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1.
Molecules ; 27(15)2022 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-35956967

RESUMEN

Studies have demonstrated that high-coordination-number rhenium polyhydride complexes are precursors to catalysts that transform a variety of organic molecules. While rhenium polyhydride complexes lead to active catalysts, little has been reported on the mechanisms for the transformations. High-coordination-number rhenium polyhydride complexes exhibit several dynamic processes that make characterizations of the chemical properties for individual atoms difficult, at best, for room-temperature solutions. This review describes what is known of the dynamic processes that occur at high-coordination-number rhenium polyhydride complexes and how that knowledge may lead to the design of catalytic precursors in which the chemical properties of individual atoms can be more readily identified in room-temperature solutions.

2.
J Acoust Soc Am ; 150(2): 734, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34470333

RESUMEN

Impinging jets are characterized by an acoustic feedback resonance capable of generating intense tones. This investigation examines changes in single impinging jet (SIJ) dynamics when another jet is added alongside to form a dual impinging jet (DIJ) arrangement of interest in vertical takeoff and landing applications. The emphasis is on the hydrodynamic and acoustic coupling in the region between the jets, which affects aircraft surface loading. Well-resolved large eddy simulations of SIJ and DIJ are employed with under-expanded Mach 1.27 jets; the nozzle exits are placed 4 diameters from the ground plane and, for the DIJ, separated 4.3 diameters from each other to mimic ongoing experiments. Three different SIJ feedback harmonics of the fundamental frequency are identified using two-point space-time correlations. Using spectral proper orthogonal decomposition, these tones are classified as either asymmetric or axisymmetric modes in the SIJ. Each individual jet in the DIJ configuration also exhibits these nominal tones. However, differences are observed on the inboard sides between the jets, where coupling effects engender an azimuthally localized Kelvin-Helmholtz instability and impingement mechanism. The global coupling between the two jets manifests as counter-rotating helical modes, which reinforce the lowest of the three identified SIJ impinging tones.

3.
Hum Reprod ; 35(10): 2188-2196, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32976601

RESUMEN

STUDY QUESTION: What is the relationship between sperm DNA fragmentation and oxidative stress (OS) with increasing male age? SUMMARY ANSWER: Sperm DNA fragmentation increases with age and is likely related to both defective spermatogenesis and increasing OS levels. WHAT IS KNOWN ALREADY: Sperm quality declines with age. The presence of DNA damage in a high fraction of spermatozoa from a raw semen sample is associated with lower male fertility in natural conception and intrauterine insemination. STUDY DESIGN, SIZE, DURATION: A retrospective cohort study of 16 945 semen samples analysed at a single reference laboratory between January 2010 and December 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS: All males were undergoing an infertility evaluation. The cohort was divided into seven age categories: <30, 30-34, 35-39, 40-44, 45-49, 50 to <54 and ≥55 years. The mean age was 37.6 years (SD 6.8). Sperm DNA fragmentation index (DFI) and high DNA stainability (HDS) were calculated using flow cytometry. OS levels were measured using the oxidative stress adducts (OSA) test, by spectrophotometry. ANOVA with weighted polynomial contrast analysis was used to evaluate trends for DFI, OSA and HDS values across age categories. MAIN RESULTS AND THE ROLE OF CHANCE: Mean DFI significantly increased across all age groups (Ptrend < 0.001). OSA was lowest in patients <30 years old (mean 3.6, SD 1.0) and also increased as age increased (Ptrend < 0.001). There was a statistically significant difference between age groups for each of the three parameters (P < 0.001). There was a significant linear trend for DFI, OSA and HDS across the seven age categories (P < 0.001). Among patients with high DFI, there was a decreasing age-dependent trend in the patients observed with high OSA (P < 0.001). LIMITATIONS, REASONS FOR CAUTION: This is a retrospective study. All males included in the study were undergoing a work-up for infertility and may not be representative of a fertile population. Additional patient demographics and clinical data were not available. WIDER IMPLICATIONS OF THE FINDINGS: DNA and/or oxidative damage in sperm may be just as important to understand as the chromosomal aberrations that are carried in the oocyte. Further studies are needed to evaluate the effect of advancing paternal age on the male genome and, ultimately, on the health of the offspring. STUDY FUNDING/COMPETING INTEREST(S): No funding was obtained for this study. V.D. is an employee of Reprosource/Quest Diagnostics. D.S. reports he was a Scientific Advisor to Cooper Surgical. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Infertilidad Masculina , Motilidad Espermática , Adulto , Fragmentación del ADN , Humanos , Infertilidad Masculina/genética , Masculino , Persona de Mediana Edad , Estrés Oxidativo , Estudios Retrospectivos , Semen , Análisis de Semen , Recuento de Espermatozoides , Espermatozoides
4.
Diabet Med ; 36(8): 982-987, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30614052

RESUMEN

AIMS: Adolescents with Type 1 diabetes commonly experience episodes of ketoacidosis. In 2014, we conducted a nationwide survey on the management of diabetic ketoacidosis in young people. The survey reported how individual adolescents with diabetes were managed. However, the costs of treating diabetic ketoacidosis were not reported. METHODS: Using this mixed population sample of adolescents, we took a 'bottom-up' approach to cost analysis aiming to determine the total expense associated with treating diabetic ketoacidosis. The data were derived using the information from the national UK survey of 71 individuals, collected via questionnaires sent to specialist paediatric diabetes services in England and Wales. RESULTS: Several assumptions had to be made when analysing the data because the initial survey collection tool was not designed with a health economic model in mind. The mean time to resolution of diabetic ketoacidosis was 15.0 h [95% confidence interval (CI) 13.2, 16.8] and the mean total length of stay was 2.4 days (95% CI 1.9, 3.0). Based on data for individuals and using the British Society of Paediatric Endocrinology and Diabetes (BSPED) guidelines, the cost analysis shows that for this cohort, the average cost for an episode of diabetic ketoacidosis was £1387 (95% CI 1120, 1653). Regression analysis showed a significant cost saving of £762 (95% CI 140, 1574; P = 0.04) among those treated using BSPED guidelines. CONCLUSION: We have used a bottom-up approach to calculate the costs of an episode of diabetic ketoacidosis in adolescents. These data suggest that following treatment guidelines can significantly lower the costs for managing episodes of diabetic ketoacidosis.


Asunto(s)
Diabetes Mellitus Tipo 1/economía , Cetoacidosis Diabética/economía , Hospitalización/economía , Adolescente , Cuidados Críticos/economía , Diabetes Mellitus Tipo 1/terapia , Cetoacidosis Diabética/terapia , Economía Hospitalaria , Utilización de Instalaciones y Servicios , Recursos en Salud/economía , Recursos en Salud/estadística & datos numéricos , Costos de Hospital/estadística & datos numéricos , Humanos , Estudios Retrospectivos , Reino Unido
5.
Colorectal Dis ; 21(9): 1079-1089, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31095879

RESUMEN

AIM: This was a prospective cohort study to determine the intrinsic non-modifiable factors influencing length of stay (LOS) in unselected consecutive patients undergoing elective colorectal surgery within an enhanced recovery pathway. METHODS: This study interrogated a prospective database of consecutive elective procedures from October 2006 to April 2011 at a tertiary referral academic hospital in the UK to identify independent predictors of prolonged length of stay (pLOS). pLOS was defined as longer than median length of stay (mLOS). Differences in determinants were identified in three groups of increasing operative complexity. RESULTS: In all, 872 procedures were identified and ranged from a simple ileostomy reversal to complex total pelvic exenteration. Preoperative anaemia and American Society of Anesthesiologists (ASA) Grade III+ predicted pLOS in stoma reversal surgery patients (n = 191, mLOS 4 days). In colonic and small bowel surgery (n = 444, mLOS 8 days), an open procedure, new stoma formation, planned critical care admission and ASA III+ predicted pLOS. New stoma formation and planned critical care admission predicted pLOS in patients undergoing pelvic rectal surgery (n = 237, mLOS 11 days). pLOS was associated with significantly higher morbidity across Dindo-Clavien grades and a longer time to postoperative functional recovery and discharge. CONCLUSIONS: Operative complexity is associated with longer LOS even with an established enhanced recovery pathway in place. Intrinsic non-modifiable predictors of pLOS differ with operative complexity, and this should be taken into account when planning benchmarking and research across units.


Asunto(s)
Enfermedades del Colon/cirugía , Recuperación Mejorada Después de la Cirugía , Tiempo de Internación/estadística & datos numéricos , Enfermedades del Recto/cirugía , Adulto , Anciano , Procedimientos Quirúrgicos Electivos , Inglaterra , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos
6.
Diabet Med ; 35(8): 1063-1071, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29687498

RESUMEN

AIM: Little is known about the challenges of transitioning from school to university for young people with Type 1 diabetes. In a national survey, we investigated the impact of entering and attending university on diabetes self-care in students with Type 1 diabetes in all UK universities. METHODS: Some 1865 current UK university students aged 18-24 years with Type 1 diabetes, were invited to complete a structured questionnaire. The association between demographic variables and diabetes variables was assessed using logistic regression models. RESULTS: In total, 584 (31%) students from 64 hospitals and 37 university medical practices completed the questionnaire. Some 62% had maintained routine diabetes care with their home team, whereas 32% moved to the university provider. Since starting university, 63% reported harder diabetes management and 44% reported higher HbA1c levels than before university. At university, 52% had frequent hypoglycaemia, 9.6% reported one or more episodes of severe hypoglycaemia and 26% experienced diabetes-related hospital admissions. Female students and those who changed healthcare provider were approximately twice as likely to report poor glycaemic control, emergency hospital admissions and frequent hypoglycaemia. Females were more likely than males to report stress [odds ratio (OR) 4.78, 95% confidence interval (CI) 3.19-7.16], illness (OR 3.48, 95% CI 2.06-5.87) and weight management issues (OR 3.19, 95% CI 1.99-5.11) as barriers to self-care. Despite these difficulties, 91% of respondents never or rarely contacted university support services about their diabetes. CONCLUSION: The study quantifies the high level of risk experienced by students with Type 1 diabetes during the transition to university, in particular, female students and those moving to a new university healthcare provider.


Asunto(s)
Diabetes Mellitus Tipo 1/terapia , Autocuidado , Estudiantes/estadística & datos numéricos , Universidades/estadística & datos numéricos , Adolescente , Adulto , Diabetes Mellitus Tipo 1/epidemiología , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Autocuidado/normas , Autocuidado/estadística & datos numéricos , Autoeficacia , Encuestas y Cuestionarios , Reino Unido/epidemiología , Adulto Joven
7.
Antimicrob Agents Chemother ; 59(8): 4526-32, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25987629

RESUMEN

Immunocompromised individuals are at increased risk of Staphylococcus aureus pneumonia. Neutralization of alpha-toxin (AT) with the monoclonal antibody (MAb) MEDI4893* protects normal mice from S. aureus pneumonia; however, the effects of the MAb in immunocompromised mice have not been reported. In this study, passive immunization with MEDI4893* increased survival rates and reduced bacterial numbers in the lungs in an immunocompromised murine S. aureus pneumonia model. Lungs from infected mice exhibited alveolar epithelial damage, protein leakage, and bacterial overgrowth, whereas lungs from mice passively immunized with MEDI4893* retained a healthy architecture, with an intact epithelial barrier. Adjunctive therapy or prophylaxis with a subtherapeutic MEDI4893* dose combined with subtherapeutic doses of vancomycin or linezolid improved survival rates, compared with the monotherapies. Furthermore, coadministration of MEDI4893* with vancomycin or linezolid extended the antibiotic treatment window. These data suggest that MAb-mediated neutralization of AT holds promise in strategies for prevention and adjunctive therapy among immunocompromised patients.


Asunto(s)
Antibacterianos/farmacología , Anticuerpos Monoclonales/farmacología , Anticuerpos Neutralizantes/farmacología , Huésped Inmunocomprometido/efectos de los fármacos , Neumonía Estafilocócica/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Animales , Anticuerpos Monoclonales Humanizados , Anticuerpos ampliamente neutralizantes , Femenino , Linezolid/farmacología , Pulmón/microbiología , Ratones , Ratones Endogámicos C57BL , Tasa de Supervivencia , Vancomicina/farmacología
8.
Antimicrob Agents Chemother ; 58(2): 1108-17, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24295977

RESUMEN

Alpha-toxin (AT) is a major virulence factor in the disease pathogenesis of Staphylococcus aureus. We previously identified a monoclonal antibody (MAb) against AT that reduced disease severity in a mouse dermonecrosis model. Here, we evaluate the activity of an affinity-optimized variant, LC10, in a mouse model of S. aureus pneumonia. Passive immunization with LC10 increased survival and reduced bacterial numbers in the lungs and kidneys of infected mice and showed protection against diverse S. aureus clinical isolates. The lungs of S. aureus-infected mice exhibited bacterial pneumonia, including widespread inflammation, whereas the lungs of mice that received LC10 exhibited minimal inflammation and retained healthy architecture. Consistent with reduced immune cell infiltration, LC10-treated animals had significantly lower (P < 0.05) proinflammatory cytokine and chemokine levels in the bronchoalveolar lavage fluid than did those of the control animals. This reduction in inflammation and damage to the LC10-treated animals resulted in reduced vascular protein leakage and CO2 levels in the blood. LC10 was also assessed for its therapeutic activity in combination with vancomycin or linezolid. Treatment with a combination of LC10 and vancomycin or linezolid resulted in a significant increase (P < 0.05) in survival relative to the monotherapies and was deemed additive to synergistic by isobologram analysis. Consistent with improved survival, the lungs of animals treated with antibiotic plus LC10 exhibited less inflammatory tissue damage than those that received monotherapy. These data provide insight into the mechanisms of protection provided by AT inhibition and support AT as a promising target for immunoprophylaxis or adjunctive therapy against S. aureus pneumonia.


Asunto(s)
Antibacterianos/farmacología , Anticuerpos Monoclonales/farmacología , Toxinas Bacterianas/antagonistas & inhibidores , Proteínas Hemolisinas/antagonistas & inhibidores , Pulmón/efectos de los fármacos , Neumonía Estafilocócica/tratamiento farmacológico , Acetamidas/farmacología , Animales , Toxinas Bacterianas/inmunología , Líquido del Lavado Bronquioalveolar/química , Quimiocinas/antagonistas & inhibidores , Quimiocinas/biosíntesis , Sinergismo Farmacológico , Quimioterapia Combinada , Femenino , Proteínas Hemolisinas/inmunología , Inmunización Pasiva , Riñón/efectos de los fármacos , Riñón/inmunología , Riñón/microbiología , Linezolid , Pulmón/inmunología , Pulmón/microbiología , Ratones , Ratones Endogámicos C57BL , Oxazolidinonas/farmacología , Neumonía Estafilocócica/inmunología , Neumonía Estafilocócica/microbiología , Neumonía Estafilocócica/mortalidad , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/metabolismo , Análisis de Supervivencia , Vancomicina/farmacología
9.
J Vis Exp ; (185)2022 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35969100

RESUMEN

Dynamic solution nuclear magnetic resonance (NMR) spectroscopy is the typical method of characterizing the dynamic rearrangements of atoms within the coordination sphere for transition metal polyhydride complexes. Line shape fitting of the dynamic NMR spectra can lead to estimates for the activation parameters of the dynamic rearrangement processes. A combination of dynamic 31P-{1H} NMR spectroscopy of metal-bound phosphorus atoms with dynamic 1H-{31P} NMR spectroscopy of hydride ligands may identify hydride ligand rearrangements that occur in conjunction with a phosphorus atom rearrangement. For molecules that exhibit such a coupled pair of rearrangements, dynamic NMR spectroscopy can be used to test theoretical models for the ligand rearrangements. Dynamic 1H-{31P} NMR spectroscopy and line shape fitting can also identify the presence of an exchange process that moves a specific hydride ligand beyond the metal's inner coordination sphere through a proton exchange with a solvent molecule such as adventitious water. The preparation of a new compound, ReH5(PPh3)2(sec-butyl amine), that exemplifies multiple dynamic rearrangement processes is presented along with line shape fitting of dynamic NMR spectra of the complex. Line shape fitting results can be analyzed by the Eyring equation to estimate the activation parameters for the identified dynamic processes.

10.
Kathmandu Univ Med J (KUMJ) ; 8(32): 426-8, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-22610775

RESUMEN

Intrauterine exposure to drugs by mothers is not an uncommon finding ine our society. Due to the mother's suppression of a medical history, the diagnosis of neonatal abstinence syndrome is often missed. We report a case of a term, female, newborn, who presented with the following features;e restlessness, inconsolable crying, along with sweating, vigorous sucking; andadiarrhoea. No conclusion was derived from routine investigations. Eventually, with a high degree of suspicion regarding maternal drug addiction, her history was reviewed and it was discovered that the mother was a heroin addict. The baby was diagnosed as a case of Neonatal Abstinence Syndrome. The neonate was successfully managed thereafter and discharged.


Asunto(s)
Dependencia de Heroína/complicaciones , Heroína/efectos adversos , Síndrome de Abstinencia Neonatal/diagnóstico , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Adulto , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Dependencia de Heroína/diagnóstico , Humanos , Recién Nacido , Narcóticos/efectos adversos , Síndrome de Abstinencia Neonatal/etiología , Embarazo , Efectos Tardíos de la Exposición Prenatal/diagnóstico
11.
Emerg Med J ; 25(9): 562-4, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18723702

RESUMEN

BACKGROUND: Lack of knowledge of an NHS trust's major incident policies by clinical staff may result in poorly coordinated responses during a mass casualty incident (MCI). AIM: To audit knowledge of the major incident policy by clinical staff working in a central London major acute NHS trust designated to receive casualties on a 24-h basis during a MCI. METHODS: A 12-question proforma was distributed to 307 nursing and medical staff in the hospital, designed to assess their knowledge of the major incident policy. Completed proformas were collected over a 2-month period between December 2006 and February 2007. RESULTS: A reply rate of 34% was obtained, with a reasonable representation from all disciplines ranging from nurses to consultants. Despite only 41% having read the policy in full, 70% knew the correct immediate action to take if informed of major incident activation. 76% knew the correct stand-down procedure. 56% knew the correct reporting point but less than 25% knew that an action card system was utilised. Nurses had significantly (p<0.01) more awareness of the policy than doctors. CONCLUSION: In view of the heightened terrorist threat in London, knowledge of major incident policy is essential. The high percentage of positive responses relating to immediate and stand-down actions reflects the rolling trust-wide MCI education programme and the organisational memory of the trust following several previous MCI in the capital. There is still scope for an improvement in awareness, however, particularly concerning knowledge of action cards, which are now displayed routinely throughout clinical areas and will be incorporated into induction packs.


Asunto(s)
Competencia Clínica/normas , Incidentes con Víctimas en Masa , Cuerpo Médico de Hospitales/normas , Personal de Enfermería en Hospital/normas , Política de Salud , Humanos , Londres , Auditoría Médica , Medicina Estatal
12.
J Clin Invest ; 108(3): 457-65, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11489939

RESUMEN

A female infant of nonconsanguineous Indian parents presented at 4 months with a hypoglycemic convulsion. Further episodes of hypoketotic hypoglycemia were associated with inappropriately elevated plasma insulin concentrations. However, unlike other children with hyperinsulinism, this patient had a persistently elevated blood spot hydroxybutyrylcarnitine concentration when fed, as well as when fasted. Measurement of the activity of L-3-hydroxyacyl-CoA dehydrogenase in cultured skin fibroblasts with acetoacetyl-CoA substrate showed reduced activity. In fibroblast mitochondria, the activity was less than 5% that of controls. Sequencing of the short-chain L-3-hydroxyacyl-CoA dehydrogenase (SCHAD) genomic DNA from the fibroblasts showed a homozygous mutation (C773T) changing proline to leucine at amino acid 258. Analysis of blood from the parents showed they were heterozygous for this mutation. Western blot studies showed undetectable levels of immunoreactive SCHAD protein in the child's fibroblasts. Expression studies showed that the P258L enzyme had no catalytic activity. We conclude that C773T is a disease-causing SCHAD mutation. This is the first defect in fatty acid beta-oxidation that has been associated with hyperinsulinism and raises interesting questions about the ways in which changes in fatty acid and ketone body metabolism modulate insulin secretion by the beta cell. The patient's hyperinsulinism was easily controlled with diazoxide and chlorothiazide.


Asunto(s)
3-Hidroxiacil-CoA Deshidrogenasas/deficiencia , 3-Hidroxiacil-CoA Deshidrogenasas/genética , Carnitina/análogos & derivados , Hiperinsulinismo/genética , Hiperinsulinismo/fisiopatología , Insulina/metabolismo , Mutación Puntual , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Carnitina/sangre , Carnitina/química , Cartilla de ADN/genética , Evolución Molecular , Ácidos Grasos/metabolismo , Femenino , Expresión Génica , Homocigoto , Humanos , Hiperinsulinismo/enzimología , Hipoglucemia/enzimología , Hipoglucemia/etiología , Hipoglucemia/fisiopatología , Técnicas In Vitro , Lactante , Secreción de Insulina , Modelos Biológicos , Datos de Secuencia Molecular , Oxidación-Reducción , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido
13.
Surg Endosc ; 21(3): 414-7, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17103283

RESUMEN

BACKGROUND: Although several reports have subjectively highlighted the benefits of hand-assisted as compared with conventional laparoscopic surgery, there has been little objective analysis comparing these two techniques. METHODS: For this study, 12 trained laparoscopic surgeons completed standardized knot-tying and dissection tasks in a laparoscopic trainer using both hand-assisted (HandPort) and traditional laparoscopic techniques. Motion analysis with the Imperial College Surgical Assessment Device was used to assess performance, measuring the number of movements made, the path length of hand travel, and the time taken. Mann-Whitney U tests were used to compare hand-assisted (HA) and conventional laparoscopic (L) performance. A p value less than 0.05 was deemed significant. Means and standard deviations are shown in the results. RESULTS: In knot tying, for both the dominant and nondominant hands, hand-assisted rather than conventional laparoscopic techniques resulted in reduced movements (dominant: HA [114 +/- 50] vs L [321 +/- 118, p < 0.001], nondominant: HA [89 +/- 36] vs L [296 +/- 96, p < 0.001]); path length (dominant: HA [1,083 +/- 680 mm] vs L [3,637 +/- 1,852 mm, p < 0.001], nondominant: HA [549 +/- 339 mm] vs L [2,556 +/- 1,042 mm, p < 0.001]); and time taken (HA [162 +/- 50 s] vs L [460 +/- 179 s, p < 0.001]). However, there was no statistical difference for any measured variable with respect to the dissection task. CONCLUSION: Hand-assisted surgery significantly improves the knot-tying ability among trained laparoscopic surgeons. However, there appears to be no improvement in performance for this specific dissection task.


Asunto(s)
Laparoscopía/métodos , Disección/métodos , Humanos , Técnicas de Sutura , Análisis y Desempeño de Tareas
14.
Ann R Coll Surg Engl ; 98(6): 353-7, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27023639

RESUMEN

Introduction Prophylactic appendicectomy is performed prior to military, polar and space expeditions to prevent acute appendicitis in the field. However, the risk-benefit ratio of prophylactic surgery is controversial. This study aimed to systematically review the evidence for prophylactic appendicectomy. It is supplemented by a clinical example of prophylactic surgery resulting in life-threatening complications. Methods A systematic review was performed using MEDLINE(®) and the Cochrane Central Register of Controlled Trials. Keyword variants of 'prophylaxis' and 'appendicectomy' were combined to identify potential papers for inclusion. Papers related to prophylactic appendicectomy risks and benefits were reviewed. Results Overall, 511 papers were identified, with 37 papers satisfying the inclusion criteria. Nine reported outcomes after incidental appendicectomy during concurrent surgical procedures. No papers focused explicitly on prophylactic appendicectomy in asymptomatic patients. The clinical example outlined acute obstruction secondary to adhesions from a prophylactic appendicectomy. Complications after elective appendicectomy versus the natural history of acute appendicitis in scenarios such as polar expeditions or covert operations suggest prophylactic appendicectomy may be appropriate prior to extreme situations. Nevertheless, the long-term risk of adhesion related complications render prophylactic appendicectomy feasible only when the short-term risk of acute appendicitis outweighs the long-term risks of surgery. Conclusions Prophylactic appendicectomy is rarely performed and not without risk. This is the first documented evidence of long-term complications following prophylactic appendicectomy. Surgery should be considered on an individual basis by balancing the risks of acute appendicitis in the field with the potential consequences of an otherwise unnecessary surgical procedure in a healthy patient.


Asunto(s)
Apendicectomía , Apendicitis/prevención & control , Procedimientos Quirúrgicos Profilácticos , Medicina Aeroespacial , Expediciones , Humanos , Medicina Militar , Procedimientos Quirúrgicos Profilácticos/efectos adversos , Medición de Riesgo
15.
J Am Coll Surg ; 193(5): 479-85, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11708503

RESUMEN

BACKGROUND: Technical performance has traditionally been assessed subjectively within the operating theater, with few successful attempts at objective analysis. The Imperial College Surgical Assessment Device (ICSAD) has already been shown to be a valid quantitative measure of dexterity in laparoscopic surgical simulation. We describe its application to the assessment of open surgical procedures. STUDY DESIGN: Fifty-one participants were recruited from four different levels of general surgical experience: basic surgical trainees (n = 12), junior specialist registrars (n = 13), senior specialist registrars (n = 13), and consultants (n = 13). They completed two tasks: a small bowel anastomosis and a vein patch insertion into an artery. Surgical performance was measured with the Imperial College Surgical Assessment Device, a motion analysis system that measures the number of hand movements made and time taken to complete a task. The four groups were compared statistically using the Kruskal-Wallis test (K-W). Pairwise group comparisons used the Mann-Whitney U test and p values were adjusted for multiple comparisons to determine the statistical significance of these comparisons. RESULTS: Mean values for number of movements and time (secs) for small bowel anastomosis were 2,080/1,236 (basic surgical trainees), 1,673/1,016 (junior specialist registrars), 1,375/862 (senior specialist registrars), and 1,337/782 (consultants), respectively. Comparison of the medians by K-W revealed a p < 0.001 for each variable (No. of movements, time), respectively. Mean vein patch insertion results were 1,653/1,258, 1,297/1,006, 1,090/912, and 925/736 for each of the four groups. Again, comparison of the medians by K-W revealed a p < 0.001 for each variable. CONCLUSIONS: These findings suggest that hand motion analysis may be an effective objective measure of dexterity in open surgical simulation.


Asunto(s)
Competencia Clínica , Consultores , Fenómenos Electromagnéticos/instrumentación , Cirugía General/educación , Internado y Residencia , Cuerpo Médico de Hospitales , Técnicas de Sutura , Anastomosis Quirúrgica , Implantación de Prótesis Vascular , Evaluación Educacional , Inglaterra , Humanos , Intestino Delgado/cirugía
16.
Surg Endosc ; 16(10): 1459-63, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12042913

RESUMEN

AIM: To demonstrate face and construct validity of a computer based flexible sigmoidoscopy trainer. METHODS: The PreOp (Immersion Medical, USA) system is a virtual reality based flexible sigmoidoscopy simulator. The system records several performance parameters, such as percentage of colonic mucosa visualized, time taken, and pathlength of endoscope travel. Forty-five subjects were divided into three groups: novice (never performed a lower GI endoscopy), intermediate (5-50 examinations), and trained (greater than 200 examinations). After initial familiarization subjects were assessed three times on a case module. Results showed a nonparametric distribution. RESULTS: There was a significant difference between all three groups with respect to percentage of mucosa visualized (novice 71.0 +/- 3.7%, intermediate 77.3 +/- 5.6%, expert 84.8 +/- 4.6%, Kruskal-Wallis p <0.001) and efficiency ratio (%mucosa/time, novice 0.163 +/- 0.055, intermediate 0.259 +/- 0.07, expert 0.306 +/- 0.058, p <0.001). The novice group was also slower and had a lower pathlength of instrument travel compared to the others. CONCLUSION: PreOp virtual reality simulator is a valid discriminator of flexible sigmoidoscopic experience. Its effect on training needs to be explored.


Asunto(s)
Competencia Clínica , Educación Médica/métodos , Cirugía General/educación , Sigmoidoscopios , Sigmoidoscopía , Interfaz Usuario-Computador , Humanos , Médicos , Reino Unido
17.
Surg Endosc ; 16(6): 957-61, 2002 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12163963

RESUMEN

BACKGROUND: "Massed" and "distributed" practice are important concepts in the acquisition of fine motor skills, and may be important in training in procedural skills. METHODS: A total of 41 novice subjects were recruited and randomized to three groups to receive training on the MIST VR surgical trainer. There were 14 subjects in each of groups A and B and 13 subjects in group C. Training comprised 20 min of massed practice for group A, 20 min of distributed practice in 5 min blocks for group B, and 15 min of distributed practice in 5-min blocks for group C. Following the training period, all groups had a 5-min rest period, followed by a 5-min retention test. Comparisons were made between groups A and B, and groups A and C. RESULTS: There was a statistically significant difference between groups A and B (p = 0.023) on the retention test, with group B performing better. The increment between the groups was 19% for the overall score on MIST VR. There were also significant differences in the time taken to complete the task during the training phase (p = 0.023, training blocks 3 and 4). Graphical representation suggests no effect between groups A and C, and statistical analysis confirms that the observed difference in median score is not significant. CONCLUSION: This study demonstrates a benefit for distributed practice over massed practice in learning laparoscopic surgical skills on the MIST VR surgical trainer. This finding has potential implications for skills training in all areas of medicine.


Asunto(s)
Competencia Clínica/estadística & datos numéricos , Instrucción por Computador , Laparoscopía/estadística & datos numéricos , Análisis y Desempeño de Tareas , Adulto , Cirugía General/educación , Humanos , Distribución Normal , Interfaz Usuario-Computador
18.
Surg Endosc ; 18(3): 372-8, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-14752634

RESUMEN

BACKGROUND: Robotic telemanipulation systems provide solutions to the problems of less dexterity and visual constraints of minimally invasive surgery (MIS). However, their influence over surgeons' dexterity and learning curve needs to be assessed. We present motion analysis as an objective method to measure performance and learning progress.METHODS. Thirteen surgeons completed five synthetic small bowel anastomoses using the da Vinci system. Objective Structured Assessment of Technical Skills (OSATS) allowed qualitative analysis. Quantitative analysis used API software of the system to retrieve real-time robotic signal data of time, path length, and number of movements. Wilcoxon signed ranks test was used for statistical analysis. A p value <0.05 was considered significant.RESULTS. OSATS global scores were 18.6 points for the first attempt and 26 for the fifth attempt ( p < 0.02, Cronbach's alpha = 0.894). Paired data of motion analysis for attempts 1 vs 5 showed significant change: time taken 3507 sec and 2287 sec ( p < 0.008), total number of movements 2411 and 1387 ( p = 0.01), total path length 21,630 cm and 13,941 cm ( p = 0.01).CONCLUSIONS. A rapid learning curve to a competent level using the da Vinci system is possible aided by the system's intuitive motion. Motion analysis is a useful tool to measure performance in the da Vinci system compared to OSATS and time alone.


Asunto(s)
Competencia Clínica , Endoscopía/educación , Intestino Delgado/cirugía , Aprendizaje , Sistemas Hombre-Máquina , Robótica/instrumentación , Anastomosis Quirúrgica , Sistemas de Computación , Evaluación Educacional , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos , Modelos Anatómicos , Desempeño Psicomotor , Método Simple Ciego , Técnicas de Sutura , Estudios de Tiempo y Movimiento , Grabación en Video
19.
J Pediatr Endocrinol Metab ; 17(11): 1575-9, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15570997

RESUMEN

DiGeorge syndrome, which falls within a wider phenotypic spectrum associated with deletions of 22q11.2, is associated with a number of endocrine disorders. These include hypoparathyroidism, hypothyroidism and growth hormone deficiency. We report an unusual case of autoimmune hyperthyroidism (Graves' disease) presenting in a 3 year-old male with DiGeorge syndrome. The development of endocrine specific autoimmune disease in a syndrome associated with immune deficiency and the spectrum of endocrine autoimmunity associated with deletions of 22q11.2 are described. Paediatricians and patients with 22q11.2 deletions should be particularly aware of the risks of developing disorders of thyroid function.


Asunto(s)
Enfermedades Autoinmunes/etiología , Deleción Cromosómica , Cromosomas Humanos Par 22/genética , Síndrome de DiGeorge/complicaciones , Síndrome de DiGeorge/genética , Enfermedades del Sistema Endocrino/etiología , Enfermedad de Graves/etiología , Enfermedad de Graves/genética , Antitiroideos/uso terapéutico , Aorta Torácica/anomalías , Autoanticuerpos/análisis , Enfermedades Autoinmunes/genética , Carbimazol/uso terapéutico , Enfermedades del Sistema Endocrino/genética , Enfermedad de Graves/tratamiento farmacológico , Defectos de los Tabiques Cardíacos/complicaciones , Defectos de los Tabiques Cardíacos/cirugía , Humanos , Recién Nacido , Recuento de Linfocitos , Masculino , Recurrencia
20.
Ir J Med Sci ; 165(4): 274-7, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8990654

RESUMEN

Pneumatic retinopexy (PR) is a technique for repairing certain retinal detachments which is easier to perform than conventional sceral buckling (SB) surgery but has comparable results. We performed a prospective, randomised, controlled trial to determine for ourselves whether PR is a safe and acceptable procedure. Twenty patients presenting consecutively with retinal detachments which fulfilled the selection criteria were randomised to have their detachments repaired by either PR or SB, ten patients in each group. The suitable patients had a single retinal break or small group of breaks of not greater than one clock hour in size, situated within the superior eight clock hours of retina. Patients with significant proliferative vitreoretinopathy or other fundus disorders were excluded. All patients in the PR group had local anaesthesia while all those in the SB group had general anaesthesia. Successful reattachment of the retina was achieved with one or more procedures in 90 percent of the PR group and in 100 percent of the SB group. We feel that narrowing the selection criteria for PR may further improve the success rate.


Asunto(s)
Criocirugía , Desprendimiento de Retina/cirugía , Curvatura de la Esclerótica , Estudios de Seguimiento , Gases , Humanos , Estudios Prospectivos , Perforaciones de la Retina/cirugía , Resultado del Tratamiento
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