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1.
Phys Rev Lett ; 104(17): 172001, 2010 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-20482102

RESUMEN

Differential cross sections and photon-beam asymmetries for the gamma(p)-->K{+}Lambda(1520) reaction have been measured with linearly polarized photon beams at energies from the threshold to 2.4 GeV at 0.6or=5/2 or by a new reaction process, for example, an interference effect with the phi photoproduction having a similar bump structure in the cross sections.

2.
J Evol Biol ; 23(7): 1547-57, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20492088

RESUMEN

It has been suggested that spiriferide morphologies have evolved to adapt to a variety of environmental conditions. Through a computational fluid dynamics approach, we examined how the spiriferide original form was optimized for a lotic condition, specifically addressing the functionalization of the Devonian spiriferide brachiopod Paraspirifer bownockeri to generate passive feeding flows. The results using four models, each of which differed in the development of the spiriferide shell depression, i.e. sulcus, showed that a deeper sulcus functions to create strong spiral flows so as to align on the feeding organ inside the shell. Among the sulcus-developed models, only the mimic of the natural form could generate comparative slow flows with a stable inflow area. The fossil record of spiriferides shows a morphological trade-off between the development of the sulcus and wing form. We concluded that spiriferide shells with such a morphological combination evolved to produce various feeding strategies, resulting in diversification.


Asunto(s)
Estructuras Animales/anatomía & histología , Evolución Biológica , Fósiles , Invertebrados/anatomía & histología , Modelos Anatómicos , Animales , Fenómenos Biomecánicos , Simulación por Computador , Conducta Alimentaria/fisiología
3.
J Am Coll Surg ; 189(2): 158-63, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10437837

RESUMEN

BACKGROUND: Although morphologic, radiographic, and manometric features of achalasia have been well defined, it has not been established by careful retrospective analysis whether achalasia is a progressive disorder resulting in complete decompensation. STUDY DESIGN: To verify the hypothesis that achalasia is a progressive disease, we retrospectively investigated manometric, radiographic, and symptomatic data in patients with achalasia. Sixty-three patients (36 women and 27 men) with a median age of 44 years (range 11 to 79 years) were evaluated. The duration of symptoms ranged from 1 to 442 months, with a median of 48 months. Patients were divided into four groups according to the duration of symptoms: 36 patients with less than 5 years, 11 with 5 to 10 years, 9 with 10 to 15 years, and 7 with 15 years or more. RESULTS: Contraction pressures of the esophageal body decreased significantly at every level when the duration of symptoms increased (p < 0.04). The percentage of simultaneous waves in the esophageal body rose as the duration of symptoms increased. All waves were synchronous in every patient who had had symptoms for more than 15 years. The maximal width of the esophageal body measured on esophagram became greater with an increase in the duration of symptoms, but this measurement did not reach statistical significance (p = 0.063). The tortuosity of the esophagus, measured by the maximal angle of the esophageal axis, was significantly greater in patients with a longer duration of symptoms (p < 0.02). The type of symptoms was not associated with the duration of symptoms. CONCLUSIONS: Achalasia is a progressive disease, as verified by manometric and radiographic findings. The classification of esophageal motor function expressed by amplitude of contraction pressure and angle of tortuosity is objective and useful. Classification of achalasia by duration of symptoms may be important in treatment selection and effectiveness.


Asunto(s)
Acalasia del Esófago/diagnóstico , Manometría , Radiografía , Adolescente , Adulto , Anciano , Sulfato de Bario , Niño , Medios de Contraste , Trastornos de Deglución/etiología , Acalasia del Esófago/fisiopatología , Acalasia del Esófago/cirugía , Esófago/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
4.
J Gastrointest Surg ; 3(5): 447-55, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10482699

RESUMEN

Technical controversies abound regarding the surgical treatment of achalasia. To determine the value of a concomitant antireflux procedure, the best antireflux procedure, the correct length for gastric myotomy, the optimal surgical approach (thoracic or abdominal), and the equivalency of minimally invasive surgery, a literature review was carried out. The review is based on 23 articles on open transabdominal or transthoracic myotomy, 14 articles on laparoscopic myotomy, and four articles on thoracoscopic myotomy. Postoperative results of traditional open thoracic or transabdominal myotomy as determined by symptomatology were better with fundoplication than without fundoplication. The incidence of postoperative reflux as proved by pH monitoring was high in patients who had an open transabdominal myotomy without fundoplication. The type of antireflux procedure used and the length of gastric myotomy had little effect on results. The results of transthoracic Heller myotomy do not require a concomitant fundoplication. Laparoscopic and thoracoscopic myotomy had excellent results at short-term follow-up. A fundoplication must be added if the myotomy is performed transabdominally. A randomized prospective study is required to determine the best fundoplication and the extent of gastric myotomy. Although minimally invasive surgery for achalasia has excellent initial results, longer follow-up in a larger population of patients is needed.


Asunto(s)
Acalasia del Esófago/cirugía , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos
5.
J Gastrointest Surg ; 3(5): 483-8, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10482704

RESUMEN

The purpose of this study was to measure the length of the esophagus and assess its relationship to sex, weight, age, height, and various esophageal disorders. A retrospective analysis was undertaken of 617 esophageal manometric studies, which included 51 normal control subjects (27 males and 24 females) and 566 patients (297 males and 269 females) with esophageal disorders (50 with achalasia, 6 with diffuse esophageal spasm, 64 with strictures, 38 with nutcracker esophagus, 398 with gastroesophageal reflux disease [GERD] with positive 24-hour pH monitoring, and 66 with possible GERD but negative 24-hour pH monitoring). Manometry was performed in all of them by the station pull-through technique. The length of the esophagus was defined as the distance between the proximal end of the upper esophageal sphincter and the distal end of the lower esophageal sphincter. In the control group the mean (+/- standard deviation) length of the esophagus was 28.3 +/- 2.41 cm. In patients with esophageal disorders the mean length of the esophagus was 28.0 +/- 2.87 cm. Length of the esophagus is related to height but not to weight, sex, age, diffuse esophageal spasm, or nutcracker esophagus. Achalasia is associated with a longer esophagus, and GERD is associated with a shorter esophagus. Stricture is associated with a shorter esophagus, but this is in part due to the association between stricture and GERD. Patients with possible GERD but negative 24-hour pH monitoring have an esophageal length similar to that of GERD patients with positive 24-hour pH monitoring. Patients with GERD and stricture formation showed esophageal shortening in shorter patients. Achalasia, GERD, and GERD with stricture formation influence esophageal length. GERD-related strictures shorten the esophagus more significantly in short patients.


Asunto(s)
Enfermedades del Esófago/fisiopatología , Esófago/patología , Adulto , Femenino , Humanos , Masculino , Manometría , Persona de Mediana Edad , Estudios Retrospectivos
6.
Surg Endosc ; 14(4): 330-5, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10790549

RESUMEN

BACKGROUND: Laparoscopic vagotomy represents a new and less invasive treatment for peptic ulcer disease, but the problem of postvagotomy dysphagia has not been solved. The aim of this study was to determine the etiologic factors related to long-term laparoscopic postvagotomy dysphagia. METHODS: Two female and 11 male patients with a mean age of 48.5 years who underwent laparoscopic vagotomy were investigated retrospectively. Preoperative diagnosis included duodenal ulcer resistant to medical treatment, gastric hypersecretion, gastric outlet obstruction, cholelithiasis, and gastroesophageal reflux disease (GERD). Ten patients underwent laparoscopic highly selective vagotomy, and three patients had laparoscopic truncal vagotomy with gastrojejunostomy or pyloroplasty. Nine of these patients had a Nissen fundoplication in conjunction with the vagotomy. RESULTS: The median long-term follow-up period was 47 months. Two patients complained of severe dysphagia, one of moderate dysphagia, and two of mild dysphagia. Neither type of vagotomy nor an additional fundoplication was correlated with the severity of postoperative long-term dysphagia. Severity of postoperative dysphagia was associated with severity of preoperative dysphagia (r = 0.752, p = 0.003) but not with heartburn (r = 0.358, p = 0.531) or regurgitation (r = 0.024, p = 0.938). The cause of preoperative dysphagia varied; however, all of these patients had GERD and consequent esophageal lesions. CONCLUSION: Preexisting dysphagia appears to play an integral role in persistent postoperative dysphagia. Care must be taken to construct a loose fundoplication in patients with dysphagia.


Asunto(s)
Trastornos de Deglución/etiología , Laparoscopía/efectos adversos , Vagotomía/efectos adversos , Colelitiasis/cirugía , Trastornos de Deglución/diagnóstico , Diagnóstico Diferencial , Úlcera Duodenal/cirugía , Femenino , Obstrucción de la Salida Gástrica/cirugía , Reflujo Gastroesofágico/cirugía , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios
7.
Surg Endosc ; 15(7): 757, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11591985

RESUMEN

Laparoscopic surgery for paraesophageal hernia is well accepted. However, the complications of this relatively new procedure have not been thoroughly investigated. Only four cases of recurrent volvulus after paraesophageal hernia repair have been reported. A 52-year-old man presented with a large right-side paraesophageal hernia. He experienced a retroperitoneal midgastric volvulus despite correct orientation of the stomach distally and proximally. We report an unusual complication that seems congenital in origin. Diagnostic and corrective measures are suggested.


Asunto(s)
Hernia Hiatal/cirugía , Laparoscopía/métodos , Complicaciones Posoperatorias/diagnóstico , Vólvulo Gástrico/congénito , Humanos , Laparoscopía/efectos adversos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/cirugía , Vólvulo Gástrico/epidemiología , Vólvulo Gástrico/cirugía , Resultado del Tratamiento
8.
Int Surg ; 81(2): 140-3, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8912079

RESUMEN

To determine the prognostic factors for splenectomy in patients with chronic idiopathic thrombocytopenic purpura (ITP), 26 consecutive patients who had undergone splenectomy as a treatment for ITP in the last 20 years were investigated retrospectively. Predictive values of age, sex, the interval between diagnosis and surgery, presence of antiplatelet antibodies or accessory spleen, bleeding time, response to corticosteroids, response to high-dose immunoglobulin, weight of spleen, serum platelet-associated immunoglobulin G, preoperative maximal platelet count, and preoperative minimal platelet count were examined with multivariate analysis by multiple regression. Age less than 50 years at surgery, platelet count of 100 x 10(9)/l or more in response to high-dose immunoglobulin, and a maximal platelet count of 100 x 10(9)/l or more before splenectomy were favorable prognostic factors (p < 0.05). The correlation coefficient, sensitivity, specificity, and positive-predictive value of the analyzed multiple regression based on prognostic factors were 0.885, 68.8%, 85.7% and 91.7%, respectively. In conclusion, splenectomy is an effective treatment for younger patients, large maximal preoperative platelet counts and preoperative immunoglobulin dependence. Multivariate function analysis was useful for predicting outcome.


Asunto(s)
Púrpura Trombocitopénica Idiopática/cirugía , Esplenectomía , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Estudios Retrospectivos , Sensibilidad y Especificidad
9.
Jpn J Antibiot ; 45(12): 1650-7, 1992 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-1289583

RESUMEN

Cefprozil (CFPZ, BMY-28100) fine granules were given orally to 21 children with acute bacterial infections including 15 cases of acute tonsillitis and 3 each of acute bronchitis and urinary tract infections. Good to excellent clinical responses were obtained in 19 of the 21 patients and bacterial eradications were obtained for all 11 strains found in these cases. Loose stool and eosinophilia were observed in 1 case each. From the above clinical results, it appears that CFPZ is a useful antibiotic for the treatment of pediatric patients with various bacterial infections.


Asunto(s)
Bronquitis/tratamiento farmacológico , Cefalosporinas/uso terapéutico , Tonsilitis/tratamiento farmacológico , Infecciones Urinarias/tratamiento farmacológico , Enfermedad Aguda , Administración Oral , Bacterias/efectos de los fármacos , Bacterias/aislamiento & purificación , Bronquitis/microbiología , Cefalosporinas/administración & dosificación , Cefalosporinas/farmacología , Niño , Preescolar , Evaluación de Medicamentos , Farmacorresistencia Microbiana , Femenino , Humanos , Masculino , Tonsilitis/microbiología , Infecciones Urinarias/microbiología , Cefprozil
10.
Jpn J Antibiot ; 44(4): 466-71, 1991 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-1880926

RESUMEN

Cefpirome (CPR, HR 810) was given intravenously to 10 children with acute bacterial infections including 8 with acute pneumonia, 1 each with acute pleuritis and urinary tract infections. Good to excellent clinical responses were obtained in all of the 10 patients and bacterial eradication were obtained for all 8 strains found in these cases. Slight elevation of GOT, GPT and eosinophilia were observed in 1 case each. From the above clinical results, it appears that CPR is a useful antibiotic for treatment of pediatric patients with various bacterial infections.


Asunto(s)
Cefalosporinas/administración & dosificación , Pleuresia/tratamiento farmacológico , Neumonía/tratamiento farmacológico , Infecciones Urinarias/tratamiento farmacológico , Adolescente , Factores de Edad , Bacterias/efectos de los fármacos , Cefalosporinas/farmacología , Cefalosporinas/uso terapéutico , Niño , Preescolar , Evaluación de Medicamentos , Farmacorresistencia Microbiana , Femenino , Humanos , Lactante , Inyecciones Intravenosas , Masculino , Pleuresia/microbiología , Neumonía/microbiología , Infecciones Urinarias/microbiología , Cefpiroma
11.
Gan To Kagaku Ryoho ; 21(13): 2222-4, 1994 Sep.
Artículo en Japonés | MEDLINE | ID: mdl-7944445

RESUMEN

To ascertain the effect of local treatment for unresectable primary liver tumor, 59 patients were investigated retrospectively. Patients were classified into four groups; transcatheter arterial embolization (TAE) group, intermittent intra-arterial infusion chemotherapy group, combined therapy group (TAE+intermittent intra-arterial infusion chemotherapy) and a group without adjuvant therapy. The results revealed that TAE and intermittent intra-arterial infusion chemotherapy both prolonged the survival period. We found that the survival rate depends largely on the therapeutic method. No correlations were confirmed with the liver function nor stage grouping of the tumor. Therefore, we concluded that intermittent intra-arterial infusion chemotherapy is a beneficial treatment, considering its minimal adverse effect, broad indication and the fact that it does not require hospitalization.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Quimioembolización Terapéutica , Neoplasias Hepáticas/terapia , Adulto , Anciano , Epirrubicina/administración & dosificación , Femenino , Arteria Hepática , Humanos , Bombas de Infusión Implantables , Infusiones Intraarteriales , Neoplasias Hepáticas/mortalidad , Masculino , Persona de Mediana Edad , Mitomicina/administración & dosificación , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Tasa de Supervivencia
15.
Phys Rev Lett ; 103(1): 012001, 2009 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-19659135

RESUMEN

Photoproduction of Lambda(1520) with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment. For the first time, the differential cross sections were measured at low energies and with a deuterium target. A large asymmetry of the production cross sections from protons and neutrons was observed at backward K+/0 angles. This suggests the importance of the contact term, which coexists with t-channel K exchange under gauge invariance. This interpretation was compatible with the differential cross sections, decay asymmetry, and photon beam asymmetry measured in the production from protons at forward K+ angles.

16.
Phys Rev Lett ; 102(1): 012501, 2009 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-19257183

RESUMEN

The Sigma(1385) resonance, or Sigma;{*}, is well known as part of the standard baryon decuplet with spin J=3/2. Measurements of the reaction gammap-->K;{+}Sigma;{*0} are difficult to extract due to overlap with the nearby Lambda(1405) resonance. However, the reaction gamman-->K;{+}Sigma;{*-} has no overlap with the Lambda(1405) due to its charge. Here we report the first measurement of cross sections and beam asymmetries for photoproduction of the Sigma;{*-} from a deuteron target. The cross sections at forward angles range from 0.4 to 1.2 mub, with a broad maximum near E_{gamma} approximately 1.8 GeV. The beam asymmetries are negative, in contrast with positive values for the gamman-->K;{+}Sigma;{-} reaction.

17.
Phys Rev Lett ; 97(8): 082003, 2006 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-17026294

RESUMEN

Differential cross sections and photon-beam asymmetries have been measured for the gamma n --> K+ Sigma- and gamma p --> K+Sigma0 reactions separately using liquid deuterium and hydrogen targets with incident linearly polarized photon beams of E gamma = 1.5-2.4 GeV at 0.6 < cos ThetacmK< 1. The cross section ratio of sigma K+ Sigma-/sigma K+ Sigma0, expected to be 2 on the basis of the isospin 1/2 exchange, is found to be close to 1. For the K+ Sigma- reaction, large positive asymmetries are observed, indicating the dominance of K* exchange. The large difference between the asymmetries for the K+ Sigma- and K+ Sigma0 reactions cannot be explained by simple theoretical considerations based on Regge model calculations.

18.
Phys Rev Lett ; 95(18): 182001, 2005 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-16383894

RESUMEN

Photoproduction of a phi meson on protons was studied by means of linearly polarized photons at forward angles in the low-energy region from threshold to Egamma = 2.37 GeV. The differential cross sections at t = -|t|min do not increase smoothly as Egamma increases but show a local maximum at around 2.0 GeV. The angular distributions demonstrate that phi mesons are photoproduced predominantly by helicity-conserving processes, and the local maximum is not likely due to unnatural-parity processes.

19.
J Clin Gastroenterol ; 30(1): 56-60, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10636211

RESUMEN

To reconfirm that the duration of symptoms is not associated with esophageal motility in patients with gastroesophageal reflux disease (GERD), esophageal manometric data from 768 patients with GERD were retrospectively analyzed with relation to the duration of symptoms. GERD was defined by positive acid reflux test results monitored by ambulatory 24-hour pH monitoring. Correlation of the duration of symptoms with esophageal body pressures, the presence of dysmotility determined by simultaneous waves, average resting pressure of the lower esophageal sphincter (LES), and abdominal and overall lengths of the LES were statistically analyzed. The median duration of the symptoms was 60 months (range, 1-600). Duration of symptoms was not associated with contraction pressures of the esophageal body at 3 and 8 cm above the LES (r = -0.070 and -0.063, respectively). There was no correlation between LES pressures, LES lengths, or the percentage of simultaneous waves and duration of symptoms. Stricture formation is related to decreased distal esophageal function in GERD patients. In conclusion, the duration of GERD has little influence on esophageal body and LES function.


Asunto(s)
Esófago/fisiopatología , Reflujo Gastroesofágico/fisiopatología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Concentración de Iones de Hidrógeno , Manometría , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo
20.
Surg Today ; 29(12): 1248-52, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10639705

RESUMEN

We performed endo-organ full thickness gastric excision to treat a high-risk patient with T2 gastric cancer. The patient, a 75-year-old white man with a gastric adenocarcinoma located just below the gastroesophageal junction, had a history of chronic obstructive pulmonary disease and cor pulmonale, and developed markedly elevated pulmonary artery pressures under general anesthesia. The less invasive endo-organ approach was utilized because of these severe morbidities. The carcinoma was staged laparoscopically, then removed utilizing the full-thickness endo-organ excision technique. This case report serves to demonstrate that full thickness endo-organ gastric excision may be indicated not only for certain early gastric cancers, but also for high-risk patients who cannot tolerate open surgery due to advanced age or serious illness.


Asunto(s)
Adenocarcinoma/cirugía , Laparoscopía/métodos , Neoplasias Gástricas/cirugía , Estómago/cirugía , Adenocarcinoma/diagnóstico , Anciano , Diseño de Equipo , Estudios de Seguimiento , Gastroscopía , Humanos , Masculino , Neoplasias Gástricas/diagnóstico , Resultado del Tratamiento
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