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1.
J Assist Reprod Genet ; 35(3): 515-522, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29243141

RESUMEN

PURPOSE: In this current study, our main goal was to establish that EmbryoScope incubation environment is comparable to standard incubation. METHODS: The development of sibling human zygotes was compared after culture in either a benchtop incubator (SI) or an EmbryoScope time-lapse incubator (ES). Between May 2015 to April 2016, a total of 581 normally fertilized 2PN, pronuclear-stage embryos, from 47 patients were allocated to culture in either a benchtop incubator (SI) or an EmbryoScope incubator (ES). RESULTS: The development of embryos to cleavage (up to day 3) and blastocyst stages (day 5/6) was compared between the two different incubators. The proportion of good quality embryos was higher in the ES group compared to the SI on day 2 (66.8 vs. 50.5%, P = 0.014) and on day 3 (75.1 vs. 56.0%, P = 0.006). Those differences were statistically significant. A higher proportion of embryos developed to good quality blastocysts when cultured in the EmbryoScope compared to the benchtop (49.4 vs. 42.0%, P = 0.24), but this was not significant. Finally, no significant differences were noted with the proportion of blastocysts chosen for cryopreservation on day 5/6 in the two incubators. CONCLUSIONS: The findings support the view that the EmbryoScope incubator supports at least equivalent in vitro development of human embryos compared to other standard incubation methods and may promote improved development during early cleavage stages.


Asunto(s)
Blastocisto/fisiología , Técnicas de Cultivo de Embriones/instrumentación , Blastocisto/citología , Técnicas de Cultivo de Embriones/métodos , Femenino , Fertilización In Vitro , Humanos , Incubadoras , Imagen de Lapso de Tiempo
2.
Public Health Pract (Oxf) ; 7: 100484, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38533304

RESUMEN

Objectives: This study aims to assess factors influencing public trust in the National Health Service (NHS) in England, focusing on the impact of waiting times in Accident & Emergency (A&E) departments and for GP-to-specialist cancer referrals. Study design: A cross-sectional survey-based research design was employed, covering the period from July 2022 to July 2023. Methods: Data were collected through YouGov surveys, yielding 7415 responses. Our analysis is based on 6952 of these responses which we were able to aggregate to 42 NHS Integrated Care Boards (ICBs) for A&E waiting times and 106 ICB sub-units for cancer referral times. Multiple regression analysis was conducted, with the dependent variable being trust in the NHS. Results: Waiting times for A&E and cancer referrals did not significantly affect trust in the NHS. However, other sociopolitical factors displayed significant influence. Specifically, being a member of an ethnic minority group, or having voted Conservative in the 2019 general election were associated with lower trust scores. Other variables such as age and local unemployment rate were also significant predictors. Conclusions: Our findings suggest that waiting times for healthcare services have no effect on public trust in the NHS. Instead, trust appears to be largely shaped by sociopolitical factors. Policymakers should therefore look beyond operational efficiency when seeking to bolster trust in the healthcare system.

3.
Br J Surg ; 100(12): 1664-70, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24264792

RESUMEN

BACKGROUND: The World Health Organization (WHO) Surgical Safety Checklist is reported to reduce surgical morbidity and mortality, and is mandatory in the U.K. National Health Service. Hospital audit data show high compliance rates, but direct observation suggests that actual performance may be suboptimal. METHODS: For each observed operation, WHO time-out and sign-out attempts were recorded, and the quality of the time-out was evaluated using three measures: all information points communicated, all personnel present and active participation. RESULTS: Observation of WHO checklist performance was conducted for 294 operations, in five hospitals and four surgical specialties. Time-out was attempted in 257 operations (87.4 per cent) and sign-out in 26 (8.8 per cent). Within time-out, all information was communicated in 141 (54.9 per cent), the whole team was present in 199 (77.4 per cent) and active participation was observed in 187 (72.8 per cent) operations. Surgical specialty did not affect time-out or sign-out attempt frequency (P = 0.453). Time-out attempt frequency (range 42-100 per cent) as well as all information communicated (15-83 per cent), all team present (35-90 per cent) and active participation (15-93 per cent) varied between hospitals (P < 0.001 for all). CONCLUSION: Meaningful compliance with the WHO Surgical Safety Checklist is much lower than indicated by administrative data. Sign-out compliance is generally poor, suggesting incompatibility with normal theatre work practices. There is variation between hospitals, but consistency across studied specialties, suggesting a need to address organizational culture issues.


Asunto(s)
Lista de Verificación/estadística & datos numéricos , Quirófanos/estadística & datos numéricos , Procedimientos Quirúrgicos Operativos/estadística & datos numéricos , Lista de Verificación/normas , Atención a la Salud/normas , Humanos , Quirófanos/normas , Tempo Operativo , Grupo de Atención al Paciente/normas , Grupo de Atención al Paciente/estadística & datos numéricos , Seguridad del Paciente , Especialización/estadística & datos numéricos , Procedimientos Quirúrgicos Operativos/normas , Reino Unido , Organización Mundial de la Salud
4.
Environ Sci Technol ; 46(20): 11028-39, 2012 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-22963451

RESUMEN

Oxygenated volatile organic compounds (OVOCs) in the atmosphere are precursors to peroxy acetyl nitrate (PAN), affect the tropospheric ozone budget, and in the remote marine environment represent a significant sink of the hydroxyl radical (OH). The sparse observational database for these compounds, particularly in the tropics, contributes to a high uncertainty in their emissions and atmospheric significance. Here, we show measurements of acetone, methanol, and acetaldehyde in the tropical remote marine boundary layer made between October 2006 and September 2011 at the Cape Verde Atmospheric Observatory (CVAO) (16.85° N, 24.87° W). Mean mixing ratios of acetone, methanol, and acetaldehyde were 546 ± 295 pptv, 742 ± 419 pptv, and 428 ± 190 pptv, respectively, averaged from approximately hourly values over this five-year period. The CAM-Chem global chemical transport model reproduced annual average acetone concentrations well (21% overestimation) but underestimated levels by a factor of 2 in autumn and overestimated concentrations in winter. Annual average concentrations of acetaldehyde were underestimated by a factor of 10, rising to a factor of 40 in summer, and methanol was underestimated on average by a factor of 2, peaking to over a factor of 4 in spring. The model predicted summer minima in acetaldehyde and acetone, which were not apparent in the observations. CAM-Chem was adapted to include a two-way sea-air flux parametrization based on seawater measurements made in the Atlantic Ocean, and the resultant fluxes suggest that the tropical Atlantic region is a net sink for acetone but a net source for methanol and acetaldehyde. Inclusion of the ocean fluxes resulted in good model simulations of monthly averaged methanol levels although still with a 3-fold underestimation in acetaldehyde. Wintertime acetone levels were better simulated, but the observed autumn levels were more severely underestimated than in the standard model. We suggest that the latter may be caused by underestimated terrestrial biogenic African primary and/or secondary OVOC sources by the model. The model underestimation of acetaldehyde concentrations all year round implies a consistent significant missing source, potentially from secondary chemistry of higher alkanes produced biogenically from plants or from the ocean. We estimate that low model bias in OVOC abundances in the remote tropical marine atmosphere may result in up to 8% underestimation of the global methane lifetime due to missing model OH reactivity. Underestimation of acetaldehyde concentrations is responsible for the bulk (∼70%) of this missing reactivity.


Asunto(s)
Acetaldehído/análisis , Acetona/análisis , Contaminantes Atmosféricos/análisis , Contaminación del Aire/estadística & datos numéricos , Metanol/análisis , Compuestos Orgánicos Volátiles/análisis , Océano Atlántico , Atmósfera/química , Cabo Verde , Monitoreo del Ambiente , Ozono/química , Estaciones del Año , Clima Tropical
5.
Infect Prev Pract ; 3(4): 100186, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34812417

RESUMEN

BACKGROUND: Point-of-care (POC) SARS-CoV-2 lateral-flow antigen detection (LFD) testing in the emergency department (ED) could inform rapid infection control decisions but requirements for safe deployment have not been fully defined. METHODS: Review of LFD test results, laboratory and POC-RT-PCR results and ED-performance metrics during a two-week high SARS-CoV-2 prevalence period followed by several months of falling prevalence. AIM: Determine whether LFD testing can be safely deployed in ED to provide an effective universal SARS-CoV-2 testing capability. FINDINGS: 93% (345/371) of COVID-19 patients left ED with a virological diagnosis during the 2-week universal LFD evaluation period compared to 77% with targeted POC-RT-PCR deployment alone, on background of approximately one-third having an NHS Track and Trace RT-PCR test-result at presentation. LFD sensitivity and specificity was 70.7% and 99.1% respectively providing a PPV of 97.7% and NPV of 86.4% with disease prevalence of 34.7%. ED discharge-delays (breaches) attributable to COVID-19 fell to 33/3532 (0.94%) compared with the preceding POC-RT-PCR period (107/4114 (2.6%); p=<0.0001). Importantly, LFD testing identified 1 or 2 clinically-unsuspected COVID-19 patients/day. Three clinically-confirmed LFD false positive patients were appropriately triaged based on LFD action-card flowchart, and only 5 of 95 false-negative LFD results were inappropriately admitted to non-COVID-19 areas where no onward-transmission was identified. LFD testing was restricted to asymptomatic patients when disease prevalence fell below 5% and detected 1-3 cases/week. CONCLUSION: Universal SARS-CoV-2 LFD testing can be safely and effectively deployed in ED alongside POC-RT-PCR testing during periods of high and low disease prevalence.

6.
Reproduction ; 138(4): 629-37, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19602522

RESUMEN

The close relationship between cumulus cell function and oocyte developmental competence indicates that analysis of cumulus gene expression is a potential non-invasive method to aid embryo selection and IVF outcome. Cumulus was isolated from 674 oocytes from 75 women undergoing ICSI and gene expression analysed by quantitative RT-PCR. Cumulus expression of cyclooxygenase 2 (PTGS2) was higher with mature oocytes, whereas brain-derived neurotrophic factor (BDNF) was lower when fertilisation was normal. Expression levels of gremlin (GREM1) and BDNF were weak positive and negative predictors of embryo quality respectively. Ranking of GREM1 expression within cohorts of oocytes showed that oocytes associated with the highest GREM1 expression were more likely to be transferred or cryopreserved than discarded (49 vs 33%, P<0.02), although the clinical pregnancy rate was not significantly different. This study demonstrates both the feasibility and difficulties of this method of analysis in the largest such group studied thus far. Novel relationships between BDNF expression and fertilisation were identified, and the potential value of GREM1 expression as a marker of embryo quality supports the further assessment of GREM1 analysis in the context of embryo selection.


Asunto(s)
Células del Cúmulo/metabolismo , Desarrollo Embrionario/genética , Infertilidad Femenina/diagnóstico , Oocitos/fisiología , Oogénesis/genética , Mantenimiento del Embarazo/genética , Desarrollo Embrionario/fisiología , Femenino , Fertilización In Vitro , Expresión Génica , Humanos , Infertilidad Femenina/genética , Masculino , Oocitos/citología , Oocitos/metabolismo , Oogénesis/fisiología , Embarazo , Pronóstico , Control de Calidad , Sensibilidad y Especificidad , Inyecciones de Esperma Intracitoplasmáticas , Resultado del Tratamiento
7.
J Cell Biol ; 104(5): 1299-308, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-3571331

RESUMEN

The distribution of microtubules and microtubule organizing centers (MTOCs) during the development of cell polarity in eight-cell mouse blastomeres was studied by immunofluorescence and immunoelectron microscopy using monoclonal anti-tubulin antibodies and an anti-pericentriolar material (PCM) serum. In early eight-cell blastomeres microtubules were found mainly around the nucleus and in the cell cortex, whereas PCM foci were observed dispersed in the cytoplasm. During the eight-cell stage, microtubules disappeared from the area adjacent to the zone of intercellular contact and accumulated in the apical part of the cell while their number decreased in the basal domain. The PCM also relocalized to the apical domain of the cell, but this occurred after the redistribution of the microtubules by a mechanism that involved the microtubule network. The possible roles of both MTOCs and microtubules in establishing cell polarity are discussed.


Asunto(s)
Blastómeros/ultraestructura , Centriolos/ultraestructura , Microtúbulos/ultraestructura , Animales , Anticuerpos Monoclonales , Bencimidazoles/farmacología , Blastómeros/citología , Blastómeros/efectos de los fármacos , Femenino , Ratones , Ratones Endogámicos , Microscopía Electrónica , Nocodazol , Tubulina (Proteína)/análisis
8.
Neuron ; 25(1): 29-41, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10707970

RESUMEN

Neuropilins are receptors for class 3 secreted semaphorins, most of which can function as potent repulsive axon guidance cues. We have generated mice with a targeted deletion in the neuropilin-2 (Npn-2) locus. Many Npn-2 mutant mice are viable into adulthood, allowing us to assess the role of Npn-2 in axon guidance events throughout neural development. Npn-2 is required for the organization and fasciculation of several cranial nerves and spinal nerves. In addition, several major fiber tracts in the brains of adult mutant mice are either severely disorganized or missing. Our results show that Npn-2 is a selective receptor for class 3 semaphorins in vivo and that Npn-1 and Npn-2 are required for development of an overlapping but distinct set of CNS and PNS projections.


Asunto(s)
Axones/fisiología , Proteínas Portadoras/metabolismo , Glicoproteínas/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Factores de Edad , Animales , Axones/química , Química Encefálica/fisiología , Células COS , Eliminación de Gen , Regulación del Desarrollo de la Expresión Génica , Habénula/química , Habénula/embriología , Habénula/patología , Ratones , Ratones Noqueados , Fibras Musgosas del Hipocampo/química , Fibras Musgosas del Hipocampo/embriología , Fibras Musgosas del Hipocampo/patología , Neuronas Motoras/química , Neuronas Motoras/fisiología , Neuronas Motoras/ultraestructura , Neuropilina-1 , Sistema Nervioso Periférico/química , Sistema Nervioso Periférico/embriología , Sistema Nervioso Periférico/patología , Unión Proteica/fisiología , Ratas , Semaforina-3A , Nervios Espinales/química , Nervios Espinales/patología , Nervios Espinales/fisiología , Ganglio Cervical Superior/química , Ganglio Cervical Superior/embriología , Ganglio Cervical Superior/patología , Tálamo/química , Tálamo/embriología , Tálamo/patología , Nervio Troclear/química , Nervio Troclear/embriología , Nervio Troclear/patología
9.
J Nanosci Nanotechnol ; 8(3): 1234-7, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18468130

RESUMEN

Gold and platinum nanocapacitors have been fabricated using a magnetron sputtering technique. TiO2 is used as a dielectric material to separate the metal layers which act as the parallel plates for the capacitors. The thickness for metal films and TiO2 layer is 80 nm and 400 nm, respectively. Capacitance of the nanocapacitors has been measured and dielectric constant of TiO2 calculated. Both capacitance and dielectric constant are observed to have strong frequency dependence.

10.
J Intensive Care Soc ; 16(3): 234-238, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28979416

RESUMEN

Therapeutic interventions administered on Critical Care are often dosed on the basis of patient body size, to ensure treatments are effective in achieving their goals and to prevent harm from overdose. Many treatment modalities use predicted weights estimated from descriptors such as sex, weight and height to reduce error that is associated with using total body weight in critically ill patients. In this article we review the size descriptors that have been described, their origin and calculation. We then examine the role they play in dosing of common therapies utilised in Critical Care and potential areas of research for the future.

11.
Knee ; 22(3): 192-6, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25818502

RESUMEN

BACKGROUND: The Scorpio Total Knee Replacement (TKR) is one of the most commonly used prosthesis in the United Kingdom. Concerns arose at our institution that there was a high revision rate for this prosthesis. No study has assessed survivorship of this prosthesis over 10 years. METHODS: Four hundred and fifty-six consecutive patients, who underwent a primary Scorpio TKR, were clinically and radiologically evaluated. WOMAC, Oxford Knee Score and all complications including the reason for revision surgery were recorded. The Knee Society Roentgenographic Evaluation and Scoring System was used to evaluate all radiographs for prosthesis alignment and degree of subsequent lucency. Survival analysis for the prosthesis was calculated using Kaplan-Meier curves, with revision as an end-point. Patient reported outcome measures were compared against radiographic evaluation. RESULTS: At a mean of 12.5 years (range 10-14 years), 196 (43.0%) patients were available for review; 124 (27.2%) were lost to follow-up and 136 (29.8%) patients had died of unrelated causes. Seven (3.6%) patients required revision surgery at a mean of 5.4 years; five because of aseptic loosening and two because of septic loosening. Cumulative survival for the prosthesis was 99.5% for any cause at five years and 97.4% at 14 years. The mean OKS and WOMAC score at final follow-up was 30.64 (range 12-48) and 74 (18.9-100) respectively. CONCLUSION: The Scorpio TKR has good long term survivorship and functional outcomes. There is no apparent increased revision rate for this prosthesis in our study. LEVEL OF EVIDENCE: Level IV case series.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Prótesis de la Rodilla , Osteoartritis de la Rodilla/cirugía , Complicaciones Posoperatorias/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/mortalidad , Osteoartritis de la Rodilla/fisiopatología , Pronóstico , Diseño de Prótesis , Rango del Movimiento Articular , Estudios Retrospectivos , Tasa de Supervivencia/tendencias , Factores de Tiempo , Resultado del Tratamiento , Reino Unido/epidemiología
12.
Neurology ; 53(7): 1447-50, 1999 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-10534249

RESUMEN

OBJECTIVE: To determine the safety and efficacy of bilateral thalamic stimulation in the treatment of essential tremor (ET). METHODS: Nine ET patients with disabling tremor refractory to pharmacotherapy underwent bilateral staged implants. Tremor was assessed by the Fahn-Tolosa-Marin Tremor Rating Scale at baseline 1 (before first implant), baseline 2 (before second implant), and at 6-month and 1-year follow-up. Blinded evaluations were performed at 3 months. Associated changes in speech were evaluated in six patients. There were seven men and two women with a mean age of 73.8 years. RESULTS: There was a significant improvement in the mean total tremor score from a baseline of 66.1+/-11.6 to 28.4+/-12.8 12 months after the second surgery. Similarly, the mean motor tremor subscore was 20.1+/-5.0 before the first surgery and improved significantly to 14.1+/-3.6 before the second surgery. Motor tremor scores 6 months after the second surgery (6.0+/-3.7) and 12 months after the second surgery (7.5+/-3.9) also improved significantly relative to the preoperative scores. The mean activities of daily living (ADL) subscore at baseline was 18.2+/-2.9 and improved significantly before the second surgery to 9.0+/-3.2. These ADL scores further improved 6 months (6.2+/-5.2) and 12 months (7.9+/-5.7) following the second surgery, but these gains were not significant. Blinded evaluations also revealed a similar degree of improvement. Complications were noted in five patients: asymptomatic intracranial hematoma (1), postoperative seizures (1), a hematoma over the implanted pulse generator (IPG) (1), lead repositioning (1), and IPG malfunction (1). Adverse effects related to stimulation were mild and resolved with adjustment of the stimulation parameters. Three of the six patients demonstrated worsening of dysarthria with both stimulators on. CONCLUSIONS: Bilateral thalamic stimulation is effective in reducing tremor and functional disability in ET; however, dysarthria is a possible complication.


Asunto(s)
Terapia por Estimulación Eléctrica , Tálamo/fisiopatología , Temblor/terapia , Actividades Cotidianas , Anciano , Método Doble Ciego , Resistencia a Medicamentos , Terapia por Estimulación Eléctrica/efectos adversos , Electrodos Implantados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Movimiento , Complicaciones Posoperatorias , Índice de Severidad de la Enfermedad , Habla , Temblor/tratamiento farmacológico , Temblor/fisiopatología , Temblor/cirugía
13.
Transplantation ; 46(6): 857-9, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3061081

RESUMEN

Loss of an allograft caused by anti-GBM antibody-mediated nephritis is a rare complication of renal transplantation in Alport's syndrome. We describe a patient in whom this occurred. He belongs to the subgroup of patients with hereditary nephritis and deafness with an abnormal Goodpasture antigen, and he developed a high level of circulating anti-GBM antibodies within 20 days of transplantation of a kidney with a presumably normal Goodpasture antigen. The antibody titer fell, only to rise again when he developed evidence of acute infection with CMV. Coincident with this second rise in antibody titer he developed an anti-GBM antibody-mediated crescentic nephritis with resultant loss of graft function and transplant nephrectomy. This case provides support for the hypothesis that the abnormality in the basement membrane in some patients with Alport's syndrome involves the Goodpasture antigen, and raises the possibility that viral infection may have triggered autoantibody production.


Asunto(s)
Membrana Basal/inmunología , Colágeno Tipo IV , Isoanticuerpos/inmunología , Glomérulos Renales/inmunología , Trasplante de Riñón , Nefritis Hereditaria/inmunología , Nefritis/inmunología , Complicaciones Posoperatorias/etiología , Adulto , Autoantígenos/inmunología , Colágeno/inmunología , Rechazo de Injerto , Humanos , Masculino , Nefritis Hereditaria/cirugía , Trasplante Homólogo
14.
Fertil Steril ; 56(5): 904-12, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1936325

RESUMEN

OBJECTIVE: To develop a systematic study of the parthenogenetic activation and early development of human oocytes. DESIGN: Human oocytes (both freshly retrieved and remaining unfertilized after exposure to spermatozoa) were exposed to alcohol or calcium ionophore and examined for evidence of activation. SETTING: Academic research department of a teaching hospital. PATIENTS, PARTICIPANTS: Couples donating oocytes were undergoing therapy for infertility with in vitro fertilization or gamete intrafallopian transfer. INTERVENTIONS: Gonadotropin-releasing hormone agonist and human menopausal gonadotropin were administered at therapeutic doses. MAIN OUTCOME MEASURES: After application of activation stimuli at varying doses and durations, oocytes were examined for evidence of meiotic reactivation, pronuclear formation, deoxyribonucleic acid content, and cleavage. RESULTS: Fresh and aged human oocytes can be activated parthenogenetically using a calcium ionophore but at lower rates than seen for mouse oocytes (typically 50% to 60% versus 90% to 100%, respectively). Ethanol was a poor activating agent (maximum activation rate 16%). Human parthenotes can complete division to the eight cell stage. CONCLUSIONS: These results indicate that parthenote embryos may provide a source of material to study changes that occur during early human development. The data also raise the possibility that some early human pregnancy losses may involve oocytes that have been parthenogenetically activated spontaneously.


Asunto(s)
Oocitos/fisiología , Partenogénesis , Calcimicina/farmacología , Senescencia Celular , ADN/análisis , Etanol/farmacología , Humanos , Inseminación , Oocitos/química , Oocitos/efectos de los fármacos
15.
Fertil Steril ; 54(1): 102-8, 1990 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2358076

RESUMEN

The effect on the microtubule system of human oocytes of cooling to room temperature for either 10 or 30 minutes has been investigated. Changes in spindle organization were found in all oocytes cooled for 30 minutes compared with control oocytes kept at 37 degrees C throughout. These changes included reduction in spindle size, disorganization of microtubules within the spindle itself, and sometimes a complete lack of microtubules. In some oocytes, chromosome dispersal from the metaphase plate was associated with these changes. Cooling the oocyte to room temperature for only 10 minutes produced a similar pattern of disruption to spindle structure in many cases. The spindles in oocytes that were cooled for either 10 or 30 minutes and then allowed to recover at 37 degrees C for either 1 or 4 hours were found to resemble those in noncooled control oocytes in less than one half of the cases examined, although in only a few cases did the chromosomes remain dispersed. The significance of these findings for the handling of oocytes during gamete intrafallopian transfer and in vitro fertilization procedures is discussed in relation to the levels of aneuploidy detected in early human embryos.


Asunto(s)
Frío , Meiosis , Microtúbulos/ultraestructura , Oocitos/ultraestructura , Cromosomas/ultraestructura , Femenino , Humanos , Inmunohistoquímica
16.
Fertil Steril ; 53(2): 266-70, 1990 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2298310

RESUMEN

Fresh and aged (24 hours after ovulation) human oocytes and recently ovulated mouse oocytes may be activated by exposure to acidified Tyrode's solution. No activation of either type of human oocyte was observed after exposure to hyaluronidase or pronase, but significant numbers of fresh mouse oocytes were activated after exposure to pronase but not to chymotrypsin. The implications of these results for the manipulation of human and mouse eggs in vitro are discussed.


Asunto(s)
Soluciones Isotónicas/farmacología , Oocitos/fisiología , Partenogénesis , Animales , Femenino , Transferencia Intrafalopiana del Gameto , Humanos , Hialuronoglucosaminidasa , Inmunohistoquímica , Ratones , Oocitos/efectos de los fármacos , Superovulación
17.
Fertil Steril ; 51(6): 1024-9, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2542097

RESUMEN

Motile morphologically normal human spermatozoa can be separated from semen by buoyant density centrifugation on Percoll (Pharmacia Fine Chemicals AB, Uppsala, Sweden) gradients. In this study, the authors have examined (1) the efficiency of washing procedures to remove contaminating Percoll particles from the separated spermatozoa, and (2) the potential of Percoll particles, which contain silica, to cause an inflammatory response when used for intrauterine insemination, or when introduced into the fallopian tube during gamete intrafallopian transfer (GIFT) procedures, as assessed by an intraperitoneal injection into mice. Although Percoll was phagocytosed at the injection site, and therefore cannot be presumed to be totally inert, no generalized inflammatory response was detected. A double spin and wash technique was found to remove most residual Percoll from the spermatozoa, as assessed by scanning electron microscopy. These results suggest that procedures involving the use of Percoll for the separation of human spermatozoa for in vitro fertilization, GIFT, or intrauterine insemination should include stringent washing protocols that will remove most, if not all, contaminating Percoll from the sample.


Asunto(s)
Povidona , Dióxido de Silicio , Espermatozoides/citología , Separación Celular/métodos , Centrifugación por Gradiente de Densidad/métodos , Femenino , Transferencia Intrafalopiana del Gameto , Humanos , Inseminación Artificial , Masculino , Motilidad Espermática , Espermatozoides/ultraestructura
18.
J Cataract Refract Surg ; 21(3): 297-301, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7674166

RESUMEN

Two hundred consecutive patients had extracapsular cataract surgery by capsulorhexis and viscoexpression. Capsulorhexis, attempted in 195 eyes, was successful in 87.7%. Viscoexpression was attempted in 162 cases and successfully delivered the nucleus in 87.7%. There were five cases of zonule rupture, one of posterior capsule rupture, and two of vitreous loss. If the capsulorhexis is larger than 5 mm, viscoexpression can be safely used on all cataracts, regardless of nuclear density, and is the ideal transition to phacoemulsification.


Asunto(s)
Extracción de Catarata/métodos , Ácido Hialurónico/administración & dosificación , Cápsula del Cristalino/cirugía , Limbo de la Córnea/cirugía , Humanos , Complicaciones Intraoperatorias , Núcleo del Cristalino/cirugía , Lentes Intraoculares , Ligamentos/lesiones , Rotura , Agudeza Visual
19.
J Cataract Refract Surg ; 22(7): 940-6, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9041086

RESUMEN

PURPOSE: To compare the clinical and cost effectiveness of two models for cataract treatment: a single-function Cataract Treatment Centre (CTC) and a general ophthalmology service. SETTING: Cataract Treatment Centre and the general ophthalmology service at Sunderland Eye Infirmary, Sunderland, United Kingdom. METHODS: Two hundred patients were studied using two models of care: 100 in the CTC and 100 in the general ophthalmology service. Outcome measures were best corrected visual at 3 months postoperatively or at discharge and occurrence of surgery-related complications. All direct costs to the National Health Service were identified, measure, and assessed. RESULTS: Clinical outcomes in the two groups were similar. The average cost per patient was 496.90 pounds ($760.25) at the CTC and 566.34 pounds ($866.50) at the general ophthalmology service. The cost per patient treated as a day case in the general service group was 495.84 pounds ($758.63). Thus, treatment at the CTC was more cost effective than in the mixed service group and as cost effective as in the day case subgroup. CONCLUSIONS: Depending on local circumstances, day care must be delivered more cost effectively in a single-function center than in a general ophthalmology service. We recommend day care using local anesthesia and protocols for assessment, surgery, and follow-up.


Asunto(s)
Extracción de Catarata/economía , Hospitales Especializados/organización & administración , Modelos Organizacionales , Centros Quirúrgicos/organización & administración , Anestesia/métodos , Análisis Costo-Beneficio , Hospitales Especializados/economía , Humanos , Oftalmología/economía , Complicaciones Posoperatorias , Medicina Estatal/economía , Centros Quirúrgicos/economía , Resultado del Tratamiento , Reino Unido , Agudeza Visual
20.
Am J Surg ; 167(1): 156-62, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7906099

RESUMEN

Luminal alpha-adrenergic agonists alter ileal water, ion, and glucose transport by a local mechanism. This study tested the hypothesis that luminal adrenergic agents modulate ileal transport selectively, via specific alpha 1 and alpha 2 receptors. Absorption studies (n = 72) were performed on dogs with 25-cm ileal Thiry-Vella fistulas (TVF). Perfusion with (14C) polyethylene glycol was used to calculate absorption of water, ions, and glucose from the TVF. Experiments included four 1-hour periods. Agonists used were phenylephrine (alpha 1), clonidine (alpha 2), and norepinephrine (alpha 1 > alpha 2 and beta). Antagonists used were terazosin (alpha 1) and yohimbine (alpha 2). Phenylephrine and norepinephrine caused significant increases in water and ion absorption (p < 0.05). Clonidine caused significant decreases in water, ion, and glucose absorption (p < 0.05). Terazosin and yohimbine had no effect alone. Terazosin prevented the proabsorptive effect of phenylephrine and norepinephrine, and yohimbine blocked the prosecretory effect of clonidine. Yohimbine significantly increased the norepinephrine-induced proabsorptive effect. Luminal alpha-adrenergic agents selectively modulate ileal transport. Alpha 1-receptor activation causes a proabsorptive response, whereas alpha 2-receptor activation causes a prosecretory response. The combination of a luminally administered mixed alpha- and beta-adrenergic agonist (norepinephrine) with alpha 2 receptor blockade (yohimbine) may prove useful in pathologic secretory states such as intestinal transplants, diabetic diarrhea, or diarrhea-associated endocrinopathies.


Asunto(s)
Agonistas alfa-Adrenérgicos/farmacología , Antagonistas Adrenérgicos alfa/farmacología , Íleon/metabolismo , Absorción Intestinal/efectos de los fármacos , Receptores Adrenérgicos alfa 1/efectos de los fármacos , Receptores Adrenérgicos alfa 2/efectos de los fármacos , Agonistas Adrenérgicos beta/farmacología , Animales , Transporte Biológico/efectos de los fármacos , Perros , Femenino , Íleon/cirugía , Absorción Intestinal/fisiología , Fístula Intestinal , Receptores Adrenérgicos alfa 1/fisiología , Receptores Adrenérgicos alfa 2/fisiología , Equilibrio Hidroelectrolítico/efectos de los fármacos
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