts and osteocytes of the regenerated bone. These results demonstrate that Gli1⁺ cells in the PDL were MSCs and could contribute to the alveolar bone regeneration.

Cryopreserved allogenic fibroblast sheets: development of a promising treatment for refractory skin ulcers

The purpose of this study was to investigate the therapeutic effect of cryopreserved allogenic fibroblast cell sheets in a mouse model of skin ulcers. It is necessary to reduce the cost of regenerative medicine for it to be widely used. We consider that cell sheets could be applied to various diseases if cryopreservation of allogenic cell sheets was possible. In this study, fibroblasts were frozen using a three-dimensional freezer. Freeze-thawed fibroblasts had ~80% cell viability, secreted ≥ 50% vascular endothelial growth factor, hepatocyte growth factor, and stromal derived factor-1α compared with non-frozen fibroblast sheets, and secreted approximately the same amount of transforming growth factor-β1. There was no difference in wound-healing rates in the skin ulcer model between non-frozen and freeze-thawed fibroblast sheets regardless of autologous and allogenic cells. The degree of angiogenesis was comparable between autologous and allogenic cells. The number of CD3-positive cells in healed tissues was larger for allogenic fibroblast sheets compared with autologous fibroblast sheets. However, histopathological images showed that the fibrosis, microvascular density, and healing phase of the wound in allogenic freeze-thawed fibroblast sheets were more similar to autologous freeze-thawed fibroblast sheets than to allogenic non-frozen fibroblast sheets. These results suggest that allogenic freeze-thawed fibroblast sheets may be a promising therapeutic option for refractory skin ulcers.

Glutamatergic dysfunction is associated with phenotypes of VGF-overexpressing mice

VGF nerve growth factor inducible (VGF) is a neuropeptide precursor, which is induced by several neurotrophic factors, including nerve growth factor and brain-derived neurotrophic factor. Clinically, an upregulation of VGF levels has been reported in the cerebrospinal fluid and prefrontal cortex of patients with schizophrenia. In our previous study, mice overexpressing VGF exhibited schizophrenia-related behaviors. In the current study, we characterized the biochemical changes in the brains of VGF-overexpressing mice. Metabolomics analysis of neurotransmitters revealed that glutamic acid and N-acetyl-L-aspartic acid were increased in the striatum of VGF-overexpressing mice. Additionally, the present study revealed that MK-801, which causes the disturbance in glutamic acid metabolism, increased the expression level of VGF-derived peptide (NAPP129, named VGF20), and VGF-overexpressing mice had higher sensitivity to MK-801. These results suggest that VGF may modulate the regulation of glutamic acid levels and the degree of glutamic acid signaling.

Perivascular Adipose Tissue Is a Major Source of Nitric Oxide in Saphenous Vein Grafts Harvested via the No-Touch Technique

Background

Saphenous vein grafts (SVGs) are broadly used in coronary artery bypass grafting despite their inferior patency compared with arterial grafts. Recently, the no‐touch technique (NT), in which an SVG is harvested with a pedicle of perivascular adipose tissue (PVAT) without conduit distension, was shown to improve long‐term patency compared with conventional preparation (CV), wherein outer tissue is removed with distension. The NT was also reportedly associated with reduced atherosclerosis. Although endothelial damage provoked by conventional distension may underlie poor patency when CV is performed, the precise mechanisms underlying the salutary effects of the NT have been unclear.

Methods and Results

Residual SVGs prepared with CV (CV‐SVGs) or NT (NT‐SVGs) were obtained during coronary artery bypass grafting. Nitric oxide (NO₂⁻/NO₃⁻ (NO_x)) levels after 24 hours of tissue culture were quantified. The protein expression and localization were analyzed. The isometric force of SVG strips was measured. NT‐SVGs showed superior NO_x production to CV‐SVGs. PVAT generated the majority of NO_x in NT‐SVGs. PVAT highly expressed arginosuccinate synthase 1, a rate‐limiting enzyme in the molecular circuit for NO synthesis, thereby continuously providing the substrate for NO. A substantial level of endothelial NO synthase was also expressed in PVAT. Pharmacological inhibition of arginosuccinate synthase 1 or endothelial NO synthase significantly suppressed the NO_x production in NT‐SVGs. PVAT induced vasorelaxation through NO production, even in the endothelium‐denuded SVG strips.

Conclusions

Preserving PVAT was predominantly involved in the superior NO_x production in NT‐SVGs. Since NO plays crucial roles in suppressing atherosclerosis, this mechanism may greatly contribute to the excellent patency in NT‐SVGs.

Whole Three-Dimensional Dosimetry of Carbon Ion Beams with an MRI-Based Nanocomposite Fricke Gel Dosimeter Using Rapid T1 Mapping Method

MRI-based gel dosimeters are attractive systems for the evaluation of complex dose distributions in radiotherapy. In particular, the nanocomposite Fricke gel dosimeter is one among a few dosimeters capable of accurately evaluating the dose distribution of heavy ion beams. In contrast, reduction of the scanning time is a challenging issue for the acquisition of three-dimensional volume data. In this study, we investigated a three-dimensional dose distribution measurement method for heavy ion beams using variable flip angle (VFA), which is expected to significantly reduce the MRI scanning time. Our findings clarified that the whole three-dimensional dose distribution could be evaluated within the conventional imaging time (20 min) and quality of one cross-section.

Hardness Sensed by Skin Palpation in Legs with Lymphedema Is Predominantly Correlated with Dermal Thickening

Background: We aimed to clarify whether pathological changes in skin and subcutaneous tissue with lymphedema affected the skin hardness sensed by palpation. Methods and Results: In 50 patients with unilateral legs with lymphedema (LE), the skin hardness of the lower inner thigh and lower inner calf was determined using a scale ranging from 1 (softest) to 7 (hardest) based on palpation. Then, the skin hardness was correlated with the measurements of skin/subcutaneous tissue ultrasonography images obtained from the palpated parts. Multivariate logistic regression analysis demonstrated that dermal thickness was a significant factor that affected the difference in skin hardness between the LE and the contralateral asymptomatic leg for both thigh (p < 0.05) and calf (p < 0.01). When the thigh and calf in the LE were individually studied, subcutaneous echogenicity (p < 0.05), indicating subcutaneous inflammation/fibrosis, and subcutaneous thickness (p < 0.01) also seemed to affect skin hardness, respectively. Conclusions: The skin hardness sensed in the LE seemed to be affected predominantly by dermal thickening. In addition, the pathological changes in the subcutaneous tissue caused by LE seemed to have an impact on skin hardness. Clinical Trial Registration number 2020-150.

A pilot study using cell-mixed sheets of autologous fibroblast cells and peripheral blood mononuclear cells to treat refractory cutaneous ulcers

BACKGROUND/AIMS

We invented a cell-mixed sheet consisting of autologous fibroblast cells and peripheral blood mononuclear cells (PBMNCs) to treat refractory cutaneous ulcers. These sheets secrete the growth factors needed throughout the wound healing process in animal models.

METHODS

We performed this study as a pilot phase I clinical trial (UMIN-CTR: UMIN000031645). Fibroblast cells were isolated and cultured from the oral tissue, and PBMNCs were collected by apheresis. A cell-mixed sheet was prepared by co-culturing these collected cells for 3 days. The primary observation index was safety, including all adverse events. Additional observation indices were wound healing over 1, 3, and 6 months; wound healing rate at 7 days and 1, 3, and 6 months.

RESULTS

Six patients with venous leg ulcers (VLUs) were enrolled in the study, including three patients who were treated with the cell-mixed sheet transplantation. One patient was excluded because no fibroblast cells grew from the oral tissue culture, and other two were excluded because the growth factor secreted from mixed-cell sheets did not reach the reference value. The VLUs of two patients who received the cell-mixed sheet transplantation healed, and the VLU in one patient decreased in size.

CONCLUSIONS

This pilot study demonstrated that cell-mixed sheets might be a new topical intervention to treat VLUs. However, it was also suggested that this treatment might be limited when using autologous cells collected from patients with VLUs. Therefore, it may be necessary to use high-quality allogeneic cells instead of autologous cells to improve the feasibility of this treatment.

Interface Pressures Derived from a Tubular Elastic Bandage

Objective: We sought to clarify the interface pressure (IP) when using a tubular elastic bandage (TEB) and examine the possibility for TEBs to provide IPs comparable to those provided by anti-thrombotic stockings.

Materials and Methods: In 40 healthy patients, IPs were measured at the level of calf at its maximum diameter (C) and transition of the medial gastrocnemius muscle into the Achilles tendon (B1) while a single or double layer of TEBs (17.5 cm in circumference) were applied with the patient in a supine position.

Results: Including both the C and B1 levels, circumferences and IPs showed a good correlation (single layer; r=0.72, double layer; r=0.75). The IP obtained with a single layer of TEB at the C level (median, 17 mmHg [range, 12–23 mmHg]) was higher than that at the B1 level (14 mmHg [11–18 mmHg], p<0.001). When double-layer TEB was used, the IP at B1 level increased to 18 (14–23) mmHg (p<0.001 vs. single layer).

Conclusion: Considering the characteristics of TEBs and using a single or double layer appropriately, creating a pressure profile mimicking that of an anti-thrombotic stocking seemed to be feasible when using a TEB.

Arterial stiffness could reflect increased cardiac load and reduced pulmonary function in the general population

Background

Pulmonary function is known to decrease with age and reduced pulmonary function has been reported to be associated with all-cause mortality and cardiovascular death. The association between pulmonary impairment and atherosclerosis was reported previously but has not been investigated sufficiently in the general population.

Purpose

We hypothesized that arterial stiffness could reflect increase of cardiac load and reduced pulmonary function. The present study aimed to investigate whether increased cardiac load and reduced pulmonary function could affect arterial stiffness in the general population.

Methods

Subjects undergoing their health check-up were enrolled. Plasma B-type natriuretic peptide (BNP) levels and serum high-sensitivity cardiac troponin I (hs-cTnI) levels were measured to evaluate cardiac load and myocardial damage. Radial augmentation index (rAI) was measured to investigate arterial stiffness using HEM-9000AI device. Subjects with an ST-T segment abnormality on the electrocardiogram, renal insufficiency, cancer, active inflammatory disease, or a history of cardiovascular events and pulmonary disease were excluded. Pulmonary function was assessed using spirometry by calculating forced vital capacity (FVC) as a percentage of predicted value (FVC%-predicted), forced expiratory volume in 1 second (FEV1) as a percentage of predicted value (FEV1%-predicted), and the ratio of FEV1 to FVC (FEV1/FVC).

Results

A total of 1100 subjects aged 57 years were enrolled and their median values of BNP and hs-cTnI were 15.5 and 2.3 pg/ml. The levels of rAI were significantly associated with the levels of BNP after adjustment for possible confounders in multivariate regression analysis, but were not with the levels of hs-TnI. While the parameters of pulmonary function were inversely associated with the levels of rAI and hs-cTnI after adjustment for possible confounders in the multivariate regression analysis, but not with the levels of BNP. The other multivariate regression analyses where BNP, hs-cTnI, parameters of pulmonary function, and the other possible factors were simultaneously included as independent variables revealed that the BNP levels and the FVC%-predicted or FEV1%-predicted, besides age, gender, smoking status, body mass index, blood pressure, heart rate, creatinine, fasting plasma glucose, and triglyceride, were significantly associated with the levels of rAI.

Conclusions

The significant associations of rAI with BNP and pulmonary function were revealed in the general population. These findings support that arterial stiffness could reflect increased cardiac load and reduced pulmonary function, in apparently healthy individuals.

Funding Acknowledgement

Type of funding source: None

Treatment Results of Endovascular Aneurysm Repair Using the Parallel Stent-Graft Double D Technique for Distal Saccular Abdominal Aortic Aneurysms and Common Iliac Aneurysms

BACKGROUND

Endovascular aneurysm repair (EVAR) using a bifurcated stent graft may involve technical challenges when aortic disease (aneurysm or dissection) consists of a length <70 mm between the inferior renal artery and aortic bifurcation or narrow aortic bifurcation that is common in asymmetric distal abdominal aortic aneurysms (AAAs) or iliac artery aneurysms (IAAs). We use EVAR with the double D technique (DDT-EVAR) for such cases, which involves straight type of stent grafts with same diameter in left and right that are deployed parallel to an aortic cuff that has been previously placed. In addition, DDT-EVAR can preserve the inferior mesenteric artery (IMA) for IAA.

METHODS

DDT-EVAR was performed for 21 of 910 (2%) cases from April 2007 to April 2019 at our institution. The median patient age was 74 years (range, 52-85). Nineteen patients (90%) were men. Six patients (all saccular; 1 rupture) had AAAs, 12 had IAAs, and 3 had chronic type B aortic dissociation (TBAD) for re-entry closure. AAA and IAA had diameters of 45 mm (range, 34-71) and 34 mm (range, 25-58), respectively. An aortic cuff was used for 19 (90%) cases. Endurant II (Medtronic, Santa Rosa, CA) was used for 12 cases. The Excluder (W.L. Gore & Associates, Inc, Flagstaff, AZ) was used for 7 cases. Endurant II was used for 20 cases, and the VBX (W.L. Gore & Associates, Inc) was used for 1 case as stent-graft limbs.

RESULTS

The procedural success rate was 100%. The median operative time was 146 min (range, 88-324). IMA planned for preservation was successful for all 12 cases. Type I and type III endoleaks were not observed. With TBAD, flow to the false lumen decreased or disappeared, and no complications during the hospital stay were associated with the procedure. For 2 patients whose procedure involved Endurant II stent-graft limb, limb occlusions were observed postoperatively, and reintervention was required. No other patients required additional treatment at a median follow-up of 18 months (range, 4-50).

CONCLUSIONS

DDT-EVAR is a safe and straightforward technique for the treatment of distal AAA, common iliac artery aneurysm, and TBAD. It may help preserve the IMA and internal iliac artery, even when it is impossible to preserve them with a bifurcated stent graft.

Extracellular Fluid Content in the Legs of Patients with Chronic Venous Disease

BACKGROUND

This study aimed to determine the factors that affect the extracellular fluid (ECF) content in the legs of patients with chronic venous disease (CVD).

METHODS

Bioimpedance analysis and air plethysmography (APG) were performed in 79 patients with CVD who visited our clinic between September 2016 and March 2019. The normal right legs (N) of 14 healthy volunteers were also reviewed for comparison. The ratio of ECF resistance (Re) of the leg to that of the arm (ReL/ReA) was used to express the ECF content in the tested leg. The severity of CVD was expressed using the clinical, etiological, anatomical, and pathophysiological (CEAP) classification.

RESULTS

The ReL/ReA decreased as the CEAP class increased (N: median; 0.81 [range 0.66-0.95], C0-1: 0.79 [0.60-0.98], C2: 0.77 [0.56-1.08], C3: 0.67 [0.57-0.85], C4: 0.64 [0.44-0.89]). Older age, female sex, and CEAP class affected the ReL/ReA, but body mass index did not. The ReL/ReA did not correlate with the parameters that were derived from APG, including the venous filling index.

CONCLUSIONS

We found that the ECF content in legs of patients with CVD might be primarily affected by patient-related factors and CEAP class, as opposed to venous hemodynamics.

Allogeneic fibroblast sheets accelerate cutaneous wound healing equivalent to autologous fibroblast sheets in mice

BACKGROUND/AIMS

This study sought to confirm the difference of the wound-healing effect, cell survival, and immune response between autologous fibroblast sheets and allogeneic fibroblast sheets.

METHODS

Regarding wound healing, autologous or allogeneic fibroblast sheets were transplanted onto a mouse cutaneous wound healing model and the wound contraction rate was evaluated. The luciferase-expressing fibroblast sheet was prepared and the survival of the cell sheet was evaluated by IVIS^® after autologous or allogeneic transplantation. Histological evaluation was performed at five and 14 days after transplantation.

RESULTS

Allogeneic fibroblast-sheet transplantation showed significant wound contraction at the early phase of wound healing, which was equivalent to that seen with the autologous fibroblast sheets. Luminescence of the autologous and allogeneic luciferase-expressing fibroblast sheets peaked on Day 5, and no luminescence was observed on Day 13. In the allogeneic fibroblast-sheet transplant group, a significant accumulation of immune cells was observed in the healed tissue but not in the early stage of wound healing.

CONCLUSION

The allogeneic fibroblast sheets showed comparable rates of cell survival and wound-healing effects to those of the autologous fibroblast sheets, despite the subsequent immunogenic response. This result supports the potential practical clinical application of scaffold-free allogeneic fibroblast sheets based on the paracrine effect.

Endovascular Aneurysm Repair With Re-entry Closure in a Patient With Abdominal Aortic Aneurysm Concomitant With Acute Type B Aortic Dissection

Introduction

Abdominal aortic aneurysm (AAA) concomitant with acute aortic dissection is rare.

Case report

An acute type B aortic dissection involving AAA in a 58 year old woman is described. Computed tomography angiography demonstrated that the false lumen of the abdominal aorta including the aneurysm remained patent, secondary to entry sites in the abdominal aorta, bilateral external iliac arteries, and a membrane tear of the left renal artery (LRA). The aneurysm was isolated by endovascular aneurysm repair and LRA stenting; all entry sites were occluded by endovascular treatment that included covered stenting of the LRA. Imaging performed three months after the procedure confirmed complete thrombosis of the false lumen and AAA sac shrinkage.

Discussion

Endovascular treatment with covered stents is reported as an alternative strategy for treatment of AAA concomitant with acute aortic dissection involving a visceral artery.

•

A 58 year old woman developed acute type B aortic dissection involving an AAA.

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AAA concomitant with acute aortic dissection is rare.

•

Endovascular treatment using a covered stent of the visceral artery can be effective.

1436Overexpression of Cytotoxic T-Lymphocyte Associated Antigen-4 suppresses aortic immunoinflammatory responses and prevents angiotensin II-induced abdominal aortic aneurysm formation in mice

Aims

Vascular inflammation via T-cell-mediated immune responses has been shown to be critically involved in the pathogenesis of abdominal aortic aneurysm (AAA). T-cell coinhibitory molecule cytotoxic T-lymphocyte–associated antigen-4 (CTLA-4) is known to act as a potent negative regulator of immune responses. However, the role of this molecule in the development of AAA remains completely unknown. In the present study, we determined the effects of CTLA-4 overexpression on experimental AAA.

Methods and results

We continuously infused 12-week-old CTLA-4 transgenic (CTLA-4-Tg)/apolipoprotein E–deficient (Apoe−/−) mice (n=35) or control Apoe−/− mice (n=40) fed a high-cholesterol diet with angiotensin II by implanting osmotic mini-pumps and evaluated the development of AAA. Ninety percent of angiotensin II-infused mice developed AAA, with 50% mortality because of aneurysm rupture. Overexpression of CTLA-4 significantly reduced the incidence (66%), mortality (26%), and diameter (18%) of AAA (incidence: P=0.0104; mortality: P=0.031; diameter: P=0.011). These protective effects were associated with a decreased number of effector CD4+ T cells and the downregulated expression of costimulatory molecules CD80 and CD86, ligands for CTLA-4, on CD11c+ dendritic cells in lymphoid tissues. In addition, by performing in situ zymography of the abdominal aortic aneurysm lesions, we observed a trend toward a decrease in MMP activity in the aneurysmal lesion following overexpression of CTLA-4. Finally, CTLA-4-Tg/Apoe−/− mice had reduced macrophage and CD4+ T cell accumulation and MMP activity in the aneurysmal lesion, leading to attenuated aortic inflammation, preserved vessel integrity, and decreased susceptibility to AAA and aortic rupture.

Conclusion

Our findings suggest that CTLA-4 protects against AAA by suppressing immunoinflammatory responses and could be an attractive therapeutic target for AAA.

Reverse slider technique using the Endurant stent graft for accurate proximal sealing in hostile neck endovascular aneurysm repair

This report introduces the reverse slider technique to obtain proximal sealing effectively in endovascular aneurysm repair in short or angulated necks. It is the deployment process of the stent graft main body by repeatedly rotating and reversing the external slider with slight loosening of the suprarenal stent. This method helps obtain accurate placement of the proximal edge and effective sealing on the greater curvature side even in short and angulated necks. It is an effective method of extending the proximal sealing zone. It is gained by changing the deployment process with the Endurant stent graft (Medtronic, Santa Rosa, Calif) as an existing popular device.

Compression Therapy Using Bandages Successfully Manages Acute or Subacute Lipodermatosclerosis

We report nine cases with acute or subacute lipodermatosclerosis treated successfully using multilayer bandages. All patients were women aged 52-90 years. Before presenting to our clinic, all patients had been treated for a tentative diagnosis of cellulitis caused by bacterial infection or inflammation of unknown cause for 3-19 weeks without improvement. Initially, we instructed all patients or their caregivers regarding the bandaging technique to achieve an interface pressure of >40 mmHg. Subsequently, this technique was continued by patients/caregivers. Symptoms subsided within 2-7 weeks in all patients except one who had been noncompliant with the compression therapy.

Chimney Endovascular Aneurysm Repair Using Endurant Stent-Grafts With Bare Balloon-Expandable Stents for Patients With Juxtarenal Aortic Aneurysms

PURPOSE

To evaluate the advantages of chimney endovascular aneurysm repair (chEVAR) using an Endurant stent-graft with uncovered balloon-expandable stents (BES) for patients with juxtarenal aortic aneurysms.

MATERIALS AND METHODS

Twenty-two patients (mean age 78.5±9.0 years; 13 men) who underwent chEVAR using Endurant and uncovered BES between January 2014 and December 2017 were analyzed retrospectively. The maximum aneurysm diameter was 59.1±11.9 mm, and the proximal neck length was 5.2±2.9 mm. Of the 22 cases, 9 (40%) involved proximal neck angulation and 9 (40%) had a conical neck. Single and double chimneys were performed using BES in 19 and 3 cases, respectively. In 2 cases, an additional self-expanding covered stent was used inside the uncovered BES.

RESULTS

The technical success was 91% (20/22) as 2 (9%) cases showed minor type Ia endoleak. No postoperative systemic complications or acute renal dysfunction (Acute Kidney Injury Network classification stage 2 or higher) were observed. The mean radiologic observation period was 16.1±9.6 months, and no aneurysm expansion (>5 mm) was observed during this time. The mean maximum aneurysm diameter decreased to 52.9±10.2 mm (p<0.001 vs preoperative), with an individual mean sac regression of 6.2±5.9 mm. Overall primary chimney stent patency was 100%. One of the 2 cases of intraoperative type Ia endoleak resolved at the 6-month imaging, and no new type Ia endoleaks developed in any cases at follow-up. No additional treatment- or aneurysm-related events were observed.

CONCLUSION

Short-term outcomes of chEVAR using Endurant with uncovered BES have been favorable when covered stents were unavailable, and it can be useful for high-risk patients with juxtarenal aortic aneurysms.

Using bifurcated endoprosthesis after iliac artery recanalization for concomitant abdominal aortic aneurysm and chronic total occlusions of access routes

OBJECTIVE

Concurrent abdominal aortic aneurysm (AAA) and unilateral iliac occlusion is a challenge in the implantation of bifurcated stent grafts (BFGs). The endovascular approach is less invasive than open surgery; the aortouni-iliac (AUI) graft with crossover femorofemoral bypass (CFFB) has many problems associated with extra-anatomic reconstruction. We attempted endovascular aneurysm repair (EVAR) using BFGs in such cases and evaluated the outcomes.

METHODS

This was a retrospective study. Between October 2012 and December 2017, there were 649 patients who underwent surgery for AAA, of whom 32 patients underwent open reconstruction and 617 patients underwent endovascular aneurysm repair; 15 patients with unilateral occluded iliac arteries and AAA were included. The analysis included patients with unilateral iliac chronic total occlusion (CTO). The intraoperative, postoperative, and follow-up variables were reviewed.

RESULTS

The occluded lesions were the common iliac artery in 5 patients, the common iliac artery-external iliac artery (EIA) in 2 patients, the EIA in 7 patients, and the EIA-common femoral artery in 1 patient. The mean occlusive length was 89.7 ± 43.6 mm, and the mean AAA size was 54.6 ± 5.6 mm. Technical success was achieved in 13 patients (87%). All patients underwent recanalization through the true lumen and stent placement. The only procedure-related complication was distal embolism, which was treated with intraoperative thrombectomy. Recanalization of CTO lesions was not possible in two patients (13%), who underwent AUI graft placement with CFFB. The 30-day mortality and morbidity rates were 0%. The mean follow-up periods were 12 and 32 months for patients who underwent BFG placement and AUI graft placement with CFFB, respectively. During follow-up, the primary patency rate of successfully recanalized arteries was 100%. Aneurysm size decreased in four patients who underwent BFG placement; no change was seen in the other 11 patients. Freedom from aneurysm-related events was 100%; no patient needed secondary interventions. All patients with claudication pain preoperatively reported improvement in their symptoms during follow-up. In addition, the ankle-brachial index improved significantly from 0.51 ± 0.25 preoperatively to 0.88 ± 0.20 postoperatively (P < .001) in patients who underwent BFG placement.

CONCLUSIONS

Recanalization of unilateral iliac CTO lesions and placement of BFG in cases with concomitant aneurysmal disease and unilateral iliac occlusive disease demonstrated a significant primary patency rate with improvements in claudication and ankle-brachial index.

Impaired Cerebellar Development in Mice Overexpressing VGF

VGF nerve growth factor inducible (VGF) is a neuropeptide precursor induced by brain-derived neurotrophic factor and nerve growth factor. VGF is increased in the prefrontal cortex and cerebrospinal fluid in schizophrenia patients. In our previous study, VGF-overexpressing mice exhibited schizophrenia-like behaviors and smaller brain weights. Brain developmental abnormality is one cause of mental illness. Research on brain development is important for discovery of pathogenesis of mental disorders. In the present study, we investigated the role of VGF on cerebellar development. We performed a histological analysis with cerebellar sections of adult and postnatal day 3 mice by Nissl staining. To investigate cerebellar development, we performed immunostaining with antibodies of immature and mature granule cell markers. To understand the mechanism underlying these histological changes, we examined MAPK, Wnt, and sonic hedgehog signaling by Western blot. Finally, we performed rotarod and footprint tests using adult mice to investigate motor function. VGF-overexpressing adult mice exhibited smaller cerebellar sagittal section area. In postnatal day 3 mice, a cerebellar sagittal section area reduction of the whole cerebellum and external granule layer and a decrease in the number of mature granule cells were found in VGF-overexpressing mice. Additionally, the number of proliferative granule cell precursors was lower in VGF-overexpressing mice. Phosphorylation of Trk and Erk1 were increased in the cerebellum of postnatal day 3 VGF-overexpressing mice. Adult VGF-overexpressing mice exhibited motor disability. All together, these findings implicate VGF in the development of cerebellar granule cells via promoting MAPK signaling and motor function in the adult stage.

VGF nerve growth factor inducible is involved in retinal ganglion cells death induced by optic nerve crush

VGF nerve growth factor inducible (VGF) is a polypeptide that is induced by neurotrophic factors and is involved in neurite growth and neuroprotection. The mRNA of the Vgf gene has been detected in the adult rat retina, however the roles played by VGF in the retina are still undetermined. Thus, the purpose of this study was to determine the effects of VGF on the retinal ganglion cells (RGCs) of mice in the optic nerve crush (ONC) model, rat-derived primary cultured RGCs and human induced pluripotent stem cells (iPSCs)-derived RGCs. The mRNA and protein of Vgf were upregulated after the ONC. Immunostaining showed that the VGF was located in glial cells including Müller glia and astrocytes but not in the retinal neurons and their axons. AQEE-30, a VGF peptide, suppressed the loss of RGCs induced by the ONC, and it increased survival rat-derived RGCs and promoted the outgrowth of neurites of rat and human iPSCs derived RGCs in vitro. These findings indicate that VGF plays important roles in neuronal degeneration and has protective effects against the ONC on RGCs. Thus, VGF should be considered as a treatment of RGCs degeneration.

Effectiveness of Embolization of Inferior Mesenteric Artery to Prevent Type II Endoleak Following Endovascular Aneurysm Repair: A Review of the Literature

Type II endoleak is a common complication that develops after endovascular aneurysm repair. Patients with type II endoleak, which has persisted for 6 months, have a significantly higher rate of aneurysmal sac enlargement, reintervention, and rupture. To date, several studies have examined the effectiveness of preoperative embolization of branch vessels for the prevention of type II endoleak. Particularly, the embolization of the large inferior mesenteric artery (IMA) seems to be a precise, safe, and effective method. IMA is a significant risk factor for type II endoleak. However, there is currently no strong evidence to prove which patients would benefit from preventive IMA embolization. In addition, considering the incidence of type II endoleak and the adverse event rate, routine embolization seems to be unreliable and time-consuming. Moreover, previous reports of preoperative IMA embolization were retrospective. Thus, prospective and randomized studies are necessary so that the usefulness of IMA embolization can be proved and the potential benefits can be assessed. To establish preventive IMA embolization as one of the effective therapeutic strategies to prevent type II endoleak and to maximize its therapeutic effect, we should provide a wide range of therapeutic strategies to suit the state of the patient.

Autologous fibroblasts, peripheral blood mononuclear cells, and fibrin glue accelerate healing of refractory cutaneous ulcers in diabetic mice

BACKGROUND/AIMS

We have developed a method to transplant sheets of autologous fibroblasts and peripheral blood mononuclear cells, which are highly angiogenic and regenerative, as treatment against refractory cutaneous ulcers in mice and rabbits. The cell sheets are also sealed with fibrin to further enhance effectiveness.

METHODS

Secretion of growth factors from cells incubated with or without fibrin in vitro was assessed by enzyme-linked immunosorbent assays, while angiogenesis and fibroblast migration were assessed by tube formation and scratch assays. Healing of cutaneous ulcers following transplantation of cells was evaluated in mice with diabetes mellitus.

RESULTS

Secretion of vascular endothelial growth factor, hepatocyte growth factor, and transforming growth factor was much higher from cell sheets supplemented with fibrin than from cell sheets only. Accordingly, supernatants from the former enhanced angiogenesis and fibroblast migration in vitro. Cutaneous ulcers treated with fibrin-glued cell sheets also healed more quickly than untreated ulcers or ulcers treated with cell sheets only.

CONCLUSION

Fibrin-sealed cells accelerate wound healing and microvascularization by supplying growth factors, and thus are promising as treatment against refractory cutaneous ulcers.

Aggressive Decongestion in Limbs with Lymphedema without Subcutaneous Echo-Free Space

BACKGROUND

To study the impact of aggressive decongestion in limbs with lymphedema without subcutaneous echo-free space (SEFS) in subcutaneous tissue ultrasonography.

METHODS

In 13 patients with arm lymphedema (ALE) (13 arms) and 16 patients with leg lymphedema (LLE) (18 legs) without SEFS, an aggressive decongestion was performed as the first phase of complex decongestive therapy. Measurements of circumference and calculation of limb volume were performed before and after the treatment.

RESULTS

In ALE, no significant reduction in arm volume (median -63 [range -251 to 176] mL) or edema ratio (-4 [-15 to 12]%) was confirmed. On the other hand, a small but significant reduction in leg volume (-207 [-834 to 131] mL, P < 0.001) and edema ratio (-4 [-14 to 2]%, P < 0.01) was confirmed in LLE.

CONCLUSION

In limbs with lymphedema without SEFS, the impact of aggressive decongestion seemed limited.

Treatment of Cutaneous Ulcers with Multilayered Mixed Sheets of Autologous Fibroblasts and Peripheral Blood Mononuclear Cells

Background/Aims: We have developed a mixed-cell sheet consisting of autologous fibroblasts and peripheral blood mononuclear cells with a high potency for angiogenesis and wound healing against refractory cutaneous ulcers in mouse and rabbit models. To increase the effectiveness of the mixed sheet, we developed a multilayered mixed sheet. Methods: We assessed the therapeutic effects of multilayered sheets on cutaneous ulcers in mice. Growth factors and chemokines were assessed by enzyme-linked immunosorbent assay. Angiogenesis and fibroblast migration were measured by using tube formation and migration assays. Wound healing rate of cutaneous ulcers was evaluated in mice with diabetes mellitus. Results: The concentration of secreted vascular endothelial growth factor, hepatocyte growth factor, transforming growth factor, C-X-C motif chemokine ligand (CXCL)-1, and CXCL-2 in multilayered sheets was much higher than that in single-layered mixed-cell sheets (single-layered sheets) and multilayered sheets of fibroblasts alone (fibroblast sheets). The supernatant in multilayered sheets enhanced angiogenic potency and fibroblast migration compared with single-layered and fibroblast sheets in an in vitro experiment. The wound healing rate in the multilayered sheet-treated group was higher compared with the no-treatment group (control) at the early stage of healing. Moreover, both vessel lumen area and microvessel density in tissues treated with multilayered sheets were significantly increased compared with tissues in the control group. Conclusion: Multilayered sheets promoted wound healing and microvascular angiogenesis in the skin by supplying growth factors and cytokines. Accordingly, our data suggest that multilayered sheets may be a promising therapeutic material for refractory cutaneous ulcers.

Venous hemodynamics assessed with air plethysmography in legs with lymphedema

This study was conducted to identify specific abnormalities using the results from air plethysmography in legs with lymphedema. A routine air plethysmography exercise protocol was performed in 31 patients with unilateral leg lymphedema, and the results were compared with those of 53 patients with unilateral great saphenous vein reflux and 15 normal subjects. The venous filling index in legs with lymphedema (2.1 ± 1.2 mL/sec) was smaller than in legs with great saphenous vein reflux (6.4 ± 4.1 mL/sec, p < 0.05), but was not different from that in normal legs (1.9 ± 1.2 mL/sec). The ejection fraction was similar in all groups. The residual volume fraction in legs with lymphedema (35 ± 32%) was larger than that in normal subjects (13 ± 23%, p < 0.05), but was not significantly different from that in the contralateral leg of the lymphedema patients (32 ± 27%). In conclusion, we found no specific air plethysmography findings in uncomplicated lymphedema.

Peculiar clinical features of cellulitis in peripheral lymphedema

Although the occurrence of cellulitis in lymphedema (LE) is believed to be an infection-related event, many findings in its clinical course seem to suggest that it is unlikely to be an infection. Therefore, we tried to clarify the specific features of cellulitis in LE. In-hospital courses of cellulitis obtained from medical charts were reviewed in the patients with leg LE (LE; 24 patients, 72admissions), chronic venous insufficiency (CVI; 28 patients, 29 admissions), and leg cellulitis secondary to wound infection without underlying disease (N; 42 patients, 42 admissions). The patients with LE complained of less local pain (peak numerical scale; LE: 1.4 ± 1.7, CVI: 4.1 ± 2.5, N: 3.2 ±2.0, p < 0.0001), showed an abnormally higher peak procalcitonin level (LE: 33.8 ± 34.8 (N = 7), CVI: 2.9 ± 5.8 (N = 8), N: 0.4 ± 0.6(N = 10), p < 0.05), and required fewer antibiotics (LE: 1.1 ± 0.3, CVI: 1.8 ± 0.9, N: 1.5 ± 0.9, p < 0.0001). These findings suggested that the occurrence of cellulitis in LE seems unlikely to be an infection-related type of cellulitis similar to that found in CVI.

Differential effects of light-to-dark transitions on phase setting in circadian expression among clock-controlled genes in Pharbitis nil

The circadian clock is synchronized by the day-night cycle to allow plants to anticipate daily environmental changes and to recognize annual changes in day length enabling seasonal flowering. This clock system has been extensively studied in Arabidopsis thaliana and was found to be reset by the dark to light transition at dawn. By contrast, studies on photoperiodic flowering of Pharbitis nil revealed the presence of a clock system reset by the transition from light to dark at dusk to measure the duration of the night. However, a Pharbitis photosynthetic gene was also shown to be insensitive to this dusk transition and to be set by dawn. Thus Pharbitis appeared to have two clock systems, one set by dusk that controls photoperiodic flowering and a second controlling photosynthetic gene expression similar to that of Arabidopsis. Here, we show that circadian mRNA expression of Pharbitis homologs of a series of Arabidopsis clock or clock-controlled genes are insensitive to the dusk transition. These data further define the presence in Pharbitis of a clock system that is analogous to the Arabidopsis system, which co-exists and functions with the dusk-set system dedicated to the control of photoperiodic flowering.

Local Echo-Free Space in a Limb with Lymphedema Represents Extracellular Fluid in the Entire Limb

BACKGROUND

We previously reported that local subcutaneous echo-free space (SEFS) in the leg was stirringly correlated with extracellular fluid (ECF) status in the same part of the leg when assessed using bioelectrical impedance analysis (BIA). In this study, we examined whether local SEFS represents the ECF status in the entire limb.

METHODS AND RESULTS

In 51 legs and 40 arms with lymphedema (LE), subcutaneous tissue ultrasonography was performed to determine SEFS severity (range, 0-2). BIA was also performed to calculate the L-Dex^® score (LDS), which is a BIA-derived parameter to represent ECF status, for the arm and modified LDS (mLDS) for the leg (the right arm was used as a reference instead of the contralateral leg). SEFS severity in any part of the leg showed good correlation with mLDS, but that in the lateral lower calf showed the strongest correlation (ρ = 0.86). In contrast, only SEFS severity in the medial forearm showed good correlation with LDS (ρ = 0.74).

CONCLUSIONS

Local SEFS may represent ECF status in the entire limb in both the leg and arm LE.

Behavioral abnormalities with disruption of brain structure in mice overexpressing VGF

VGF nerve growth factor inducible (VGF) is a neuropeptide induced by nerve growth factor and brain-derived neurotrophic factor. This peptide is involved in synaptic plasticity, neurogenesis, and neurite growth in the brain. Patients with depression and bipolar disorder have lower-than-normal levels of VGF, whereas patients with schizophrenia and other cohorts of patients with depression have higher-than-normal levels. VGF knockout mice display behavioral abnormalities such as higher depressive behavior and memory dysfunction. However, it is unclear whether upregulation of VGF affects brain function. In the present study, we generated mice that overexpress VGF and investigated several behavioral phenotypes and the brain structure. These adult VGF-overexpressing mice showed (a) hyperactivity, working memory impairment, a higher depressive state, and lower sociality compared with wild-type mice; (b) lower brain weight without a change in body weight; (c) increased lateral ventricle volume compared with wild-type mice; and (d) striatal morphological defects. These results suggest that VGF may modulate a variety of behaviors and brain development. This transgenic mouse line may provide a useful model for research on mental illnesses.

Correlation Between the Severity of Subcutaneous Echo-Free Space and the Amount of Extracellular Fluid Determined by Bioelectrical Impedance Analysis of Leg Edema

BACKGROUND

Both subcutaneous echo-free space (SEFS) observed by ultrasonography and the ratio of intracellular fluid resistance to extracellular fluid resistance (R_i/R_e) calculated from bioelectrical impedance analysis (BIA) represent extracellular edema status in the extremities. We tried to correlate these parameters.

METHODS AND RESULTS

In 70 legs with venous edema (VE) and 68 legs with lymphedema (LE), subcutaneous tissue ultrasonography to determine SEFS severity (range, 0-2) and BIA to calculate R_i/R_e were performed. In the calf, SEFS severity showed good linear correlation with R_i/R_e, particularly in the lower lateral calf where the mean R_i/R_e for LE (SEFS grade 0: 3.2 ± 0.8; SEFS grade 1: 4.0 ± 0.9; SEFS grade 2: 6.3 ± 3.6) and VE (SEFS grade 0: 3.6 ± 0.6; SEFS grade 1: 4.4 ± 1.6; SEFS grade 2: 5.3 ± 2.0) was similar. In the thigh, a mild correlation was confirmed only in LE.

CONCLUSIONS

It may be concluded that SEFS in the lower calf area well represents the local fluid status regardless of the type of edema, but not so in the thigh.

Ulcer healing effect of autologous mixed sheets consisting of fibroblasts and peripheral blood mononuclear cells in rabbit ischemic hind limb

We developed mixed cell sheets consisting of fibroblasts and peripheral blood mononuclear cells that had high potency for secreting vascular endothelial growth factor. The purpose of this study was to confirm the therapeutic effects of mixed sheets in rabbits suffering from ulcers at the ischemic hind limbs. We used the ulcer model, which was constructed by implantation and sandwiching the skin between two magnets to be a representative of human refractory cutaneous ulcer. The ulcer healing rate of mixed cell sheets was higher than that of the control at an early stage of healing. The calf blood pressure and angiographic score, which were considered to reflect rough collateral blood flow, did not vary amongmixed cell sheets. However, through laser Doppler perfusion image, implantation of mixed cell sheets revealed a significant improvement in microvascular blood flow in the healed skin of the ischemic limb compared to trafermin, a recombinant human basic fibroblast growth factor, and the control. These results suggest that mixed cell may operate predominantly on the surface of the ischemic tissue by their angiogenic potency, thereby promoting healing of the ischemic ulcer. Mixed cell sheets could become a promising therapeutic material for refractory cutaneous ulcers.

Early and Mid-Term Outcomes Following TEVAR for Chronic Type B Aortic Dissection

We examined the outcomes of aortic remodeling for chronic type B aortic dissection (cTBD) after thoracic endovascular aneurysm repair (TEVAR).

Objective & Methods: Thirty-eight patients underwent TEVAR for cTBD at our institution. We classified cTBD patients into the early cTBD group (16 cases, 2 weeks–4 months from onset) and late cTBD group (22 cases, >4 months from onset).

Results: There were no cases of paraplegia, stroke, and hospital death in both groups. There was no worsening of complicated cases. We achieved false lumen thrombosis in cases with a double-barreled thoracic aorta. The early cTBD group had more complete shrinkage cases (60%) than the late cTBD group (11%).

Conclusion: We obtained favorable mid-term outcomes after TEVAR for cTBD patients. Early cTBD patients obtained good aortic remodeling with TEVAR. (This is a translation of Jpn J Vasc Surg 2016; 25: 233–239.)

Self-Care-Based Treatment Using Ordinary Elastic Bandages for Venous Leg Ulcers

Objective: We aimed to study venous leg ulcer (VLU) healing and recurrence rates of VLU using a self-care-based treatment strategy. Methods: The study included 36 patients (43 legs) who visited our clinic between April 2009 and June 2015 because of non-healing VLUs and who had been treated by us for more than a year (until June 2016). Patients or their caregivers were first provided instructions for performing the "no-intentional-stretch" bandaging technique using ordinary elastic bandages. Wounds were cleansed with tepid water daily, and bandages were re-applied by patients or their caregivers; this was continued until VLUs were healed. Compression was discontinued after healing, but was restarted if persistent swelling and/or dermatitis was noticed on their legs. Results: The median ulcer size was 6.5 cm² (range, 1-105 cm²). The median number of clinic visits until healing was six (range, 3-35). The 6- and 12-month healing rates were 67% and 86%, respectively. Twenty (44%) legs required compression therapy after VLU healing. The cumulative recurrence-free rate at 60 months was 86%. Conclusion: Reasonable healing and recurrence rates were achieved by applying a self-care-based VLU treatment strategy.

Skin and Subcutaneous Tissue Ultrasonography Features in Breast Cancer-Related Lymphedema

Objective: To investigate skin, subepidermal low echogenic band (SELEB), and subcutaneous tissue (SCT) thickness as well as the degree of increase in subcutaneous echogenicity (SEG) and subcutaneous echo-free space (SEFS) in arms with lymphedema (LE). Materials and Methods: The skin and SCT of both arms of 30 patients with unilateral stage II breast cancer-related LE were scanned at five points (medial/lateral upper arm/forearm and dorsum of the hand). SEG and SEFS grades were determined according to severity (range: 0-2). Results: All measured parameters, except the SEFS in the medial upper arm, were significantly higher on the LE side than on the normal (N) side. The parameters differed most remarkably in the medial forearm (MFA; skin: LE 1.7 ± 0.8 mm vs. N 0.8 ± 0.2 mm; SELEB: LE 1.0 ± 0.6 mm vs. N 0.3 ± 0.1 mm; SCT: LE 8.7 ± 3.4 mm vs. N 3.8 ± 2.0 mm; SEG: LE 0.9 ± 0.5 vs. N 0.1 ± 0.3; and SEFS: LE 0.5 ± 0.7 vs. N 0). Conclusion: The differences in the thickness of the skin, SELEB, and SCT and the SEG and SEFS grades between the LE and N arms seemed most evident in the MFA.

Risk Factors in Patients with Venous Stasis-Related Skin Lesions without Major Abnormalities on Duplex Ultrasonography

Purpose: To clarify the risk factors for venous stasis-related skin lesions in the legs in patients without major abnormalities on duplex ultrasonography (DUS). Methods: Fifty patients (nine males and 41 females, age 27-93 years) with symptoms of C4 or greater according to the Clinical, Etiological, Anatomical, Pathological (CEAP) classification, but having no abnormalities on DUS were reviewed for known risk factors for chronic venous insufficiency (CVI) such as older age (>70 years), obesity (body mass index [BMI] >30 kg/m²), short walking distance (<200 m/day), reduced ankle range of motion (<20°), and occupation requiring prolonged standing (>8h per day). Results: The risk factor was different between male and female patients; although all patients had at least one of the above risk factors, the most commonly found risk factor in male patients was occupation requiring prolonged standing (63%), while advanced age (78%) and limited walking distance (83%) were risk factors in female patients. Conclusions: Although male and female patients had different risk factors, insufficient walking seemed to be closely related to the development of venous stasis-related skin lesions.

Improvement of immunoassay detection system by using alternating current magnetic susceptibility

A major goal with this research was to develop a low-cost and highly sensitive immunoassay detection system by using alternating current (AC) magnetic susceptibility. We fabricated an improved prototype of our previously developed immunoassay detection system and evaluated its performance. The prototype continuously moved sample containers by using a magnetically shielded brushless motor, which passes between two anisotropic magneto resistance (AMR) sensors. These sensors detected the magnetic signal in the direction where each sample container passed them. We used the differential signal obtained from each AMR sensor's output to improve the signal-to-noise ratio (SNR) of the magnetic signal measurement. Biotin-conjugated polymer beads with avidin-coated magnetic particles were prepared to examine the calibration curve, which represents the relation between AC magnetic susceptibility change and polymer-bead concentration. For the calibration curve measurement, we, respectively, measured the magnetic signal caused by the magnetic particles by using each AMR sensor installed near the upper or lower part in the lateral position of the passing sample containers. As a result, the SNR of the prototype was 4.5 times better than that of our previous system. Moreover, the data obtained from each AMR sensor installed near the upper part in the lateral position of the passing sample containers exhibited an accurate calibration curve that represented good correlation between AC magnetic susceptibility change and polymer-bead concentration. The conclusion drawn from these findings is that our improved immunoassay detection system will enable a low-cost and highly sensitive immunoassay.

Comparing immunocompetent and immunodeficient mice as animal models for bone tissue engineering

OBJECTIVES

To understand the differences and similarities between immunocompetent and immunodeficient mice as ectopic transplantation animal models for bone tissue engineering.

MATERIALS AND METHODS

Osteogenic cells from mouse leg bones were cultured, seeded on β-TCP granules, and transplanted onto the backs of either immunocompetent or immunodeficient nude mice. At 1, 2, 4, and 8 weeks postoperatively, samples were harvested and evaluated by hematoxylin-eosin staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemical staining and quantitative PCR.

RESULTS

In immunocompetent mice, inflammatory cell infiltration was evident at 1 week postoperatively and relatively higher expression of TNF-α and IL-4 was observed. In immunodeficient mice, new bone area and the number of TRAP-positive cells were larger at 4 weeks than in immunocompetent mice. The volume of new bone area in immunodeficient mice was reduced by 8 weeks.

CONCLUSIONS

Bone regeneration was feasible in immunocompetent mice. However, some differences were observed between immunocompetent and immunodeficient mice in the bone regeneration process possibly due to different cytokine expression, which should be considered when utilizing in vivo animal models.

Stimulation of liver functions in hierarchical co-culture of bone marrow cells and hepatocytes

A hierarchial co-culture, in which rat hepatocytes and non-parenchymal liver cells (NPLCs) were separated by a collagen layer and which was designed to mimic the in vivo microenvironment, was carried out with the aim of developing a module for bio-artificial liver support. Compared with a monolayer co-culture and hepatocytes cultured alone in a monolayer, higher urea synthesis activity was maintained for 6 d in the hierarchical co-culture. When a rat hepatoma cell line H4-II-E-C3, which retains the induction of tyrosine aminotransferase (TAT), was co-cultured in a monolayer with NPLCs, dose-dependent stimulation of TAT induction was observed. In a hierarchical co-culture, NPLCs further stimulated TAT induction in H4-II-E-C3 cells. Since peritoneal macrophages could stimulate TAT induction in hepatocytes in both monolayer and hierarchical co-cultures, bone marrow cells, which can proliferate and differentiate into macrophages in vitro, were investigated as a possible substitute for NPLCs. Bone marrow cells isolated from rat femurs were cultivated in the presence of IL-3 and macrophage colony-stimulating factor (M-CSF), and co-cultured with hepatocytes. Urea synthesis and TAT induction of hepatocytes were stimulated in the co-culture. The co-culture of bone marrow and H4-II-E-C3 cells, both of which have proliferation ability in vitro, was also shown to be effective in stimulating liver functions. The hierarchical configuration, in which two cell types can communicate with the soluble factor(s) through a collagen layer, was found to be more effective than a monolayer in long-term co-culture.

Monitoring of fluconazole in serum of patients undergoing hemodiafiltration by solid-phase extraction and high-performance liquid chromatography with ultraviolet detection

A high-performance liquid chromatographic assay for monitoring the antifungal drug fluconazole in human serum was developed using a C18 reversed-phase column with isocratic elution. The method involved sample clean-up by solid-phase column extraction, and subsequent analysis required only 14 min per sample for separation and quantitation. The assay was precise, with intra- and inter-assay relative standard deviations of < or = 1.5% and < or = 3.1%. The minimum detectable concentration of fluconazole was 0.3 nmol/ml. This assay has the advantage of minimizing the risk of interference from co-administered drugs to critically ill patients undergoing hemodiafiltration.