Unique Extraction of a Fractured Pacemaker Lead Adhered to the Spermatic Vein.

Transvenous lead extraction has been increasingly recognized as a safe and effective method of lead extraction, but there are only few references for extracting leads migrating outside the heart. We present a successful extraction of a fractured pacemaker lead from the spermatic vein using several approaches and multiple tools.

Histology of metastatic colorectal cancer in a lymph node.

BACKGROUND: A primary colorectal cancer (CRC) tumor can contain heterogeneous cancer cells. As clones of cells with different properties metastasize to lymph nodes (LNs), they could show different morphologies. Cancer histologies in LNs of CRC remains to be described. METHODS: Our study enrolled 318 consecutive patients with CRC who underwent primary tumor resection with lymph node dissection between January 2011 and June 2016. 119 (37.4%) patients who had metastatic LNs (mLNs) were finally included in this study. Cancer histologies in LNs were classified and compared with pathologically diagnosed differentiation in the primary lesion. The association between histologies in lymph node metastasis (LNM) and prognosis in patients with CRC was investigated. RESULTS: The histologies of the cancer cells in the mLNs were classified into four types: tubular, cribriform, poorly differentiated, and mucinous. Same degree of pathologically diagnosed differentiation in the primary tumor produced various histological types in LNM. In Kaplan-Meier analysis, prognosis was worse in CRC patients with moderately differentiated adenocarcinoma who had at least some mLN also showing cribriform carcinoma than for those whose mLNs all showed tubular carcinoma. CONCLUSIONS: Histology in LNM from CRC might indicate the heterogeneity and malignant phenotype of the disease.

Successful Extraction of Guidewire Entrapped in the Tricuspid Valve Leaflet Using a Laser Sheath.

Right ventriculography is a necessary step for implantation of leadless pacemaker and is considered a safe procedure. However, an inappropriate manipulation of the guidewire can lead to serious complications. We present a case where the guide-wire was entrapped in the tricuspid valve, and its successful extraction using a laser sheath. (Level of Difficulty: Advanced.).

p600/UBR4 in the central nervous system.

A decade ago, the large 600 kDa mammalian protein p600 (also known as UBR4) was discovered as a multifunctional protein with roles in anoikis, viral transformation and protein degradation. Recently, p600 has emerged as a critical protein in the mammalian brain with roles in neurogenesis, neuronal migration, neuronal signaling and survival. How p600 integrates these apparently unrelated functions to maintain tissue homeostasis and murine survival remains unclear. The common molecular basis underlying many of the actions of p600 suggests, however, certain conservation and transposition of these functions across systems. In this review, we summarize the central nervous system functions of p600 and propose new perspectives on its biological complexity in neuronal physiology and neurological diseases.

An amino terminal phosphorylation motif regulates intranuclear compartmentalization of Olig2 in neural progenitor cells.

The bHLH transcription factor Olig2 is expressed in cycling neural progenitor cells but also in terminally differentiated, myelinating oligodendrocytes. Sustained expression of Olig2 is counterintuitive because all known functions of the protein in expansion of neural progenitors and specification of oligodendrocyte progenitors are completed with the formation of mature white matter. How are the biological functions of Olig2 suppressed in terminally differentiated oligodendrocytes? In previous studies, we have shown that a triple serine motif in the amino terminus of Olig2 is phosphorylated in cycling neural progenitors but not in their differentiated progeny. We now show that phosphorylation of the triple serine motif regulates intranuclear compartmentalization of murine Olig2. Phosphorylated Olig2 is preferentially localized to a transcriptionally active "open" chromatin compartment together with coregulator proteins essential for regulation of gene expression. Unphosphorylated Olig2, as seen in mature white matter, is localized mainly within a transcriptionally inactive, chromatin fraction characterized by condensed and inaccessible DNA. Of special note is the observation that the p53 tumor suppressor protein is confined to the open chromatin fraction. Proximity ligation assays show that phosphorylation brings Olig2 within 30 nm of p53 within the open chromatin compartment. The data thus shed light on previously noted promitogenic functions of phosphorylated Olig2, which reflect, at least in part, an oppositional relationship with p53 functions.

p600 regulates spindle orientation in apical neural progenitors and contributes to neurogenesis in the developing neocortex.

Apical neural progenitors (aNPs) drive neurogenesis by means of a program consisting of self-proliferative and neurogenic divisions. The balance between these two manners of division sustains the pool of apical progenitors into late neurogenesis, thereby ensuring their availability to populate the brain with terminal cell types. Using knockout and in utero electroporation mouse models, we report a key role for the microtubule-associated protein 600 (p600) in the regulation of spindle orientation in aNPs, a cellular event that has been associated with cell fate and neurogenesis. We find that p600 interacts directly with the neurogenic protein Ndel1 and that aNPs knockout for p600, depleted of p600 by shRNA or expressing a Ndel1-binding p600 fragment all display randomized spindle orientation. Depletion of p600 by shRNA or expression of the Ndel1-binding p600 fragment also results in a decreased number of Pax6-positive aNPs and an increased number of Tbr2-positive basal progenitors destined to become neurons. These Pax6-positive aNPs display a tilted mitotic spindle. In mice wherein p600 is ablated in progenitors, the production of neurons is significantly impaired and this defect is associated with microcephaly. We propose a working model in which p600 controls spindle orientation in aNPs and discuss its implication for neurogenesis.

p600 Plays Essential Roles in Fetal Development.

p600 is a multifunctional protein implicated in cytoskeletal organization, integrin-mediated survival signaling, calcium-calmodulin signaling and the N-end rule pathway of ubiquitin-proteasome-mediated proteolysis. While push, the Drosophila counterpart of p600, is dispensable for development up to adult stage, the role of p600 has not been studied during mouse development. Here we generated p600 knockout mice to investigate the in vivo functions of p600. Interestingly, we found that homozygous deletion of p600 results in lethality between embryonic days 11.5 and 13.5 with severe defects in both embryo and placenta. Since p600 is required for placental development, we performed conditional disruption of p600, which deletes selectively p600 in the embryo but not in the placenta. The conditional mutant embryos survive longer than knockout embryos but ultimately die before embryonic day 14.5. The mutant embryos display severe cardiac problems characterized by ventricular septal defects and thin ventricular walls. These anomalies are associated with reduced activation of FAK and decreased expression of MEF2, which is regulated by FAK and plays a crucial role in cardiac development. Moreover, we observed pleiotropic defects in the liver and brain. In sum, our study sheds light on the essential roles of p600 in fetal development.

A Ca2+-dependent mechanism of neuronal survival mediated by the microtubule-associated protein p600.

In acute and chronic neurodegeneration, Ca(2+) mishandling and disruption of the cytoskeleton compromise neuronal integrity, yet abnormalities in the signaling roles of cytoskeletal proteins remain largely unexplored. We now report that the microtubule-associated protein p600 (also known as UBR4) promotes neuronal survival. Following depletion of p600, glutamate-induced Ca(2+) influx through NMDA receptors, but not AMPA receptors, initiates a degenerative process characterized by endoplasmic reticulum fragmentation and endoplasmic reticulum Ca(2+) release via inositol 1,4,5-trisphosphate receptors. Downstream of NMDA receptors, p600 associates with the calmodulin·calmodulin-dependent protein kinase IIα complex. A direct and atypical p600/calmodulin interaction is required for neuronal survival. Thus, p600 counteracts specific Ca(2+)-induced death pathways through regulation of Ca(2+) homeostasis and signaling.

DNA ends alter the molecular composition and localization of Ku multicomponent complexes.

The Ku heterodimer plays an essential role in non-homologous end-joining and other cellular processes including transcription, telomere maintenance and apoptosis. While the function of Ku is regulated through its association with other proteins and nucleic acids, the specific composition of these macromolecular complexes and their dynamic response to endogenous and exogenous cellular stimuli are not well understood. Here we use quantitative proteomics to define the composition of Ku multicomponent complexes and demonstrate that they are dramatically altered in response to UV radiation. Subsequent biochemical assays revealed that the presence of DNA ends leads to the substitution of RNA-binding proteins with DNA and chromatin associated factors to create a macromolecular complex poised for DNA repair. We observed that dynamic remodeling of the Ku complex coincided with exit of Ku and other DNA repair proteins from the nucleolus. Microinjection of sheared DNA into live cells as a mimetic for double strand breaks confirmed these findings in vivo.

Management of obstructive colorectal cancer: evaluation of preoperative bowel decompression using ileus tube drainage.

PURPOSE: This study evaluated a better treatment for patients with obstructive colorectal cancer (CRC) that have a poor prognosis. METHOD: This study compared the outcomes of 138 patients with obstructive CRC, including 70 primary resections, 50 resections after bowel decompression using an ileus tube, and 18 delayed resections after colostomy. RESULTS: The ileus tube and delayed resection groups included more left-sided primary lesions. The physiologic POSSUM, types 3-4, tumor size, CEA, and hospital stay of the delayed resection group were different, in comparison to both the primary resection and ileus tube groups. The histopathological type and depth of invasion of the delayed resection group included less well types and more T4 than those of the ileus tube group. The operative blood loss of the delayed resection group was more than that of the ileus tube group. There were no differences in the overall and disease-free survival among the three groups. CONCLUSION: Separately analyzing the data of the right-sided cancer group and the left-sided cancer group demonstrated that primary resection might be acceptable for right-sided obstructive CRC and delayed resection might be done for patients with poorer general conditions (high PPS) and poorer oncological prognostic factors such as more type 3/type 4 cases, a larger tumor size, a less well-differentiated histopathological type, more T4 cases, and a higher CEA level.

Differential expression of Toll-like receptor 4 and human monocyte subsets in acute myocardial infarction.

OBJECTIVE: To investigate the involvement of Toll-like receptor 4 (TLR4) expression on two monocyte subsets in the pathologic processes related to acute coronary syndrome. How monocytes, which have recently been shown to comprise two distinct subsets, mediate the process of coronary plaque rupture remains to be fully elucidated. Recent studies have shown that TLR4 is involved in monocyte activation of patients with accelerated forms of atherosclerosis. METHODS: We enrolled 65 patients with acute myocardial infarction (AMI, n=22), unstable angina pectoris (UAP, n=16), and stable angina pectoris (SAP, n=27) who underwent coronary angiography and 15 healthy controls. The expression of TLR4 on two monocyte subsets (CD14(+)CD16(-) and CD14(+)CD16(+)) was measured by flow cytometry. RESULTS: In patients with AMI, TLR4 was more expressed on circulating CD14(+)CD16(+) monocytes than on CD14(+)CD16(-) monocytes (p<0.001). The expression levels of TLR4 on CD14(+)CD16(+) monocytes were significantly elevated in patients with AMI compared with other 3 groups. TLR4 expression levels on CD14(+)CD16(+) monocytes were significantly elevated at the culprit site compared with the systemic level (p=0.044). The up-regulation of TLR4 on admission was remarkably decreased 12 days after AMI (p<0.001). In addition, plasma levels of tumor necrosis factor-α were positively correlated with TLR4 expression levels on monocytes in patients with AMI (r=0.47, p=0.027). CONCLUSION: TLR overexpression on CD14(+)CD16(+) monocytes in AMI, as demonstrated both in the circulation and at the coronary culprit site, might be associated with the pathogenesis of AMI.

[A case of giant heterotopic Brunner's gland adenoma prolapsing into the duodenum].

A 81-year-old woman admitted with general fatigue was found to have a giant polyp in the gastric antrum by endoscopy. The polyp prolapsed into the duodenum through the pylorus. Angiographic examination of the abdomen revealed the polyp to be about 90×35 mm in size. Laparotomy was performed. It was finally diagnosed as heterotopic Brunner's gland adenoma which had a stalk on the antrum of the stomach. Heterotopic Brunner's gland adenoma is rare. Only 3 cases including the present case have been reported in Japan.

Tissue plasminogen activator and plasminogen are critical for osmotic homeostasis by regulating vasopressin secretion.

Systemic osmotic homeostasis is regulated mainly by neuroendocrine system of arginine-vasopressin (AVP) in mammalians. In the present study, we demonstrated that the immunoreactivity of tissue plasminogen activator (tPA) was observed specifically at neurosecretory granules of AVP-positive magnocellular terminals and that of plasminogen was seen at astrocytes in the neurohypophysis (NH). Both tPA and plasminogen knockout (KO) mice revealed higher plasma osmolarity upon water deprivation, a chronic osmotic stimulation, as compared with their wild-type (WT) animals, indicating abnormal osmotic control in these KO mice. tPA KO mice but not plasminogen ones revealed lower ability in secreting AVP into the blood circulation upon an acute osmotic stimulation. Both tPA and plasminogen KO animals showed lower ability in secreting AVP into the blood circulation upon a chronic osmotic stimulation. The recombinant tPA was able to promote the release of AVP from isolated NH. Chronic osmotic stimulation decreased the laminin expression level of neurohypophysial microvessel in WT mice but not in plasminogen KO ones. We suggest that AVP secretion is critically regulated by tPA-dependent facilitation of AVP release from terminals and plasminogen-dependent increase of AVP permeability across microvessels possibly via laminin degradation.

Dual role for the methyltransferase G9a in the maintenance of beta-globin gene transcription in adult erythroid cells.

Using a proteomics screen, we have identified the methyltransferase G9a as an interacting partner of the hematopoietic activator NF-E2. We show that G9a is recruited to the beta-globin locus in a NF-E2-dependent manner and spreads over the entire locus. While G9a is often regarded as a corepressor, knocking down this protein in differentiating adult erythroid cells leads to repression of the adult beta(maj) globin gene and aberrant reactivation of the embryonic beta-like globin gene E(y). While in adult cells G9a maintains E(y) in a repressed state via dimethylation of histone H3 at lysines 9 and 27, it activates beta(maj) transcription in a methyltransferase-independent manner. Interestingly, the demethylase UTX is recruited to the beta(maj) (but not the E(y)) promoter where it antagonizes G9a-dependent H3K27 dimethylation. Collectively, these results reveal a dual role for G9a in maintaining proper expression (both repression and activation) of the beta-globin genes in differentiating adult erythroid cells.

The HP1alpha-CAF1-SetDB1-containing complex provides H3K9me1 for Suv39-mediated K9me3 in pericentric heterochromatin.

Trimethylation of lysine 9 in histone H3 (H3K9me3) enrichment is a characteristic of pericentric heterochromatin. The hypothesis of a stepwise mechanism to establish and maintain this mark during DNA replication suggests that newly synthesized histone H3 goes through an intermediate methylation state to become a substrate for the histone methyltransferase Suppressor of variegation 39 (Suv39H1/H2). How this intermediate methylation state is achieved and how it is targeted to the correct place at the right time is not yet known. Here, we show that the histone H3K9 methyltransferase SetDB1 associates with the specific heterochromatin protein 1alpha (HP1alpha)-chromatin assembly factor 1 (CAF1) chaperone complex. This complex monomethylates K9 on non-nucleosomal histone H3. Therefore, the heterochromatic HP1alpha-CAF1-SetDB1 complex probably provides H3K9me1 for subsequent trimethylation by Suv39H1/H2 in pericentric regions. The connection of CAF1 with DNA replication, HP1alpha with heterochromatin formation and SetDB1 for H3K9me1 suggests a highly coordinated mechanism to ensure the propagation of H3K9me3 in pericentric heterochromatin during DNA replication.

Why the carrot is more effective than the stick: different dynamics of punishment memory and reward memory and its possible biological basis.

One of the most extensively debated topics in educational psychology is whether punishment or reward is more effective for producing short-term and long-term behavioral changes, and it has been proposed that the effect of punishment is less durable than the effect of reward. However, no conclusive evidence to support this proposal has been obtained in any animals. We recently found that punishment memory decayed much faster than reward memory in olfactory learning and visual pattern learning in crickets. We also found that neurotransmitters conveying punishment and reward signals differ in crickets: dopaminergic and octopaminergic neurons play critical roles in conveying punishment and reward signals, respectively. In this study, we investigated whether these features are general features of cricket learning or are specific to olfactory and visual pattern learning. We found that crickets have the capability of color learning and that their color learning has the same features. Based on our findings in crickets and those reported in other species of insects, we conclude that these two features are conserved in many forms of insect learning. In mammals, aminergic neurons are known to convey reward and punishment signals in learning of a variety of sensory stimuli. We propose that the faster decay of punishment memory than reward memory observed in insects and humans reflects different cellular and biochemical processes after activation of receptors for amines conveying punishment and reward signals. The possible adaptive significance of relatively limited durability of punishment memory is proposed.

HJURP is a cell-cycle-dependent maintenance and deposition factor of CENP-A at centromeres.

The histone H3 variant CenH3, called CENP-A in humans, is central in centromeric chromatin to ensure proper chromosome segregation. In the absence of an underlying DNA sequence, it is still unclear how CENP-A deposition at centromeres is determined. Here, we purified non-nucleosomal CENP-A complexes to identify direct CENP-A partners involved in such a mechanism and identified HJURP. HJURP was not detected in H3.1- or H3.3-containing complexes, indicating its specificity for CENP-A. HJURP centromeric localization is cell cycle regulated, and its transient appearance at the centromere coincides precisely with the proposed time window for new CENP-A deposition. Furthermore, HJURP downregulation leads to a major reduction in CENP-A at centromeres and impairs deposition of newly synthesized CENP-A, causing mitotic defects. We conclude that HJURP is a key factor for CENP-A deposition and maintenance at centromeres.

Structural basis of UV DNA-damage recognition by the DDB1-DDB2 complex.

Ultraviolet (UV) light-induced pyrimidine photodimers are repaired by the nucleotide excision repair pathway. Photolesions have biophysical parameters closely resembling undamaged DNA, impeding discovery through damage surveillance proteins. The DDB1-DDB2 complex serves in the initial detection of UV lesions in vivo. Here we present the structures of the DDB1-DDB2 complex alone and bound to DNA containing either a 6-4 pyrimidine-pyrimidone photodimer (6-4PP) lesion or an abasic site. The structure shows that the lesion is held exclusively by the WD40 domain of DDB2. A DDB2 hairpin inserts into the minor groove, extrudes the photodimer into a binding pocket, and kinks the duplex by approximately 40 degrees. The tightly localized probing of the photolesions, combined with proofreading in the photodimer pocket, enables DDB2 to detect lesions refractory to detection by other damage surveillance proteins. The structure provides insights into damage recognition in chromatin and suggests a mechanism by which the DDB1-associated CUL4 ubiquitin ligase targets proteins surrounding the site of damage.

Nonhepatocytic malignant mixed tumor of the liver in adults: report of a long surviving case.

A primary nonhepatocytic malignant mixed tumor in the liver contains both epithelial and mesenchymal components, and the incidence in adults is extremely rare. A 45-year-old female was admitted because of abdominal fullness. Abdominal imaging studies revealed a huge cystic tumor with a mural nodule in the right lobe. A right trisegmentectomy and an invaded partial diaphragm resection were performed. Diagnosis was established after surgery. The patient is still alive 11 years after surgery, and to our knowledge is the longest surviving patient with a primary nonhepatocytic malignant mixed primary tumor of the liver.