[A Case of Drug-Induced Pneumomediastinum Preceding Interstitial Pneumonitis Onset during Treatment with a First-Line Regimen of GnP in a Patient with Unresectable Pancreatic Cancer].

BACKGROUND: The highest prevalence of drug-induced interstitial pneumonitis(IP)occurs in patients receiving antineoplastic agents, such as cytotoxic chemotherapeutic drugs, molecular targeted drugs, and immune checkpoint inhibitors. A certain period of the treatment for IP requires discontinuation of the anticancer therapy, resulting in progression of the malignant status. CASE: A 70-year-old man was incidentally diagnosed with locally advanced unresectable pancreatic cancer in the course of his treatment for ventricular dysrhythmia. After the insertion of a pacing instrument, he was ensured to be eligible to receive combination chemotherapy with gemcitabine and nab-paclitaxel(GnP)as the primary regimen. Shortly after the second course of GnP, the patient had high fever and developed pneumomediastinum 3 days prior to the onset of IP. The GnP treatment was suspended, and the IP was treated with pulse steroid therapy. The respiratory disorder took approximately 3 months to resolve; however, this concomitantly led to aggravation of the malignancy, which developed multiple metastases to the liver. The patient was no longer allowed to receive antineoplastic treatment. CONCLUSION: Although GnP may be a key regimen for the treatment of unresectable pancreatic cancer, patients should be closely monitored to ensure early detection of adverse events, such as interstitial pneumonia. Furthermore, drug-induced pneumomediastinum may be a precursor to the onset of interstitial pneumonia.

[A Case of Advanced Late Recurrence of Hormone Receptor Positive Breast Cancer Successfully Treated with Abemaciclib and Anastrozole].

BACKGROUND: In step with the aging of the Japanese population, late recurrence of hormone receptor positive (HR+) breast cancer occurring especially beyond 20 years after the initial diagnosis has been recognized as not rare anymore, as it has been occurring at a constant rate lately. The administration of an aromatase inhibitor with a CDK4/6 inhibitor has become the gold standard in Japan for cases of recurring HR+ breast cancer without severe visceral metastasis. CASE: A 73- year-old woman was diagnosed by chance with late recurrence of HR+ breast cancer 21 years after undergoing radical resection followed by adjuvant anastrozole for 5 years for stage Ⅲb right breast cancer. Asymptomatic multiple bone metastases on her ribs and sternum with bilateral lung metastasis and malignant effusion all disappeared while she was on a year- long administration of anastrozole and an optimal dose of abemaciclib(100 mg bid). However, because of the Grade 3 digestive adverse event that occurred at approximately 1 year of treatment, she could only maintain the treatment for up to 13 months. After then, no recurrence has been detectable for 6 months so far. CONCLUSION: CDK4/6 inhibitors, in combination with anastrozole, will play a pivotal role in the initial approach to elderly patients with HR+ late recurrence as a chemotherapy- free strategy.

Long-term remission of bilateral Wilms tumors that developed from premature separation of chromatids/mosaic variegated aneuploidy syndrome due to bilateral nephrectomy and peritoneal dialysis.

We report a 38-month-old Japanese male with premature chromatid separation/mosaic variegated aneuploidy syndrome bearing biallelic BUB1B germline mutations who suffered from bilateral Wilms tumor. After right nephrectomy, dactinomycin monotherapy was administered for the left Wilms tumor; however, severe adverse reaction prevented the patient from receiving further chemotherapy. Left nephrectomy was then performed without postoperative chemotherapy. The patient survived for 15 months after bilateral nephrectomy without peritoneal relapse, metastasis of Wilms tumor, or the occurrence of rhabdomyosarcoma and maintained a good quality of life while receiving peritoneal dialysis at home.

A Case of Portal Venous Stenting for Metastatic Hilar Stricture After the Radical Resection of Colon Cancer.

Like standard stenting in an unresectable malignant stricture of the biliary or digestive tract, minimally invasive modality for portal stenosis is indispensable for palliation. We describe here a safe and practical procedure of portal stenting in a case of metastatic hilar strictures developed nine years after the radical resection of sigmoid colon cancer. After urgent delivery of the biliary tract stenting for the relief of jaundice, the patient received palliative stenting for the stricture of the portal trunk. Transhepatic approach, via the anterior branch, of the portal vein intervention may fit into the standard aspects for portal stenting.

TBCD may be a causal gene in progressive neurodegenerative encephalopathy with atypical infantile spinal muscular atrophy.

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder caused by survival motor neuron gene mutations. Variant forms of SMA accompanied by additional clinical presentations have been classified as atypical SMA and are thought to be caused by variants in as yet unidentified causative genes. Here, we presented the clinical findings of two siblings with an SMA variant followed by progressive cerebral atrophy, and the results of whole-exome sequencing analyses of the family quartet that was performed to identify potential causative variants. We identified two candidate homozygous missense variants, R942Q in the tubulin-folding cofactor D (TBCD) gene and H250Q in the bromo-adjacent homology domain and coiled-coil containing 1 (BAHCC1) gene, located on chromosome 17q25.3 with an interval of 1.4 Mbp. The in silico analysis of both variants suggested that TBCD rather than BAHCC1 was likely the pathogenic gene (TBCD sensitivity, 0.68; specificity, 0.97; BAHCC1 sensitivity, 1.00; specificity, 0.00). Thus, our results show that TBCD is a likely novel candidate gene for atypical SMA with progressive cerebral atrophy. TBCD is predicted to have important functions on tubulin integrity in motor neurons as well as in the central nervous system.

Genotype-phenotype correlations in alternating hemiplegia of childhood.

OBJECTIVE: Clinical severity of alternating hemiplegia of childhood (AHC) is extremely variable. To investigate genotype-phenotype correlations in AHC, we analyzed the clinical information and ATP1A3 mutations in patients with AHC. METHODS: Thirty-five Japanese patients who were clinically diagnosed with AHC participated in this study. ATP1A3 mutations were analyzed using Sanger sequencing. Detailed clinical information was collected from family members of patients with AHC and clinicians responsible for their care. RESULTS: Gene analysis revealed 33 patients with de novo heterozygous missense mutations of ATP1A3: Glu815Lys in 12 cases (36%), Asp801Asn in 10 cases (30%), and other missense mutations in 11 cases. Clinical information was compared among the Glu815Lys, Asp801Asn, and other mutation groups. Statistical analysis revealed significant differences in the history of neonatal onset, gross motor level, status epilepticus, and respiratory paralysis in the Glu815Lys group compared with the other groups. In addition, 8 patients who did not receive flunarizine had severe motor deteriorations. CONCLUSIONS: The Glu815Lys genotype appears to be associated with the most severe AHC phenotype. Although AHC is not generally seen as a progressive disorder, it should be considered a disorder that deteriorates abruptly or in a stepwise fashion, particularly in patients with the Glu815Lys mutation.

Amygdala kindling induces nestin expression in the leptomeninges of the neocortex.

Nestin is an intermediate filament found in neurogenic progenitors and non-neuronal cells. Nestin-immunoreactivity (IR) in the brain often increases after brain damage. Here we show that amygdala kindling, which mimics the epileptic seizures, also induces nestin expression in the brain. Nestin-IR was greatly enhanced in the leptomeninges (pia and arachnoid maters) and neocortical parenchyma, but not much in the SVZ around the lateral ventricle, SGZ in the dentate gyrus, or the endothelial progenitor cells of blood vessels, fimbria, or choroid plexus after kindling. Electron microscopy revealed that nestin-IR in the leptomeninges was localized to granule cells, where it co-localized with GAD67-IR after electrical stimulation. The nestin-positive granule cells in the leptomeninges, especially around the emissary vein, were proliferative. However, nestin-IR in the neocortical parenchyma was expressed in NG2 glia and did not co-localize with GAD67-IR. Deletion of nestin-positive cells resulted in a high susceptibility to electrical stimulation. Consequently, almost all of the mice died or dropped out during kindling progression in 20 days, from naturally generated epileptic seizure or exhaustion. We speculate that the nestin-positive cells activated by amygdala kindling may involve in the protection of the brain from epilepsy.

[A case of S-1-resistant resected advanced gastric cancer with para-aortic lymph node recurrence responding to bi-weekly CPT-11 and CDDP].

A 64-year-old man with advanced gastric cancer who underwent a curative total gastrectomy(LM, Less, Type 3, 70×55 mm, por1>tub2>sig, pT3(ss), med, INF b, ly3, v3, pN3b(41/61), pPM0, pDM0, pT3N3bM0, Stage III B)followed by adjuvant chemotherapy(paclitaxel+S-1)a year ago, revealed an increasing level of serum CEA and para-aortic lymphnode (#16b1)recurrence on abdominal CT. He was given chemotherapy with low-dose weekday CDDP+S-1 for the recurrence, after which he failed to respond. Thereafter, he received 2nd-line chemotherapy with bi-weekly CPT-11+CDDP as a S-1- refractory regimen. 3 courses of the regimen reduced the serum CEA level accompanied by grade 3 of anemia. After recovery from the adverse event, another 4 courses at a 20% lower dosage for safety were administered. Complete response to the lymphnode was ensured on the abdominal CT with a reduced serum CEA level into the normal range. The patient has no signs of recurrence and has survived in fair condition for more than 5 years after the surgery. The combination treatment of biweekly CPT-11+CDDP can be a worthwhile regimen for patient with S-1-refractory recurrence of the resected advanced gastric cancer.

ERK2 contributes to the control of social behaviors in mice.

Signaling through extracellular signal-regulated kinase (ERK) is important in multiple signal transduction networks in the CNS. However, the specific role of ERK2 in in vivo brain functions is not fully understood. Here we show that ERK2 play a critical role in regulating social behaviors as well as cognitive and emotional behaviors in mice. To study the brain function of ERK2, we used a conditional, region-specific, genetic approach to target Erk2 using the Cre/loxP strategy with a nestin promoter-driven cre transgenic mouse line to induce recombination in the CNS. The resulting Erk2 conditional knock-out (CKO) mice, in which Erk2 was abrogated specifically in the CNS, were viable and fertile with a normal appearance. These mice, however, exhibited marked anomalies in multiple aspects of social behaviors related to facets of autism-spectrum disorders: elevated aggressive behaviors, deficits in maternal nurturing, poor nest-building, and lower levels of social familiarity and social interaction. Erk2 CKO mice also exhibited decreased anxiety-related behaviors and impaired long-term memory. Pharmacological inhibition of ERK1 phosphorylation in Erk2 CKO mice did not affect the impairments in social behaviors and learning disabilities, indicating that ERK2, but not ERK1 plays a critical role in these behaviors. Our findings suggest that ERK2 has complex and multiple roles in the CNS, with important implications for human psychiatric disorders characterized by deficits in social behaviors.

Role of mouse hepatitis virus (MHV) receptor murine CEACAM1 in the resistance of mice to MHV infection: studies of mice with chimeric mCEACAM1a and mCEACAM1b.

Although most inbred mouse strains are highly susceptible to mouse hepatitis virus (MHV) infection, the inbred SJL line of mice is highly resistant to its infection. The principal receptor for MHV is murine CEACAM1 (mCEACAM1). Susceptible strains of mice are homozygous for the 1a allele of mCeacam1, while SJL mice are homozygous for the 1b allele. mCEACAM1a (1a) has a 10- to 100-fold-higher receptor activity than does mCEACAM1b (1b). To explore the hypothesis that MHV susceptibility is due to the different MHV receptor activities of 1a and 1b, we established a chimeric C57BL/6 mouse (cB61ba) in which a part of the N-terminal immunoglobulin (Ig)-like domain of the mCeacam1a (1a) gene, which is responsible for MHV receptor function, is replaced by the corresponding region of mCeacam1b (1b). We compared the MHV susceptibility of these chimeric mice to that of SJL and B6 mice. B6 mice that are homozygous for 1a are highly susceptible to MHV-A59 infection, with a 50% lethal dose (LD(50)) of 10(2.5) PFU, while chimeric cB61ba mice and SJL mice homozygous for 1ba and 1b, respectively, survived following inoculation with 10(5) PFU. Unexpectedly, cB61ba mice were more resistant to MHV-A59 infection than SJL mice as measured by virus replication in target organs, including liver and brain. No infectious virus or viral RNA was detected in the organs of cB61ba mice, while viral RNA and infectious virus were detected in target organs of SJL mice. Furthermore, SJL mice produced antiviral antibodies after MHV-A59 inoculation with 10(5) PFU, but cB61ba mice did not. Thus, cB61ba mice are apparently completely resistant to MHV-A59 infection, while SJL mice permit low levels of MHV-A59 virus replication during self-limited, asymptomatic infection. When expressed on cultured BHK cells, the mCEACAM1b and mCEACAM1ba proteins had similar levels of MHV-A59 receptor activity. These results strongly support the hypothesis that although alleles of mCEACAM1 are the principal determinants of mouse susceptibility to MHV-A59, other as-yet-unidentified murine genes may also play a role in susceptibility to MHV.

[A case of advanced breast cancer with multiple bone metastases responding to docetaxel and high-dose toremifene as fourth-line chemo-endocrine therapy].

A 55-year old woman, who underwent left mastectomy (Bt+Ax), was revealed to have sternum metastasis by postoperative 99mTc bone scanning(T1bN1M1). She received daily aromatase inhibitor (anastrozole), as a primary systemic endocrine therapy, and biweekly pamidronate for metastatic breast cancer. However, she depended on folk medicine a year later, at which time the primary treatment was discontinued. Another year later, the bone metastases developed with increased serum levels of tumor markers (CEA, CA19-9, and NCC-ST-439). Then, she underwent three different regimens of systemic chemo-endocrine therapy over the following three years, including CAF+MPA as the first-line, paclitaxel (PTX) + anastrozole as the second-line, and S-1+anastrozole as the third-line regimen. She recently completed 10 courses of the fourth-line regimen[tri-weekly docetaxel (DOC) and high-dose toremifene (TOR 120 mg/day)], which reduced levels of 99mTc accumulation in the multiple bone metastases and levels of the serum tumor markers to the normal range. No severe adverse events occurred except peripheral thrombovasculitis (grade 2) in her left anterior arm during the fourth regimen. She recently maintains the current status by taking a regular dose (40 mg/day) of toremifene for 5 months. Combination treatment with DOC and high-dose TOR can be one of the worthwhile regimens as systemic chemo-endocrine therapy for patients with advanced breast cancer who develop bone metastases.

Cytomegalovirus infection mimicking juvenile myelomonocytic leukemia showing hypersensitivity to granulocyte-macrophage colony stimulating factor.

We describe an infant with cytomegalovirus (CMV) infection presenting as transient myeloproliferation resembling juvenile myelomonocytic leukemia (JMML). The patient fulfilled the international diagnostic criteria of JMML, including hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). Viral studies using serologic assays and polymerase chain reaction (PCR) were positive for CMV. Clinical symptoms disappeared and laboratory values returned to normal without specific treatment within 1 year. Follow-up showing a decrease in viral titers suggested CMV infection as an etiologic factor for the development of myeloproliferative features. We conclude that the CMV infection transiently induced abnormal myelopoiesis in this infant.

Dual involvement of G-substrate in motor learning revealed by gene deletion.

In this study, we generated mice lacking the gene for G-substrate, a specific substrate for cGMP-dependent protein kinase uniquely located in cerebellar Purkinje cells, and explored their specific functional deficits. G-substrate-deficient Purkinje cells in slices obtained at postnatal weeks (PWs) 10-15 maintained electrophysiological properties essentially similar to those from WT littermates. Conjunction of parallel fiber stimulation and depolarizing pulses induced long-term depression (LTD) normally. At younger ages, however, LTD attenuated temporarily at PW6 and recovered thereafter. In parallel with LTD, short-term (1 h) adaptation of optokinetic eye movement response (OKR) temporarily diminished at PW6. Young adult G-substrate knockout mice tested at PW12 exhibited no significant differences from their WT littermates in terms of brain structure, general behavior, locomotor behavior on a rotor rod or treadmill, eyeblink conditioning, dynamic characteristics of OKR, or short-term OKR adaptation. One unique change detected was a modest but significant attenuation in the long-term (5 days) adaptation of OKR. The present results support the concept that LTD is causal to short-term adaptation and reveal the dual functional involvement of G-substrate in neuronal mechanisms of the cerebellum for both short-term and long-term adaptation.

A novel form of memory for auditory fear conditioning at a low-intensity unconditioned stimulus.

Fear is one of the most potent emotional experiences and is an adaptive component of response to potentially threatening stimuli. On the other hand, too much or inappropriate fear accounts for many common psychiatric problems. Cumulative evidence suggests that the amygdala plays a central role in the acquisition, storage and expression of fear memory. Here, we developed an inducible striatal neuron ablation system in transgenic mice. The ablation of striatal neurons in the adult brain hardly affected the auditory fear learning under the standard condition in agreement with previous studies. When conditioned with a low-intensity unconditioned stimulus, however, the formation of long-term fear memory but not short-tem memory was impaired in striatal neuron-ablated mice. Consistently, the ablation of striatal neurons 24 h after conditioning with the low-intensity unconditioned stimulus, when the long-term fear memory was formed, diminished the retention of the long-term memory. Our results reveal a novel form of the auditory fear memory depending on striatal neurons at the low-intensity unconditioned stimulus.

Roles of continuous neurogenesis in the structural and functional integrity of the adult forebrain.

Neurogenesis occurs continuously in the forebrain of adult mammals, but the functional importance of adult neurogenesis is still unclear. Here, using a genetic labeling method in adult mice, we found that continuous neurogenesis results in the replacement of the majority of granule neurons in the olfactory bulb and a substantial addition of granule neurons to the hippocampal dentate gyrus. Genetic ablation of newly formed neurons in adult mice led to a gradual decrease in the number of granule cells in the olfactory bulb, inhibition of increases in the granule cell number in the dentate gyrus and impairment of behaviors in contextual and spatial memory, which are known to depend on hippocampus. These results suggest that continuous neurogenesis is required for the maintenance and reorganization of the whole interneuron system in the olfactory bulb, the modulation and refinement of the existing neuronal circuits in the dentate gyrus and the normal behaviors involved in hippocampal-dependent memory.

Inducible cAMP early repressor acts as a negative regulator for kindling epileptogenesis and long-term fear memory.

Long-lasting neuronal plasticity as well as long-term memory (LTM) requires de novo synthesis of proteins through dynamic regulation of gene expression. cAMP-responsive element (CRE)-mediated gene transcription occurs in an activity-dependent manner and plays a pivotal role in neuronal plasticity and LTM in a variety of species. To study the physiological role of inducible cAMP early repressor (ICER), a CRE-mediated gene transcription repressor, in neuronal plasticity and LTM, we generated two types of ICER mutant mice: ICER-overexpressing (OE) mice and ICER-specific knock-out (KO) mice. Both ICER-OE and ICER-KO mice show no apparent abnormalities in their development and reproduction. A comprehensive battery of behavioral tests revealed no robust changes in locomotor activity, sensory and motor functions, and emotional responses in the mutant mice. However, long-term conditioned fear memory was attenuated in ICER-OE mice and enhanced in ICER-KO mice without concurrent changes in short-term fear memory. Furthermore, ICER-OE mice exhibited retardation of kindling development, whereas ICER-KO mice exhibited acceleration of kindling. These results strongly suggest that ICER negatively regulates the neuronal processes required for long-term fear memory and neuronal plasticity underlying kindling epileptogenesis, possibly through suppression of CRE-mediated gene transcription.

Morning rise of blood pressure assessed by home blood pressure monitoring is associated with left ventricular hypertrophy in hypertensive patients receiving long-term antihypertensive medication.

To assess the influence of morning rise of systolic blood pressure (SBP) as assessed by home blood pressure monitoring on the left ventricular mass index (LVMI) in relation to the blood pressure control status, we evaluated M-mode cardiac echocardiography in 626 hypertensive subjects (412 men and 214 women; mean age, 61.3+/-10.1 years) who were receiving antihypertensive medication. The subjects were requested to measure their blood pressure at home in the morning and evening over a 3-month period. They were distributed into the following four groups by the average (ME Ave) and the difference (ME Dif) of the morning and evening SBP. The well-controlled hypertensives with a morning rise of SBP (ME Ave<135 mmHg and ME Dif>or=10 mmHg; n=45; 7.2%) had a greater LVMI (122.9+/-22.7 vs. 92.7+/-15.6 g/m2, p<0.001) than the well-controlled hypertensives without a morning rise of SBP (ME Ave<135 mmHg and ME Dif<10 mmHg; n=367; 58.6%). The uncontrolled hypertensives with a morning rise of SBP (ME Ave>or=135 mmHg and ME Dif>or=10 mmHg; n=91; 14.5%) also had a greater LVMI (136.8+/-21.9 vs. 100.2+/-17.5 g/m2, p<0.001) than the uncontrolled hypertensives without a morning rise of SBP (ME Ave>or=135 mmHg and ME Dif<10 mmHg; n=123; 19.6%). A stepwise multivariate regression analysis revealed that the ME Dif was the most important factor related to the LVMI (r2=35.1% for all subjects, p<0001; r2=39.7% for men, p<0.001; and r2=18.7% for women, p<0.001). These results suggest that morning rise of blood pressure is an important factor influencing the development of left ventricular hypertrophy in hypertensive patients on antihypertensive medication.

Innate versus learned odour processing in the mouse olfactory bulb.

The mammalian olfactory system mediates various responses, including aversive behaviours to spoiled foods and fear responses to predator odours. In the olfactory bulb, each glomerulus represents a single species of odorant receptor. Because a single odorant can interact with several different receptor species, the odour information received in the olfactory epithelium is converted to a topographical map of multiple glomeruli activated in distinct areas in the olfactory bulb. To study how the odour map is interpreted in the brain, we generated mutant mice in which olfactory sensory neurons in a specific area of the olfactory epithelium are ablated by targeted expression of the diphtheria toxin gene. Here we show that, in dorsal-zone-depleted mice, the dorsal domain of the olfactory bulb was devoid of glomerular structures, although second-order neurons were present in the vacant areas. The mutant mice lacked innate responses to aversive odorants, even though they were capable of detecting them and could be conditioned for aversion with the remaining glomeruli. These results indicate that, in mice, aversive information is received in the olfactory bulb by separate sets of glomeruli, those dedicated for innate and those for learned responses.

Extracellular signal-regulated kinase 2 (ERK2) knockdown mice show deficits in long-term memory; ERK2 has a specific function in learning and memory.

The extracellular signal-regulated kinase (ERK) 1 and 2 are important signaling components implicated in learning and memory. These isoforms display a high degree of sequence homology and share a similar substrate profile. However, recent findings suggest that these isoforms may have distinct roles: whereas ERK1 seems to be not so important for associative learning, ERK2 might be critically involved in learning and memory. Thus, the individual role of ERK2 has received considerable attention, although it is yet to be understood. Here, we have generated a series of mice in which ERK2 expression decreased in an allele dose-dependent manner. Null ERK2 knock-out mice were embryonic lethal, and the heterozygous mice were anatomically impaired. To gain a better understanding of the influence of ERK2 on learning and memory, we also generated knockdown mice in which ERK2 expression was partially (20-40%) reduced. These mutant mice were viable and fertile with normal appearance. The mutant mice showed a deficit in long-term memory in classical fear conditioning, whereas short-term memory was normal. The mice also showed learning deficit in the water maze and the eight-arm radial maze. The ERK1 expression level of the knockdown mice was comparable with the wild-type control. Together, our results indicate a noncompensable role of ERK2-dependent signal transduction in learning and memory.

Pael receptor is involved in dopamine metabolism in the nigrostriatal system.

Pael receptor (Pael-R) has been identified as one of the substrates of Parkin, a ubiquitin ligase responsible for autosomal recessive juvenile Parkinsonism (AR-JP). When Parkin is inactivated, unfolded Pael-R accumulates in the endoplasmic reticulum and results in neuronal death by unfolded protein stress, suggesting that Pael-R has an important role in the pathogenesis of AR-JP. Here we report the analyses on Pael-R-deficient (KO) and Pael-R-transgenic (Tg) mice. The striatal dopamine (DA) level of Pael-R KO mice was only 60% of that in normal mice, while in Pael-R Tg mice, striatal 3,4-dihydroxyphenylacetic acid (DOPAC) as well as vesicular DA content increased. Moreover, the nigrostriatal dopaminergic neurons of Pael-R Tg mice are more vulnerable to Parkinson's disease-related neurotoxins while those of Pael-R KO mice are less. These results strongly suggest that the Pael-R signal regulates the amount of DA in the dopaminergic neurons and that excessive Pael-R expression renders dopaminergic neurons susceptible to chronic DA toxicity.