RESUMEN
Germline DNA alterations affecting homologous recombination pathway genes have been associated with pancreatic cancer (PC) risk. BRCA2 is the most studied gene and affects the management of PC patients and their families. Even though recent reports have suggested a similar role of germline ATM pathogenic variants (PV) in familial PC, there is still a disagreement between experts on how it could affect patient management given the lack of proper PC risk estimates. We retrospectively analyzed the germline data of 257 PC patients among whom nearly 50% were sporadic cases. We showed similar frequencies of BRCA2 (4.9%) and ATM (4.4%) PV or likely pathogenic variants, which were not related to familial history. Based on our findings and that of the literature, we suggest including ATM gene among the panel of genes analyzed in PC patients pending the publication of prospective studies.
Asunto(s)
Predisposición Genética a la Enfermedad , Neoplasias Pancreáticas , Humanos , Estudios Retrospectivos , Estudios Prospectivos , Mutación de Línea Germinal , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologíaRESUMEN
The timing of an invasive diagnosis and treatment strategy in patients with an acute coronary syndrome without ST-elevation (NSTE-ACS) depends on the patient's risk profile. In addition to the clinical symptoms, ST/T alterations in the resting ECG as well as an increase and kinetics of troponin are of crucial importance in this setting. For the majority of patients the highly sensitive troponin enables a rapid rule in or rule out strategy of a non-ST-segment elevation myocardial infarction (NSTEMI) with a 0/3 h algorithm. An even faster 0/1 h algorithm is increasingly being used; however, troponin only helps to identify patients with NSTEMI. Troponin-negative patients can still suffer from unstable angina pectoris. A dual antiplatelet therapy (DAPT) with acetylsalicylic acid (ASS) and an ADP receptor antagonist should be initiated in the acute phase and continued for 12 months, irrespective of the initial treatment strategy, e.g. percutaneous coronary intervention (PCI), bypass surgery or conservative treatment. In patients with a high bleeding risk a duration of 6 months only may be considered, whereas in patients with a high risk of ischemia the DAPT might be prolonged for up to 36 months.
Asunto(s)
Síndrome Coronario Agudo , Infarto del Miocardio sin Elevación del ST , Intervención Coronaria Percutánea , Síndrome Coronario Agudo/terapia , Angina Inestable , Humanos , Infarto del Miocardio sin Elevación del ST/terapiaRESUMEN
An increasing number of reports suggest that Propionibacterium acnes can cause serious invasive infections. Currently, only limited data exist regarding the spectrum of invasive P. acnes infections. We conducted a non-selective cohort study at a tertiary hospital in the UK over a 9-year-period (2003-2012) investigating clinical manifestations, risk factors, management, and outcome of invasive P. acnes infections. Forty-nine cases were identified; the majority were neurosurgical infections and orthopaedic infections (n = 28 and n = 15 respectively). Only 2 cases had no predisposing factors; all neurosurgical and 93.3 % of orthopaedic cases had a history of previous surgery and/or trauma. Foreign material was in situ at the infection site in 59.3 % and 80.0 % of neurosurgical and orthopaedic cases respectively. All neurosurgical and orthopaedic cases required one or more surgical interventions to treat P. acnes infection, with or without concomitant antibiotic therapy; the duration of antibiotic therapy was significantly longer in the group of orthopaedic cases (median 53 vs 19 days; p = 0.0025). All tested P. acnes isolates were susceptible to penicillin, ampicillin and chloramphenicol; only 1 was clindamycin-resistant. Neurosurgical and orthopaedic infections account for the majority of invasive P. acnes infections. Most cases have predisposing factors, including previous surgery and/or trauma; spontaneous infections are rare. Foreign material is commonly present at the site of infection, indicating that the pathogenesis of invasive P. acnes infections likely involves biofilm formation. Since invasive P. acnes infections are associated with considerable morbidity, further studies are needed to establish effective prevention and optimal treatment strategies.
Asunto(s)
Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/patología , Propionibacterium acnes/aislamiento & purificación , Adulto , Antibacterianos/uso terapéutico , Estudios de Cohortes , Femenino , Infecciones por Bacterias Grampositivas/diagnóstico , Infecciones por Bacterias Grampositivas/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Centros de Atención Terciaria , Resultado del Tratamiento , Reino Unido/epidemiología , Adulto JovenRESUMEN
BACKGROUND: Vaginal microbiota composition is associated with spontaneous preterm birth (sPTB), depending on ethnicity. Host-microbiota interactions are thought to play an important underlying role in this association between ethnicity, vaginal microbiota and sPTB. METHODS: In a prospective cohort of nulliparous pregnant women, we assessed vaginal microbiota composition, vaginal immunoglobulins (Igs), and local inflammatory markers. We performed a nested case-control study with 19 sPTB cases, matched based on ethnicity and midwifery practice to 19 term controls. RESULTS: Of the 294 included participants, 23 pregnancies ended in sPTB. We demonstrated that Lactobacillus iners-dominated microbiota, diverse microbiota, and ethnicity were all independently associated with sPTB. Microbial Ig coating was associated with both microbiota composition and ethnicity, but a direct association with sPTB was lacking. Microbial IgA and IgG coating were lowest in diverse microbiota, especially in women of any ethnic minority. When correcting for microbiota composition, increased microbial Ig coating correlated with increased inflammation. CONCLUSION: In these nulliparous pregnant women, vaginal microbiota composition is strongly associated with sPTB. Our results support that vaginal mucosal Igs might play a pivotal role in microbiota composition, microbiota-related inflammation, and vaginal community disparity within and between ethnicities. This study provides insight in host-microbe interaction, suggesting that vaginal mucosal Igs play an immunomodulatory role similar to that in the intestinal tract. Video Abstract.
Asunto(s)
Etnicidad , Lactobacillus , Microbiota , Nacimiento Prematuro , Vagina , Adulto , Femenino , Humanos , Embarazo , Adulto Joven , Estudios de Casos y Controles , Interacciones Microbiota-Huesped , Inmunoglobulina A , Inmunoglobulinas , Lactobacillus/aislamiento & purificación , Nacimiento Prematuro/microbiología , Nacimiento Prematuro/etnología , Estudios Prospectivos , Vagina/microbiologíaRESUMEN
Finding genes that cause human hypertension is not straightforward, since the determinants of blood pressure in primary hypertension are multifactorial. One approach to identifying relevant genes is to elucidate rare forms of monogenic hypertension. A relevant mutation may provide a rational starting point from which to analyse the pathophysiology of a condition affecting 20% of the world's population. In 1973 a family with autosomal dominantly inherited brachydactyly and severe hypertension, where the two traits cosegregated completely, was described. We have now re-examined this kindred, and localized the hypertension and brachydactyly locus to chromosome 12p in a region defined by markers D12S364 and D12S87. As the renin-angiotensin-system and sympathetic nervous system respond normally in this form of hypertension, the condition resembles essential hypertension. This feature distinguishes this form of hypertension from glucocorticoid remediable aldosteronism and Liddle's syndrome, which are salt-sensitive forms of monogenic hypertension with very low plasma renin activity. We suggest that identification of the gene involved in hypertension and brachydactyly and its mutation will be of great relevance in elucidating new mechanisms leading to blood pressure elevation.
Asunto(s)
Mapeo Cromosómico , Cromosomas Humanos Par 12 , Dedos/anomalías , Hipertensión/genética , Dedos del Pie/anomalías , Adulto , Anciano , Femenino , Ligamiento Genético , Marcadores Genéticos , Genotipo , Humanos , Escala de Lod , Masculino , Persona de Mediana Edad , Linaje , Análisis de Regresión , Sistema Renina-Angiotensina/genética , Síndrome , TurquíaRESUMEN
The detection of a novel coronavirus in patients from the Arabian Peninsula in late 2012 raised serious concerns of a possible international outbreak. Ministries of health of the three affected countries invited missions from the World Health Organization to participate in a review of data and capacity to detect and respond to further cases. Recommendations were made for investigations to answer critical questions about human-to-human transmission and the geographic extent of the virus. Additional recommendations were made to improve surveillance capacity by acquiring the capacity to test for the virus and enhance syndromic surveillance. Available evidence continues to suggest an unknown animal reservoir for the virus with sporadic zoonotic transmission the primary epidemiological pattern of transmission. Human-to-human transmission, while it can occur, does not appear to be sustained in the community.
Asunto(s)
Infecciones por Coronavirus/epidemiología , Coronavirus/aislamiento & purificación , Brotes de Enfermedades , Vigilancia de la Población/métodos , Animales , Infecciones por Coronavirus/transmisión , Humanos , Internacionalidad , Medio Oriente/epidemiología , Organización Mundial de la SaludRESUMEN
Focal liver lesions are a very common occurrence. The detection and differentiation of such lesions is particularly important for the management of oncology patients and is a core task for radiology. The early and conclusive detection of malignant liver processes in a cost-efficient manner and with a low radiation dose for the patient requires systematic and skillful use of the various radiological methods. This review explains the application of current radiological methods for the detection and differentiation of malignant liver lesions and the typical appearance of the most commonly found liver malignancies.
Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/secundario , Hígado/patología , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada Multidetector/métodos , Imagen Multimodal/métodos , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Ultrasonografía/métodos , Carcinoma Hepatocelular/patología , Medios de Contraste/administración & dosificación , Diagnóstico Diferencial , Hiperplasia Nodular Focal/diagnóstico , Hiperplasia Nodular Focal/patología , Humanos , Neoplasias Hepáticas/patología , Sensibilidad y EspecificidadRESUMEN
Excitable media are spatially distributed systems characterized by their ability to propagate signals undamped over long distances. Wave propagation in excitable media has been modeled extensively both by continuous partial differential equations and by discrete cellular automata. Cellular automata are desirable because of their intuitive appeal and efficient digital implementation, but until now they have not served as reliable models because they have lacked two essential properties of excitable media. First, traveling waves show dispersion, that is, the speed of wave propagation into a recovering region depends on the time elapsed since the preceding wave passed through that region. Second, wave speed depends on wave front curvature: curved waves travel with normal velocities noticeably different from the plane-wave velocity. These deficiencies of cellular automation models are remedied by revising the classical rules of the excitation and recovery processes. The revised model shows curvature and dispersion effects comparable to those of continuous models, it predicts rotating spiral wave solutions in quantitative accord with the theory of continuous excitable media, and it is parameterized so that the spatial step size of the automation can be adjusted for finer resolution of traveling waves.
Asunto(s)
Comunicación Celular/fisiología , Simulación por Computador , Modelos Biológicos , Animales , Humanos , MatemáticaRESUMEN
In breast reconstruction with autologous tissue the DIEP flap has become the gold standard in recent years. The superior gluteal artery perforator (s-GAP) flap is an alternative harvested from the buttock. We present our experience with the s-GAP flap and discuss its role in breast reconstruction. All s-GAP flaps performed for breast reconstruction in the Department of Plastic and Hand Surgery, Behandlungszentrum Vogtareuth from June 2002 until February 2007 were retrospectively analysed. Out of 59 flaps 4 flaps failed, the success rate was 94 %. Partial or fat necrosis occurred in 2 cases. The s-GAP flap served as a safe reconstructive alternative to the DIEP flap. Advantages of the s-GAP flap are reliable perforators, the safe vascular supply and the firm fat structure which facilitates the breast reconstruction. The donor site morbidity is minimal, the gluteal muscles stay intact and the scar is easy to hide in the underwear. Disadvantages are a demanding preparation with a prolonged operating time compared to the DIEP flap. The s-GAP flap is a reliable and safe option for autologeous breast reconstruction. It is the method of choice for staged bilateral breast reconstruction or if the DIEP flap is not available, particularly in the thin patient.
Asunto(s)
Neoplasias de la Mama/cirugía , Mamoplastia/métodos , Microcirugia/métodos , Colgajos Quirúrgicos/irrigación sanguínea , Adolescente , Adulto , Anciano , Estética , Femenino , Estudios de Seguimiento , Supervivencia de Injerto/fisiología , Humanos , Escisión del Ganglio Linfático , Persona de Mediana Edad , Flujo Sanguíneo Regional/fisiología , Reoperación , Recolección de Tejidos y Órganos/métodosRESUMEN
Malignant transformation of mediastinal mature teratoma is extremely rare and worsens the prognosis of the disease. Transformation can appear synchronously to or several years after the initial diagnosis. Clinical and radiological signs can orientate the clinician but the definitive diagnosis is obtained thanks to histology. An 11 year-old boy presented with a mediastinal mature teratoma and bone and pulmonary metastases. He received six cycles of chemotherapy combining etoposide, ifosfamide, cisplatin, followed by resection of a 16×14×9cm mediastinal mass. Karyotype analysis revealed the presence of an additional sex chromosome X (47 XXY) pathognomonic of Klinefelter's syndrome. Ten years later, sciatalgia revealed malignant transformation of a pre-existing sacral bone metastasis into gastrointestinal adenocarcinoma. The patient received four cycles of chemotherapy combining oxaliplatin, 5-fluorouracil and cetuximab. This treatment was followed by a complete resection of the sacral metastasis and completed with adjuvant irradiation of 54Gy in 30 daily fractions. Twelve months after the diagnosis of relapse, the patient remained alive without disease. To our knowledge, this is the first case of adenocarcinoma developed in bone metastases of a mediastinal mature teratoma in a boy with a Klinefelter's syndrome. We propose a review of the literature and an analysis of 20 others published cases of mediastinal teratoma with malignant transformation into adenocarcinoma.
Asunto(s)
Adenocarcinoma/patología , Neoplasias Óseas/patología , Neoplasias Gastrointestinales/patología , Neoplasias del Mediastino/patología , Teratoma/patología , Adenocarcinoma/complicaciones , Neoplasias Óseas/complicaciones , Neoplasias Óseas/secundario , Transformación Celular Neoplásica , Niño , Neoplasias Gastrointestinales/complicaciones , Humanos , Síndrome de Klinefelter/complicaciones , Masculino , Neoplasias del Mediastino/complicaciones , Teratoma/complicaciones , Teratoma/secundario , Adulto JovenRESUMEN
More than half of all deaths in Western society are related to arteriosclerotic cardiovascular diseases. Inherited disturbances in the low-density-lipoprotein (LDL) receptor and similar lipid-related defects account for the majority of these deaths. Testing procedures thus far rely on total cholesterol, LDL cholesterol, high-density-lipoprotein cholesterol, and triglyceride determinations. These tests are not able to provide any genetic information. We have developed an oligonucleotide ligation assay (OLA) that enables us to screen for high-risk individuals by testing for 19 common mutations in the LDL receptor and the apolipoprotein B genes using an automated genotyping-based two-step protocol. The novel OLA uses oligomeric pentaethyleneoxide mobility modifiers. The automated test will be useful in screening large populations for genetic data to distinguish relative from absolute risk, as well as for cost-effective familial analysis.
Asunto(s)
Técnicas Genéticas , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/genética , Sondas de Oligonucleótidos/genética , Apolipoproteínas B/genética , Secuencia de Bases , Biotecnología , Análisis Mutacional de ADN , Cartilla de ADN/genética , Pruebas Genéticas , Genotipo , Humanos , Mutación , Reacción en Cadena de la Polimerasa , Receptores de LDL/genéticaRESUMEN
BACKGROUND: This article is about 7 cases of free axillary flaps based on the lateral thoracic vessels. PATIENTS AND METHODS: Preoperative ultrasound markings were performed. Indications were defects which needed very smooth and plicable flaps for coverage with a short and well detectable scar. RESULTS: Flap loss was not noticed, dissection was demanding due to the very small venous drainage of the flaps and took all over 6.5 hours. A comparison with standard flaps of the subscapular vascular system is given. CONCLUSIONS: The authors recommend the free axillary flap based on the lateral thoracic vessels as a versatile flap for special indications.
Asunto(s)
Microcirugia , Colgajos Quirúrgicos/irrigación sanguínea , Adulto , Cicatriz/cirugía , Asimetría Facial/cirugía , Femenino , Humanos , Masculino , Mamoplastia , Persona de Mediana Edad , Parestesia/cirugía , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía , Reoperación , Arterias Torácicas/cirugía , Venas/cirugíaRESUMEN
Marine ecosystems are subject to anthropogenic change at global, regional and local scales. Global drivers interact with regional- and local-scale impacts of both a chronic and acute nature. Natural fluctuations and those driven by climate change need to be understood to diagnose local- and regional-scale impacts, and to inform assessments of recovery. Three case studies are used to illustrate the need for long-term studies: (i) separation of the influence of fishing pressure from climate change on bottom fish in the English Channel; (ii) recovery of rocky shore assemblages from the Torrey Canyon oil spill in the southwest of England; (iii) interaction of climate change and chronic Tributyltin pollution affecting recovery of rocky shore populations following the Torrey Canyon oil spill. We emphasize that "baselines" or "reference states" are better viewed as envelopes that are dependent on the time window of observation. Recommendations are made for adaptive management in a rapidly changing world.
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Cambio Climático , Explotaciones Pesqueras , Contaminación por Petróleo , Contaminación del Agua , Animales , Ecosistema , Ecotoxicología/métodos , Inglaterra , Ambiente , Peces , Biología Marina/métodos , Compuestos de Trialquiltina/toxicidad , Contaminantes Químicos del Agua/toxicidadRESUMEN
We study two authentic cases of protein-losing enteropathy, the diagnosis of which was facilitated using Given M2A videocapsule endoscopy. The first case corresponded to a primary intestinal lymphangiectasia confirmed by jejunum biopsies and the second one to a protein-losing enteropathy with lymphatic abnormalities secondary to a chronic constrictive pericarditis. In the first case, the mucosa of jejunum presented with a diffuse oedematous aspect, whitish villi, white curved lines probably related to submucosal dilated lymphatics and lacteal juice. In the second case, capsule endoscopy showed oedematous aspect of jejunum mucosa associated with white curved lines similar to those observed in the first case. Videocapsule endoscopy is useful in cases of protein-losing enteropathy to identify presence of intestinal lymphangiectasia and to specify their localisation after ruling out other disorders liable to induce protein-losing gastrointestinal syndrome.
Asunto(s)
Endoscopía Capsular , Linfangiectasia Intestinal/diagnóstico , Adulto , Biopsia , Edema/diagnóstico , Femenino , Humanos , Mucosa Intestinal/patología , Yeyuno/patología , Masculino , Pericarditis Constrictiva/complicaciones , Enteropatías Perdedoras de Proteínas/etiologíaRESUMEN
Prophages P1 and P7 exist as unit copy DNA plasmids in the bacterial cell. Maintenance of the prophage state requires the continuous expression of two repressors: (i) C1 is a protein which negatively regulates the expression of lytic genes including the C1 inactivator gene coi, and (ii) C4 is an antisense RNA which specifically inhibits the synthesis of an anti-repressor Ant. In addition, C1 repression is strengthened by lxc encoding an auxiliary repressor protein. The repressors C1, C4 and Lxc are components of a tripartite immunity system of the two phages. Here, the mode of action of these regulatory components including their antagonists Coi and Ant is described.
Asunto(s)
Bacteriófago P1/inmunología , Bacteriófagos/inmunología , ARN sin Sentido/fisiología , Proteínas Represoras/fisiología , Secuencia de Bases , Datos de Secuencia MolecularRESUMEN
Recent studies suggest that multiple myeloma is an immunogenic disease, which might be effectively targeted by antigen-specific T-cell immunotherapy. As standard of care in myeloma includes proteasome inhibitor therapy, it is of great importance to characterize the effects of this treatment on HLA-restricted antigen presentation and implement only robustly presented targets for immunotherapeutic intervention. Here, we present a study that longitudinally and semi-quantitatively maps the effects of the proteasome inhibitor carfilzomib on HLA-restricted antigen presentation. The relative presentation levels of 4780 different HLA ligands were quantified in an in vitro model employing carfilzomib treatment of MM.1S and U266 myeloma cells, which revealed significant modulation of a substantial fraction of the HLA-presented peptidome. Strikingly, we detected selective down-modulation of HLA ligands with aromatic C-terminal anchor amino acids. This particularly manifested as a marked reduction in the presentation of HLA ligands through the HLA allotypes A*23:01 and A*24:02 on MM.1S cells. These findings implicate that carfilzomib mediates a direct, peptide motif-specific inhibitory effect on HLA ligand processing and presentation. As a substantial proportion of HLA allotypes present peptides with aromatic C-termini, our results may have broad implications for the implementation of antigen-specific treatment approaches in patients undergoing carfilzomib treatment.
Asunto(s)
Presentación de Antígeno/efectos de los fármacos , Presentación de Antígeno/inmunología , Epítopos/inmunología , Antígenos HLA/inmunología , Mieloma Múltiple/inmunología , Oligopéptidos/farmacología , Péptidos/inmunología , Biomarcadores , Línea Celular Tumoral , Membrana Celular/metabolismo , Epítopos/química , Epítopos/metabolismo , Epítopos de Linfocito T/inmunología , Epítopos de Linfocito T/metabolismo , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidad Clase I/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Inmunofenotipificación , Ligandos , Espectrometría de Masas , Mieloma Múltiple/metabolismo , Mieloma Múltiple/patología , Mieloma Múltiple/terapia , Péptidos/química , Péptidos/metabolismo , Inhibidores de Proteasoma/farmacología , Inhibidores de Proteasoma/uso terapéuticoRESUMEN
BACKGROUND: The rate-corrected QT interval (QTc) is heritable, and the discovery of quantitative trait loci that influence the QTc would be an important step in identifying the genes responsible for life-threatening arrhythmias in the general population. We studied 66 pairs of unselected normal dizygotic (DZ) twin subjects and their parents in a sib-pair analysis. We tested for linkage of gene loci harboring genes known to cause the long-QT syndrome (LQT) to the quantitative trait QTc. METHODS AND RESULTS: We found genetic variance on QRS duration, QRS axis, T-wave axis, and QTc. Women had a longer QTc than men. Microsatellite markers were tested in the vicinity of the gene loci for the 5 known LQT genes. We found significant linkage of QTc with the loci for LQT1 on chromosome 11 and LQT4 on chromosome 4 but not to LQT2, LQT3, or LQT5. We also found linkage of the QRS axis with LQT2 and LQT3. CONCLUSIONS: We suggest that these quantitative trait loci may represent the presence of variations in LQT genes that could be important to the risk for rhythm disturbances in the general population.
Asunto(s)
Cromosomas Humanos Par 11 , Cromosomas Humanos Par 4 , Ligamiento Genético , Síndrome de QT Prolongado/genética , Adulto , Alelos , ADN Satélite/análisis , Electrocardiografía , Femenino , Marcadores Genéticos , Humanos , Síndrome de QT Prolongado/diagnóstico , Masculino , Persona de Mediana Edad , Gemelos Dicigóticos , Gemelos MonocigóticosRESUMEN
BACKGROUND: We identified a family with a monogenic syndrome of hypertension, brachydactyly, and neurovascular contact of the brain stem. Neurovascular contact of the ventrolateral medulla may lead to arterial hypertension by interfering with baroreflex function. METHODS AND RESULTS: In 5 patients with monogenic hypertension (18 to 34 years old), we conducted detailed autonomic function tests. Blood pressure during complete ganglionic blockade was 134+/-4.9/82+/-4.1 mm Hg and 90+/-6/49+/-2.4 mm Hg in patients and in control subjects, respectively. During ganglionic blockade, plasma vasopressin concentration increased 24-fold in control subjects and <2-fold in patients. In patients, cold pressor testing, hand-grip testing, and upright posture all increased blood pressure excessively. In contrast, muscle sympathetic nerve activity was not increased at rest or during cold pressor testing. The phenylephrine dose that increased systolic blood pressure 12.5 mm Hg was 8.0+/-2.0 microg in patients and 135+/-35 microg in control subjects before ganglionic blockade and 5.4+/-0.4 microg in patients and 13+/-4.8 microg in control subjects during ganglionic blockade. CONCLUSIONS: In patients with monogenic hypertension and neurovascular contact, basal blood pressure was increased even during sympathetic and parasympathetic nerve traffic interruption. However, sympathetic stimuli caused an excessive increase in blood pressure. This excessive response cannot be explained by increased sympathetic nerve traffic or increased vascular sensitivity. Instead, we suggest that baroreflex buffering and baroreflex-mediated vasopressin release are severely impaired.
Asunto(s)
Barorreflejo , Tronco Encefálico/anomalías , Tronco Encefálico/fisiopatología , Arterias Cerebrales/anomalías , Hipertensión/fisiopatología , Adolescente , Adulto , Barorreflejo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Tronco Encefálico/irrigación sanguínea , Cerebelo/irrigación sanguínea , Frío , Electrofisiología , Dedos/anomalías , Bloqueadores Ganglionares/farmacología , Genes Dominantes , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hipertensión/complicaciones , Hipertensión/diagnóstico , Hipertensión/genética , Imagen por Resonancia Magnética , Fenilefrina/farmacología , Postura , Presorreceptores/efectos de los fármacos , Síndrome , Maniobra de Valsalva , Vasoconstrictores/farmacología , Vasodilatadores/farmacologíaRESUMEN
The repressor of bacteriophage P1, encoded by the c1 gene, represses the phage lytic functions and is responsible for maintaining the P1 prophage in the lysogenic state. The c1 repressor interacts with at least 11 binding sites or operators widely scattered over the P1 genome. From these operators, a 17 base-pair asymmetric consensus sequence, ATTGCTCTAATAAATTT, was derived. Here, we show that the operator, Op72 of the P1ban operon consists of two overlapping 17 base-pair sequences a and b forming an incomplete palindrome. Op72a matches the consensus sequence, whereas Op72b contains two mismatches. The evidence is based on the sequence analysis of 27 operator mutants constitutive for ban expression. They were identified as single-base substitutions at positions 2 to 10 of Op72a (26 mutants) and at position 8 of Op72b (one mutant). We conclude from gel retardation and footprinting studies that two repressor molecules bind to the operator and that positions 4, 5 and 7 to 10 of the operator play an essential role in repressor recognition.