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BACKGROUND: Juxta-papillary duodenal diverticulum (JPDD) has been associated with obstructive jaundice and ascending cholangitis. Potential mechanisms include periampullary colonization of pathogenic bacteria and mechanical obstruction. However, the relation of JPDD with pyogenic liver abscess (PLA) has not been reported. Moreover, approximately one third of patients with PLA have no identifiable risk factors and are labelled as "cryptogenic". We hypothesized that JPDD is an unidentified risk factor for cryptogenic PLA and the aim of this study was to examine this association. METHODS: We conducted a retrospective chart review to identify cases of PLA (n = 66) and compare those to matched controls (n = 66). 66 patients met the study inclusion criteria of a diagnosis of PLA using computerized tomography (CT) imaging and either positive culture or confirmed resolution after antibiotic therapy. Patients with diagnoses of amebic liver abscess, traumatic liver abscess, post cholecystectomy liver abscess, concurrent acute cholecystitis, and hepatobiliary malignancy were excluded. Controls were identified from a radiology database and matched one-to-one with the cases by age and sex. Demographic and clinical data was extracted from electronic medical records. CT scan images of all cases and controls were reviewed by a single expert radiologist to identify the presence of JPDD. Statistical tests including Chi-square and t-test with multiple logistic regression were used to examine the group differences in JPDD and other factors. RESULTS: Among 132 study samples, 13.6% (9/66) of the cases were found to have JPDD, compared to 3.0% (2/66) among controls (p = 0.03). This corresponded to an odds ratio (OR) of 5.05 [OR 5.05; CI 1.05-24.4] on multiple logistic regression analysis. In addition, 1/3rd of PLA cases with JPDD had no other traditional risk factors (cryptogenic PLA). However, a statistically significant association of JPDD with cryptogenic PLA could not be established possibly because of a small number of cases. We found significantly high rate of diabetes mellitus (DM) (42.4%; n = 28/66) among cases compared to controls (21.2%; n = 14/66; p = 0.01). CONCLUSION: We found a significant association between JPDD and PLA. We need studies with larger sample sizes to confirm this relationship and to explore if JPDD could be related to cryptogenic liver abscesses.
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Colangitis , Divertículo , Absceso Piógeno Hepático , Estudios de Casos y Controles , Colangitis/complicaciones , Divertículo/complicaciones , Divertículo/diagnóstico por imagen , Humanos , Absceso Piógeno Hepático/complicaciones , Estudios RetrospectivosRESUMEN
Analytic gradients of electronic eigenvalues require one calculation per nuclear geometry, compared to at least 3n + 1 calculations for finite difference methods, where n is the number of nuclei. Analytic nonadiabatic derivative coupling terms (DCTs), which are calculated in a similar fashion, are used to remove nondiagonal contributions to the kinetic energy operator, leading to more accurate nuclear dynamics calculations than those that employ the Born-Oppenheimer approximation, i.e., that assume off-diagonal contributions are zero. The current methods and underpinnings for calculating both of these quantities, gradients and DCTs, for the State-Averaged MultiReference Configuration Interaction with Singles and Doubles (MRCI-SD) wavefunctions in COLUMBUS are reviewed. Before this work, these methods were not available for wavefunctions of a relativistic MRCI-SD Hamiltonian. Calculation of these terms is critical in successfully modeling the dynamics of systems that depend on transitions between potential energy surfaces split by the spin-orbit operator, such as diode-pumped alkali lasers. A formalism for calculating the transition density matrices and analytic derivative coupling terms for such systems is presented.
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A method for calculating the analytic nonadiabatic derivative coupling terms (DCTs) for spin-orbit multi-reference configuration interaction wavefunctions is reviewed. The results of a sample calculation using a Stuttgart basis for KHe are presented. Additionally, the DCTs are compared with a simple calculation based on the Nikitin's 3 × 3 description of the coupling between the Σ and Π surfaces, as well as a method based on Werner's analysis of configuration interaction coefficients. The nonadiabatic coupling angle calculated by integrating the radial analytic DCTs using these different techniques matches extremely well. The resultant nonadiabatic energy surfaces for KHe are presented.
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The excited state interatomic potential energy surfaces for Rb + He are computed at the spin-orbit multi-reference configuration interaction level of theory using all-electron basis sets of triple and quadruple-zeta quality that have been contracted for Douglas-Kroll-Hess (DKH) Hamiltonian and includes core-valence correlation. Davidson-Silver corrections (MRCI+Q) are employed to ameliorate size consistency error. An extrapolation of CASSCF energies is performed using the procedure of Karton and Martin whereas extrapolation of correlation energy is performed using an expression involving the inverse powers of (lmax + 1/2), the highest angular momentum value present in the basis set. The spin-orbit energies in the limit of complete basis set are obtained by replacing the energy eigenvalues in the spin-orbit matrix by the relativistic-corrected MRCI+Q energies extrapolated to the complete basis set limit. MRCI diabatic potential energy surfaces for a few selected 2Σ states are calculated to study the general topology and avoided crossings and repulsive form of the 6s 2Σ+ state. Important features of the potential energy surfaces are discussed with implications for alkali laser spectroscopy.
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The potential energy curves (PECs) of the ground and excited states that correlate in the atomic limit with Ar([Ne]3s 23p 6,1S), Ar([Ne]3s 23p 54s 1, 3P, 1P), and Ar([Ne]3s 23p 54p 1, 3D, 3P, 3S, 1D, 1P, 1S) are calculated at the multireference configuration interaction (MRCI+Q) theoretical level with extrapolations to the complete basis set limit using all-electron correlation consistent triple-, quadruple-, and quintuple-zeta basis sets. Scalar relativistic corrections are calculated using second-order Douglas-Kroll-Hess Hamiltonian with the corresponding basis sets contracted for scalar relativistic Hamiltonians. For these calculations, the 3s orbitals of the Ar atom are not included in the active space but are correlated through single and double excitations. Spin-orbit eigenstates are computed by diagonalizing the Breit-Pauli matrix between internal configurations with no electrons in external orbitals and added to the scalar relativistic results. A total of 32 molecular PECs are computed with spin-orbit contributions, which correlate with 1s1, 1s5-2, and 2p10-1 atomic Ar energies in Paschen notation. Important features of the PECs and system crossings are discussed.
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Scattering matrix elements of the inelastic fine structure transition M(2P1/2) + Ng â M(2P3/2) + Ng are computed using the channel packet method (CPM) for alkali-metal atoms M = K, Rb, and Cs, as they collide with noble-gas atoms Ng = He, Ne, and Ar. The calculations are performed within the block Born-Oppenheimer approximation where excited state VA2Π1/2(R), VA2Π3/2(R), and VB2Σ1/2(R) adiabatic potential energy surfaces are used together with a Hund's case (c) basis to construct a 6 × 6 diabatic representation of the electronic Hamiltonian. Matrix elements of the angular kinetic energy of the nuclei incorporate Coriolis coupling and, together with the diabatic representation of the electronic Hamiltonian, yield a 6 × 6 effective potential energy matrix. This matrix is diagonal in the asymptotic limit of large internuclear separation with eigenvalues that correlate to the 2Pj alkali atomic energy levels. Scattering matrix elements are computed using the CPM by preparing reactant and product wave packets on the effective potential energy surfaces that correspond to the excited 2Pj alkali states of interest. The reactant wave packet is then propagated forward in time using the split operator method together with a unitary transformation between the adiabatic and diabatic representations. The Fourier transformation of the correlation function between the evolving reactant wave packet and stationary product wave packet yields state-to-state scattering matrix elements as a function of energy for a particular choice of total angular momentum J. Calculations are performed for energies that range from 0.0 to 0.01 hartree and values of J that start with a minimum of J = 0.5 for all M + Ng pairs up to a maximum that ranges from J = 450.5 for KAr to J = 100.5 for CsAr. A sum over J together with an average over energy is used to compute thermally averaged cross sections for a temperature range of T = 0-400 K.
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PURPOSE: To report the lifetime activities and accomplishments of Jules Stein, MD. DESIGN: Retrospective review. METHODS: Assessment of published and unpublished biographical material. RESULTS: Jules Stein combined his love of music and medicine with organizational skills to achieve successive careers as a musician, an ophthalmologist, an entertainment magnate, and an advocate for vision. To preserve vision, he founded Research to Prevent Blindness, founded the Jules Stein Eye Institute at the University of California, Los Angeles, and led a multiyear campaign to establish the National Eye Institute. CONCLUSIONS: With successive careers and extraordinary achievements, Jules Stein created an enduring legacy of benefits to ophthalmology, vision research, and the prevention of blindness.
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Actividades Recreativas , Oftalmología/historia , Defensa del Paciente/historia , Visión Ocular , Donaciones , Historia del Siglo XIX , Historia del Siglo XX , Humanos , Estados UnidosRESUMEN
The X(2)Σ(1/2)(+), A(2)Π(1∕2), A(2)Π(3∕2), and B(2)Σ(1/2)(+) potential energy curves and associated dipole matrix elements are computed for M + Ng at the spin-orbit multi-reference configuration interaction level, where M = K, Rb, Cs and Ng = He, Ne, Ar. Dissociation energies and equilibrium positions for all minima are identified and corresponding vibrational energy levels are computed. Difference potentials are used together with the quasistatic approximation to estimate the position of satellite peaks of collisionally broadened D2 lines. The comparison of potential energy curves for different alkali atom and noble gas atom combinations is facilitated by using the same level of theory for all nine M + Ng pairs.
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Lemierre Syndrome (LS) is relatively rare, and its clinical features are potentially confusing. Without proper therapy, LS is associated with significant morbidity and is potentially fatal. Recognition of the imaging features of LS in the chest and the neck may permit a timely diagnosis and lead to prompt institution of appropriate therapy. The emergency imaging features of LS in five cases are reviewed with emphasis on computed tomography of the chest and neck.
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Infecciones por Fusobacterium/diagnóstico por imagen , Adolescente , Adulto , Femenino , Infecciones por Fusobacterium/diagnóstico , Humanos , Masculino , Orofaringe/diagnóstico por imagen , Orofaringe/microbiología , Faringitis/diagnóstico , Faringitis/diagnóstico por imagen , Síndrome , Tomografía Computarizada por Rayos X , UltrasonografíaRESUMEN
OBJECTIVES: Because oxidation affects platelet and coagulation factors, hemoglobin auto-oxidation in HBOCs results in the transformation to methemoglobin, which may have additive adverse effects on coagulation. The risk of coagulopathy after different dilutions of HBOC-200 with low and high methemoglobin concentrations was studied. DESIGN: A laboratory study on donor blood using thromboelastography (TEG; Haemoscope, Niles, IL). SETTING: A university laboratory. PARTICIPANTS: Volunteer donor blood. INTERVENTIONS: Blood samples simulated hemodilution during clinical resuscitation of hemorrhagic shock with varying doses of HBOC-200 (Oxyglobin; Biopure Corp, Cambridge, MA). Coagulopathy related to 1:11, 1:5, 1:2, and 1:1 dilution of whole blood with HBOC-200 high methemoglobin concentrations (65%) and HBOC-200 low methemoglobin concentrations (1%) were analyzed. MEASUREMENTS AND MAIN RESULTS: Analysis of fixed effects of dilution on coagulation showed that the progressive dilution of HBOC-200 (low methemoglobin) and HBOC-200 (high methemoglobin) produced significant prolongation in reaction time (R) and clot propagation (K) and significant decreases in clot kinetics (alpha) and clot strength (MA and G). Analysis of fixed effects of treatment group on coagulation showed that clot propagation (K, alpha) and clot strength (MA and G) are significantly different in HBOC-200 (high methemoglobin) compared with HBOC-200 (low methemoglobin). CONCLUSIONS: High methemoglobin concentrations in HBOC-200 cause additive coagulation impairment that likely results from the effects of oxidative substances on platelet function and coagulation proteins. Oxidative products adversely react with coagulation factors and modify redox-sensitive sites in the platelets. Therefore, if methemoglobinemia occurs as a result of HBOC administration and if the levels are significantly elevated (greater than 10%), impairment of coagulation is possible.
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Coagulación Sanguínea/fisiología , Hemoglobinas/farmacología , Metahemoglobina/fisiología , Tromboelastografía/métodos , Coagulación Sanguínea/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , HumanosRESUMEN
The objective of this study was to determine if coagulation is different between 6% hetastarch in normal saline (NS) and 6% hetastarch in lactated Ringer's solution (LR), with use of an ex vivo thromboelastography (TEG) model with healthy donated volunteer blood. We simulated hemodilution that occurs during clinical resuscitation of hemorrhagic or hypovolemic shock, using healthy human donor whole blood (WB) ex vivo. Coagulopathy related to low, medium, high, or very high dilution of WB with NS or a high-molecular-weight hetastarch-based plasma expander, 6% hetastarch in NS (HSNS) or 6% hetastarch in lactated Ringer's [Hextend (HSLR)], was analyzed by thromboelastography (TEG). No changes were noted in the TEG profile of undiluted WB controls during the 6-hour period of use (P > 0.95). Dilution with HSNS and HSLR significantly impaired coagulation compared to both WB control and NS. Progressive dilution with NS impaired coagulation but to a lesser extent than colloids (P < 0.01). Low dilution of blood with NS increased clot strength by 12% (not significant; P = 0.097). We conclude that WB containing citrate obtained from healthy donors for TEG analysis yields reproducible data over a minimum of 6 hours. Either hetastarch, when present at concentrations comparable to the manufacturer's maximum recommended dose of 20 mL/kg (equivalent to the high dilution used in these experiments), decreases clot tensile strength to levels associated with an increased risk of bleeding. Substitution of lactated Ringer's for NS in 6% hetastarch appears to offer no advantage in avoiding hemostatic compromise in an in vitro model.
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Coagulación Sanguínea/efectos de los fármacos , Derivados de Hidroxietil Almidón/farmacología , Sustitutos del Plasma/farmacología , Tromboelastografía/métodos , Relación Dosis-Respuesta a Droga , Hemodilución , Humanos , Derivados de Hidroxietil Almidón/administración & dosificación , Técnicas In Vitro , Soluciones Isotónicas/química , Vehículos Farmacéuticos/química , Sustitutos del Plasma/administración & dosificación , Lactato de Ringer , Cloruro de Sodio/química , Resistencia a la Tracción , Factores de TiempoRESUMEN
OBJECTIVES: Because hetastarches have deleterious effects on coagulation that increase with molecular weight (MWt), risk of coagulopathy associated with a high MWt hemoglobin-based oxygen carrier (HBOC) was studied. DESIGN: Preliminary laboratory study of donor blood using thromboelastography (TEG). SETTING: University laboratory. PARTICIPANTS: Volunteer donor blood. INTERVENTIONS: Experiments simulated hemodilution during clinical resuscitation of hemorrhagic shock with varying doses of HBOCs. Coagulopathy related to 1:11, 1:5, 1:2, or 1:1 dilution of whole blood with normal saline, 6% hetastarch (670 kilodaltons [kD]), hemoglobin glutamer-200 (HBOC-200, 200 kD), or OxyVita (OXYVITA Inc, New Windsor, NY) (a new-generation, zero-link polymerized bovine hemoglobin-based oxygen carrier, 33 megadaltons) were analyzed. MEASUREMENTS AND MAIN RESULTS: At 2 lower levels of hemodilution, hetastarch, HBOC-200, and OxyVita produced equivalent reductions in maximum clot strength (TEG-MA and TEG-G) that reached statistical significance compared with whole blood and normal saline. At 2 higher dilutions, OxyVita and HBOC-200 impaired maximum clot strength compared with whole blood, normal saline, and hetastarch. Dilution with hetastarch had a greater effect on clot propagation (K and alpha) than either HBOC. CONCLUSIONS: OxyVita and HBOC-200, HBOCs with different MWt, had similar effects on coagulation as measured by TEG. The impairment of coagulation by HBOCs and hetastarch occurred at doses corresponding to 12 mL/kg or a blood volume replacement of 17%. The use of HBOCs at doses corresponding to 23 mL/kg or a blood volume replacement of 33% significantly decreased coagulation to levels associated with increased clinical bleeding in this preliminary study. Minimal coagulopathic effects are expected with use of OxyVita at the manufacturer's anticipated effective dose of 10 g or 2 to 3 mL/kg.
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Coagulación Sanguínea/efectos de los fármacos , Sustitutos Sanguíneos/farmacología , Hemoglobinas/farmacología , Tromboelastografía/efectos de los fármacos , Sustitutos Sanguíneos/administración & dosificación , Relación Dosis-Respuesta a Droga , Hemoglobinas/administración & dosificación , Humanos , Derivados de Hidroxietil Almidón/administración & dosificación , Derivados de Hidroxietil Almidón/farmacología , Choque Hemorrágico/sangre , Choque Hemorrágico/terapia , Cloruro de Sodio/farmacologíaRESUMEN
IMPORTANCE: Long-term exposure to solar radiation produces deleterious photoaging of the skin. It is not known if diet can influence skin photoaging. OBJECTIVES: To study the influence of a calorie-restricted diet and an obesity diet in mice exposed to long-term UV-B irradiation to assess if there is an association between diet and histopathological response to UV-B irradiation. DESIGN, SETTING, AND PARTICIPANTS: In this animal model study in an academic setting, the dorsal skin of SKH1 hairless mice receiving normal, calorie-restricted, and obesity diets was exposed to UV-B irradiation 3 times a week for 10 weeks and were compared with corresponding controls. The mice were placed in the following groups, with 8 animals in each group: (1) intact control (C) with regular diet and no UV-B exposure, (2) intact control with UV-B exposure (CR), (3) calorie-restricted diet (CrC), (4) calorie-restricted diet with UV-B exposure (CrR), (5) obesity diet (OC), and (6) obesity diet with UV-B exposure (OR). The experiment was conducted during October through December 2013. Tissue processing and histological analysis were completed in 2016. MAIN OUTCOMES AND MEASURES: Histomorphometric analysis was performed on paraffin-embedded skin sections stained by histological and immunohistochemical methods for estimation of epidermal thickness, epidermal proliferating cell nuclear antigen index, collagen I, elastic fibers, fibroblasts, mast cells, dermal cellularity, and adipose layer ratio. Changes in wrinkles were noted. RESULTS: Hairless female mice (age range, 6-8 weeks) were obtained. With a normal diet, changes from UV-B irradiation occurred in epidermal thickness, epidermal proliferating cell nuclear antigen index, collagen I, elastic fibers, fibroblasts, and mast cells, which were modestly influenced by an obesity diet. Calorie restriction influenced the skin in nonirradiated control animals, with higher values for most variables. After UV-B exposure in animals with calorie restriction, epidermal thickness was increased, but other variables were unaffected. Animals receiving the calorie-restricted diet lost weight when exposed to long-term UV-B irradiation. Wrinkles were reduced in the calorie-restricted control group and in UV-B-exposed animals who received the obesity diet. CONCLUSIONS AND RELEVANCE: Dietary alterations seem to modify histopathological responses to UV-B exposure in the skin of hairless mice. LEVEL OF EVIDENCE: NA.
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Dieta , Envejecimiento de la Piel/patología , Envejecimiento de la Piel/efectos de la radiación , Piel/patología , Piel/efectos de la radiación , Rayos Ultravioleta/efectos adversos , Animales , Femenino , RatonesRESUMEN
Decreased myocardial attenuation on contrast-enhanced multidetector computed tomography (MDCT) images can be observed in subjects with myocardial infarctions (MIs). It was hypothesized that myocardial hypoattenuation in MDCT can accurately detect the presence of a healed MI as determined by cardiac magnetic resonance delayed hyperenhancement (CMR-DH). Coronary MDCT and CMR-DH were performed in 42 subjects. Pre- and postcontrast MDCT images were analyzed for the presence of myocardial hypoattenuation, and volumes of MIs were quantified on MDCT and CMR-DH images in a blinded manner. The sensitivity, specificity, and negative and positive predictive values of postcontrast MDCT for the detection of MI were 91%, 81%, 83%, and 90%, respectively. MI sizes by postcontrast MDCT and by CMR-DH were strongly correlated (r=0.87, p<0.0001), although MDCT systematically underestimated MI volume (2.7+/-2.5 vs 25.9+/-19.9 ml, p<0.0001). MI size by MDCT was correlated negatively with the left ventricular ejection fraction (r=-0.62, p=0.03) and positively with left ventricular volumes (r=0.68 to 0.72, p<0.01). In 71% of subjects with MIs by CMR-DH, corresponding areas of hypoattenuation were noted also in precontrast MDCT. In conclusion, healed MIs can be detected as areas of myocardial hypoattenuation on MDCT images with high diagnostic accuracy, although their sizes are largely underestimated compared with CMR-DH. The presence of precontrast hypoattenuation suggests that mechanisms independent of reduced contrast delivery contribute to this finding.
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Aumento de la Imagen , Imagen por Resonancia Magnética/métodos , Infarto del Miocardio/diagnóstico , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: Laparoscopic and robotic simple prostatectomy (SP) have been introduced with the aim of reducing the morbidity of the standard open technique. OBJECTIVE: To report a large multi-institutional series of minimally invasive SP (MISP). DESIGN, SETTING, AND PARTICIPANTS: Consecutive cases of MISP done for the treatment of bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE) between 2000 and 2014 at 23 participating institutions in the Americas and Europe were included in this retrospective analysis. INTERVENTION: Laparoscopic or robotic SP. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Demographic data and main perioperative outcomes were gathered and analyzed. A multivariable analysis was conducted to identify factors associated with a favorable trifecta outcome, arbitrarily defined as a combination of the following postoperative events: International Prostate Symptom Score <8, maximum flow rate >15ml/s, and no perioperative complications. RESULTS AND LIMITATIONS: Overall, 1330 consecutive cases were analyzed, including 487 robotic (36.6%) and 843 laparoscopic (63.4%) SP cases. Median overall prostate volume was 100ml (range: 89-128). Median estimated blood loss was 200ml (range: 150-300). An intraoperative transfusion was required in 3.5% of cases, an intraoperative complication was recorded in 2.2% of cases, and the conversion rate was 3%. Median length of stay was 4 d (range: 3-5). On pathology, prostate cancer was found in 4% of cases. Overall postoperative complication rate was 10.6%, mostly of low grade. At a median follow-up of 12 mo, a significant improvement was observed for subjective and objective indicators of BOO. Trifecta outcome was not significantly influenced by the type of procedure (robotic vs laparoscopic; p=0.136; odds ratio [OR]: 1.6; 95% confidence interval [CI], 0.8-2.9), whereas operative time (p=0.01; OR: 0.9; 95% CI, 0.9-1.0) and estimated blood loss (p=0.03; OR: 0.9; 95% CI, 0.9-1.0) were the only two significant factors. Retrospective study design, lack of a control arm, and limited follow-up represent major limitations of the present analysis. CONCLUSIONS: This study provides the largest outcome analysis reported for MISP for BOO/BPE. These findings confirm that SP can be safely and effectively performed in a minimally invasive fashion in a variety of healthcare settings in which specific surgical expertise and technology is available. MISP can be considered a viable surgical treatment in cases of large prostatic adenomas. The use of robotic technology for this indication can be considered in centers that have a robotic program in place for other urologic indications. PATIENT SUMMARY: Analysis of a large data set from multiple institutions shows that surgical removal of symptomatic large prostatic adenomas can be carried out with good outcomes by using robot-assisted laparoscopy.
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Adenocarcinoma/cirugía , Adenoma/cirugía , Complicaciones Posoperatorias/epidemiología , Próstata/cirugía , Hiperplasia Prostática/cirugía , Neoplasias de la Próstata/cirugía , Obstrucción del Cuello de la Vejiga Urinaria/cirugía , Anciano , Estudios de Cohortes , Europa (Continente)/epidemiología , Humanos , Laparoscopía , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Próstata/patología , Prostatectomía , Hiperplasia Prostática/complicaciones , Estudios Retrospectivos , Procedimientos Quirúrgicos Robotizados , Estados Unidos/epidemiología , Obstrucción del Cuello de la Vejiga Urinaria/etiologíaRESUMEN
The past 25 years have seen an amazing improvement in the treatment and understanding of acid-related disorders. In particular, the introduction of selective histamine receptor antagonists and proton pump inhibitors has made the medical control of acid secretion an effective means of therapy. The demonstration that infection with Helicobacter pylori is responsible for most cases of peptic ulcer disease resulted in another major improvement in therapy in these areas as a result of the eradication of the organism. Research continues in an attempt to find improved means of acid control and better methods for the eradication of H. pylori based on unique proteins expressed by the organism to resist gastric acidity.
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Antiácidos/uso terapéutico , Reflujo Gastroesofágico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Inhibidores de la Bomba de Protones , Reflujo Gastroesofágico/tratamiento farmacológico , Neoplasias Gastrointestinales/prevención & control , HumanosRESUMEN
Helicobacter pylori is an aetiological agent of gastric disease. Although the role of urease in gastric colonization of H. pylori has been shown, it remains unclear as to where urease is located in this bacterial cell. The purpose of this study was to define the urease-associated apparatus in the H. pylori cytoplasm. H. pylori was incubated at both a neutral and an acidic pH in the presence or absence of urea and examined by double indirect immunoelectron microscopy. The density of gold particles for UreA was greatest in the inner portion of the wild-type H. pylori cytoplasm at neutral pH but was greatest in the outer portion at acidic pH. This difference was independent of the presence of urea and was not observed in the ureI-deletion mutant. Also, the eccentric shift of urease in acidic pH was not observed in UreI. After a 2 day incubation period at acidic pH, it was observed that the urease gold particles in H. pylori assembled and were associated with UreI gold particles. Urease immunoreactivity shifted from the inner to the outer portion of H. pylori as a result of an extracellular decrease in pH. This shift was urea-independent and UreI-dependent, suggesting an additional role of UreI in urease-dependent acid resistance. This is the first report of the intracellular transport of molecules in bacteria in response to changes in the extracellular environment.
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Helicobacter pylori/enzimología , Proteínas de Transporte de Membrana , Ureasa/metabolismo , Proteínas Bacterianas/genética , Citoplasma/enzimología , Relación Dosis-Respuesta a Droga , Eliminación de Gen , Genes Bacterianos/genética , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/genética , Helicobacter pylori/ultraestructura , Concentración de Iones de Hidrógeno , Urea/metabolismo , Urea/farmacologíaRESUMEN
The increased demand for facial cosmetic surgery has come from a more diverse, informed, and selective patient population from all walks of life. Virtually no two patients have the same background or cosmetic objectives. However, the classic tenets of beauty including phi, symmetry, averageness, youthfulness, and sexual dimorphism can be applied to persons of all ethnicities to assist in objectifying the abstract concept.
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Belleza , Procedimientos de Cirugía Plástica , Cultura , Humanos , Nariz/anatomía & histología , RinoplastiaRESUMEN
OBJECTIVE: To determine the quantitative effects of Z-plasty vs spreader grafts on nasal valve surface area. METHODS: Eight fresh cadaver heads were used that provided 16 total nasal valve procedures. Surgical sides were randomized, and Z-plasty was performed on 8 valves and endonasal spreader grafts were performed on 8 valves. The minimal cross-sectional area at the level of the nasal valve was measured preoperatively and postoperatively using acoustic rhinometry. We then compared Z-plasty and spreader grafts using a Wilcoxon signed rank test. RESULTS: The mean nasal surface area at the nasal valve before Z-plasty was 1.37 cm(2) (range, 0.39-2.25 cm(2)) and after Z-plasty was 1.95 cm(2) (range, 1.08-2.62 cm(2)). The mean surface area at the nasal valve before spreader grafts was 1.15 cm(2) (range, 0.75-1.48 cm(2)) and after spreader grafts was 1.48 cm(2) (0.95-1.95 cm(2)). This correlates with a mean increase in the nasal valve surface area of 65% when Z-plasty was performed (95% CI, 28%-88%; P = .007) and 31% when a spreader graft was performed (95% CI, 15%-54%; P = .01). CONCLUSIONS: Z-plasty and spreader grafts were shown to increase nasal valve surface area. Z-plasty seems to increase nasal valve surface area more than spreader grafts.
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Cavidad Nasal/cirugía , Cirugía Endoscópica por Orificios Naturales/métodos , Rinoplastia/métodos , Colgajos Quirúrgicos , Humanos , Cavidad Nasal/anatomía & histología , Técnicas de SuturaRESUMEN
The purpose of this study was to examine the impact of surgical pathology, anesthesiologist experience, and airway technique on surgically relevant outcomes in patients identified by preoperative laryngoscopy to have a difficult airway due to head and neck pathology. We prospectively recorded a series of 152 difficult airway cases due to head and neck pathology out of 2,145 direct laryngoscopies undertaken between November 2005 and June 2008. One of two senior anesthesiologists specializing in head and neck procedures intubated 101 (66.4%) of the 152 patients and did so 3.3 minutes faster (p = 0.51), with better oxygenation (87.3 vs. 81.8%; p = 0.02) and fewer airway plan changes (p = 0.001) than did other, nonspecialist anesthesiologists. Predictors of failure of the first intubation plan included: cancer diagnosis (p = 0.02), previous radiotherapy (p = 0.03), and supraglottic lesions (p = 0.03). Glottic/subglottic lesions required the most intubation attempts (p = 0.02). Awake fiberoptic intubation was the most common method used (44.7%) but resulted in a change in the airway plan in 6 cases (8.8%). Gas induction maintained the best oxygenation (p = 0.01). Awake tracheostomy was infrequent (1.3%) and took the longest (p = 0.006). We concluded that difficult airways due to head and neck pathology require teamwork and a backup plan. An anesthesiologist specializing in head and neck procedures may help to avoid adverse outcomes associated with cancer, especially previously irradiated supraglottic/glottic lesions, leading to a less frequent need for awake tracheostomy.