A bolus of saline injection leads to increase in coronary flow based on the viscosity reduction effect: the mechanism of saline induced Pd/Pa ratio

Background

In conjunction with fractional flow reserve (FFR), our previous study has shown the accuracy and utility of saline induced Pd/Pa ratio (SPR) for the assessment of myocardial ischemia. However, the potential mechanism how saline injection leads to increase in coronary flow remains speculative.

Purpose

This study aimed to clarify the underlying mechanism of SPR by using swine models.

Methods

The study was conducted in four swine models, and bolus of 25°C saline, 40°C saline, and 25°C dextran was injected at rates of 40mL/5sec through a catheter inserted into the superior mesenteric artery. Its peripheral arterioles were observed and recorded by a digital microscope, and transit time of each fluid and a luminal diameter of arterioles before and after injection were measured.

Results

The result from arterioles diameters of pre- and post-injection (0.049±0.016mm vs. 0.050±0.016mm; P=0.636) indicated that luminal diameters remained unchanged regardless of fluid administration. The transit time of 25°C saline was significantly shorter than 25°C dextran (3.19±0.68sec vs. 6.15±1.19sec; P<0.0001). Although the result showed no significance, the transit time of 40°C saline with lower viscosity was shorten compared to 25°C saline (3.1±0.43sec vs. 3.65±0.46sec; P=0.088).

Conclusions

Compared to 25°C dextran (viscosity of 4.991mPa·s) having the same viscosity as 37°C whole blood, 25°C saline (viscosity of 1.012mPa·s) caused increasing to double the intravascular flow volume without dilating arterioles. The results strongly suggested that the potential mechanism of SPR was viscosity reduction effect. Combined with FFR which is based on vasodilation-mediated hyperemia, these findings may contribute to clarifying the pathophysiology and especially the microcirculation in coronary artery diseases.

Funding Acknowledgement

Type of funding source: None

The efficacy of eribulin mesylate for patients with cutaneous angiosarcoma previously treated with taxane: a multicentre prospective observational study

BACKGROUND

Taxanes are the current first-line treatment for advanced cutaneous angiosarcoma (CAS) for patients who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. However, no effective second-line therapy for such patients has been established.

METHODS

We designed a single-arm prospective observational study of eribulin mesylate (ERB) administered at a dose of 1·4 mg m^-2 on days 1 and 8 in a 21-day cycle. Patients with advanced CAS who were previously treated with a taxane and were scheduled to begin ERB treatment were enrolled. The primary endpoint was overall survival (OS) and the secondary endpoints were response rate (RR), progression-free survival (PFS) and toxicity assessment.

RESULTS

We enrolled a total of 25 patients. The median OS and PFS were 8·6 months and 3·0 months, respectively. The best overall RR was 20% (five of 25). In total, 16 grade 3/4 severe adverse events (SAEs) occurred; however, all patients recovered. Patients who achieved partial response or stable disease as best response had longer OS than those with progressive disease (median OS not reached and 3·3 months, respectively; P < 0·001). Patients who did not experience SAEs showed longer OS than those who did (median OS 18·8 months and 7·5 months, respectively; P < 0·05). Patients with distant metastasis had shorter median OS than those with locoregional disease, but without statistically significant difference.

CONCLUSIONS

ERB showed a promising RR and is a potential candidate for second-line treatment for patients with CAS, after treatment with taxanes. However, owing to the occurrence of SAEs in over half of the participants, caution should be exercised regarding ERB use in elderly patients. What is already known about this topic? Taxanes are the current first-line treatment for patients with advanced cutaneous angiosarcoma (CAS) who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. No effective therapy for taxane-resistant CAS has been established thus far. Eribulin suppresses microtubule polymerization and elicits an antitumour effect similar to that of taxanes. What does this study add? In our single-arm prospective observational study to evaluate the efficacy of eribulin for treating patients with advanced CAS who previously received taxanes, the median overall survival and progression-free survival were 8·6 and 3·0 months, respectively. Response rates at weeks 7, 13 and 25 were 20%, 17% and 14%, respectively. Although 16 grade 3/4 severe adverse events occurred, all patients recovered. Eribulin showed a promising response rate and is a potential candidate for second-line treatment in CAS after taxane treatment. Linked Comment: Smrke and Benson. Br J Dermatol 2020; 183:797-798.

P315In-vivo and vitro mitochondrial transfer from adipose-derived mesenchymal stem cell to ischemic cardiomyocyte

Background

Although transplantation of human Adipose-derived Mesenchymal stem cell (hADSC) shows efficacy in the treatment of ischemic cardiomyopathy, its therapeutic mechanisms have not been fully elucidated. It has been already reported that mitochondria transfer to recipient cells have impact on resistance to injury and tissue regeneration, however this phenomenon has not been elucidated in the damaged heart. Therefore, we hypothesized that ADSC transfer own mitochondria to cardiomyocytes in-vivo and in-vitro under ischemic condition, resulting in the functional recovery of cardiomyocyte.

Method and result

Transplantation of hADSC (group A) to the heart surface or sham operation (group C) was performed in rats that were subjected to LAD ligation 2 weeks prior to the treatment (n=10 each). The number of transplant cell was 1x106/body. Three days after transplantation, transferred hADSCs' mitochondria were observed in recipient cardiomyocytes histologically (Figure). Quantitative PCR analysis revealed that mitochondrial genome of recipient myocytes increased over time. The cardiac function assessed with echocardiography was significantly better in group A. Furthermore, live-imaging of hADSC transplantation revealed the suspected transfer of mitochondria to beating heart.

In-vitro, the co-culture of rat cardiomyocytes (rCM) and hADSC was observed with time-lapse photography and demonstrated mitochondrial transfer under the hypoxic condition. The measuring the oxygen consumption rate (OCR) of these cells showed that OCR of rCM was reinforced by co-culture with hADSC conspicuously.

Figure 1

Conclusion

Mitochondrial transfer from hADSC to rCM was suggested in-vivo and in-vitro ischemic condition and suspected to be related to functional recovery of ischemic cardiomyocyte.

Abstract P1-11-01: Oral care evaluation to prevent oral mucositis in estrogen receptor positive metastatic breast cancer patients treated with everolimus (Oral Care-BC): A randomized controlled phase III trial

Introduction

Oral mucositis is a clinically significant complication of mucotoxic cancer therapy. The incidence of oral mucositis (any grade) as an adverse drug reaction of everolimus is 58%, while an analysis of Asian people has reported its occurrence as 81%.This study hypothesizes that the occurrence of oral mucositis will reduce with professional oral care (POC) administered prior to everolimus treatment.

Method:

This was a randomized, multi-center, open-label, phase III study, to evaluate the efficacy of POC in preventing mucositis induced by everolimus in postmenopausal, estrogen receptor (ER)-positive, metastatic breast cancer patients. Patients were randomized into POC and control groups (1:1 ratio). All patients received everolimus with exemestane and continued the everolimus until disease progression. In the POC group, patients were subjected to teeth surface cleaning, scaling and tongue cleaning, before initiating everolimus, and continued to receive weekly POC from dentist or oral surgeons throughout the 8 weeks of treatment. In the control group, patients brushed their own teeth and gargled with 0.9% sodium chloride solution or water. The primary end-point was to measure the incidence of all grades of oral mucositis. Target accrual was 200 patients with a 2-sided type I error rate of 5% and 80% power to detect 25% risk reduction. This trial has been registered at ClinicalTrials.gov, number NCT 02069093.

Result:

Between May 26, 2014 and Dec 28, 2017, we enrolled 174 women from 31 institutions; 168 were evaluable for efficacy but 5 were excluded (had not received the protocol treatment [n=4]; no efficacy data [n=1]). In 8 weeks, the incidence of grade 1 oral mucositis was significantly different between the POC group (76.5%, 62 of 81 patients) and control group (89.7%, 78 of 87 patients) (p=0.035). The incidence of grade 2 (severe) oral mucositis was also significantly different between the POC group (34.6%, 28 of 81 patients) and control group (54%, 47 of 87 patients) (p= 0.015). As a result of oral mucositis, 18 (22.2%) patients in the POC group and 28 (32.2%) in the control group had to undergo everolimus dose reduction.

Conclusion:

POC reduced the incidence and severity of oral mucositis in patients receiving everolimus and exemestane. This could be a new standard in oral care for patients undergoing this treatment.

Primary Analysis: Incidence Probability of Oral Mucositis POC Group (n=81) Controll (n=87)P-valuneOral Mucositis over Grade1n% n% Yes6276.5 7889.70.035No1923.5 910.3        Risk Difference, % (95% CI)-11.83 (-22.80, -0.85)    POC: Professional oral Care

Citation Format: Niikura N, Nakatukasa K, Amamiya T, Watanabe K-i, Hata H, Kikawa Y, Taniike N, Yamanaka T, Mitsunaga S, Nakagami K, Adachi M, Kondo N, Horii K, Hayashi N, Naito M, Kashiwabara K, Yamashita T, Umeda M, Mukai H, Ota Y. Oral care evaluation to prevent oral mucositis in estrogen receptor positive metastatic breast cancer patients treated with everolimus (Oral Care-BC): A randomized controlled phase III trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-11-01.

Identification and expression analysis of cDNA encoding insulin-like growth factor 2 in horses

Insulin-like growth factor 2 (IGF2) is responsible for a broad range of physiological processes during fetal development and adulthood, but genomic analyses of IGF2 containing the 5ʹ- and 3ʹ-untranslated regions (UTRs) in equines have been limited. In this study, we characterized the IGF2 mRNA containing the UTRs, and determined its expression pattern in the fetal tissues of horses. The complete equine IGF2 mRNA sequence harboring another exon approximately 2.8 kb upstream from the canonical transcription start site was identified as a new transcript variant. As this upstream exon did not contain the start codon, the amino acid sequence was identical to the canonical variant. Analysis of the deduced amino acid sequence revealed that the protein possessed two major domains, IlGF and IGF2_C, and analysis of IGF2 sequence polymorphism in fetal tissues of Hokkaido native horse and Thoroughbreds revealed a single nucleotide polymorphism (T to C transition) at position 398 in Thoroughbreds, which caused an amino acid substitution at position 133 in the IGF2 sequence. Furthermore, the expression pattern of the IGF2 mRNA in the fetal tissues of horses was determined for the first time, and was found to be consistent with those of other species. Taken together, these results suggested that the transcriptional and translational products of the IGF2 gene have conserved functions in the fetal development of mammals, including horses.

Ultrasonographic findings can identify 'pseudoprogression' under nivolumab therapy

'Pseudoprogression' is often seen in patients with melanomas who are treated with immune checkpoint inhibitors such as nivolumab or ipilimumab. We sometimes evaluate metastatic lesions by imaging tests such as computed tomography (CT) or positron emission tomography-CT. 'Pseudoprogression' usually occurs upon the initial administration, which may make it difficult for the physician to determine the disease condition. In our two cases of metastatic melanoma treated with nivolumab (antiprogrammed cell death-1 antibody), we examined the ultrasonography (US) of target lesions that could be accessed from the body surface, such as those of the regional lymph node or subcutaneous metastasis. In both cases, the US revealed a lesion approximately 10% greater in size after 40-50 days of nivolumab administration, even though the blood flow inside the tumour was reduced by about 20% within 50 days. From about 100 days after blood flow reduction was detected by US, the tumours began to decrease in size. However, contrast CT was unable to detect the association between tumour size and tumour blood flow. The present cases suggest that US could be a powerful tool for differentiating between 'pseudoprogression' and real progressive disease in patients treated with cancer immunotherapies such as those involving immune checkpoint inhibitors. The misdiagnosis of progressive disease can lead to unnecessary alterations to the current treatment. Therefore, the US findings in our study could be clinically useful and educational for physicians.

Adjuvant therapy with low-dose interferon-beta for stage II and III melanoma: results of a retrospective analysis

Interferon (IFN)-alfa as an adjuvant therapy has been found to improve relapse-free survival in patients with malignant melanoma (MM). However, the efficacy of IFN-beta has not been studied in detail. This study evaluated the contribution of adjuvant IFN-beta therapy to improvements in the prognosis of patients with MM. We reviewed 63 patients with resected stage II/III primary MM at our institution. Of these, 36 had been treated with IFN-beta adjuvant therapy (subcutaneous injection, 3 × 10⁶ IU/day, 10 days), while 27 patients had undergone observation alone. In comparisons of all patients (stage II/III), overall survival and relapse-free survival were significantly better in the IFN-beta group than in the observation group (P < 0.001 for both). The 75-month overall survival rate was 41.2% in the observation group and 68.7% in the IFN-beta group. Adjuvant therapy with IFN-beta may become a new treatment option for patients with stage II/III MM.

Multiple skin cancers in patients with mycosis fungoides after long-term ultraviolet phototherapy

Phototherapy is a useful noninvasive therapy, but it can induce cutaneous malignant tumours, including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). We report on a 79-year-old man who had long-standing mycosis fungoides for 40 years, which had been treated with psoralen ultraviolet A therapy for 37 years at a dose of approximately 5000 J/cm² . Approximately 6 years before presentation, numerous types of cutaneous malignancies, including actinic keratosis, BCC and SCC, had begun to develop all over the patient's body. We hypothesized that he was experiencing a pathogenesis similar to patients with xeroderma pigmentosum (XP), and we therefore assessed his DNA repair capacity. Based on these investigations, the patient was eventually diagnosed as non-XP, even though we detected that his DNA repair capacity was slightly lower than that of normal controls, which may have led to the skin cancers. We speculate that multiple skin malignancies can be induced by long-term phototherapy in patients with slightly impaired DNA repair capacity.

Percutaneous Coronary Intervention and Coronary Artery Bypass Grafting in Heart Transplant Recipients With Transplant Coronary Arterial Vasculopathy

BACKGROUND

Transplant coronary arterial vasculopathy (TCAV) is a major cause of death after heart transplantation (HTx). Palliative coronary revascularization has been attempted in patients with severe TCAV; however, the outcome has not been fully elucidated.

METHODS

Ninety-six patients who were treated after HTx at our institute between 1999 and 2015 were screened for TCAV. TCAV was defined as >70% stenosis on coronary angiography (CAG) or a maximal intimal thickness of >0.5 mm in the right or left coronary arteries on intracoronary ultrasonography (IVUS). In the present study, the outcomes of patients with severe TCAV who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were investigated.

RESULTS

TCAV containing donor-transmitted atherosclerosis was cumulatively found in 69 patients (71.9% of the total; mean age, 34.6 ± 13.1 years; 52 men; mean follow-up duration, 83.0 ± 60.4 months). Five (7.2%) and 64 (92.8%) of the 69 patients were diagnosed as having TCAV by use of CAG and IVUS, respectively. All 5 patients diagnosed by with the use of CAG underwent coronary revascularization between 1 and 236 months after HTx. Three patients underwent PCI with drug-eluting stents, with a primary success rate of 100%. No angiographic restenosis occurred in 2 patients at 31 and 36 months after PCI, respectively. Meanwhile, 2 patients underwent CABG. No peri-operative complications occurred, and all grafts were patent as assessed by use of CAG at 34 and 5 months after CABG.

CONCLUSIONS

Coronary revascularization was feasible and effective for severe TCAV with middle-term follow-up.

PU.1 acts as tumor suppressor for myeloma cells through direct transcriptional repression of IRF4

We previously reported that PU.1 is downregulated in the majority of myeloma cell lines and primary myeloma cells of certain myeloma patients, and conditional expression of PU.1 in such myeloma cell lines induced cell cycle arrest and apoptosis. We found downregulation of IRF4 protein in the U266 myeloma cell line following induction of PU.1. Previous studies reported that knockdown of IRF4 in myeloma cell lines induces apoptosis, prompting us to further investigate the role of IRF4 downregulation in PU.1-induced cell cycle arrest and apoptosis in myeloma cells. PU.1 induced downregulation of IRF4 at the protein level, cell cycle arrest and apoptosis in six myeloma cell lines. Chromatin immunoprecipitation (ChIP) revealed that PU.1 directly binds to the IRF4 promoter, whereas a reporter assay showed that PU.1 may suppress IRF4 promoter activity. Stable expression of IRF4 in myeloma cells expressing PU.1 partially rescued the cells from apoptosis induced by PU.1. As it was reported that IRF4 directly binds to the IRF7 promoter and downregulates its expression in activated B cell-like subtype of diffuse large B cell lymphoma cells, we performed ChIP assays and found that IRF4 directly binds the IRF7 promoter in myeloma cells. It is known that IRF7 positively upregulates interferon-β (IFNβ) and induces apoptosis in many cell types. Binding of IRF4 to the IRF7 promoter decreased following PU.1 induction, accompanied by downregulation of IRF4 protein expression. Knockdown of IRF7 protected PU.1-expressing myeloma cells from apoptosis. Furthermore, IFNβ, which is a downstream target of IRF7, was upregulated in myeloma cells along with IRF7 after PU.1 induction. Finally, we evaluated the mRNA expression levels of PU.1, IRF4 and IRF7 in primary myeloma cells from patients and found that PU.1 and IRF7 were strongly downregulated in contrast to the high expression levels of IRF4. These data strongly suggest that PU.1-induced apoptosis in myeloma cells is associated with IRF4 downregulation and subsequent IRF7 upregulation.

Spatial variation in the parasitic isopod load of the Japanese halfbeak in western Japan

Cymothoid isopods (family Cymothoidae) are commonly found parasitizing diverse fishes, including commercial species. However, the effects of these parasites on host body condition are still poorly known. Here we investigated the spatial variation of the effects of parasite infection on host body condition, using the parasitic load of the cymothoid Mothocya parvostis on the Japanese halfbeak Hyporhamphus sajori at 4 sampling sites in western Japan. M. parvostis prevalence at each site (41.6-74.4%) was higher than that known for other fish host-cymothoid systems (usually less than 30%). The number of isopods in infected hosts, the reproductive status of female isopods (i.e. ovigerous/non-ovigerous), and the body size of female and male isopods relative to the size of their hosts were not significantly different among sites. However, at the site where human activity was most intense, M. parvostis infection had a significantly negative effect on host body condition. These results suggest that the effect of cymothoid infection on host body condition might be benign under natural conditions but becomes detrimental in habitats that are unsuitable for the host, such as highly human-impacted areas.

Snell's Law for Spin Waves

We report the experimental observation of Snell's law for magnetostatic spin waves in thin ferromagnetic Permalloy films by imaging incident, refracted, and reflected waves. We use a thickness step as the interface between two media with different dispersion relations. Since the dispersion relation for magnetostatic waves in thin ferromagnetic films is anisotropic, deviations from the isotropic Snell's law known in optics are observed for incidence angles larger than 25° with respect to the interface normal between the two magnetic media. Furthermore, we can show that the thickness step modifies the wavelength and the amplitude of the incident waves. Our findings open up a new way of spin wave steering for magnonic applications.