Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Clin Auton Res ; 34(1): 191-201, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38064009

RESUMEN

PURPOSE: Guanfacine is an α2A-adrenergic receptor agonist, FDA-approved to treat attention-deficit hyperactivity disorder and high blood pressure, typically as an extended-release formulation up to 7 mg/day. In our dysautonomia clinic, we observed that off-label use of short-acting guanfacine at 1 mg/day facilitated symptom relief in two families with multiple members presenting with severe generalized anxiety. We also noted anecdotal improvements in associated dysautonomia symptoms such as hyperhidrosis, cognitive impairment, and palpitations. We postulated that a genetic deficit existed in these patients that might augment guanfacine susceptibility. METHODS: We used whole-exome sequencing to identify mutations in patients with shared generalized anxiety and dysautonomia symptoms. Guanfacine-induced changes in the function of voltage-gated Na+ channels were investigated using voltage-clamp electrophysiology. RESULTS: Whole-exome sequencing uncovered the p.I739V mutation in SCN9A in the proband of two nonrelated families. Moreover, guanfacine inhibited ionic currents evoked by wild-type and mutant NaV1.7 encoded by SCN9A, as well as other NaV channel subtypes to a varying degree. CONCLUSION: Our study provides further evidence for a possible pathophysiological role of NaV1.7 in anxiety and dysautonomia. Combined with off-target effects on NaV channel function, daily administration of 1 mg short-acting guanfacine may be sufficient to normalize NaV channel mutation-induced changes in sympathetic activity, perhaps aided by partial inhibition of NaV1.7 or other channel subtypes. In a broader context, expanding genetic and functional data about ion channel aberrations may enable the prospect of stratifying patients in which mutation-induced increased sympathetic tone normalization by guanfacine can support treatment strategies for anxiety and dysautonomia symptoms.


Asunto(s)
Enfermedades del Sistema Nervioso Autónomo , Guanfacina , Humanos , Guanfacina/uso terapéutico , Canal de Sodio Activado por Voltaje NAV1.7/genética , Mutación , Ansiedad/tratamiento farmacológico , Ansiedad/genética , Agonistas alfa-Adrenérgicos
2.
Surg Case Rep ; 9(1): 92, 2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37254018

RESUMEN

BACKGROUND: Local resection is the standard treatment for gastrointestinal stromal tumors (GISTs). Laparoscopic and endoscopic cooperative surgery (LECS) is a minimally invasive surgery used to resect GISTs. Herein, we report an extremely rare case of a gastric GIST that grossly vanished during LECS. CASE PRESENTATION: A 50-year-old Japanese female was referred to our hospital after an abnormality was detected during an esophagogastroduodenoscopy (EGD) at her annual health checkup. Based on EGD, endoscopic ultrasound (EUS), and computer tomography (CT) findings, the patient was diagnosed with a 50-mm submucosal tumor (SMT) with intraluminal growth on the anterior wall of the lesser curvature of the upper body of the stomach. We routinely use LECS to treat the intraluminal growth type of GISTs. During the intraoperative endoscopy, the intraluminal submucosal tumor, which was detected preoperatively, had vanished. A red-white scar was observed in the regressed tumor region. LECS was performed by resecting at a distance away from the scar tissue and closing the gastric wall with intracavitary sutures. In the evaluation from the tumor section view of the original resected specimen, a 22 × 14 × 8 mm lobular neoplasm was observed that was predominantly located in the gastric submucosa to the muscularis propia. Pathological findings confirmed the diagnosis of GIST with intermediate risk indicated by the Fletcher classification. The patient continued postoperative adjuvant chemotherapy with imatinib and no recurrence was detected over 12 months after surgery. CONCLUSION: LECS was performed on the vanished gastric GIST, providing the best surgical treatment and leading to an accurate diagnosis and optimal postoperative care.

3.
Surg Case Rep ; 9(1): 86, 2023 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-37204618

RESUMEN

BACKGROUND: Advanced gastric cancer has an unfavorable prognosis and poor curability. Immune checkpoint inhibitors, such as nivolumab, have recently emerged as a potential solution for this aggressive disease. However, there is a lack of established evidence on the clinical efficacy of these agents, particularly in the perioperative period for advanced gastric cancer patients who are unresectable, recurrent, or preoperative. Despite the limited data available, there have been rare cases of dramatic therapeutic effects. In this study, we present a successful case of nivolumab treatment along with surgery. CASE PRESENTATION: A 69-year-old female presented with pericardial discomfort and was diagnosed with advanced gastric cancer following upper gastrointestinal endoscopy. Laparoscopic distal gastrectomy with D2 lymph node dissection was performed, resulting in a final pathological diagnosis of Stage IIIA. The patient received postoperative adjuvant chemotherapy with oral S-1 therapy, but was found to have multiple liver metastases at 8 months postsurgery. Weekly paclitaxel and ramucirumab therapy was initiated, but the patient experienced adverse side effects, leading to the discontinuation of treatment. Nivolumab monotherapy was then administered for 18 cycles, resulting in a partial therapeutic response and PET-CT revealed a complete metabolic response. However, the patient developed a Grade 3 pemphigoid as an immune-related adverse event, leading to the cessation of nivolumab. The patient underwent laparoscopic partial hepatectomy. Postoperative pathology showed no residual tumor cells, indicating a complete response. At present, 25 months after surgery, the patient was alive without recurrence. CONCLUSION: In this report, we present a case of gastric cancer with liver metastatic recurrence, in which a complete pathological response was achieved with nivolumab treatment. Although determining whether surgical intervention is necessary following successful drug treatment can be challenging, PET-CT imaging may be useful in decision-making regarding surgical treatment.

4.
Surg Endosc ; 37(8): 5931-5942, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37076615

RESUMEN

BACKGROUND: The transorally inserted anvil (OrVil™) is frequently selected for esophagojejunostomy after laparoscopic total gastrectomy (LTG) because of its versatility. During anastomosis with OrVil™, the double stapling technique (DST) or hemi-double stapling technique (HDST) can be selected by overlapping the linear stapler and the circular stapler. However, no studies have reported the differences between the methods and their clinical significance. METHODS: A randomized controlled clinical trial with a parallel assignment and single-blind outcomes assessment analysis was conducted. Patients with gastric cancer eligible for LTG who met the selection criteria were randomized. Preoperative characteristics and perioperative and postoperative outcomes were compared between the DST and HDST. The primary endpoint was an anastomosis-related complication, and the secondary endpoints were perioperative outcomes and postoperative complications, excluding anastomosis-related complications. RESULTS: Thirty patients with gastric cancer were eligible and randomized. LTG and esophagojejunostomy were successfully performed in all patients, without conversion to laparotomy. Preoperative characteristics, excluding preoperative chemotherapy, were not significantly different between the two groups. One anastomotic leakage of Clavien-Dindo classification grade ≥ IIIa was observed in the DST, although no significant difference was found between the two groups (6.6% vs. 0%, P = 0.30). In the HDST, one case of anastomotic stricture required endoscopic balloon dilation. No significant differences were found in operative time, whereas the anastomosis time was significantly shorter in the HDST than in the DST (47.5 ± 15.8 vs. 38.2 ± 8.8 min, P = 0.028). Except for anastomosis-related complications, postoperative complications (P = 0.282) and postoperative hospital stay for the DST and HDST were not significantly different. CONCLUSIONS: No superiority was found between the DST and HDST with OrVil™ in esophagojejunostomy of LTG for gastric cancer with respect to postoperative complications, whereas the HDST may be preferable in terms of the simplicity of the surgical technique.


Asunto(s)
Laparoscopía , Neoplasias Gástricas , Humanos , Esófago/cirugía , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/complicaciones , Método Simple Ciego , Grapado Quirúrgico/métodos , Laparoscopía/métodos , Anastomosis Quirúrgica/métodos , Gastrectomía/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía
5.
Cureus ; 14(4): e23960, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35415059

RESUMEN

Agenesis of the left hepatic lobe is an exceedingly rare morphological anomaly. Moreover, agenesis of the left hepatic lobe accompanied by esophagogastric cancer is even rarer, with no reports to date. Agenesis of the hepatic lobe is commonly related to some anatomical variations of the gastrohepatic system. A 76-year-old man was referred to our hospital for surgery for esophagogastric cancer with short Barrett's esophagus. Multiple preoperative imaging modalities revealed agenesis of the left hepatic lobe accompanied by esophagogastric cancer. Robotic proximal gastrectomy and transhiatal lower esophagectomy were performed. Intraoperative findings showed agenesis of the left hepatic lobe. The patient's postoperative course was favorable. Today, 16 months after surgery, the patient is alive without recurrence of esophagogastric cancer. We report a case of agenesis of the left hepatic lobe in a patient undergoing robotic proximal gastrectomy and transhiatal lower esophagectomy for esophagogastric cancer. Preoperative comprehension of various visceral anomalies reduces the risk of surgical complications.

6.
World J Gastrointest Surg ; 14(2): 120-131, 2022 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-35317549

RESUMEN

BACKGROUND: For total laparoscopic distal gastrectomies for gastric cancer, the reconstruction method is critical to the clinical outcome of the procedure. However, which reconstruction technique is optimal remains controversial. We originally reported the augmented rectangle technique (ART) as a reconstruction option for total laparoscopic Billroth I reconstructions. Still, little is known about its effect on long-term outcomes, specifically the incidence of postgastrectomy syndrome and its impact on quality of life. AIM: To analyze postgastrectomy syndrome and quality of life after ART using the Postgastrectomy Syndrome Assessment Scale-37 (PGSAS-37) questionnaire. METHODS: At Juntendo University, a total of 94 patients who underwent ART for Billroth I reconstruction with total laparoscopic distal gastrectomies for gastric cancer between July 2016 and March 2020 completed the PGSAS-37 questionnaire. Multidimensional analysis was performed, comparing those 94 ART cases from our institution (ART group) to 909 distal gastrectomy cases with a Billroth I reconstruction from other Japanese institutions who also completed the PGSAS-37 as part of a larger national database (PGSAS group). RESULTS: Patients in the ART group had significantly better total symptom scores in all the symptom subscales (i.e., esophageal reflux, abdominal pain, meal-related distress, indigestion, diarrhea, constipation, and dumping). The loss of body weight was marginally greater for those in the ART group than in the PGSAS group (-9.3% vs -7.9%, P = 0.054). The ART group scored significantly lower in their dissatisfaction of ongoing symptoms, during meals, and with daily life. CONCLUSION: ART for Billroth I reconstruction provided beneficial long-term results for postgastrectomy syndrome and quality of life in patients undergoing total laparoscopic distal gastrectomies for gastric cancer.

7.
World J Gastroenterol ; 26(13): 1490-1500, 2020 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-32308349

RESUMEN

BACKGROUND: Total laparoscopic distal gastrectomy (TLDG) is increasing due to some advantages over open surgery, which has generated interest in gastrointestinal surgeons. However, TLDG is technically demanding especially for lymphadenectomy and gastrointestinal reconstruction. During the course of training, trainee surgeons have less chances to perform open gastrectomy compared with that of senior surgeons. AIM: To evaluate an appropriate, efficient and safe laparoscopic training procedures suitable for trainee surgeons. METHODS: Ninety-two consecutive patients with gastric cancer who underwent TLDG plus Billroth I reconstruction using an augmented rectangle technique and involving trainees were reviewed. The trainees were taught a laparoscopic view of surgical anatomy, standard operative procedures and practiced essential laparoscopic skills. The TLDG procedure was divided into regional lymph node dissections and gastrointestinal reconstruction for analyzing trainee skills. Early surgical outcomes were compared between trainees and trainers to clarify the feasibility and safety of TLDG performed by trainees. Learning curves were used to assess the utility of our training system. RESULTS: Five trainees performed a total of 52 TLDGs (56.5%), while 40 TLDGs were conducted by two trainers (43.5%). Except for depth of invasion and pathologic stage, there were no differences in clinicopathological characteristics. Trainers performed more D2 gastrectomies than trainees. The total operation time was significantly longer in the trainee group. The time spent during the lesser curvature lymph node dissection and the Billroth I reconstruction were similar between the two groups. No difference was found in postoperative complications between the two groups. The learning curve of the trainees plateaued after five TLDG cases. CONCLUSION: Preparing trainees with a laparoscopic view of surgical anatomy, standard operative procedures and practice in essential laparoscopic skills enabled trainees to perform TLDG safely and feasibly.


Asunto(s)
Gastrectomía/educación , Gastroenterostomía/educación , Laparoscopía/educación , Cirujanos/educación , Enseñanza , Adulto , Competencia Clínica/estadística & datos numéricos , Femenino , Gastrectomía/métodos , Gastroenterostomía/métodos , Humanos , Laparoscopía/métodos , Curva de Aprendizaje , Masculino , Tempo Operativo , Estudios Retrospectivos , Resultado del Tratamiento
8.
Ann Transl Med ; 8(5): 196, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32309343

RESUMEN

BACKGROUND: The rapid expansion of laparoscopic gastrectomy (LG) for gastric cancer has generated interest among surgeons. The adequate dissemination of correct information about such advanced laparoscopic surgery can certainly be useful for surgeons and trainees. Online video resources such as YouTube are frequently used for education. This study aimed to evaluate the quality, utility, and completeness of LG videos for gastric cancer on the video website YouTube. METHODS: The terms "laparoscopic gastrectomy" and "gastric cancer" were searched on YouTube on August 16, 2019. The first 100 videos in three sorting categories (website's default setting, view count, and length of duration) were checked by two experienced surgeons. The popularity was evaluated with the video power index (VPI). The reliability was measured using the Journal of American Medical Association (JAMA) benchmark criteria. The educational value and completeness were evaluated with a checklist developed by the researchers. RESULTS: A total of 102 videos were analyzed. Laparoscopic distal gastrectomy (LDG) and laparoscopic total gastrectomy were the most frequently recorded techniques. Lymph node (LN) dissection was the most frequently covered topic (89.2%), followed in descending order by GI reconstruction (87.3%). The mean VPI, JAMA benchmark score and completeness score of all videos were 2.63, 1.94 and 8.53, respectively. The types of sources were as follows: private users, 73 (71.6%); academic institutions, 20 (19.6%); and others, 9 (8%). A total of 97 videos with an identifiable primary surgeon originated from eighteen different countries. CONCLUSIONS: Laparoscopic videos represented by YouTube represent a useful and appropriate educational tool. However, the quality of videos varied, and the level of information incompleteness was fairly high due to insufficient reviews. The role of private uploaders and academic institutions in surgical education cannot be overestimated. It is necessary that surgeon trainers and surgical educators critically analyze the quality of video content and exercise responsibility in directing trainee surgeons. In the current era, it is best for trainees to search for peer-reviewed content.

9.
BMC Cancer ; 17(1): 622, 2017 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-28874135

RESUMEN

BACKGROUND: Replication-competent adenoviruses (Ad) produced cytotoxic effects on infected tumors and have been examined for the clinical applicability. A biomarkers to predict the cytotoxicity is valuable in a clinical setting. METHODS: We constructed type 5 Ad (Ad5) of which the expression of E1A gene was activated by a 5' regulatory sequences of survivin, midkine or cyclooxygenase-2, which were highly expressed in human tumors. We also produced the same replication-competent Ad of which the fiber-knob region was replaced by that of Ad35 (AdF35). The cytotoxicity was examined by a colorimetric assay with human tumor cell lines, 4 kinds of pancreatic, 9 esophageal carcinoma and 5 mesothelioma. Ad infectivity and Ad-mediated gene expression were examined with replication-incompetent Ad5 and AdF35 which expressed the green fluorescence protein gene. Expression of cellular receptors for Ad5 and AdF35 was also examined with flow cytometry. A transcriptional activity of the regulatory sequences was investigated with a luciferase assay in the tumor cells. We then investigated a possible correlation between Ad-mediated cytotoxicity and the infectivity/gene expression, the transcriptional activity or the p53 genotype. RESULTS: We found that the cytotoxicity was greater with AdF35 than with Ad5 vectors, but was not correlated with the Ad infectivity/gene expression irrespective of the fiber-knob region or the E1A-activating transcriptional activity. In contrast, replication-competent Ad produced greater cytotoxicity in p53 mutated than in wild-type esophageal carcinoma cells, suggesting a possible association between the cytotoxicity and the p53 genotype. CONCLUSIONS: Sensitivity to Ad-mediated cytotoxic activity was linked with the p53 genotype but was not lineally correlated with the infectivity/gene expression or the E1A expression.


Asunto(s)
Adenoviridae/genética , Adenoviridae/metabolismo , Proteínas E1A de Adenovirus/metabolismo , Expresión Génica , Vectores Genéticos/genética , Secuencias Reguladoras de Ácidos Nucleicos , Proteína p53 Supresora de Tumor/genética , Replicación Viral , Línea Celular Tumoral , Efecto Citopatogénico Viral , Genes Reporteros , Genotipo , Humanos , Unión Proteica , Receptores Virales/genética , Receptores Virales/metabolismo , Activación Transcripcional , Transducción Genética , Transgenes , Proteína p53 Supresora de Tumor/metabolismo
10.
Apoptosis ; 20(12): 1587-98, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26373551

RESUMEN

Pancreatic carcinoma is relatively resistant to chemotherapy and cell death induced by replication of adenoviruses (Ad) can be one of the therapeutic options. Transduction efficacy of conventional type 5 Ad (Ad5) is however low and the cytotoxic mechanism by replication-competent Ad was not well understood. We constructed replication-competent Ad5 of which the E1A promoter region was replaced with a transcriptional regulatory region of the midkine, the survivin or the cyclooxygenase-2 gene, all of which were expressed at a high level in human tumors. We also prepared replication-competent Ad5 that were activated with the same region but had the type 35 Ad-derived fiber-knob region (AdF35) to convert the major cellular receptor for Ad infection from the coxsackie adenovirus receptor to CD46 molecules. Replication-competent AdF35 that were activated with the exogenous region produced cytotoxic effects on human pancreatic carcinoma cells greater than the corresponding Ad5 bearing with the same regulatory region. Cells infected with the AdF35 showed cytopathic effects and increased sub-G1 fractions. Caspase-9, less significantly caspase-8 and poly (ADP-ribose) polymerase, but not caspase-3 was cleaved and expression of molecules involved in autophagy and caspase-independent cell death pathways remained unchanged. Nevertheless, H2A histone family member X molecules were phosphorylated, and N-acetyl-L-cystein, an inhibitor for reactive oxygen species, suppressed the AdF35-mediated cytotoxicity. These data indicated a novel mechanism of Ad-mediated cell death and suggest a possible clinical application of the fiber-knob modified Ad.


Asunto(s)
Adenoviridae/genética , Neoplasias Pancreáticas/virología , Especies Reactivas de Oxígeno/metabolismo , Replicación Viral/genética , Acetilcisteína/metabolismo , Caspasas/metabolismo , Muerte Celular/fisiología , Línea Celular , Línea Celular Tumoral , Proteína de la Membrana Similar al Receptor de Coxsackie y Adenovirus/metabolismo , Ciclooxigenasa 2/metabolismo , Células HEK293 , Humanos , Proteína Cofactora de Membrana/metabolismo , Neoplasias Pancreáticas/metabolismo , Poli(ADP-Ribosa) Polimerasas/metabolismo , Regiones Promotoras Genéticas/genética , Transducción Genética/métodos , Neoplasias Pancreáticas
11.
BMC Cancer ; 15: 464, 2015 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-26059686

RESUMEN

BACKGROUND: Improvement of transduction and augmentation of cytotoxicity are crucial for adenoviruses (Ad)-mediated gene therapy for cancer. Down-regulated expression of type 5 Ad (Ad5) receptors on human tumors hampered Ad-mediated transduction. Furthermore, a role of the p53 pathways in cytotoxicity mediated by replication-competent Ad remained uncharacterized. METHODS: We constructed replication-competent Ad5 of which the E1 region genes were activated by a transcriptional regulatory region of the midkine or the survivin gene, which is expressed preferentially in human tumors. We also prepared replication-competent Ad5 which were regulated by the same region but had a fiber-knob region derived from serotype 35 (AdF35). We examined the cytotoxicity of these Ad and a possible combinatory use of the replication-competent AdF35 and Ad5 expressing the wild-type p53 gene (Ad5/p53) in esophageal carcinoma cells. Expression levels of molecules involved in cell death, anti-tumor effects in vivo and production of viral progenies were also investigated. RESULTS: Replication-competent AdF35 in general achieved greater cytotoxic effects to esophageal carcinoma cells than the corresponding replication-competent Ad5. Infection with the AdF35 induced cleavages of caspases and increased sub-G1 fractions, but did not activate the autophagy pathway. Transduction with Ad5/p53 in combination with the replication-competent AdF35 further enhanced the cytotoxicity in a synergistic manner. We also demonstrated the combinatory effects in an animal model. Transduction with Ad5/p53 however suppressed production of replication-competent AdF35 progenies, but the combination augmented Ad5/p53-mediated p53 expression levels and the downstream pathways. CONCLUSIONS: Combination of replication-competent AdF35 and Ad5/p53 achieved synergistic cytotoxicity due to enhanced p53-mediated apoptotic pathways.


Asunto(s)
Adenoviridae/genética , Carcinoma/genética , Neoplasias Esofágicas/genética , Terapia Genética , Proteína p53 Supresora de Tumor/genética , Apoptosis/genética , Carcinoma/patología , Carcinoma/terapia , Línea Celular Tumoral , Proliferación Celular/genética , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/terapia , Regulación Neoplásica de la Expresión Génica , Vectores Genéticos , Humanos , ARN Mensajero/biosíntesis , Transducción Genética , Proteína p53 Supresora de Tumor/biosíntesis
12.
Inorg Chem ; 53(12): 5961-71, 2014 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-24892984

RESUMEN

Two Tb(III) complexes with the same N6O3 donor atoms but different coordination geometries, "fac"-[Tb(III)(HL(DL-ala))3]·7H2O (1) and "mer"-[Tb(III)(HL(DL-phe))3]·7H2O (2), were synthesized, where H2L(DL-ala) and H2L(DL-phe) are N-[(imidazol-4-yl)methylidene]-DL-alanine and -DL-phenylalanine, respectively. Each Tb(III) ion is coordinated by three electronically mononegative NNO tridentate ligands to form a coordination geometry of a tricapped trigonal prism. Compound 1 consists of enantiomers "fac"-[Tb(III)(HL(D-ala))3] and "fac"-[Tb(III)(HL(L-ala))3], while 2 consists of "mer"-[Tb(III)(HL(D-phe))2(HL(L-phe))] and "mer"-[Tb(III)(HL(D-phe))(HL(L-phe))2]. Magnetic data were analyzed by a spin Hamiltonian including the crystal field effect on the Tb(III) ion (4f(8), J = 6, S = 3, L = 3, gJ = 3/2, (7)F6). The Stark splitting of the ground state (7)F6 was evaluated from magnetic analysis, and the energy diagram pattern indicated easy-plane and easy-axis (Ising type) magnetic anisotropies for 1 and 2, respectively. Highly efficient luminescences with Φ = 0.50 and 0.61 for 1 and 2, respectively, were observed, and the luminescence fine structure due to the (5)D4 → (7)F6 transition is in good accordance with the energy diagram determined from magnetic analysis. The energy diagram of 1 shows an approximate single-well potential curve, whereas that of 2 shows a double- or quadruple-well potential within the (7)F6 multiplets. Complex 2 displayed an onset of the out-of-phase signal in alternating current (ac) susceptibility at a direct current bias field of 1000 Oe on cooling down to 1.9 K. A slight frequency dependence was recorded around 2 K. On the other hand, 1 did not show any meaningful out-of-phase ac susceptibility. Pulsed-field magnetizations of 1 and 2 were measured below 1.6 K, and only 2 exhibited magnetic hysteresis. This finding agrees well with the energy diagram pattern from crystal field calculation on 1 and 2. DFT calculation allowed us to estimate the negative charge distribution around the Tb(III) ion, giving a rationale to the different magnetic anisotropies of 1 and 2.

13.
FEBS Lett ; 585(21): 3372-7, 2011 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-22004763

RESUMEN

The efficient processing of human immunodeficiency virus type 1 Gag-Pol requires not only protease activity but also specific reverse transcriptase (RT) and integrase sequences. However, the critical amino acid residues of the HIV-1 Pol gene involved in protease-mediated Gag-Pol processing have not been precisely defined. Here, we found that the substitution of Thr-128 or Tyr-146 with Ala markedly impaired the proteolytic processing of the MA/CA, p66/p51 and RT/IN sites but did not affect the normal processing of other sites. Moreover, a Thr-128 or Tyr-146 mutation in RT abolished RT dimerization in vitro. These results suggest that Thr-128 and Tyr-146 within the RT region play important roles in protease-mediated Gag-Pol processing.


Asunto(s)
Aminoácidos , Proteínas de Fusión gag-pol/metabolismo , Transcriptasa Inversa del VIH/química , Transcriptasa Inversa del VIH/metabolismo , VIH-1/enzimología , Precursores de Proteínas/metabolismo , Proteolisis , Sustitución de Aminoácidos , Células HEK293 , Transcriptasa Inversa del VIH/genética , VIH-1/genética , VIH-1/metabolismo , VIH-1/fisiología , Humanos , Mutación , Fosforilación , Multimerización de Proteína , Estructura Cuaternaria de Proteína , Virión/enzimología , Virión/genética , Virión/metabolismo , Virión/fisiología , Replicación Viral/genética
14.
J Biol Chem ; 279(31): 32028-34, 2004 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-15155728

RESUMEN

We found for the first time that Zygomycetes species showed resistance to Aureobasidin A, an antifungal agent. A novel family of neutral glycosphingolipids (GSLs) was found in these fungi and isolated from Mucor hiemalis, which is a typical Zygomycetes species. Their structures were completely determined by compositional sugar, fatty acid, and sphingoid analyses, methylation analysis, matrix-assisted laser desorption ionization time-of-flight/mass spectrometry, and (1)H NMR spectroscopy. They were as follows: Gal beta 1-6Gal beta 1-1Cer (CDS), Gal alpha 1-6Gal beta 1-6Gal beta 1-1Cer (CTS), Gal alpha 1-6Gal alpha 1-6Gal beta 1-6Gal beta 1-1Cer (CTeS), and Gal alpha 1-6Gal alpha 1-6Gal alpha 1-6Gal beta 1-6Gal beta 1-1Cer (CPS). The ceramide moieties of these GSLs consist of 24:0, 25:0, and 26:0 2-hydroxy acids as major fatty acids and 4-hydroxyoctadecasphinganine (phytosphingosine) as the sole sphingoid. However, the glycosylinositolphosphoceramide families that are the major GSLs components in fungi were not detected in Zygomycetes at all. This seems to be the reason that Aureobasidin A is not effective for Zygomycetes as an antifungal agent. Our results indicate that the biosynthetic pathway for GSLs in Zygomycetes is significantly different from those in other fungi and suggest that any inhibitor of this pathway may be effective for mucormycosis, which is a serious pathogenic disease for humans.


Asunto(s)
Depsipéptidos , Resistencia a Medicamentos , Glucolípidos/química , Glicoesfingolípidos/química , Péptidos Cíclicos/farmacología , Esfingosina/análogos & derivados , Absidia/metabolismo , Antifúngicos/farmacología , Aspergillus/metabolismo , Carbohidratos/química , Cromatografía en Capa Delgada , Cromatografía de Gases y Espectrometría de Masas , Glicósido Hidrolasas/metabolismo , Espectroscopía de Resonancia Magnética , Modelos Químicos , Mucor/metabolismo , Mucormicosis , Familia de Multigenes , Penicillium/metabolismo , Rhizopus/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Esfingolípidos/metabolismo , Esfingosina/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA