The impact of rare cancer and early-line treatments on the benefit of comprehensive genome profiling-based precision oncology

BACKGROUND

Comprehensive genome profiling (CGP) serves as a guide for suitable genomically matched therapies for patients with cancer. However, little is known about the impact of the timing and types of cancer on the therapeutic benefit of CGP.

MATERIALS AND METHODS

A single hospital-based pan-cancer prospective study (TOP-GEAR; UMIN000011141) was conducted to examine the benefit of CGP with respect to the timing and types of cancer. Patients with advanced solid tumors (>30 types) who either progressed with or without standard treatments were genotyped using a single CGP test. The subjects were followed up for a median duration of 590 days to examine therapeutic response, using progression-free survival (PFS), PFS ratio, and factors associated with therapeutic response.

RESULTS

Among the 507 patients, 62 (12.2%) received matched therapies with an overall response rate (ORR) of 32.3%. The PFS ratios (≥1.3) were observed in 46.3% (19/41) of the evaluated patients. The proportion of subjects receiving such therapies in the rare cancer cohort was lower than that in the non-rare cancer cohort (9.6% and 17.4%, respectively; P = 0.010). However, ORR of the rare cancer patients was higher than that in the non-rare cancer cohort (43.8% and 20.0%, respectively; P = 0.046). Moreover, ORR of matched therapies in the first or second line after receiving the CGP test was higher than that in the third or later lines (62.5% and 21.7%, respectively; P = 0.003). Rare cancer and early-line treatment were significantly and independently associated with ORR of matched therapies in multivariable analysis (P = 0.017 and 0.004, respectively).

CONCLUSION

Patients with rare cancer preferentially benefited from tumor mutation profiling by increasing the chances of therapeutic response to matched therapies. Early-line treatments after profiling increase the therapeutic benefit, irrespective of tumor types.

Anatase and rutile titanium oxide nanoparticles induce acute kidney injury by coadministration with paraquat, cisplatin or 5-aminosalicylic acid

Nanoparticles are used in a variety of fields; for example, titanium oxide nanoparticles are used in paints, food additives, cosmetics, and sunscreen materials. Although the use of titanium oxide nanoparticles is regulated, their safety has not been established. Furthermore, the interaction between titanium oxide nanoparticles and various chemical substances and pharmaceuticals is unknown. We co-administered rutile-type titanium oxide nanoparticles (nTR) or anatase-type titanium oxide nanoparticles (nTA) to mice together with paraquat (PQ), cisplatin (CDDP), or anti-5-aminosalicylic acid (5-ASA), and investigated the extent, if any, of liver and kidney injury. As a result, when nTA and nTR were administered alone, no increases were observed in aspartate aminotransferase (AST) and alanine aminotransferase (ALT), which are indicators of liver damage, or urea nitrogen (BUN), which is an indicator of kidney damage. Next, nTA and nTR were co-administered with PQ, CDDP or 5-ASA. Although no increase in ALT or AST was observed, BUN levels increased significantly and acute kidney injury was induced. The findings suggested that titanium oxide nanoparticles induce acute kidney injury through their interaction with chemicals and drugs.

[Long-Term Complete Response following Chemotherapy for Advanced Gastric Cancer in an Elderly Patient]

A 78-year-old man was diagnosed with HER2-positive advanced gastric cancer, cT3N2M1(LYM: #16a1, 16b1), cStage ⅣB, after being referred for anemia. The lesion was deemed unresectable, and first-line chemotherapy was initiated using S-1, cisplatin(CDDP), and trastuzumab(T-mab). After 2 courses of chemotherapy, the patient developed febrile neutropenia( Grade 3). At this point, the lesion showed partial response(PR), and chemotherapy was continued using oral S-1 as a single agent. After 3 months of S-1 monotherapy, the para-aortic lymph node metastases showed a complete response (CR). S-1 monotherapy was continued without major adverse events for 2 years, and the patient is presently alive and well 6 years after obtaining clinical CR. This may suggest that S-1 is a safe and effective treatment for unresectable advanced gastric cancer in elderly patients.

P–611 Innovative controlled ovarian stimulation (COS) for polycystic ovary syndrome (PCOS) produces high-quality oocytes and no ovarian hyper stimulation syndrome (OHSS)

Study question

How can we find an ovarian stimulation method that does not cause hyper stimulation syndrome but can produce a high pregnancy rate at one cycle?

Summary answer

This newly developed method for PCOS has a higher accumulative clinical outcome for one trial and no OHSS.

What is known already

Almost all conventional treatments for PCOS have managed to avoid OHSS by reducing the number of growing follicles, which are associated with high Estradiol levels and stimulate the production of vessel endothelial growth hormone (VEGF), leading to increased vessel permeability. Low dose FSH administration, In vitro maturation (IVM), Ovarian Drilling and Coasting have been performed to achieve this. However, their actual clinical outcome is still unsatisfactory.

Study design, size, duration

Evaluation of the efficiency of this method was conducted retrospectively at St. Mother Clinic. The embryonic development and the clinical outcome were studied for 34 PCOS patients during the period between November 2018 and December 2019.

Participants/materials, setting, methods

We started injections of FSH (150iu/ml), then we did ultrasound follicle monitoring. GnRH antagonist shots were started when the leading follicle reached 18mm and continued until the largest follicle was 22–24mm and the E2 value was over 4000pg/ml. Letrozole (2.5mg) and leuprorelin acetate (1.88mg) was injected as trigger. Two tablets each of Letrozole, Cabergoline and GnRH antagonist were given for 5 consecutive days after the oocyte retrieval. All embryos were cryopreserved.

Main results and the role of chance

Number of patients and cycles were 34 and 59. Average number of cryopreserved blastocysts was 6.12 (1–16). The frequencies of OHSS (mild, moderate, severe) were 29.4% (10/34), 0% (0/34), 0% (0/34). Average days between oocyte collection and withdrawal hemorrhage was 5.44(5–7). Cryopreservation rate was 100.0% (34/34). Clinical pregnancy rate and miscarriage rate was 42.3% (25/59) and 16.0% (4/25). The cumulative pregnancy rate was 73.7% (25/34). The four remaining unsuccessful cases still have 10,6,3 and 7 frozen embryos. So, there is a high possibility that they become successful, that would bring the cumulative pregnancy rate up to 82.3% (28/34).

Limitations, reasons for caution

This COS for PCOS seems promising, however it is premature to conclude that this method is established. This method requires caution monitoring for hormone level, follicle size and number and coagulant function. It also accompanied with the risk of ovarian hemorrhage on aspiration of a great number of oocytes.

Wider implications of the findings: This COS seems viable for PCOS cases. It could control the cohort of antral follicles with different doses of Letrozole to find the optimal COH method and it could become the first option for COS of PCOS.

Trial registration number

N/A

Anomalous origin of the coronary artery coursing between the great vessels presenting with a cardiovascular event (J-CONOMALY Registry)

AIMS

Anomalous origin of the coronary artery (AOCA) with an inter-arterial course (IAC) between the great vessels poses a risk for a life-threatening cardiovascular event. We assessed, in a registry-based study, the clinical features, treatment strategies, and prognoses of life-threatening cardiovascular events ensuant to AOCA.

METHODS AND RESULTS

Included were 65 AOCA patients (48 men/17 women, aged 41 ± 23 years) from 40 clinical centres who had experienced sudden cardiac arrest (SCA) (n = 30), acute myocardial infarction (AMI) (n = 5), angina (n = 23), or syncope (n = 7). The anomalous vessel was the right coronary artery in 72% of patients and left coronary artery in 28%; the ostium was slit-like in 42%. Coronary luminal narrowing ≥75% was absent in patients with SCA or syncope (86% and 57%, respectively), but occlusion or narrowing was seen in those with AMI (100%) or angina (52%). Age ≤40 years, male sex, sporting activity, absence of prodromal symptoms, acutely angled (≤30°) take-off from the aorta, and absence of luminal narrowing of the IAC segment were associated with SCA in this patient group. Coronary vasospasm was inducible in 12 of 17 patients without coronary narrowing. Management included surgical revascularization (n = 26) percutaneous coronary intervention (n = 9), and medical treatment (n = 26). Four SCA patients died while hospitalized; no others died during the median 5.0 (range, 1.8-7.0)-year follow-up period.

CONCLUSIONS

In patients with AOCA, age ≤40 years, male sex, sporting activity, and an acute take-off angle appear to be risk factors for SCA. Appropriate management can be beneficial. Confirmation in a large-scale study is warranted.

Effect of Endovascular Treatment on Systemic Vascular Resistance in Patients with Lower-Limb Peripheral Artery Disease

Objective: Endovascular treatment (EVT) for lower-limb peripheral artery disease patients reduces blood pressure (BP) and improves prognosis. This study retrospectively examined hemodynamics during EVT to clarify the mechanism. Materials and Methods: Systemic vascular resistance (SVR) was measured using a noninvasive continuous cardiac output monitoring system during EVT. Furthermore, ankle brachial index was measured before and after EVT. Results: The study included 88 lesions of 56 patients (hypertension in 98%). SVR significantly decreased from 2409.1±746.8 dynes·s·cm^-5 to 2033.7±635.0 dynes·s·cm^-5 (p<0.0001). The difference in SVR before and after EVT was significantly greater in the Fontaine IV group than in the Fontaine IIa group (554.7±406.6 dynes·s·cm^-5 vs. 312.9±245.7 dynes·s·cm^-5, p=0.0151). The change in SVR was correlated with a change in mean BP in the upper limb (p=0.0026). When the change in pressure gradient between the upper limb and the diseased lower limb was large, mean BP of the upper limb significantly decreased (p=0.0022). Conclusion: EVT can reduce SVR and BP by canceling the pressure gradient between central BP and diseased lower-limb BP.

P2560Metalloprotease nardilysin controls heart rate through the transcriptional regulation of ion channels critical for sinus automaticity

Acknowledgement/Funding

KAKENHI (17K09575)

238Pu/(239+240)Pu activity ratio as an indicator of Pu originating from the FDNPP accident in the terrestrial environment of Fukushima Prefecture

The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident has caused significant radionuclide contamination. Pu isotopes at the level of GBq were released from the damaged reactors to terrestrial and marine ecosystems. In this work, 35 samples were collected at different locations of Fukushima. Samples consisted of three types, soil, forest litter and alluvial dust (road dust, sludges from drainage systems and below gutter pipe outflows). The obtained activity ratios of ²³⁸Pu/^(239+240)Pu ranged from 0.030 to 1.86. 14 of our samples contained trace amounts of Pu originating from the damaged reactors (2SM verification). Our study identified a few previously unknown "hot spots" of ²³⁸Pu/^(239+240)Pu activity ratio localized in an area between 15 and 30 km in the northwest direction from the FDNPP. Additionally, results obtained in this study combined with previously published data allowed us to prepare a map of spatial distribution of the Pu isotope fingerprints (²³⁸Pu/^(239+240)Pu) in Fukushima Prefecture.

Aspects of splice site selection in constitutive and alternative pre-mRNA splicing

RNA splicing is an indispensable step for expression of many eukaryotic genes. Combinations of 5' and 3' splice sites should be correctly selected in both constitutive and alternative splicing. Recent studies have revealed mechanisms of alternative splicing in some systems, in which specific regulators play vital roles in splice site selection. On the other hand, essential splicing factors such as SR proteins modulate splice site usage of general machinery. Specific regulators and splicing factors such as SR proteins have some common structural features. With these related components, a similar machinery of splice site selection is involved in constitutive and alternative splicing.

Evaluation of economic burden of colonic surgical site infection at a Japanese hospital

BACKGROUND

Several reports have been published regarding cost increases attributable to surgical site infections (SSIs) in Europe and the USA. However, such studies have been limited in Japan.

AIM

To evaluate the economic burden of colorectal SSIs on hospitals in Japan.

METHODS

This study was undertaken at a Japanese university hospital. Amongst 265 patients who had undergone colorectal surgery in the Department of Coloproctological Surgery between November 2014 and March 2016, 16 patients who developed SSIs and could be allocated a diagnosis procedure combination code were selected as SSI cases. Individual SSI cases were matched to non-SSI cases based on a combination of surgical category, age band, sex, wound class, presence of stoma and risk index. Median length of stay (LOS) and piecework reference cost were compared between SSI episodes and non-SSI episodes.

FINDINGS

The median LOS for patients with SSI and without SSI was 25.5 [interquartile range (IQR) 21.5-39.3] and 16.5 (IQR 12.5-18.5) days, respectively (P<0.01). The median piecework reference cost for patients with SSI and without SSI was ¥842,155 (IQR ¥716,423-1,388,968) and ¥575,795 (IQR ¥529,638-680,105), respectively (P<0.01).

CONCLUSION

SSIs led to a significant increase in LOS and economic burden. Although the SSI episodes appear to be more profitable than the non-SSI episodes, the economic profit for SSI episodes was less than that for non-SSI episodes in the observation period, when opportunity costs were taken into account.

Occurrence of Focal Atrial Tachycardia During the Ablation Procedure Is Associated With Arrhythmia Recurrence After Termination of Persistent Atrial Fibrillation

INTRODUCTION

Catheter ablation can terminate persistent atrial fibrillation (AF). However, atrial tachycardia (AT) often arises after termination of AF.

METHODS AND RESULTS

Of 215 patients who underwent index stepwise ablation for persistent AF, 141 (66%) patients (64 ± 9 years) in whom AF terminated during the ablation procedure were studied. If AF converted into AT, ablation for AT was subsequently performed. ATs were categorized as focal or macroreentrant AT. We assessed whether type of AT occurring after conversion of AF during the ablation procedure was associated with freedom from atrial tachyarrhythmia (AF or AT) during follow-up. Sinus rhythm was directly restored from AF in 37 patients, while 34, 37, and 33 patients had focal AT alone, a mix of focal and macroreentrant AT, and macroreentrant AT alone after termination of AF, respectively. Arrhythmia-free survival rates at 1 year after the index procedure were 30%, 34%, 61%, and 59% in the patients with focal AT alone, a mix of focal AT and macroreentrant AT, macroreentrant AT alone, and direct restoration of sinus rhythm, respectively (P = 0.004). Type of AT occurring during the index procedure was associated with type of recurrent AT (P = 0.03), but the origin of focal AT occurring during the index ablation differed from that of the recurrent AT in 85% of patients.

CONCLUSION

In patients who had AF termination by ablation, occurrence of focal AT during the ablation procedure was associated with worse clinical outcome than occurrence of macroreentrant AT, likely due to ATs arising from other foci during follow-up.

[A Case of Severe Bradycardia Induced by Combination Chemotherapy with Cisplatin and 5-Fluorouracil]

A 78-year-old man with Stage III esophageal cancer was referred to our hospital. Combination chemotherapy with cisplatin (CDDP) and 5-fluorouracil (5-FU) was initiated. The patient experienced bradycardia episodes after starting the cisplatin infusion on day 1; he was otherwise asymptomatic. Therefore, combination chemotherapy was continued. However, on day 4, his heart rate dropped to 22 beats/min, with no other symptoms; however, treatment was stopped. After treatment was stopped, the patient's heart rate improved gradually and returned to normal in a few days. Combination chemotherapy with CDDP and 5-FU is a useful treatment for esophageal cancer, but it may induce severe bradycardia. Therefore, we must perform infusion therapy with caution.

Paget's disease of the male breast: a case report

The patient was a 91-year-old man with change in nipple appearance, itching and redness, and a palpable breast mass. At presentation, mammary Paget’s disease (PD) was clinically suspected. Skin biopsy was performed and showed epidermis invaded by Paget cells, characterized by hyperchromatic nuclei and abundant pale-staining cytoplasm. Computed tomography and mammary ultrasonography confirmed the absence of an underlying invasive carcinoma, and the patient underwent right mastectomy and sentinel lymph node biopsy (SLNB). Both sentinel lymph nodes were found to be negative perioperatively, and further axillary dissection was not performed. Pathological results revealed no malignancy under the nipple, yet the Paget cells were more widely spread than expected. The patient was followed up without the need of postoperative chemotherapy. Male mammary PD is an extremely rare breast cancer, and there is no standard preoperative assessment or operative procedure. Mammography is many times unable to detect possible underlying breast carcinoma in female patients with mammary PD, and previous studies have reported that the detection rate was less than 50 %. However, some researchers reported that magnetic resonance imaging (MRI) might be more detectable to confirm the extent of the cancer. The extent of the skin change around the nipple is often different from the actual perimeter of Paget cells. In extra-mammary PD, mapping biopsy is known to be useful to determine areas free of cancer. The benefits of SLNB have also been demonstrated for the management of less invasive breast cancers, and previous reports have shown that the use of SLNB is reasonable for treatment of mammary PD without underlying invasive cancer. MRI, mapping biopsy, and SLNB are all less invasive procedures and thus may be suitable for treatment of male mammary PD.

Effects of BACE1 haploinsufficiency on APP processing and Aβ concentrations in male and female 5XFAD Alzheimer mice at different disease stages

β-Site APP-cleaving enzyme 1 (BACE1) initiates the generation of amyloid-β (Aβ), thus representing a prime therapeutic target for Alzheimer's disease (AD). Previous work including ours has used BACE1 haploinsufficiency (BACE1(+/-); i.e., 50% reduction) as a therapeutic relevant model to evaluate the efficacy of partial β-secretase inhibition. However, it is unclear whether the extent of Aβ reductions in amyloid precursor protein (APP) transgenic mice with BACE1(+/-) gene ablation may vary with sex or disease progression. Here, we compared the impacts of BACE1 haploinsufficiency on Aβ concentrations and APP processing in 5XFAD Alzheimer mice (1) between males and females and (2) between different stages with moderate and robust Aβ accumulation. First, male and female 5XFAD mice at 6-7 months of age showed equivalent levels of Aβ, BACE1, full-length APP and its metabolites. BACE1 haploinsufficiency significantly lowered soluble Aβ oligomers, total Aβ42 levels and plaque burden in 5XFAD mouse brains irrespective of sex. Furthermore, there was no sex difference in reductions of β-cleavage products of APP (C99 and sAPPβ) found in BACE1(+/-)·5XFAD mice relative to BACE1(+/+)·5XFAD controls. Meanwhile, APP and sAPPα levels in BACE1(+/-)·5XFAD mice were higher than those of 5XFAD controls regardless of sex. Based on these observations, we next combined male and female data to examine the effects of BACE1 haploinsufficiency in 5XFAD mice at 12-14 months of age, as compared with those in 6-7-month-old 5XFAD mice. Oligomeric Aβ and C99 levels were dramatically elevated in older 5XFAD mice. Although the β-metabolites of APP were significantly reduced by BACE1 haploinsufficiency in both age groups, high levels of these toxic amyloidogenic fragments remained in 12-14-month-old BACE1(+/-)·5XFAD mice. The present findings are consistent with our previous behavioral data showing that BACE1 haploinsufficiency rescues memory deficits in 5XFAD mice irrespective of sex but only in the younger age group.

Recurrent mutations of CD79B and MYD88 are the hallmark of primary central nervous system lymphomas

AIMS

Primary central nervous system lymphoma (PCNSL) manifest aggressive clinical behaviour and have poor prognosis. Although constitutive activation of the nuclear factor-κB (NF-κB) pathway has been documented, knowledge about the genetic alterations leading to the impairment of the NF-κB pathway in PCNSLs is still limited. This study was aimed to unravel the underlying genetic profiles of PCNSL.

METHODS

We conducted the systematic sequencing of 21 genes relevant to the NF-κB signalling network for 71 PCNSLs as well as the pyrosequencing of CD79B and MYD88 mutation hotspots in a further 35 PCNSLs and 46 glioblastomas (GBMs) for validation.

RESULTS

The results showed that 68 out of 71 PCNSLs had mutations in the NF-κB gene network, most commonly affecting CD79B (83%), MYD88 (76%), TBL1XR1 (23%), PRDM1 (20%) and CREBBP1 (20%). These mutations, particularly CD79B and MYD88, frequently coincided within each tumour in various combinations, simultaneously affecting diverse pathways within the network. No GBMs had hotspot mutation of CD79B Y196 and MYD88 L265.

CONCLUSIONS

The prevalence of CD79B and MYD88 mutations in PCNSLs was considerably higher than reported in systemic diffuse large B-cell lymphomas. This observation could reflect the paucity of antigen stimuli from the immune system in the central nervous system (CNS) and the necessity to substitute them by the constitutive activation of CD79B and MYD88 that would initiate the signalling cascades. These hotspot mutations may serve as a genetic hallmark for PCNSL serving as a genetic marker for diagnose and potential targets for molecular therapy.

PSORIASIS OCCURING IN YOUNG MONOZYGOTIC TWINS

Psoriasis occuring in monozygotic twins is reported. Although these patients had a different living environment since birth the similarity in psoriatic pattern and its time of onset suggested the strong influence of genetic factors. However the major histocompatibility antigens A2, A11, Bw(16), found in these patients were not those, which have been reported to be significantly increased among Japanese psoriatics.

Peripheral microvascular dysfunction predicts residual risk in coronary artery disease patients on statin therapy

OBJECTIVE

Although lowering of low-density lipoprotein cholesterol (LDL-C) by statins is essential in treatment of coronary artery disease (CAD) patients, there is considerable residual risk of secondary coronary artery events (CAE). We examined whether microvascular dysfunction (MiD), measured by peripheral artery tonometry (PAT), can predict prognosis of CAD patients previously treated with statins.

METHODS

We measured log-transformed reactive hyperemia index (L_RHI) in 213 CAD patients who had already achieved LDL-C <100 by statin therapy. Patients were followed-up for secondary CAE for a median of 2.7 years. Patients were divided into two groups: L_RHI ≥ 0.54 (n = 99) and L_RHI < 0.54 (n = 114).

RESULTS

During follow-up, CAE occurred in 4 (4.0%) patients in the L_RHI ≥ 0.54 group and 18 (15.8%) patients in the L_RHI < 0.54 group (P = 0.006). Cox regression analysis indicated that L_RHI was an independent predictor for CAE even after adjustment by Framingham traditional risk factors (FRF; age, T-C/HDL-C ratio, systolic blood pressure, diabetes, current smoker, and gender) and estimated glomerular filtration rate (eGFR) for secondary CAE (HR 0.79, 95% CI: 0.66-0.95). ROC analysis for CAE prediction showed that the AUC for models including FRF only, FRF + eGFR, and FRF + eGFR + L_RHI were 0.60, 0.71, and 0.77, respectively. Moreover, adding eGFR to FRF only (0.63, P = 0.003) and adding L_RHI to the FRF + eGFR model were associated with significant improvement of net reclassification improvement (0.79, P = 0.007).

CONCLUSION

MiD measured by non-invasive PAT adds incremental predictive ability to traditional risk factors for prognosis of CAD patients successfully treated with statins.

Gallbladder bed pocket score as a preoperative measure for assessing the difficulty of laparoscopic cholecystectomy

INTRODUCTION

Laparoscopic cholecystectomy (Lap-C) is a standard surgery for symptomatic gallbladder stones and acute or chronic cholecystitis. Resident surgeons often perform this operation early in their training, but they sometimes encounter difficulties for various technical reasons. Although encountering a gallbladder buried deep within the gallbladder bed is a common operative difficulty, literature on the subject scarcely exists.

METHODS

Forty-two patients underwent Lap-C at our hospitals and were analyzed retrospectively. We defined the gallbladder bed pocket score (GBPS) as the maximum ratio between the height and width of the gallbladder bed measured based on multi-detector computed tomography (MDCT) images. GBPS and clinical factors were assessed in terms of their correlation with the time required for gallbladder dissection from the gallbladder bed.

RESULTS

Of the 42 patients, 20 had histories of acute or chronic cholecystitis. The mean gallbladder dissection time was 14.9 min, and the mean GBPS was 0.43 in the coronal MDCT section and 0.56 in the sagittal section. The correlation coefficient between the GBPS and gallbladder dissection time was 0.40 (P = 0.01) in the coronal section and 0.38 (P = 0.02) in the sagittal section of the MDCT images. There was no statistically significant correlation between gallbladder dissection time and the surgeon's experience, patient's history of cholecystitis, gallstone size, or blood loss. However, GBPS > 0.4 predicted more difficult and prolonged dissection.

CONCLUSION

GBPS is a useful tool for preoperatively predicting the time needed to dissect the gallbladder from the gallbladder bed during Lap-C. Cases with GBPS < 0.4 seem more suitable for resident surgeons who are performing gallbladder dissection early in their Lap-C training.

Mechanisms that lessen benefits of β-secretase reduction in a mouse model of Alzheimer's disease

The β-secretase enzyme BACE1 (β-site amyloid precursor protein-cleaving enzyme 1), which initiates amyloid-β (Aβ) production, is an excellent therapeutic target for Alzheimer's disease (AD). However, recent evidence raises concern that BACE1-inhibiting approaches may encounter dramatic declines in their abilities to ameliorate AD-like pathology and memory deficits during disease progression. Here, we used BACE1 haploinsufficiency as a therapeutic relevant model to evaluate the efficacy of partial inhibition of this enzyme. Specifically, we crossed BACE1(+/-) mice with 5XFAD transgenic mice and investigated the mechanisms by which Aβ accumulation and related memory impairments become less sensitive to rescue by BACE1(+/-) reduction. Haploinsufficiency lowered BACE1 expression by ∼50% in 5XFAD mice regardless of age in concordance with reduction in gene copy number. However, profound Aβ plaque pathology and memory deficits concomitant with BACE1 equivalent to wild-type control levels remained in BACE1(+/-)·5XFAD mice with advanced age (15-18 months old). Therefore, BACE1 haploinsufficiency is not sufficient to block the elevation of BACE1 expression (approximately twofold), which is also reported to occur during human AD progression, in 5XFAD mice. Our investigation revealed that PERK (PKR-endoplasmic reticulum-related kinase)-dependent activation of eIF2α (eukaryotic translation initiation factor-2α) accounts for the persistent BACE1 upregulation in BACE1(+/-)·5XFAD mouse brains at 15-18 months of age. Moreover, BACE1 haploinsufficiency was also no longer able to prevent reduction in the expression of neprilysin, a crucial Aβ-degrading enzyme, in 5XFAD mice with advanced age. These findings demonstrate that partial BACE1 suppression cannot attenuate deleterious BACE1-elevating or neprilysin-reducing mechanisms, limiting its capabilities to reduce cerebral Aβ accumulation and rescue memory defects during the course of AD development.

MicroRNAs and liver function

MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate gene expression post-transcriptionally through complementary base pairing with thousands of messenger RNAs. Although the target genes and precise biological functions of individual miRNAs remain largely unknown, miRNAs are speculated to play important roles in diverse biological processes in both normal and pathological states. The liver is a vital organ that plays major roles in a number of physiological functions. Recent advances in the study of liver miRNAs using gene-modified mice or in vivo nucleic acid delivery to overexpress specific miRNAs or inhibit miRNA functions have revealed the crucial biological roles of individual miRNAs in physiologically essential liver functions in vivo. Because miRNA-based strategies are being applied to clinical therapeutics, the importance of precise knowledge of miRNA functions cannot be underestimated, not only from a scientific point of view, but also from a clinical perspective to make the most of such drugs and avoid unexpected harmful effects. The aims of this review are to describe current knowledge regarding both known and as-yet-undiscovered molecular aspects of the biological roles of miRNAs in the liver, with a special emphasis on lipid, glucose, drug, and iron metabolism as vital functions of the liver as well as important therapeutic targets.

A c-fos-monomeric red fluorescent protein 1 fusion transgene is differentially expressed in rat forebrain and brainstem after chronic dehydration and rehydration

We have previously shown that an acute osmotic stimulation induces the expression of a c-fos and monomeric red fluorescent protein 1 (mRFP1) fusion transgene in osmosensitive rat brain areas, including the supraoptic (SON) and paraventricular nuclei (PVN). However, the effects of chronic stimuli, such as dehydration, have not been investigated. In the present study, the expression patterns of the c-fos-mRFP1 fusion gene in the forebrain and the brainstem of male and female transgenic rats were studied in seven experimental groups: ad lib. water (euhydration), water deprivation for 12, 24 or 48 h (dehydration) and water deprivation for 46 h + ad lib. water for 2, 6 or 12 h (rehydration). The number of cells that express nuclear mRFP1 fluorescence was quantified in the hypothalamus, the circumventricular organs and the brainstem. Compared to the euhydrated state, the number of transgene expressing cells significantly increased in all forebrain areas and in the rostral ventrolateral medulla after dehydration and 2 h of rehydration. In the nucleus of the solitary tract and area postrema, the number of mRFP1 fluorescent cells was markedly increased after 2 h of rehydration. Although the number of mRFP1 fluorescent cells in the organum vasculosum laminae terminalis, median preoptic nucleus and subfornical organ remained significantly increased after 6 h of rehydration, reaching control levels after 12 h of rehydration, the number of mRFP1 fluorescent cells in the SON and the PVN reached control levels after 6 h of rehydration. There were no significant differences between male and female rats. These results show that the expression of the c-fos-mRFP1 fusion gene changes in the forebrain and the brainstem not only after acute osmotic stimulation, but also after chronic osmotic stimulation. Interestingly, these studies reveal the differential activation of different neuronal groups over the time course of dehydration and rehydration.

Large current MOSFET on photonic silicon-on-insulator wafers and its monolithic integration with a thermo-optic 2 × 2 Mach-Zehnder switch

n-channel body-tied partially depleted metal-oxide-semiconductor field-effect transistors (MOSFETs) were fabricated for large current applications on a silicon-on-insulator wafer with photonics-oriented specifications. The MOSFET can drive an electrical current as large as 20 mA. We monolithically integrated this MOSFET with a 2 × 2 Mach-Zehnder interferometer optical switch having thermo-optic phase shifters. The static and dynamic performances of the integrated device are experimentally evaluated.