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1.
S Afr J Surg ; 61(4): 33-39, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38450694

RESUMEN

BACKGROUND: Palliation of irresectable malignant gastric outlet obstruction (GOO) using self-expanding metal stents (SEMS) is gaining popularity with high technical success rates. The aim of this study was to review and compare GOO stenting for malignancy with other series. METHODS: A retrospective review of all patients undergoing pyloroduodenal stenting for malignant GOO at Groote Schuur Hospital, 1 March 2018-31 August 2021, evaluating demographics, technical success, pathology, and stentrelated complications was done. RESULTS: One hundred and fourteen patients, of which 38.6% were female, were included, with gastric malignancies (74.6%) being the most frequent underlying pathology. Median age was 64 years (IQR 53-70 years), with 48.2% having at least one comorbidity. The majority (96 patients; 85.7%) required only one stent. In total, 132 stent insertion attempts were undertaken. Three technical failures were experienced (one incorrect stent placement and two failed insertions), equating to a 97.4% technical success rate. Four immediate complications occurred (3.1%): two related to sedation, one incorrect stent placement and an oesophagogastric junction perforation with procedural death. Fifteen delayed complications occurred: 13 tumour in-growth blockages, one stent fracture and one case of poor radial stent expansion. Stent blockages occurred at a median of 107 days (IQR 80-275 days). Salvage stenting was 100% successful in 14 cases requiring re-stenting. CONCLUSION: Technical insertion success rates of primary and salvage duodenal stenting for malignant GOO are on par with international high-volume units. The leading pathology locally is gastric adenocarcinoma, with palliative stenting remaining a feasible and accessible option.


Asunto(s)
Adenocarcinoma , Anestesia , Obstrucción de la Salida Gástrica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obstrucción de la Salida Gástrica/etiología , Obstrucción de la Salida Gástrica/cirugía , Hospitales , Stents , Anciano
2.
S Afr J Surg ; 61(4): 27-32, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38450693

RESUMEN

BACKGROUND: Oesophageal stenting effectively palliates malignant dysphagia with reported high technical and clinical success rates approaching 90% and a low, though often problematic, complication frequency. This study aimed to benchmark success rates, the incidence and management of complications at a tertiary interventional endoscopy centre. METHODS: This single centre three-year (March 2018-March 2021) study reviewed demographics, tumour histology/ position, and early and late complications of palliative oesophageal stenting. A multivariate analysis of tumour position association with complications was performed. RESULTS: A total of 297 patients (73.4% squamous cell carcinoma) underwent 354 stent insertion attempts. Immediate technical insertion success rate was 97.5% with dysphagia improvement achieved in all successful insertions (100% clinical success rate). Three hundred and forty-six (98.6%) were fully covered stents, with 17 (4.8%) placed for tracheaoesophageal fistulae. Twenty-one (6.0%) immediate insertion-related complications occurred, including two oesophageal perforations, but no insertion-related mortalities. Late complications occurred in 73 (20.8%) with tumour overgrowth (10.1%) and stent migration (6.1%) being the most frequent. Of all 354 stents, 75.2% had no documented complications for the lifetime of that stent, while 68 complications required re-intervention, equating to a re-intervention rate of 19.4% per stent insertion. Stent migration was significantly higher in distal tumours (11.8% vs 1.8%, p < 0.001), while discomfort necessitating same-day stent removal was higher in proximal tumours starting at < 20 cm from the incisors (16.7% vs 0.5%, p < 0.001). CONCLUSION: Oesophageal stenting for malignant dysphagia is peri-procedurally safe and effective. Outcomes reported from this South African cohort compare favourably to high-volume international units.


Asunto(s)
Carcinoma de Células Escamosas , Trastornos de Deglución , Neoplasias Esofágicas , Humanos , Incidencia , Trastornos de Deglución/epidemiología , Trastornos de Deglución/etiología , Trastornos de Deglución/terapia , Neoplasias Esofágicas/terapia , Carcinoma de Células Escamosas/cirugía , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/terapia
3.
S Afr J Surg ; 58(4): 182-186, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34096203

RESUMEN

BACKGROUND: Various inguinal hernia repair techniques exist, without one 'single best' option. Hernia society guidelines recommend laparoscopic repair as one of its mainstays, provided surgeons are adequately trained. The current practice for hernia repair in South Africa as well as the surgical registrar exposure to laparoscopic repair training is unknown. OBJECTIVES: To quantify the current practice of inguinal hernia surgery in hospitals affiliated to the University of Cape Town (UCT) and to assess trainee exposure to laparoscopic repair. METHODS: Adult patients who underwent inguinal hernia repair during the 12-month study period, at the four UCT affiliated hospitals were included. Collected data parameters included age, gender, primary or recurrent, uni- or bilateral hernia, primary surgeon consultant or non-consultant, operative time, and open or laparoscopic technique used. RESULTS: Three hundred and seventy-seven patients were included. Eighty-eight (23.2%) repairs were performed laparoscopically, of which five (5.7%) were converted to open. Non-consultants were present at 70/88 (79.5%) cases performed laparoscopically and were the primary surgeon at only 15 (17%). Laparoscopic repair was performed for 63.6% of bilateral versus 19.5% of unilateral hernias, 39.4% of recurrent hernias and 45% of hernias in females. Two of the four hospitals in this study performed 81.8% of all laparoscopic repairs. CONCLUSIONS: Inguinal hernias in our setting are predominantly repaired by open surgery. The likelihood of laparoscopic repair varies significantly depending on which hospital the patient is referred to. Non-consultants have limited exposure to performing laparoscopic hernia repairs as the primary surgeon.


Asunto(s)
Hernia Inguinal , Laparoscopía , Adulto , Femenino , Hernia Inguinal/cirugía , Herniorrafia , Hospitales , Humanos , Estudios Retrospectivos
4.
Burns ; 45(7): 1518-1527, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-30638666

RESUMEN

Thermal injuries amongst infants are common and a cause of significant mortality and morbidity in South Africa. This has been attributed to the lack of an enabling environment (poverty-related lack of safe living conditions) and the cognitive and physical developmental immaturity of infants, who depend on their surroundings and adults to keep them safe. This is a retrospective observational study of 548 infant admissions over 48 months. Infant was defined as children below 13 months of age. The 548 infants constituted 23% of all paediatric burn admissions of ages 0-12 years. Three hundred and fourteen were males (57%) and 234 (42.7%) females. The infants were divided in a pre-ambulatory group of 143 (26%) infants of 0-6 months and an ambulatory group of 7 months to 12 months consisting of 457 (83.3%). The total body surface area (TBSA) ranged from 2-65%. Seventy-six percent (417 infants) occurred in the home environment. Scalds accounted for 86% (471 infants) and 6% (33 infants) were as a result of flame burns. Non-accidental injuries accounted for 1.2%. The anatomical distributions varied between the pre-ambulatory and ambulatory groups. Conservative management was done in 397 (72.4%) and 101(18.4%) infants underwent surgery. Infection was suspected in 76 (13.5%) infants with positive blood cultures in 15(20%) of the 76. ICU care was received in 46 (8.3%) infants and 15 (32.6%) of these had inhalation injuries. Of the inhalation injuries 11(23.9%) infants underwent mechanical ventilation of an average of 4.4 days. Ventilator associated pneumonia was diagnosed in 8(17%) of the ventilated children. The mortality rate was 0.36%. The surgically treated patients acquired more complications than the conservatively treated group. Special treatment considerations should be considered in this paediatric sub-group.


Asunto(s)
Quemaduras/terapia , Tratamiento Conservador , Nutrición Enteral , Fluidoterapia , Trasplante de Piel , Bacteriemia/epidemiología , Superficie Corporal , Quemaduras/patología , Niño , Desarrollo Infantil , Comorbilidad , Femenino , Infecciones por VIH/epidemiología , Humanos , Lactante , Trastornos de la Nutrición del Lactante/epidemiología , Recién Nacido , Masculino , Mortalidad , Neumonía Asociada al Ventilador/epidemiología , Infecciones del Sistema Respiratorio/epidemiología , Estudios Retrospectivos , Sedestación , Sudáfrica/epidemiología , Tuberculosis Pulmonar/epidemiología , Caminata , Infección de Heridas/epidemiología
5.
S Afr J Surg ; 55(2): 32-35, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28876621

RESUMEN

BACKGROUND: When multiple repeat laparotomies are required to manage intra-abdominal sepsis, questions about futility of treatment frequently arise. This study focuses specifically on patients who required two or more repeat laparotomies and describes the spectrum of disease necessitating multiple repeat laparotomies and the associated outcomes in the hope of clarifying the issue. METHOD: This study was conducted over a 20-month period (December 2012 - July 2014) at Greys Hospital in Pietermaritzburg, South Africa. All surgical patients at Greys Hospital have admission, discharge and operative data prospectively entered into a computerised electronic registry, the Hybrid Medical Electronic Registry (HEMR). The ethics approval required to maintain this registry has been obtained from the Biomedical Research Ethics Committee (BCA221/13 BREC) of the University of KwaZulu-Natal and from the Research Unit of the Department of Health. Full ethical approval for this study was granted by the University of KwaZulu-Natal Biomedical Research Ethics Committee (BE047/14). All patients aged 13 years and older who needed at least two repeat laparotomies were included in the study. This included general surgical and trauma patients. RESULTS: During the study period, 72 patients required more than one repeat laparotomy and a total of 182 repeat laparotomy operations were performed on this patient cohort. Demographics showed a male predominance, with 54 (75%) being male and 18 (25%) being female patients. The average age was 39 years. General surgical patients accounted for 60% and trauma patients for 40% of the total. The majority of patients required only two repeat laparotomy (65 %), while two patients required a total of 6 repeat laparotomy each, both with an initial diagnosis of appendicitis and both these patients survived. Temporary abdominal closure (TAC) was performed in 26 (36%) of initial laparotomies, while 33 (46%) of patients had an open abdomen at the time of discharge or death. Sixty percent required intensive care or high care unit (ICU/HCU) admission and 53 patients (74%) had a total of 71 documented morbidities. Total mortality for this study was 21%, however there was no correlation between number of procedures and mortality. CONCLUSION: The total number of procedures is associated with increased morbidity rates but not necessarily with increased mortality rates. This is important to consider when the issue of futility of treatment arises, as the absolute number of repeat laparotomies is a poor marker of futility and other factors must be considered.


Asunto(s)
Laparotomía/mortalidad , Reoperación/mortalidad , Sepsis/cirugía , Abdomen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Toma de Decisiones Clínicas , Femenino , Humanos , Laparotomía/efectos adversos , Laparotomía/estadística & datos numéricos , Masculino , Inutilidad Médica , Persona de Mediana Edad , Reoperación/efectos adversos , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Sepsis/etiología , Sepsis/mortalidad , Adulto Joven
6.
J Exp Biol ; 220(Pt 4): 573-581, 2017 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-27913599

RESUMEN

Poor environmental conditions experienced during early development can have negative long-term consequences on fitness. Animals can compensate for negative developmental effects through phenotypic plasticity by diverting resources from non-vital to vital traits such as spatial memory to enhance foraging efficiency. We tested in young feral pigeons (Columba livia) how diets of different nutritional value during development affect the capacity to retrieve food hidden in a spatially complex environment, a process we refer to as 'spatial memory'. Parents were fed with either high- or low-quality food from egg laying until young fledged, after which all young pigeons received the same high-quality diet until memory performance was tested at 6 months of age. The pigeons were trained to learn a food location out of 18 possible locations in one session, and then their memory of this location was tested 24 h later. Birds reared with the low-quality diet made fewer errors in the memory test. These results demonstrate that food quality during development has long-lasting effects on memory, with a moderate nutritional deficit improving spatial memory performance in a foraging context. It might be that under poor feeding conditions resources are redirected from non-vital to vital traits, or pigeons raised with low-quality food might be better in using environmental cues such as the position of the sun to find where food was hidden.


Asunto(s)
Conducta Apetitiva , Columbidae/crecimiento & desarrollo , Calidad de los Alimentos , Aprendizaje Espacial , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Columbidae/fisiología , Femenino , Masculino , Consolidación de la Memoria , Memoria Espacial
7.
World J Surg ; 40(7): 1558-64, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27160454

RESUMEN

INTRODUCTION/BACKGROUND: This study compares planned repeat laparotomy (PR) with on-demand repeat laparotomy (OD) in a developing world setting. MATERIALS AND METHODS: This study was conducted over a 30-month study period (December 2012-May 2015) at Greys Hospital, Pietermaritzburg, South Africa. All trauma and general surgery adult patients requiring a single relaparotomy were included in this study. Prospectively gathered data entered into an established electronic registry were retrospectively analysed. Full ethical approval for the registry and this study was granted by the University of KwaZulu-Natal Biomedical Ethics Committee. RESULTS: A total of 162 patients were included, with an average age of 36 years (standard deviation 17) and 69 % male predominance. Appendicitis and stab abdomen were the most common underlying diagnoses. PR strategy was used in 46 % and an OD approach in 54 %. Patients selected for the PR strategy had higher admission pulse rates, higher Modified Early Warning System (MEWS) scores and significantly higher rates of diffuse intra-abdominal sepsis at initial laparotomy. However, findings at relaparotomy were similar in both groups. The PR group had a much shorter time between operations, but much higher need for intensive care unit (ICU) admission. There was no difference between the groups in terms of open abdomen at discharge, length of hospital stay, morbidity or mortality. CONCLUSION: In our environment, a planned approach to relaparotomy shows no major outcome advantages over an on-demand approach. There is however increased need for ICU admission with the PR approach. This is in keeping with international literature. Of concern is the much longer time delay between index procedure and repeat operation in the OD group. Improved post-operative decision making may help address this.


Asunto(s)
Laparotomía/métodos , Reoperación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Apendicitis/cirugía , Femenino , Humanos , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sudáfrica
8.
J Evol Biol ; 27(10): 2057-68, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25056556

RESUMEN

Understanding the function of variation in sleep requires studies in the natural ecological conditions in which sleep evolved. Sleep has an impact on individual performance and hence may integrate the costs and benefits of investing in processes that are sensitive to sleep, such as immunity or coping with stress. Because dark and pale melanic animals differentially regulate energy homeostasis, immunity and stress hormone levels, the amount and/or organization of sleep may covary with melanin-based colour. We show here that wild, cross-fostered nestling barn owls (Tyto alba) born from mothers displaying more black spots had shorter non-REM (rapid eye movement) sleep bouts, a shorter latency until the occurrence of REM sleep after a bout of wakefulness and more wakefulness bouts. In male nestlings, the same sleep traits also correlated with their own level of spotting. Because heavily spotted male nestlings and the offspring of heavily spotted biological mothers switched sleep-wakefulness states more frequently, we propose the hypothesis that they could be also behaviourally more vigilant. Accordingly, nestlings from mothers displaying many black spots looked more often towards the nest entrance where their parents bring food and towards their sibling against whom they compete. Owlets from heavily spotted mothers might invest more in vigilance, thereby possibly increasing associated costs due to sleep fragmentation. We conclude that different strategies of the regulation of brain activity have evolved and are correlated with melanin-based coloration.


Asunto(s)
Pigmentación/fisiología , Sueño , Estrigiformes/fisiología , Vigilia , Animales , Plumas , Femenino , Modelos Lineales , Masculino , Melaninas/análisis , Fenotipo , Análisis de Componente Principal , Estrigiformes/genética
9.
Nanotechnology ; 25(9): 094004, 2014 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-24521927

RESUMEN

Printed Electronics is a rapidly developing sector in the electronics industry, in which nanostructured materials are playing an increasingly important role. In particular, inks containing dispersions of semiconducting nanoparticles, can form nanocomposite materials with unique electronic properties when cured. In this study we have extended on our previous studies of functional nanoparticle electronic inks, with the development of a solvent-based silicon ink for printed electronics which is compatible with existing silver inks, and with the investigation of other metal nanoparticle based inks. It is shown that both solvent-based and water-based inks can be used for both silver conductors and semiconducting silicon, and that qualitatively there is no difference in the electronic properties of the materials printed with a soluble polymer binder to when an acrylic binder is used.

10.
Philos Trans R Soc Lond B Biol Sci ; 368(1630): 20120418, 2013 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-24101628

RESUMEN

The use and manufacture of tools have been considered to be cognitively demanding and thus a possible driving factor in the evolution of intelligence. In this study, we tested the hypothesis that enhanced physical cognitive abilities evolved in conjunction with the use of tools, by comparing the performance of naturally tool-using and non-tool-using species in a suite of physical and general learning tasks. We predicted that the habitually tool-using species, New Caledonian crows and Galápagos woodpecker finches, should outperform their non-tool-using relatives, the small tree finches and the carrion crows in a physical problem but not in general learning tasks. We only found a divergence in the predicted direction for corvids. That only one of our comparisons supports the predictions under this hypothesis might be attributable to different complexities of tool-use in the two tool-using species. A critical evaluation is offered of the conceptual and methodological problems inherent in comparative studies on tool-related cognitive abilities.


Asunto(s)
Cognición , Cuervos/fisiología , Pinzones/fisiología , Comportamiento del Uso de la Herramienta , Animales , Conducta de Elección , Ecuador , Modelos Logísticos , Nueva Caledonia , Distribución Aleatoria
11.
Artículo en Inglés | MEDLINE | ID: mdl-23207908

RESUMEN

Insight into the function of sleep may be gained by studying animals in the ecological context in which sleep evolved. Until recently, technological constraints prevented electroencephalogram (EEG) studies of animals sleeping in the wild. However, the recent development of a small recorder (Neurologger 2) that animals can carry on their head permitted the first recordings of sleep in nature. To facilitate sleep studies in the field and to improve the welfare of experimental animals, herein, we test the feasibility of using minimally invasive surface and subcutaneous electrodes to record the EEG in barn owls. The EEG and behaviour of four adult owls in captivity and of four chicks in a nest box in the field were recorded. We scored a 24-h period for each adult bird for wakefulness, slow-wave sleep (SWS), and rapid-eye movement (REM) sleep using 4 s epochs. Although the quality and stability of the EEG signals recorded via subcutaneous electrodes were higher when compared to surface electrodes, the owls' state was readily identifiable using either electrode type. On average, the four adult owls spent 13.28 h awake, 9.64 h in SWS, and 1.05 h in REM sleep. We demonstrate that minimally invasive methods can be used to measure EEG-defined wakefulness, SWS, and REM sleep in owls and probably other animals.


Asunto(s)
Recolección de Datos/instrumentación , Electroencefalografía/veterinaria , Polisomnografía/veterinaria , Sueño/fisiología , Estrigiformes/fisiología , Animales , Conducta Animal/fisiología , Electrodos/veterinaria , Electroencefalografía/instrumentación , Electroencefalografía/métodos , Diseño de Equipo , Etología/instrumentación , Femenino , Masculino , Polisomnografía/instrumentación , Polisomnografía/métodos , Fases del Sueño/fisiología , Vigilia/fisiología
12.
Micron ; 43(8): 863-9, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22487243

RESUMEN

Titanium nanoparticles are widely used by industry in consumer products such as sunscreens and some cosmetic products due to their specifically engineered properties. Some of these properties may, however, increase the toxicity of the nanoparticles which in turn may affect human and environmental health. Therefore, it is of utmost importance to study the possible effects of these particles through in vivo studies, which might produce different results than in vitro cell studies. The current study aimed to investigate the possible remodelling in the lungs of BALB/c mice by means of light and transmission electron microscopy after inhalation of spherical and rod-shaped titanium nanoparticles at two different concentrations. The focus of this paper was to demonstrate whether whole body exposure to different concentrations of the said nanoparticles could induce an inflammatory response in the lungs and no inter particle comparison was done or retention investigated. Animals were divided into five experimental groups: control, high and low concentration groups exposed to the spherical-shaped particles, as well as high and low concentration groups exposed to the rod-shaped particles. Histological and ultrastructural changes, typical of an inflammatory response, were noted in the lungs of the exposed animals. These changes were not observed in the lungs of the control animals. It can be concluded from this study that titanium nanoparticles may cause inflammatory reactions in the lungs of animals exposed through inhalation, as indicated by the presence of inflammatory cells and congestion of inter-alveolar areas. This has implications for individuals who may be potentially exposed during the production and use of titanium nanoparticles.


Asunto(s)
Pulmón/patología , Nanopartículas/administración & dosificación , Nanopartículas/efectos adversos , Titanio/administración & dosificación , Titanio/efectos adversos , Administración por Inhalación , Animales , Exposición a Riesgos Ambientales , Femenino , Ratones , Ratones Endogámicos BALB C , Microscopía , Neumonía/inducido químicamente , Neumonía/patología
13.
J Nanosci Nanotechnol ; 11(2): 1201-4, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21456159

RESUMEN

A cadmium tetrahydroisoquinoline dithiocarbamate (DTC) complex has been used as single-source precursor for the synthesis of highly faceted hexadecylamine (HDA) capped CdS nanoparticles. Hexagonal and close to cubic shaped particles with distinct lattice fringes are visible in the high resolution transmission electron microscopy images. Crystalline particles in the shape of a hexagon are clearly visible in the high resolution TEM images. The X-ray diffraction pattern of the particles is indexed to the stable wurtzite phase of CdS. The optical absorption spectrum of the particles is blue shifted from bulk CdS and the photoluminescence (PL) spectrum shows a relatively narrow emission peak.

14.
Nanoscale Res Lett ; 5(2): 389-397, 2009 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-20671779

RESUMEN

Laser photolysis of WCl(6) in ethanol and a specific mixture of V(2)O(5) and VCl(3) in ethanol lead to carbon modified vanadium and tungsten oxides with interesting properties. The presence of graphene's aromatic rings (from the vibrational frequency of 1,600 cm(-1)) together with C-C bonding of carbon (from the Raman shift of 1,124 cm(-1)) present unique optical, vibrational, electronic and structural properties of the intended tungsten trioxide and vanadium dioxide materials. The morphology of these samples shows nano-platelets in WO(x) samples and, in VO(x) samples, encapsulated spherical quantum dots in conjunction with fullerenes of VO(x). Conductivity studies revealed that the VO(2)/V(2)O(5) nanostructures are more sensitive to Cl than to the presence of ethanol, whereas the C:WO(3) nano-platelets are more sensitive to ethanol than atomic C.

15.
J Nanosci Nanotechnol ; 7(10): 3638-42, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18330185

RESUMEN

Hot-filament chemical vapor deposition has developed into an attractive method for the synthesis of various carbon nanostructures, including carbon nanotubes. This is primarily due to its versatility, low cost, repeatability, up-scalability, and ease of production. The resulting nano-material synthesized by this technique is dependent on the deposition conditions which can be easily controlled. In this paper we report on the effect of the deposition pressure on the structural properties and morphology of carbon nanotubes synthesized by hot-filament chemical vapor deposition, using Raman spectroscopy and high-resolution scanning electron microscopy, respectively. A 10 nm-thick Ni layer, deposited on a SiO2/Si substrate, was used as catalyst for carbon nanotube growth. Multi-walled carbon nanotubes with diameters ranging from 20-100 nm were synthesized at 500 degrees C with high structural perfection at deposition pressures between 150 and 200 Torr. Raman spectroscopy measurements confirm that the carbon nanotube deposit is homogeneous across the entire substrate area.


Asunto(s)
Cristalización/métodos , Nanotecnología/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestructura , Gases/química , Calor , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Presión , Propiedades de Superficie
16.
Ann Urol (Paris) ; 30(3): 139-46, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8766151

RESUMEN

In a prospective study, the prevalence of specific antibodies against Chlamydia trachomatis in serum and seminal plasma evaluated by a genus specific immunofluorescence test in 101 men without acute urethritis was investigated. The results were compared to the clinical diagnosis, cell culture of urethral swabs, demonstration of DNA particles by Polymerase Chain Reaction (PCR) in the ejaculate and signs of genital inflammation by counting peroxidase-positive leukocytes and elastase level in semen. The objective was to evaluate the significance of chlamydial antibodies in genital infection. Serum specific IgG and IgA antibodies were found in 26% and 15%, respectively; seminal IgG and IgA antibodies were present in 6% and 7%, respectively. Serum specific antibodies were not associated with the clinical diagnosis of infection nor with C. trachomatis cell culture, PCR findings, peroxidase positive leukocytes or PMN-elastase level. It is concluded that serum antibodies are not useful in detecting a chlamydial infection. Seminal plasma antibodies were not correlated with the clinical diagnosis of infection, positive cell culture, PMN-elastase levels and leukocytes in semen. However, a significant correlation was found for positive PCR in the ejaculate (p < 0.001 for IgG, p < 0.05 for IgA, p < 0.001 when combined). Though seminal antibodies may be more useful in detecting ascended or occult chlamydial infection, their significance remains unclear, their absence does not exclude chlamydial infection. In particular, the biological significance of locally derived IgA needs further evaluation.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Chlamydia trachomatis/inmunología , Semen/inmunología , Enfermedad Aguda , Adolescente , Adulto , Anticuerpos Antibacterianos/análisis , Balanitis/inmunología , Balanitis/microbiología , Infecciones por Chlamydia/inmunología , Chlamydia trachomatis/genética , ADN Bacteriano/análisis , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina G/análisis , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Elastasa Pancreática/análisis , Estudios Prospectivos , Prostatitis/inmunología , Prostatitis/microbiología , Semen/enzimología , Uretra/inmunología , Uretra/microbiología , Uretritis/inmunología
17.
Infect Immun ; 61(10): 4523-6, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8406847

RESUMEN

Three human monoclonal immunoglobulin M antibodies against Borrelia burgdorferi, obtained from in vitro-stimulated peripheral blood lymphocytes, reacted in Western blots (immunoblots) with a prominent 39-kDa peptide and a faint band of approximately 66 kDa. Two of these antibodies showed bactericidal activity without addition of complement. All three antibodies were reactive in an enzyme immunoassay with cloned P39 (W.J. Simpson, M.E. Schrumpf, and T.G. Schwan, J. Clin. Microbiol. 28:1329-1337, 1990), suggesting that the target molecule of these antibodies is identical to the P39 protein. In addition, the majority of supernatants from human lymphocytes stimulated in vitro with crude B. burgdorferi antigen reacted in this assay, demonstrating that P39, although a minor component of B. burgdorferi, is an immunodominant antigen in these spirochetes. A fourth monoclonal antibody, reacting with OspA, also exhibited bactericidal activity.


Asunto(s)
Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Grupo Borrelia Burgdorferi/inmunología , Anticuerpos Antibacterianos/inmunología , Especificidad de Anticuerpos , Antígenos Bacterianos/química , Proteínas Bacterianas/química , Citotoxicidad Inmunológica , Humanos , Técnicas In Vitro , Activación de Linfocitos , Peso Molecular
18.
J Infect Dis ; 163(6): 1344-7, 1991 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1645384

RESUMEN

The safety and pharmacokinetics of the two neutralizing human IgG1 monoclonal antibodies to cytomegalovirus (CMV) SDZ 89-104 and 89-109 in bone marrow transplant (BMT) recipients was assessed in an open phase I trial. Thirteen patients, 8 seropositive and 5 seronegative for CMV, were treated with allogeneic or autologous bone marrow transplantation. SDZ 89-104 was given to 5 and SDZ 89-109 to 8 patients. Patients were divided into high- and low-dose groups. A fixed prestudy dose of 0.1 mg/kg was given 4 days before BMT. On days 3, 17, 31, 45, 59, and 73, patients were treated with either 0.5 or 2 mg/kg of the respective antibody. Results indicate that doses of 2 mg/kg of SDZ 89-104 or SDZ 89-109 in alternating weeks can be safely administered to BMT patients. Serum trough levels measured by antiidiotype ELISA were approximately 10 micrograms/ml after administration of 0.5 mg/kg and approximately 50 micrograms/ml after treatment with 2 mg/kg of SDZ 89-104 or SDZ 89-109. High serum levels defined by antiidiotype ELISA techniques closely paralleled increased neutralizing activity. Serum half-lives calculated from these data were approximately 6 days.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Trasplante de Médula Ósea , Infecciones por Citomegalovirus/prevención & control , Citomegalovirus/inmunología , Inmunización Pasiva , Adolescente , Adulto , Anticuerpos Monoclonales/farmacocinética , Evaluación de Medicamentos , Ensayo de Inmunoadsorción Enzimática , Femenino , Semivida , Humanos , Masculino , Persona de Mediana Edad
19.
Vox Sang ; 60(4): 203-6, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1656609

RESUMEN

By selecting blood donors with high cytomegalovirus (CMV) antibody titres, a plasma pool was obtained which was used to produce an IgG hyperimmunoglobulin by means of pepsin fractionation. After administration of approximately 100 mg/kg body weight to healthy subjects, the time course both of anti-CMV IgG antibody titres by ELISA and of virus neutralisation (VN) titres was followed for 15 days. Seronegative subjects showed an increase in CMV-IgG antibodies as well as a significant enhancement of VN. The time course of both titres was non-uniform. The decline of both titres was biphasic: CMV-IgG antibodies fell slowly during the first week and remained unchanged thereafter, whereas VN titres decreased markedly faster in the first than in the second week. In seropositive subjects, on the other hand, VN remained unchanged. CMV-IgG antibodies increased by approximately 3 times, followed by a similar biphasic decline as seen in seronegative subjects. Due to the differences between seronegative and seropositive subjects and to the non-uniform time course, no calculations of the elimination rate were feasible.


Asunto(s)
Anticuerpos Antivirales/metabolismo , Citomegalovirus/inmunología , Inmunoglobulina G/metabolismo , Adulto , Anticuerpos Antivirales/administración & dosificación , Anticuerpos Antivirales/análisis , Semivida , Humanos , Sueros Inmunes/administración & dosificación , Inmunoglobulina G/administración & dosificación , Masculino , Pruebas de Neutralización
20.
Scand J Rheumatol Suppl ; 75: 117-22, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-2853448

RESUMEN

In rheumatoid arthritis patients with malignant progress, short remissions and unimprovement response of activity to therapy Ab with both properties (antiviral and anti IgG) are compared. The selective binding of RF to antigen structures of CMV were tested by 180 patients in a new established ELISA with antiidiotypic goat antibodies of CMV neutralizing human monoclonal Ab and against virus antigen directly. Displacement reactions on the idiotypic binding side as well as comparative ELISA proved the special RF activity. 24.2% of patient suffering from RA with IgM RF showed selective bindings to antigen structures of CMV and anti IgG activity. The evidence of the specific binding capacity of RF to virus antigen in chronical CMV infection as well as their defined binding capacity to the Fc Fragment of IgG suggest CMV specific RF as pathogenetic factor of malignant forms of inflammatory rheumatism.


Asunto(s)
Antígenos Virales/inmunología , Citomegalovirus/inmunología , Factor Reumatoide/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Inmunoglobulina M/inmunología , Pruebas de Neutralización
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