43 research outputs found
Neuroendocrine (Merkel cell) carcinoma of the retroperitoneum with no identifiable primary site
<p>Abstract</p> <p>Background</p> <p>Neuroendocrine carcinoma is an aggressive neoplasm that mainly affects elderly Caucasians and typically arises in sun-exposed areas of the skin. The disease is rather rare and only a relatively few cases present with no apparent primary lesion.</p> <p>Case presentation</p> <p>We report a case of an 81-year-old Caucasian male with neuroendocrine carcinoma, which initially presented as a large retroperitoneal mass. Pathological and immunohistochemical analysis of the transabdominal CT-guided biopsy specimen revealed tissue consistent with neuroendocrine carcinoma. The patient underwent exploratory laparotomy and the mass was successfully excised along with an associated mesenteric lymph node.</p> <p>Discussion</p> <p>There are currently two possible explanations for what occurred in our patient. First, the retroperitoneal mass could be a massively enlarged lymph node where precursor cells became neoplastic. This would be consistent with a presumptive diagnosis of primary nodal disease. Alternatively, an initial skin lesion could have spontaneously regressed and the retroperitoneal mass represents a single site of metastasis. Since Merkel cell precursors have never been identified within lymph nodes, the latter theory seems more befitting. Moreover, metastasis to the retroperitoneal lymph nodes has been reported as relatively common when compared to other sites such as liver, bone, brain and skin.</p> <p>Conclusion</p> <p>Wide local excision of the primary tumor is the surgical treatment of choice for localized disease. We propose that further studies are needed to elucidate the true efficacy of chemotherapy in conventional as well as unconventional patients with neuroendocrine carcinoma.</p
A High-Density EEG Investigation into Steady State Binaural Beat Stimulation
Binaural beats are an auditory phenomenon that has been suggested to alter physiological and cognitive processes including vigilance and brainwave entrainment. Some personality traits measured by the NEO Five Factor Model have been found to alter entrainment using pulsing light stimuli, but as yet no studies have examined if this occurs using steady state presentation of binaural beats for a relatively short presentation of two minutes. This study aimed to examine if binaural beat stimulation altered vigilance or cortical frequencies and if personality traits were involved. Thirty-one participants were played binaural beat stimuli designed to elicit a response at either the Theta (7 Hz) or Beta (16 Hz) frequency bands while undertaking a zero-back vigilance task. EEG was recorded from a high-density electrode cap. No significant differences were found in vigilance or cortical frequency power during binaural beat stimulation compared to a white noise control period. Furthermore, no significant relationships were detected between the above and the Big Five personality traits. This suggests a short presentation of steady state binaural beats are not sufficient to alter vigilance or entrain cortical frequencies at the two bands examined and that certain personality traits were not more susceptible than others
Stem Cell Factor SALL4 Represses the Transcriptions of PTEN and SALL1 through an Epigenetic Repressor Complex
Background The embryonic stem cell (ESC) factor, SALL4, plays an essential role in both development and leukemogenesis. It is a unique gene that is involved in self-renewal in ESC and leukemic stem cell (LSC).Methodology/Principal Findings To understand the mechanism(s) of SALL4 function(s), we sought to identify SALL4-associated proteins by tandem mass spectrometry. Components of a transcription repressor Mi-2/Nucleosome Remodeling and Deacetylase (NuRD) complex were found in the SALL4-immunocomplexes with histone deacetylase (HDAC) activity in ESCs with endogenous SALL4 expression and 293T cells overexpressing SALL4. The SALL4-mediated transcriptional regulation was tested on two potential target genes: PTEN and SALL1. Both genes were confirmed as SALL4 downstream targets by chromatin-immunoprecipitation, and their expression levels, when tested by quantitative reverse transcription polymerase chain reaction (qRT-PCR), were decreased in 293T cells overexpressing SALL4. Moreover, SALL4 binding sites at the promoter regions of PTEN and SALL1 were co-occupied by NuRD components, suggesting that SALL4 represses the transcriptions of PTEN and SALL1 through its interactions with the Mi-2/NuRD complex. The in vivo repressive effect(s) of SALL4 were evaluated in SALL4 transgenic mice, where decreased expressions of PTEN and SALL1 were associated with myeloid leukemia and cystic kidneys, respectively.Conclusions/Significance In summary, we are the first to demonstrate that stem cell protein SALL4 represses its target genes, PTEN and SALL1, through the epigenetic repressor Mi-2/NuRD complex. Our novel finding provides insight into the mechanism(s) of SALL4 functions in kidney development and leukemogenesis
A CI-Independent Form of Replicative Inhibition: Turn Off of Early Replication of Bacteriophage Lambda
Several earlier studies have described an unusual exclusion phenotype exhibited by cells with plasmids carrying a portion of the replication region of phage lambda. Cells exhibiting this inhibition phenotype (IP) prevent the plating of homo-immune and hybrid hetero-immune lambdoid phages. We have attempted to define aspects of IP, and show that it is directed to repλ phages. IP was observed in cells with plasmids containing a λ DNA fragment including oop, encoding a short OOP micro RNA, and part of the lambda origin of replication, oriλ, defined by iteron sequences ITN1-4 and an adjacent high AT-rich sequence. Transcription of the intact oop sequence from its promoter, pO is required for IP, as are iterons ITN3–4, but not the high AT-rich portion of oriλ. The results suggest that IP silencing is directed to theta mode replication initiation from an infecting repλ genome, or an induced repλ prophage. Phage mutations suppressing IP, i.e., Sip, map within, or adjacent to cro or in O, or both. Our results for plasmid based IP suggest the hypothesis that there is a natural mechanism for silencing early theta-mode replication initiation, i.e. the buildup of λ genomes with oop+
oriλ+ sequence
Current and prospective pharmacological targets in relation to antimigraine action
Migraine is a recurrent incapacitating neurovascular disorder characterized by unilateral and throbbing headaches associated with photophobia, phonophobia, nausea, and vomiting. Current specific drugs used in the acute treatment of migraine interact with vascular receptors, a fact that has raised concerns about their cardiovascular safety. In the past, α-adrenoceptor agonists (ergotamine, dihydroergotamine, isometheptene) were used. The last two decades have witnessed the advent of 5-HT1B/1D receptor agonists (sumatriptan and second-generation triptans), which have a well-established efficacy in the acute treatment of migraine. Moreover, current prophylactic treatments of migraine include 5-HT2 receptor antagonists, Ca2+ channel blockers, and β-adrenoceptor antagonists. Despite the progress in migraine research and in view of its complex etiology, this disease still remains underdiagnosed, and available therapies are underused. In this review, we have discussed pharmacological targets in migraine, with special emphasis on compounds acting on 5-HT (5-HT1-7), adrenergic (α1, α2, and β), calcitonin gene-related peptide (CGRP 1 and CGRP2), adenosine (A1, A2, and A3), glutamate (NMDA, AMPA, kainate, and metabotropic), dopamine, endothelin, and female hormone (estrogen and progesterone) receptors. In addition, we have considered some other targets, including gamma-aminobutyric acid, angiotensin, bradykinin, histamine, and ionotropic receptors, in relation to antimigraine therapy. Finally, the cardiovascular safety of current and prospective antimigraine therapies is touched upon
Impact of siltuximab on patient-related outcomes in multicentric Castleman’s disease
Jenna Sitenga,1 Gregory Aird,1 Aabra Ahmed,1 Peter T Silberstein2 1Division of Education, Creighton University School of Medicine, Omaha, NE, USA; 2Division of Hematology/Oncology, Creighton University School of Medicine, Omaha, NE, USA Abstract: Multicentric Castleman’s disease (MCD) is a rare, widespread lymphoproliferative disorder and a life-threatening disease involving hyperactivity of the immune system, excessive proinflammatory cytokine release, immune cell proliferation, and organ system dysfunction. Interleukin-6 (IL-6) is a cytokine that plays a key role in the pathogenesis of MCD, as it is involved in the synthesis of acute-phase reactants and aids in the induction of B-cell proliferation. Siltuximab is an anti-IL-6 chimeric monoclonal antibody that acts as a novel treatment modality to bind to IL-6 with high affinity, thus neutralizing the cytokine bioactivity and inhibiting B-cell proliferation. Clinical trials with siltuximab have shown early clinical promise for patients with MCD for many years, leading to recent US Food and Drug Administration approval as a novel agent for the treatment of MCD. Here, a systematic review was conducted to include 171 cases of MCD patients treated with siltuximab. While traditional treatment methods were able to achieve a 5-year survival rate of only 55%–77%, results of siltuximab treatment demonstrated 5-year survival rates of nearly 96.4% (only 2 deaths reported out of 55 patients with follow-up data). Ultimately, the results from multiple clinical trials have demonstrated that siltuximab is extremely efficacious in alleviating disease symptoms (fatigue, pain, and lymphadenopathy) while simultaneously achieving disease remission, thus extending progression-free survival for years longer than the average 5-year survival rates for MCD. Keywords: Castleman’s disease, angiofollicular lymph node hyperplasia, giant lymph node hyperplasia, siltuximab, IL-6 recepto