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1.
Unfallchirurgie (Heidelb) ; 126(3): 175-183, 2023 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-36746799

RESUMEN

BACKGROUND: Interdisciplinary case conferences are well-established in the field of oncology in order to provide the best possible treatment for patients with complex disease patterns which overlap several disciplines. METHODS: After studying the available literature the aims, indications, frequency, patient enrolment and documentation modalities, disciplines necessary to create the reconstruction plan and evaluation parameters of the board, were agreed in an interdisciplinary discussion among colleagues. The utilization of the extremity board and demographic features of the cases presented in the extremity board within the first 6 months were subsequently descriptively analyzed. RESULTS: The agreed primary aim of an extremity board is the timely and transparent preparation of a high-quality holistic reconstruction plan for optimized treatment of a challenging patient collective with complex injuries of the extremities. Decisive interfaces of an extremity board are the participation of interdisciplinary disciplines, established enrolment and documentation modalities and a longitudinal analysis of parameters of the acute medical treatment, the long-term function and quality of life of those affected. The patient collective so far mostly includes men under 40 years old with traumatic soft tissue defects and combined injuries. On average, reconstruction plans for 1-2 patients were approved in an interdisciplinary team per session. CONCLUSION: The extremity board serves as a platform for coordinated planning of treatment for patients with complex injuries. The limited personnel and time resources represent the greatest challenge for the successful implementation. The extremity board enables a high degree of interdisciplinary networking. The digital registration and documentation modality within the internal hospital documentation system is of utmost relevance. The preparation of the reconstruction plan is of decisive importance for the qualitative success of treatment and the restoration of function. The longitudinal analysis of appropriate parameters is imperative to measure the quality of treatment.


Asunto(s)
Procedimientos de Cirugía Plástica , Calidad de Vida , Masculino , Humanos , Adulto , Extremidades/lesiones
2.
Gen Comp Endocrinol ; 329: 114099, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-35914652

RESUMEN

Increased poaching in northern South Africa has necessitated relocation of large numbers of southern white rhinoceros (Ceratotherium simum simum) to the Eastern Cape Province. The climate and grassland ecology of this province differ from that of northern South Africa which may impact the health of this species. This assessment of fecal steroid levels and microbiome in 10 free-ranging southern white rhinoceros in the Eastern Cape will provide insights into white rhinoceros physiology in this biome. Fecal steroid metabolites were analyzed using enzyme immunoassay (EIA) and ultra-performance convergence chromatography tandem mass spectrometry (UPC2-MS/MS). Fecal microbial composition was assessed via next generation sequencing. EIAs with antibodies raised against progesterone (P4; mouse monoclonal - CL425 clone), testosterone (T; rabbit polyclonal), corticosterone (B; sheep polyclonal) were utilized. Pregnant females had large quantities of fecal progesterone metabolites (FPMs) detected by CL425 EIA. Pregnant females also had native P4 and 11α-hydroxydihydroprogesterone (11αOHDHP4; 4-pregnen-11α-ol-3,20-dione) detected by UPC2-MS/MS but these concentrations were 1000-fold less than the concentrations of FPMs detected by the CL425 EIA. By contrast, non-pregnant females had FPM concentrations detected by CL425 EIA which were similar to native P4 and 11αOHDHP4 concentrations detected by UPC2-MS/MS. Mean fecal androgen metabolite (FAM) concentrations detected by the T EIA were similar between males and females. 11-ketoandrostenedione (11KA4) detected by UPC2-MS/MS was higher in females than males. However, there was no difference between males and females in the concentration of fecal glucocorticoid metabolites (FGMs) detected by the B EIA. Bacteroidia, followed by Clostridia, was the most abundant classes of fecal microbes. The unfiltered microbiome of females was more diverse than that of males. The core fecal microbiome of young rhinoceros had a higher observed species richness (Shannon diversity index, and Simpson diversity index) than that of old rhinoceros. In the alpha male, immobilization was associated with an increase in FGMs detected by 11-deoxycortisol (S) detected by UPC2-MS/MS coupled with decreased abundance of Spirochaetia. We detected substantially different FAM and FPM concentrations from those previously reported for both captive and wild white rhinoceros. Comparison of our UPC2-MS/MS and EIA results underscores the fact that most EIAs are highly cross reactive for many steroid metabolites. Our data also demonstrates a distinct effect of stress not only on FGMs but also on the fecal microbiome. This is the first non-invasive assessment of fecal steroid metabolites by UPC2-MS/MS and the fecal microbiome in wild white rhinoceros.


Asunto(s)
Microbiota , Progesterona , Femenino , Masculino , Animales , Ovinos , Conejos , Ratones , Progesterona/metabolismo , Andrógenos/metabolismo , Glucocorticoides/metabolismo , Espectrometría de Masas en Tándem , Sudáfrica , Perisodáctilos/metabolismo
3.
J Nanosci Nanotechnol ; 18(2): 865-871, 2018 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-29448508

RESUMEN

There is increasing requirement for the development of new drug protocols against malaria, a fatal disease caused by the lethal parasite Plasmodium falciparum. Leucine aminopeptidase (Pf LAP) of Plasmodium falciparum, is being pursued as a promising target for the discovery of novel antimalarials. The effects of silver nanoparticles (AgNPs) against P. falciparum leucine amino-peptidase (Pf LAP) and the human homolog (HsLAP) were compared. Pf LAP and HsLAP were expressed in Escherichia coli, and AgNPs (3-10 nm) characterized by ultra-violet spectroscopy and transmission electron microscopy. Pf LAP indicated a Km of 694 µM towards leucine-p-nitroanilide and a Vmax of 57.9 µmol.ml-1 · min-1 while HsLAP had a Km of 1.6 mM and Vmax of 119.6 µmol · ml-1 · min-1. On interaction with AgNPs (670 nM) Pf LAP was selectively inhibited (57.1%; Ki = 610 nM) relative to HsLAP (10.8%; Ki = 5.22 µM). Structural differences between the enzyme variants, particularly the orientation and distance of surface Met349 in Pf LAP and Met306 in HsLAP to the zinc binding sites were significant and may allow for selective targeting of Pf LAP by AgNPs. The viability of P. falciparum parasites was decreased when exposed to silver nanoparticles, with an IC50 value of 6.96 µM, compared to an IC50 value of 647.7 µM for human HeLa cells.


Asunto(s)
Nanopartículas del Metal , Plasmodium falciparum/efectos de los fármacos , Plata , Escherichia coli , Células HeLa , Humanos , Leucil Aminopeptidasa
4.
Eplasty ; 17: e42, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29348784

RESUMEN

Objective: Recipient vessel caliber may be the single most important variable for flow to free tissue transfer. We performed cadaveric dissection of the external carotid artery and its branches to analyze average diameter in order to determine an algorithm for recipient vessel selection in head and neck reconstruction. Methods: The external carotid artery and branches were exposed on 3 lightly embalmed male human cadavers, aged 82 to 85 years. Each vessel was dissected, and luminal diameters were recorded with calipers. Results: The proximal ECA had the greatest average diameter (4 ± 0.6 mm) and potential flow; followed by distal ECA (2.85 ± 0.4 mm) facial (2.0 ± 0.6 mm), lingual (1.65 ± 0.6 mm), superior thyroid (1 ± 0.3  mm), and superficial temporal (0.85 ± 0.4 mm). There was a trend towards size variation between sides of the same cadaver. Conclusion: The external carotid artery has the greatest internal diameter and potential blood flow. It should be considered, when feasible, especially for defects of the upper third of the head. For defects of the lower third, the facial artery and the lingual artery should be utilized before the smaller diameter superior thyroid artery. Vessel selection is more challenging in the setting of radiation therapy, complex trauma, and prior neck surgery. In these settings, it is useful to have knowledge of the vascular anatomy and an objective algorithm for recipient vessel selection.

5.
J Biomed Nanotechnol ; 11(6): 1071-9, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26353595

RESUMEN

Recombinant triosephosphate isomerase from Plasmodium falciparum (PfTIM) and humans (hTIM) were expressed, purified and characterised. High specific activity (1207 U x mg(-1)) with a fold purification of -1.8 and a yield of 48% were obtained for hTIM after gel filtration while, in contrast PfTIM afforded a specific activity of 1387 U x mg(-1) with a fold purification of -6.8 and a yield of 57% after gel filtration and prior to dialysis. PfTIM had an optimal pH and temperature, K(m) and V(max) of 5.25, 25 degrees C, 12.8 mM and 1.13 µmol x mL(-1) min(-1) respectively while for hTIM the pH and temperature optima, K(m) and V(max) were 6.75, 30 degrees C; 8.2 mM and 1.35 µmol x ml(-1) min(-1). Polyvinylpyrrolidone stabilised silver nanoparticles (60 nM; 2-6 nm diameter) selectively inhibited PfTIM with a 7-fold decrease in enzyme catalytic efficiency (K(cat)/K(m)) over hTIM. Respective K(i) values were 283 nM [hTIM] and 85.7 nM [PfTIM]. Key structural differences between the two enzyme variants, especially with Cys13 at the dimer interface of PfTIM, were significant enough to suggest unique characteristics allowing for selective targeting of PfTIM by AgNPs.


Asunto(s)
Nanopartículas del Metal , Plasmodium falciparum/enzimología , Plata/química , Triosa-Fosfato Isomerasa/metabolismo , Clonación Molecular , Humanos , Nanopartículas del Metal/química , Modelos Moleculares , Plasmodium falciparum/genética , Plasmodium falciparum/metabolismo , Povidona/análogos & derivados , Povidona/química , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Plata/farmacología , Triosa-Fosfato Isomerasa/antagonistas & inhibidores , Triosa-Fosfato Isomerasa/química , Triosa-Fosfato Isomerasa/genética
6.
Eplasty ; 15: e36, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26301001

RESUMEN

HYPOTHESIS: Using Lister's tubercle and the ulnar styloid as landmarks, accurate localization of the distal radioulnar joint can be achieved without the need for an image-guided approach. METHODS: Cadaveric dissection of 16 upper extremities was performed to measure the relationships between the ulnar styloid, Lister's tubercle, and the distal radioulnar joint. In each specimen, the location of the distal radioulnar joint (point A) in relation to Lister's tubercle and the ulnar styloid was determined as follows: (1) the perpendicular distance between the distal radioulnar joint and ulnar styloid-Lister's tubercle was measured; (2) with A' marking the intersection of this distance and the ulnar styloid-Lister's tubercle line, the location of the distal radioulnar joint along the ulnar styloid-Lister's tubercle axis was determined by comparing ulnar styloid-A' and A'-Lister's tubercle with ulnar styloid-Lister's tubercle. RESULTS: The mean distance between ulnar styloid-Lister's tubercle was 4.3 ± 0.4 cm. The mean perpendicular distance between the distal radioulnar joint and the ulnar styloid-Lister's tubercle line was 0.2 ± 0.1 cm proximal to the ulnar styloid-Lister's tubercle line. The ratio of ulnar styloid-A' and A'-Lister's tubercle to ulnar styloid-Lister's tubercle was 0.5 ± 0.03 and 0.5 ± 0.03, respectively. CONCLUSIONS: Simple relationships between the ulnar styloid and Lister's tubercle serve as reliable landmarks for locating the distal radioulnar joint. The distal radioulnar joint is centered about the midpoint of the ulnar styloid-Lister's tubercle axis and slightly proximal to it. This may improve the accuracy and efficacy of corticosteroid injections in the treatment of distal radioulnar joint arthritis without the need for image guidance.

7.
Eplasty ; 15: e22, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26171094

RESUMEN

BACKGROUND: Abdominoplasty is one of the most common aesthetic procedures performed in the United States. While poor contour and unsatisfactory cosmetic result have been recognized, neuropathic pain from lateral femoral cutaneous nerve injury has been poorly described. We aim to improve outcomes by using an anatomical study to develop a strategy to avoid injury to the lateral femoral cutaneous nerve in abdominoplasty. METHODS: Twenty-three fresh cadaver abdomens were dissected to evaluate the course of the lateral femoral cutaneous nerve, using 2.5× loupe magnification. Measurements were taken from the nerve to the anterior superior iliac spine and from the pubic symphysis to the lateral femoral cutaneous nerve. Recordings of the relationship of the nerve to the inguinal ligament and depth at scarpa's fascia were also made. Statistical analysis was performed to find average distances with a standard deviation. RESULTS: On average, the distance from the lateral femoral cutaneous nerve to the anterior superior iliac spine was 3.62 (SD = 1.32) cm and 13.58 (SD = 2.41) cm from the pubic symphysis in line with the inguinal ligament. The lateral femoral cutaneous nerve was found at the inguinal ligament 80% of the time and 20% of the time superior to the ligament and always deep to scarpa's fascia. CONCLUSION: Abdominoplasty carries a high patient and surgeon satisfaction rate. The plastic surgeon is continuously challenged to identify ways to improve outcomes, efficiency, and morbidity. Minimal and careful dissection in the area around 4 cm of the anterior superior iliac spine in addition to preserving scarpa's fascia near the inguinal ligament may serve as key strategies to avoiding lateral femoral cutaneous nerve injury.

8.
Int J Biol Macromol ; 79: 644-53, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26049116

RESUMEN

Malaria, a mosquito-borne infectious disease, is caused by the Plasmodium genus, and remains one of the greatest health challenges worldwide. The malarial parasite possess a biosynthetic pathway for the B-group vitamin incorporating the thiamine metabolizing enzymes; humans on the other hand cannot synthesize the vitamin and require it from within their diet. The vitamin B1 biosynthetic enzyme 5-(2-hydroxyethyl)-4-methylthioazolekinase [EC. 2.7.1.50] from Plasmodium (PfThzK) is particularly attractive as a biomedical target since any inhibition of this enzyme may lead to an effective treatment for malaria. In the present study, PfThzK was recombinantly produced as a 6× His fusion protein in Escherichia coli BL21(DE3) and purified using nickel affinity and size exclusion chromatography. The enzyme was monomeric with a molecular mass of 34 kDa, a specific activity of 295.04 nmol min(-1) mg(-1) and showed an optimum temperature and pH of 37 °C and 7.5, respectively. The purified PfThzK was non-competitively inhibited (79%) by silver nanoparticles (2-6 nm); Ki=6.45 µM. A mechanism is suggested for the interaction of the silver nanoparticle with PfThzK through two sulphur bearing amino acids (Met(1), Cys(206)) on the surface of each subunit of the enzyme.


Asunto(s)
Antimaláricos/farmacología , Nanopartículas del Metal/química , Fosfotransferasas (Aceptor de Grupo Alcohol)/química , Plasmodium falciparum/enzimología , Subunidades de Proteína/química , Proteínas Protozoarias/química , Plata/farmacología , Secuencia de Aminoácidos , Antimaláricos/química , Sitios de Unión , Cromatografía en Gel , Clonación Molecular , Pruebas de Enzimas , Escherichia coli/genética , Escherichia coli/metabolismo , Expresión Génica , Humanos , Cinética , Modelos Moleculares , Datos de Secuencia Molecular , Peso Molecular , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Subunidades de Proteína/antagonistas & inhibidores , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Proteínas Protozoarias/antagonistas & inhibidores , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Alineación de Secuencia , Plata/química , Especificidad de la Especie , Tiamina/antagonistas & inhibidores , Tiamina/biosíntesis
9.
Eplasty ; 15: e5, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25848442

RESUMEN

OBJECTIVE: We report a case in which an avulsion-amputation of the thumb proximal to the lunula was repaired by reattaching the amputated segment as a composite graft. The graft demonstrated complete survival with only a minimal sacrifice in length. METHODS: A 23-year-old man presented 4 hours after an avulsion injury of the thumb with associated distal and proximal phalanx fractures. The amputated segment included the sterile and germinal matrix. He underwent defatting and composite grafting of the amputated segment followed by K-wire fixation of his proximal phalanx fracture. RESULTS: In his 1-week follow-up, the patient's composite graft-including his nail bed-demonstrated complete survival. At one month, the composite graft maintained stable soft tissue coverage and showed signs of nail plate regrowth. Four months after repair, he was able to return to light duty and was advanced to full duty within 5 months. He continued to report gradually improving hypersensitivity at the margins of the graft and stiffness of the interphalangeal joint. At five months he regained full mobility of his carpometacarpal joint. The range of motion of his interphalangeal and metacarpophalangeal joint were 0 to 10 degrees and 0 to 25 degrees, respectively. He was able to oppose his thumb to all 4 digits. Six months after repair, he demonstrated protective sensation of the tip of the thumb. CONCLUSION: Composite grafting of the thumb, even in less than ideal cases, can still provide useful length for function as a opposable post and can be considered in reconstruction of thumb amputations at or proximal to the lunula.

10.
J Ind Microbiol Biotechnol ; 41(6): 893-906, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24793124

RESUMEN

The industrial production of short-chain fructooligosaccharides (FOS) and inulooligosaccharides is expanding rapidly due to the pharmaceutical importance of these compounds. These compounds, concisely termed prebiotics, have biofunctional properties and hence health benefits if consumed in recommended dosages. Prebiotics can be produced enzymatically from sucrose elongation or via enzymatic hydrolysis of inulin by exoinulinases and endoinulinases acting alone or synergistically. Exoinulinases cleave the non-reducing ß-(2, 1) end of inulin-releasing fructose while endoinulinases act on the internal linkages randomly to release inulotrioses (F3), inulotetraoses (F4) and inulopentaoses (F5) as major products. Fructosyltransferases act by cleaving a sucrose molecule and then transferring the liberated fructose molecule to an acceptor molecule such as sucrose or another oligosaccharide to elongate the short-chain fructooligosaccharide. The FOS produced by the action of fructosyltransferases are 1-kestose (GF2), nystose (GF3) and fructofuranosyl nystose (GF4). The production of high yields of oligosaccharides of specific chain length from simple raw materials such as inulin and sucrose is a technical challenge. This paper critically explores recent research trends in the production and application of short-chain oligosaccharides. Inulin and enzyme sources for the production of prebiotics are discussed. The mechanism of FOS chain elongation and also the health benefits associated with prebiotics consumption are discussed in detail.


Asunto(s)
Inulina/metabolismo , Oligosacáridos/biosíntesis , Prebióticos , Bacterias/enzimología , Fructanos/química , Fructanos/clasificación , Fructanos/metabolismo , Fructosa/química , Fructosa/metabolismo , Hongos/enzimología , Glicósido Hidrolasas/metabolismo , Hexosiltransferasas/metabolismo , Inulina/química , Oligosacáridos/metabolismo , Sacarosa/metabolismo , Trisacáridos/metabolismo
11.
Water Sci Technol ; 63(1): 149-55, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21245567

RESUMEN

The process of platinum group metal (PGM) refining can be up to 99.99% efficient at best, and although it may seem small, the amount of valuable metal lost to waste streams is appreciable enough to warrant recovery. The method currently used to remove entrained metal ions from refinery wastewaters, chemical precipitation, is not effective for selective recovery of PGMs. The yeast Saccharomyces cerevisiae has been found capable of sorbing numerous precious and base metals, and is a cheap and abundant source of biomass. In this investigation, S. cerevisiae was immobilised using polyethyleneimine and glutaraldehyde to produce a suitable sorbent, capable of high platinum uptake (150-170 mg/g) at low pH (<2). The sorption mechanism was found to be a chemical reaction, which made effective desorption impossible. When applied to PGM refinery wastewater, two key wastewater characteristics limited the success of the sorption process; high inorganic ion content and complex speciation of the platinum ions. The results proved the concept principle of platinum recovery by immobilised yeast biosorption and indicated that a more detailed understanding of the platinum speciation within the wastewater is required before biosorption can be applied. Overall, the sorption of platinum by the S. cerevisiae sorbent was demonstrated to be highly effective in principle, but the complexity of the wastewater requires that pretreatment steps be taken before the successful application of this process to industrial wastewater.


Asunto(s)
Platino (Metal)/metabolismo , Saccharomyces cerevisiae/metabolismo , Contaminantes Químicos del Agua/metabolismo
12.
Appl Biochem Biotechnol ; 159(1): 65-77, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19127444

RESUMEN

An exoinulinase has been isolated, purified and characterised from a commercially available broth of Aspergillus ficuum. The enzyme was purified 4.2-fold in a 21% yield with a specific activity of 12,300 U mg(-1)(protein) after dialysis, ammonium sulphate fractionation and Sephacryl S-200 size exclusion and ion exchange chromatography. The molecular weight of this enzyme was estimated to be 63 kDa by SDS-PAGE. It exhibited a pH and temperature optima of 5.4 and 50 degrees C respectively and under such conditions the enzyme remained stable with 96% and 63.8% residual activity after incubation for 12 h and 72 h respectively. The respective K (m) and V (max) values were 4.75 mM and 833.3 micromol min(-1) ml(-1), respectively. Response surface methodological statistical analysis was evaluated for the maximal production of fructose from the hydrolysis of pure commercial chicory inulin. Incubation of the dialyzed crude exoinulinase (100 U/ml, 48 h, 50 degrees C, 150% inulin, pH 5.0) produced the highest amount of fructose (106.4 mg/ml) under static batch conditions. The purified exoinulinase was evaluated for fructose production and the highest amount (98 mg/ml) was produced after 12 h incubation at 50 degrees C, 150% inulin pH 5.0. The use of a crude exoinulinase preparation is economically desirable and the industrial production of fructose from inulin hydrolysis is biotechnologically feasible.


Asunto(s)
Aspergillus/enzimología , Fructosa/síntesis química , Glicósido Hidrolasas/química , Inulina/química , Modelos Químicos , Simulación por Computador , Activación Enzimática , Estabilidad de Enzimas
13.
Bioresour Technol ; 100(6): 2040-5, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19028090

RESUMEN

A transferase was isolated, purified and characterised from Aspergillus aculeatus. The enzyme exhibited a pH and temperature optima of 6.0 and 60 degrees C, respectively and under such conditions remained stable with no decrease in activity after 5h. The enzyme was purified 7.1 fold with a yield of 22.3% and specific activity of 486.1Umg(-1) after dialysis, concentration with polyethyleneglycol (30%) and DEAE-Sephacel chromatography. It was monomeric with a molecular mass of 85kDa and K(m) and V(max) values of 272.3mM and 166.7micromolmin(-1)ml(-1). The influence of pH, temperature, reaction time, and enzyme and sucrose concentration on the formation of short-chain fructooligosaccharides (FOS) was examined by statistical response surface methodology (RSM). The enzyme showed both transfructosylation and hydrolytic activity with the transfructosylation ratio increasing to 88% at a sucrose concentration of 600mgml(-1). Sucrose concentration (400mgml(-1)) temperature (60 degrees C), and pH (5.6) favoured the synthesis of high levels of GF(3) and GF(4). Incubation time had a critical effect on the yield of FOS as the major products were GF(2) after 4h and GF(4) after 8h. A prolonged incubation of 16h resulted in the conversion of GF(4) into GF(2) as a result of self hydrolase activity.


Asunto(s)
Aspergillus/enzimología , Hexosiltransferasas/metabolismo , Oligosacáridos/biosíntesis , Estabilidad de Enzimas , Hexosiltransferasas/aislamiento & purificación , Concentración de Iones de Hidrógeno , Cinética , Peso Molecular , Temperatura
14.
Biotechnol Adv ; 25(3): 264-71, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17293076

RESUMEN

Biosorption has emerged as a low-cost and often low-tech option for removal or recovery of base metals from aqueous wastes. The conditions under which precious metals such as gold, platinum and palladium are sorbed by biomass are often very different to those under which base metals are sorbed. This, coupled with the increasingly high demand for precious metals, drives the increase in research into efficient recovery of precious metal ions from all waste material, especially refining wastewaters. Common biosorbents for precious metal ions include various derivatives of chitosan, as well as other compounds with relatively high surface amine functional group content. This is generally due to the ability of the positively charged amine groups to attract anionic precious metal ions at low pH. Recent research regarding the biosorption of some precious metals is reviewed here, with emphasis on the effects of the biosorption environment and the biosorption mechanisms identified.


Asunto(s)
Biomasa , Metales/química , Metales/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Adsorción , Ambiente , Aguas del Alcantarillado/química
15.
Postgrad Med J ; 78(926): 746-7, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12509693

RESUMEN

INTRODUCTION: The unreliability of the pulse examination of the foot has primarily been due to variability of technique between examiners. Whereas the groove between the medial malleolus and the Achilles tendon more readily defines the location of the posterior tibial pulse, the location of the dorsalis pedis pulse remains vague. In this paper a novel method of locating the dorsalis pedis pulse by physical examination is described. METHODS: Forty one consecutive patients admitted to a general surgery service of a tertiary medical centre within a two month period were examined. Using the dorsal most prominence of the navicular bone as a landmark, the distance to the dorsalis pedis pulse in bilateral lower extremities was measured by palpation and compared to Doppler ultrasound. Measurements were confirmed by two separate examiners blinded to each others' results. RESULTS: The dorsalis pedis artery was palpable in 78% of extremities and present by Doppler ultrasound in 95%. The location of the left dorsalis pedis artery was a mean (SD) 9.8 (1.4) mm by palpation and 11.1 (2.1) mm by Doppler ultrasound from the dorsal most prominence of the navicular bone. The right dorsalis pedis artery was 10.4 (3.4) mm by palpation and 11.5 (0.7) mm from the dorsal most prominence of the navicular bone. No significant differences in location of the dorsalis pedis artery were observed bilaterally between Doppler ultrasound and palpation; No significant differences were observed comparing contralateral dorsalis pedis arteries nor any differences between the examiners' results. CONCLUSION: The dorsal most prominence of the navicular bone provides a bony landmark to readily locate the dorsalis pedis artery. Reliability of the examination may be increased as to the patency of the dorsalis pedis artery by using this dependable anatomic landmark.


Asunto(s)
Pie/irrigación sanguínea , Palpación/métodos , Pulso Arterial/métodos , Adulto , Anciano , Anciano de 80 o más Años , Arterias/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ultrasonografía Doppler
16.
Plast Reconstr Surg ; 108(7): 2137-40; discussion 2141-2, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11743419

RESUMEN

The trochlea and superior oblique muscle tendon separate the medial and central fat compartments in the upper lid. The purpose of this study was to determine anatomical landmarks to predict the location of and avoid injuring the trochlea and superior oblique muscle tendon with orbital fat resection during upper blepharoplasty. The trochlea and superior oblique muscle tendon were identified in 14 cadaver heads. Bony anatomical landmarks were identified to predict the oblique vector along which the trochlea and superior oblique tendon lie. The trochlea was measured in millimeters from the palpable superior orbital foramen. The oblique course of the superior oblique muscle tendon was measured from its medial location in the lateral direction in millimeters from the frontozygomatic suture. These measurements were obtained with 4.0-power loupe magnification. The trochlea was identified 10.0 +/- 0.9 mm inferior to the palpable superior orbital foramen. The superior oblique muscle tendon coursed laterally along an oblique vector to within 1 mm of the frontozygomatic suture for all 14 dissections. The vertical vector of the superior orbital foramen was measured 15.9 +/- 1.1 mm lateral to the medial canthus. The width of the bony orbit measured 42.2 +/- 1.6 mm. In two dissections, the superior orbital foramen could not be palpated, and the latter measurements were used to predict the superior orbital foramen. This anatomical study showed that when performing orbital fat resection with upper blepharoplasty, the trochlea and superior oblique muscle tendon can be identified and avoided with the above-described bony landmarks.


Asunto(s)
Blefaroplastia/métodos , Órbita/anatomía & histología , Tejido Adiposo/cirugía , Párpados/anatomía & histología , Párpados/cirugía , Humanos , Músculos Oculomotores/anatomía & histología , Tendones/anatomía & histología , Tendones/cirugía
17.
Plast Reconstr Surg ; 108(4): 908-15, 2001 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11547146

RESUMEN

The purpose of this study was to identify surface landmark ratios to locate the A1 pulley and clarify the controversy of differing anatomic descriptions of the A1, C0, and A2 pulleys. Minimally invasive and percutaneous approaches to A1 pulley release may be facilitated with surface landmark ratios, which identify and predict the proximal and distal margins of the A1 pulley. Two-hundred fifty-sixty fingers were dissected in 64 preserved cadaver hands. Measurements of A1 pulley lengths and pulley margins in relation to surface landmarks were obtained. We found that the distance from the palmar digital crease to the proximal interphalangeal crease (mean, 2.42 +/- 0.03 cm) corresponds to the distance of the proximal edge of the A1 pulley from the palmar digital crease (mean, 2.45 +/- 0.03 cm). The mean absolute difference between these two measured distances in each finger was 0.13 cm, with a 95 percent confidence interval of 0.11 to 0.14 cm. Thus, the distance between the palmar digital crease and the proximal interphalangeal crease can be used to predict the distance between the palmar digital crease and the A1 pulley proximal edge with reasonable accuracy. A1 pulley length averaged 0.98 +/- 0.02 cm for the small finger and 1.17 +/- 0.02 cm for the index, middle, and ring fingers. The length of the A1 pulley was significantly shorter (p < 0.001) for the small finger than for the index, middle, and ring fingers. Additionally, a cruciate (C0) pulley was consistently located between the A1 and A2 pulleys, an average of 0.46 cm proximal to the palmar digital crease, which can serve as guide for concluding the release of the A1 pulley. Clinically, hand surface landmark ratios were used to release 32 trigger fingers with a minimally invasive technique, without a complication during 4- to 30-week follow-up. We conclude that hand surface landmark ratios can serve to locate the proximal A1 pulley edge, thus facilitating complete trigger finger release by either open or minimally invasive techniques. Additionally, our study clarifies the discrepancy of prior smaller reports of the pulley system anatomy regarding the existence of the C0 pulley between the A1 and A2 pulleys. The cruciate fibers of this C0 pulley can serve as the distal boundary for release of trigger finger.


Asunto(s)
Mano/anatomía & histología , Fenómenos Biofísicos , Biofisica , Cadáver , Mano/fisiología , Humanos
18.
Ann Plast Surg ; 46(6): 647-50, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11405368

RESUMEN

The authors present the 16th case of a pseudoaneurysm forming at the site of an infected radial artery catheter and only the third case that presented with rupture and hemorrhage requiring emergent operative repair. Radial artery catheters are quite safe, and most infections can be treated effectively with line removal and intravenous antibiotics. However, two factors correlate strongly with the subsequent development of pseudoaneurysms. Infection with Staphylococcus aureus was seen in 15 of 16 cases, and persistent signs of infection lasting more than 48 hours after the institution of antibiotic therapy and line removal were seen in 16 of 16 cases. Therefore, patients with S. aureus radial artery line infections with persistence of infection more than 48 hours after the induction of treatment are at high risk and should be observed closely for signs of pseudoaneurysm formation. Once a pseudoaneurysm has formed, surgical repair is required. Most recommend ligating the artery if there is pulsatile backbleeding from the distal stump and Allen's test shows good perfusion of the hand by the ulnar artery.


Asunto(s)
Aneurisma Falso/etiología , Aneurisma Roto/etiología , Catéteres de Permanencia/efectos adversos , Arteria Radial , Infecciones Estafilocócicas/etiología , Anciano , Anciano de 80 o más Años , Aneurisma Falso/cirugía , Aneurisma Roto/cirugía , Humanos , Masculino , Arteria Radial/cirugía
19.
Plast Reconstr Surg ; 107(2): 315-8, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11214043

RESUMEN

The purpose of this study was to examine the palatal fistula rate after repair with the two-flap palatoplasty technique. This is a retrospective review of 119 consecutive cleft-palate repairs performed over a 5-year interval by a single surgeon. The two-flap palatoplasty technique was used to provide tension-free, multilayer repairs. The age of these children at the time of repair ranged from 7 to 84 months (mode, 9 months). The initial follow-up visit occurred 2 to 12 weeks after the repair operation (mean, 4 weeks). The postoperative follow-up duration ranged from 7 to 48 months. This review of 119 cleft-palate repairs revealed a fistula rate of 3.4 percent (four fistulas in 119 repairs). This experience demonstrates the lowest reported palatal fistula complication rate with use of the two-flap palatoplasty technique.


Asunto(s)
Fisura del Paladar/cirugía , Fístula Oral/cirugía , Complicaciones Posoperatorias/cirugía , Colgajos Quirúrgicos , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Hueso Paladar/cirugía , Reoperación , Técnicas de Sutura
20.
Plast Reconstr Surg ; 107(2): 393-7, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11214054

RESUMEN

The purpose of this study was to examine the role for epinephrine augmentation of digital block anesthesia by safely prolonging its duration of action and providing a temporary hemostatic effect. After obtaining approval from the review board of the authors' institution, 60 digital block procedures were performed in a prospective randomized double-blinded study. The digital blocks were performed using the dorsal approach. All anesthetics were delivered to treat either posttraumatic injuries or elective conditions. Of the 60 digital block procedures, 31 were randomized to lidocaine with epinephrine and 29 to plain lidocaine. Of the procedures performed using lidocaine with epinephrine, one patient required an additional injection versus five of the patients who were given plain lidocaine (p = 0.098). The need for control of bleeding required digital tourniquet use in 20 of 29 block procedures with plain lidocaine and in 9 of 31 procedures using lidocaine with epinephrine (p < 0.002). Two patients experienced complications after plain lidocaine blocks, while no complications occurred after lidocaine with epinephrine blocks (p = 0.23). By prolonging lidocaine's duration of action, epinephrine may prevent the need for an additional injection and prolong post-procedure pain relief. This study demonstrated that the temporary hemostatic effect of epinephrine decreased the need for, and thus the potential risk of, using a digital tourniquet (p < 0.002). As the temporary vasoconstrictor effect is reversible, the threat of complication from vasoconstrictor-induced ischemia is theoretical.


Asunto(s)
Epinefrina , Traumatismos de los Dedos/cirugía , Hemostasis Quirúrgica , Lidocaína , Bloqueo Nervioso , Contraindicaciones , Método Doble Ciego , Epinefrina/administración & dosificación , Epinefrina/efectos adversos , Humanos , Estudios Prospectivos , Reoperación , Colgajos Quirúrgicos , Torniquetes
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