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2.
Br J Surg ; 107(6): 687-694, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32026467

RESUMEN

BACKGROUND: This study evaluated the incidence, patterns and risk factors for recurrence after hemithyroidectomy in patients with low- and intermediate-risk papillary thyroid carcinoma (PTC), and verified the predictive role of the risk staging systems in current use. METHODS: The clinicopathological characteristics and risk categories were analysed according to recurrence in patients who underwent hemithyroidectomy for low- and intermediate-risk conventional PTC, and were followed up for at least 24 months. Five risk staging systems were used to stratify risk: the 2015 American Thyroid Association (ATA) system; Age, Metastases, Extent and Size (AMES) system; Metastases, Age, Complete resection, Invasion and Size (MACIS) system; Grade, Age, Metastases, Extent and Size (GAMES) system; and the eighth AJCC system. RESULTS: The study included 561 patients; 93·9 per cent of the study population (527 of 561) had a papillary thyroid microcarcinoma 1 cm or smaller in size. At a mean follow-up of 83 months, 25 patients (4·5 per cent) had recurrence; among these patients, 23 (92%) presented with a remaining thyroid lobe. Multifocality was significantly associated with recurrence in univariable and multivariable analyses (adjusted hazard ratio 3·16, 95 per cent c.i. 1·25 to 7·98; P = 0·015). Disease-free survival (DFS) varied according to multifocality (P = 0·010). The five risk staging systems were not associated with recurrence, and their Harrell's C-index ranged from 0·500 to 0·531. DFS rates did not differ between the risk categories in each system. CONCLUSION: Although the recurrence rate after hemithyroidectomy in patients with low- and intermediate-risk PTC was low, meticulous follow-up focusing on the remaining thyroid lobe is needed for early detection and timely management of recurrence. The risk scoring systems in current use have no predictive role in these patients.


ANTECEDENTES: Este estudio evaluó la incidencia, patrones y factores de riesgo de recidiva tras hemitiroidectomía en pacientes con carcinoma papilar de tiroides (papillary thyroid carcinoma, PTC) de riesgo bajo e intermedio y verificó el papel predictivo de los sistemas de estadificación del riesgo utilizados en la actualidad (risk staging systems, RSSs). MÉTODOS: Se analizaron las características clinicopatológicas y las categorías de riesgo en base a la recidiva en 561 pacientes que fueron sometidos a hemitiroidectomía por PTC convencional de riesgo bajo e intermedio y seguidos durante ≥ 24 meses. Para estratificar el riesgo se utilizaron cinco RSSs, incluyendo el sistema de la American Thyroid Association (ATA) de 2015; la edad, las metástasis, la extensión y el tamaño del sistema AMES; las metástasis, la edad, la resección completa, la invasión y el tamaño del sistema GAMES; y la octava edición de la American Joint Committee on Cancer system (AJCC). RESULTADOS: La proporción de la población de estudio con microcarcinoma papilar de tiroides de tamaño ≤ 1 cm fue 93,9% (527/561). A los 83 meses de seguimiento, 25 pacientes (4,5%) presentaron recidiva y entre estos pacientes, 23 (92%) no habían sido sometidos a tiroidectomía total. La multifocalidad se asoció significativamente con la recidiva en los análisis univariado y multivariable con un cociente de riesgos instantáneos (hazard ratio, HR) ajustado de 3,163; i.c. del 95% 1,253-7,983; P = 0,015. La supervivencia libre de enfermedad (disease-free survival, DFS) varió según la multifocalidad (P = 0,010). Los cinco RSSs no se asociaron con la recidiva, y su índice C de Harrell fue 0,500-0,531. Las DFSs no fueron diferentes entre las categorías de riesgo de cada RSS. CONCLUSIÓN: La tasa de recidiva tras hemitiroidectomía en pacientes con PTC de riesgo bajo e intermedio fue baja. Sin embargo, es necesario efectuar un seguimiento meticuloso, centrándose en el lóbulo tiroideo restante, para la detección precoz y el tratamiento oportuno de la recidiva. Los RSSs que se utilizan en la actualidad no tienen valor predictivo en estos pacientes.


Asunto(s)
Recurrencia Local de Neoplasia , Cáncer Papilar Tiroideo/cirugía , Neoplasias de la Tiroides/cirugía , Tiroidectomía , Adolescente , Adulto , Anciano , Reglas de Decisión Clínica , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/epidemiología , Recurrencia Local de Neoplasia/etiología , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Análisis de Supervivencia , Cáncer Papilar Tiroideo/mortalidad , Cáncer Papilar Tiroideo/patología , Neoplasias de la Tiroides/mortalidad , Neoplasias de la Tiroides/patología , Tiroidectomía/métodos , Resultado del Tratamiento , Adulto Joven
3.
Br J Oral Maxillofac Surg ; 56(5): 406-410, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29678374

RESUMEN

We report the design of a new V-shaped incision for parotidectomy that involves only preauricular and postauricular incisions and no hairline or upper cervical incision. It can be used to approach almost all the superficial parotid region, including the superior and anterior divisions, with minimal scarring. To evaluate its technical feasibility, safety, and cosmetic results, we prospectively enrolled 15 patients (between September 2015 and September 2016) who had partial parotidectomy as the primary treatment for benign parotid tumours. Operations were successfully completed through this approach alone in 14 (mean (range) operating time: 120 (105-142) minutes; drainage volume: 51 (23-70) ml; and duration of drainage: 2.6 (2-4) days). There were no serious complications such as paralysis of the facial nerve or necrosis of the wound. The mean (range) visual analogue scale (VAS) and Vancouver Scar Scale scores for the scars were 9 (8-10) and 0.9 (0-3), respectively. A V-shaped incision for partial parotidectomy is technically feasible and safe, and can produce good cosmetic results in selected patients with benign parotid tumours. Our results need to be confirmed in larger studies and case-control trials.


Asunto(s)
Disección/métodos , Glándula Parótida/cirugía , Neoplasias de la Parótida/cirugía , Adulto , Anciano , Cicatriz/prevención & control , Drenaje , Estética , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tempo Operativo , Satisfacción del Paciente , Complicaciones Posoperatorias/prevención & control , Estudios Prospectivos , Factores de Tiempo , Escala Visual Analógica
5.
Eur J Trauma Emerg Surg ; 41(1): 69-74, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26038168

RESUMEN

PURPOSE: There are several diagnostic tools to support the decision for abdominal stab wounds. The aim of this study is to evaluate the ability of computed tomography (CT) to facilitate decisions on the initial management in patients with anterior abdominal stab wounds. METHODS: The medical records of all 118 patients who sustained abdominal stab wounds from March 2004 to January 2012 were reviewed retrospectively. RESULTS: The average age of patients was 41 years, and 84 (71%) patients were male. Ten patients underwent an immediate laparotomy due to hemodynamic instability, peritonitis, or definite evisceration. The other 108 patients underwent CT scans, and 91 patients had positive CT findings, leading to performance of laparotomy in 82 patients. One patient underwent a non-therapeutic laparotomy. Seventeen patients had negative CT results; however, seven patients underwent early laparotomy according to the attending surgeon's decision using serial physical examination or other diagnostic tools. The sensitivity of the CT scan was 94.2%, and the positive-predictive value was 98.8%. CONCLUSIONS: CT can be used efficiently along with physical examination as an initial diagnostic tool in patients with abdominal stab wounds. However, there can be missed injuries, then surgeon should consider other diagnostic methods.


Asunto(s)
Traumatismos Abdominales/diagnóstico por imagen , Laparotomía , Examen Físico/métodos , Tomografía Computarizada por Rayos X , Heridas Punzantes/diagnóstico por imagen , Traumatismos Abdominales/cirugía , Adulto , Algoritmos , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Laparotomía/métodos , Masculino , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodos , Heridas Punzantes/cirugía
6.
Insect Mol Biol ; 24(3): 311-8, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25492518

RESUMEN

Metabolic organs such as the liver and adipose tissue produce several peptide hormones that influence metabolic homeostasis. Fat bodies, the Drosophila counterpart of liver and adipose tissues, have been thought to analogously secrete several hormones that affect organismal physiology, but their identity and regulation remain poorly understood. Previous studies have indicated that microRNA miR-8, functions in the fat body to non-autonomously regulate organismal growth, suggesting that fat body-derived humoral factors are regulated by miR-8. Here, we found that several putative peptide hormones known to have mitogenic effects are regulated by miR-8 in the fat body. Most members of the imaginal disc growth factors and two members of the adenosine deaminase-related growth factors are up-regulated in the absence of miR-8. Drosophila insulin-like peptide 6 (Dilp6) and imaginal morphogenesis protein-late 2 (Imp-L2), a binding partner of Dilp, are also up-regulated in the fat body of miR-8 null mutant larvae. The fat body-specific reintroduction of miR-8 into the miR-8 null mutants revealed six peptides that showed fat-body organ-autonomous regulation by miR-8. Amongst them, only Imp-L2 was found to be regulated by U-shaped, the miR-8 target for body growth. However, a rescue experiment by knockdown of Imp-L2 indicated that Imp-L2 alone does not account for miR-8's control over the insect's growth. Our findings suggest that multiple peptide hormones regulated by miR-8 in the fat body may collectively contribute to Drosophila growth.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Cuerpo Adiposo/metabolismo , MicroARNs/genética , Hormonas Peptídicas/metabolismo , Animales , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Glicoproteínas/genética , Glicoproteínas/metabolismo , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteínas de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Péptidos y Proteínas de Señalización Intercelular , Larva/genética , Larva/metabolismo , MicroARNs/metabolismo , Mutación , Hormonas Peptídicas/genética , Unión Proteica
7.
J Hand Surg Eur Vol ; 40(3): 281-6, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25005564

RESUMEN

Spontaneous flexor tendon rupture is a rare condition and the aetiology is not clear. We report 12 elderly Korean farmers with spontaneous flexor tendon ruptures. We found the rupture in the dominant hand in ten patients. A rupture in the little finger was found in all 12 patients (seven with both flexor tendons ruptured and five with only the profundus ruptured), in the ring finger in four patients (the profundus ruptured in all and both flexor tendons in two patients), and in the middle finger a partial rupture of the profundus in one patient. The tendons were ruptured close to the hook of the hamate. Repetitive friction between the flexor tendons and the hamate hook may cause the ruptures. The hamate hook was excised and the ruptured profundus tendons were reconstructed with tendon transfers with quite favourable functional recovery at follow-up of 1 to 2 years. The ruptured superficialis tendons were not reconstructed. Level of Evidence IV.


Asunto(s)
Traumatismos de la Mano/cirugía , Procedimientos Ortopédicos/métodos , Procedimientos de Cirugía Plástica/métodos , Traumatismos de los Tendones/cirugía , Adolescente , Adulto , Humanos , Articulación Metacarpofalángica/fisiopatología , Rango del Movimiento Articular , Recuperación de la Función , República de Corea , Estudios Retrospectivos , Rotura , Adulto Joven
8.
Artículo en Inglés | MEDLINE | ID: mdl-24110549

RESUMEN

This study quantitatively investigated the postoperative effects of radiofrequency (RF) application on the normal dermal extracellular matrix (ECM) of in vivo rabbits. Postoperative effects were evaluated by histology and atomic force microscopy analysis of dermal tissues treated using three RF energy levels (10 ~ 30 W) and either a single- or multiple-pass procedure. Progressive changes in the morphology of rabbit dermal ECMs were investigated over a 30-day postoperartive period. All RF-treated groups, except for the low energy group (10 W), displayed more prominent inflammatory responses compared to the control. This inflammatory reaction was more prominent a day after application. Dermal tissues 30 days after RF application exhibited prominent myofibroblast activity associated with ECM contractile activity during wound healing in addition to chronic inflammation. A decrease in the morphology of dermal ECMs after RF application continued until seven days postoperatively. The ECM diameter increased to near baseline at 30 days postoperatively. Low energy and multi-pass applications resulted in greater collagen fibril contraction and recovery at the ultra-structural level at 30 days postoperatively than did a single high energy application.


Asunto(s)
Dermis/efectos de la radiación , Matriz Extracelular/efectos de la radiación , Animales , Técnicas Cosméticas , Procedimientos Quirúrgicos Dermatologicos , Dermis/citología , Dermis/metabolismo , Colágenos Fibrilares/metabolismo , Humanos , Masculino , Miofibroblastos/metabolismo , Conejos , Ondas de Radio
9.
J Plast Reconstr Aesthet Surg ; 59(9): 928-34, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16920584

RESUMEN

This retrospective study was designed to evaluate a salvage technique for free flaps suffering venous congestion by using a cross-leg vein repair in patients with venous-impaired lower extremities. Four free flap reconstructions were performed using the latissimus dorsi muscle to reconstruct soft tissue defects in the lower extremity. The recipient artery was confined to the ipsilateral leg and the venous anastomosis was performed with a long saphenous vein from the contralateral side. The legs were immobilised together by means of an external fixator. All patients were males with a mean age of 31 years. The mean time of pedicle division was 8.8 days (7-10). The mean size of the free flap was 186.5 cm(2). All flaps survived after pedicle division without venous congestion. There were no complications such as joint stiffness or donor site morbidity except for a linear scar. The cross-leg venous repair is a refinement of a salvage procedure for compromised free flaps used in the reconstruction of severe soft tissue defects in vascularly compromised lower extremities.


Asunto(s)
Recuperación del Miembro/métodos , Extremidad Inferior/cirugía , Traumatismos de los Tejidos Blandos/cirugía , Colgajos Quirúrgicos/irrigación sanguínea , Accidentes de Tránsito , Adulto , Preescolar , Humanos , Extremidad Inferior/lesiones , Masculino , Microcirugia/métodos , Procedimientos de Cirugía Plástica/métodos , Flujo Sanguíneo Regional , Reoperación/métodos
10.
J Biomed Mater Res A ; 74(3): 366-73, 2005 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-15983984

RESUMEN

Osteoblast response to Ti implants depends not only on the chemistry of the implant but also on the physical properties of the implant surface, such as microtopography and roughness. This study was undertaken to examine early changes in cell morphology and gene expression during the early phase of osteoblast interaction with titanium alloy (Ti-6Al-4V) surfaces of two different roughnesses. MG63 osteoblast-like cells were cultured for 2, 6, 24, and 72 h on smooth (Ra=0.18+/-0.03 microm) and rough (Ra=2.95+/-0.23 microm) Ti-6Al-4V surfaces. Changes in cell proliferation were assessed by measuring cell number after 72 h in culture. Morphological characteristics were observed by scanning electron microscopy after 2, 6, and 24 h of culture. Changes in gene expression for extracellular signal-regulated kinase 2 (Erk2), type I collagen (alpha2[I] collagen), phospholipase C-gamma2 (Plc-gamma2), and beta-actin were measured by RT-PCR after 6 and 24 h in culture. Cell number was significantly higher on the smooth surface. In scanning electron micrographs, cells on smooth Ti-6Al-4V were spherical and raised up from the surface after 2 h in culture. In contrast, cells on the rough surface adopted an irregular, elongated shape that spanned across pits in the surface. At 24 h, cells on the smooth surface had flattened, become elongate, and covered the surface. In contrast, cells on the rough surface appeared more differentiated in shape and the margins of the cells were irregular, with many processes extending out, following the contour of the surface. Of the genes examined, only Erk2 and beta-actin showed a change in expression with surface roughness. Both genes were upregulated (p<0.05) on the rough surface at 6 h. These results indicate that Ti-6Al-4V surface roughness affects osteoblast proliferation, morphology, and gene expression, and that these effects can be measured after periods as short as 2-6 h.


Asunto(s)
Materiales Biocompatibles , Osteoblastos/fisiología , Titanio , Aleaciones , Línea Celular Tumoral , Proliferación Celular , Perfilación de la Expresión Génica , Humanos , Microscopía Electrónica de Rastreo , Osteoblastos/citología , Osteoblastos/ultraestructura , Propiedades de Superficie
11.
Acta Neurochir (Wien) ; 143(11): 1177-81, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11731871

RESUMEN

In cerebral arteriovenous malformations (AVMs), a pseudo-aneurysm represents rupture site, and its presence is known as a factor for rebleeding. We report a case of cerebral AVM presenting with intracerebral haemorrhage in which cerebral angiography showed a lesion mimicking pseudo-aneurysm. Although the patient needed urgent surgical decompression, it was delayed because early haematoma evacuation would induce rebleeding from the rupture site. The authors attempted to occlude the pseudoaneurysm interventionally before surgery. After surgical excision, the lesion that was believed to be a pseudo-aneurysm was revealed as a partially thrombosed venous sac having a thick fibrous wall. In this report, the authors discuss the pitfalls in the interpretation of pseudo-aneurysms in angiographic AVM architecture.


Asunto(s)
Fístula Arteriovenosa/congénito , Angiografía Cerebral , Malformaciones Arteriovenosas Intracraneales/complicaciones , Trombosis Intracraneal/diagnóstico , Adolescente , Aneurisma Falso/diagnóstico , Fístula Arteriovenosa/diagnóstico por imagen , Descompresión Quirúrgica , Diagnóstico Diferencial , Humanos , Aneurisma Intracraneal/diagnóstico , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Malformaciones Arteriovenosas Intracraneales/etiología , Trombosis Intracraneal/diagnóstico por imagen , Trombosis Intracraneal/etiología , Masculino , Resultado del Tratamiento
12.
Mol Cells ; 12(2): 250-6, 2001 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-11710530

RESUMEN

A cDNA library was constructed with mRNA extracted from TMV resistant hot pepper plants 24 and 48 h after inoculation by TMV. The library was screened differentially with radio-labeled cDNA synthesized with mRNA from the leaves of either TMV-inoculated or mock-inoculated hot pepper plants. CaSAR8.2 clone was one of the clones isolated by this differential screening. The predicted amino acid sequence of CaSAR8.2 has a homology of 52% similarity to that of tobacco SAR8.2 genes. Southern blot analysis showed that a multigene family of CaSAR8.2 was present in the hot pepper genome. Transcripts homologous to CaSAR8.2 accumulated abundantly in the leaves and the flowers, but little in other tissues. CaSAR8.2 gene expression was induced by avirulent pathotype TMV-P0 inoculation but not by virulent TMV-P1.2 inoculation. Effects of exogenously applied abiotic elicitors on CaSAR8.2 expression were also examined. Salicylic acid and ethephon treatments caused a rapid accumulation of CaSAR8.2 transcripts in pepper leaves and methyl jasmonate treatment slightly induced the expression of CaSAR8.2. A strain of Xanthomonas campestris pv. vesicatoria (Xcv) that contains an avirulence gene avrBs2, was infiltrated into the leaves of a pepper cultivar containing the Bs2 resistance gene. A marked induction of CaSAR8.2 gene expression was observed in Xcv-infiltrated leaves. These results suggest possible roles of CaSAR8.2 as pathogenesis-related protein against varieties of pathogens including virus and bacteria.


Asunto(s)
Capsicum/genética , Capsicum/virología , Proteínas de Plantas/genética , Virus del Mosaico del Tabaco/patogenicidad , Secuencia de Aminoácidos , Secuencia de Bases , Capsicum/microbiología , ADN Complementario/genética , ADN de Plantas/genética , Expresión Génica , Genes de Plantas , Datos de Secuencia Molecular , Familia de Multigenes , ARN Mensajero/genética , ARN de Planta/genética , Homología de Secuencia de Aminoácido , Distribución Tisular , Nicotiana/genética , Xanthomonas campestris/patogenicidad
14.
J Korean Med Sci ; 16(2): 241-4, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11306756

RESUMEN

Hemangioendothelioma is borderline or intermediate type of vascular neoplasm. Hemangioendothelioma is rare lesion that constitutes less than 0.5% of the malignant tumors of bone. We present a case of low-grade hemagioendothelioma of the skull in a 29-yr-old woman. She had pain, diplopia and exophthalmos of the left eye. Radiographic images showed a relatively well-demarcated, expansile osteolytic lesion with irregularly thickened trabeculae and calcifications in the left greater wing of sphenoid bone. Histologically, the tumor was an infiltrative vasoformative lesion. The vessels are generally well-formed with open or compressed lumina surrounded by endothelial cells showing mild atypia. It lacked frequent mitotic figures and severe atypia. Although excessive bleeding occurred during the operation, the mass was totally resected. Postoperative radiation was not necessary. She is free of disease and well 6 months postoperatively.


Asunto(s)
Neoplasias Óseas/patología , Hemangioendotelioma/patología , Hueso Esfenoides/patología , Adulto , Neoplasias Óseas/diagnóstico por imagen , Femenino , Hemangioendotelioma/diagnóstico por imagen , Humanos , Embarazo , Radiografía
15.
Mol Cells ; 11(1): 122-7, 2001 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-11266114

RESUMEN

Hot pepper (Capsicum annuum) plants exhibit a hypersensitive response (HR) against infection by many tobamoviruses. A clone (CaPR-4) encoding a putative pathogenesis-related protein 4 was isolated by differential screening of a cDNA library prepared from resistant pepper plant leaves inoculated with tobacco mosaic virus (TMV) pathotype P0. The predicted amino acid sequence of CaPR-4 is very similar to those of other plant PR-4s. Southern blot analysis showed that small gene families of PR-4-related sequences were present in the pepper genome. Hot pepper cultivar Bugang, resistant to TMV-P0 and susceptible to TMV-P1.2, induced CaPR-4 expression by pathotype P0 inoculation in inoculated and systemic leaves, but not by pathotype P1.2. Effects of exogenously applied abiotic elicitors upon the CaPR-4 expression were also examined. The expression of the CaPR-4 gene was stimulated by methyl jasmonate (MeJA), ethephon and wounding treatment. However, application of salicylic acid (SA) did not trigger the expression. Evidence is emerging that jasmonic acid and ethylene play key roles in the SA-independent pathways of plant-pathogen interaction. Taken together, these results suggest that the CaPR-4 gene is one of the defense-related genes conferring resistance on pepper plants by the SA-independent pathway and the cross-talk between signaling compounds, jasmonic acid and ethylene could have a great regulatory potential in a plant's defense against TMV.


Asunto(s)
Capsicum/virología , Proteínas de Plantas/genética , Plantas Medicinales , Virus del Mosaico del Tabaco , Acetatos/farmacología , Secuencia de Bases , Capsicum/genética , Clonación Molecular , Ciclopentanos/farmacología , ADN Complementario , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/fisiología , Inmunidad Innata , Datos de Secuencia Molecular , Compuestos Organofosforados/farmacología , Oxilipinas , Reguladores del Crecimiento de las Plantas/farmacología , ARN Mensajero , Homología de Secuencia de Aminoácido
17.
Chemosphere ; 41(1-2): 235-42, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10819206

RESUMEN

Two rural soils contaminated by cadmium (Cd) and lead (Pb) were used to evaluate the effect of different chemical treatments on changes in speciation and extractability of Cd and Pb, and in phytoavailability to wheat. Triplicates of seven chemical treatments were tested to compare and evaluate the remediation techniques for contaminated soils using pot experiments. Treatments applied were calcium carbonate, a high quantity of phosphate salt, hog composts, iron oxide, manganese oxide, zeolite, and unamended control. Wheat (Triticum aestivum) was planted in the different amended soils for a further one month to evaluate the effectiveness of treatments on uptake of Cd and Pb by the wheat shoots. Results indicated that addition of calcium carbonate, manganese oxide, or zeolite reduces the extractability of Cd or Pb in both soils, and significantly reduce the uptake of Cd and Pb by wheat shoots. Changes in the extractability and metal sequential fractionations indicate that the exchangeable (or available) form of Cd and Pb in two soils can be transformed into unavailable forms after these amendments.


Asunto(s)
Cadmio/química , Plomo/química , Contaminantes del Suelo/farmacocinética , Disponibilidad Biológica , Cadmio/farmacocinética , Carbonato de Calcio , Contaminación Ambiental/prevención & control , Compuestos Inorgánicos , Plomo/farmacocinética , Triticum/química
19.
Plant Physiol ; 114(4): 1477-85, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9276957

RESUMEN

Higher plants synthesize small heat-shock proteins (smHSPs) from five related gene families. The class I and II families encode cytosolic smHSPs. We characterized the class II smHSPs of pea (Pisum sativum) and compared them with class I smHSPs. Antibodies against recombinant HSP17.7, a class II smHSP, recognized four heat-inducible 17- to 18-kD polypeptides and did not cross-react with class I smHSPs. On sucrose gradients the class II smHSPs sedimented primarily at 8 Svedberg units, indicating that they are components of large complexes similar in size to class I smHSP complexes. However, the class I and II complexes were readily distinguishable by nondenaturing polyacrylamide gel electrophoresis and isoelectric focusing. Nondenaturing immune precipitations using anti-HSP17.7 or anti-HSP18.1 (a class I smHSP) antiserum provide further evidence that the class I and II smHSPs exist in different complexes, composed primarily of smHSPs. Recombinant HSP17.7 and HSP18.1 formed complexes of sizes similar to those formed in vivo. When these two smHSPs were mixed, denatured with urea, and then dialyzed, the distinct class I and II complexes again formed, each containing only HSP18.1 or HSP17.7. Thus, cytosolic smHSPs from two related gene families expressed simultaneously form distinct complexes in vivo, suggesting that they have subtly different functions.


Asunto(s)
Proteínas de Choque Térmico/genética , Pisum sativum/genética , Especificidad de Anticuerpos , Expresión Génica , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/inmunología , Calor , Sueros Inmunes , Conformación Proteica
20.
Biochemistry ; 31(8): 2304-8, 1992 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-1540586

RESUMEN

Site-directed mutagenesis was used to change Ser376 in the active site of ribulose-1,5-bisphosphate carboxylase/oxygenase from the cyanobacterium Anacystis nidulans to Cys, Thr, or Ala. When expressed in Escherichia coli and purified, the mutant enzymes exhibited carboxylase activities that were reduced by 99% or more with respect to the activity of the wild-type enzyme. The Km values for ribulose bisphosphate at pH 8.0, 30 degrees C, were elevated from 46 microM for wild-type enzyme to 287, 978, and 81 microM for mutants in which Cys, Thr, or Ala, respectively, replaced Ser376. The Cys and Thr variants were almost devoid of oxygenase activity whereas the Ala variant had 16% as much oxygenase as wild-type enzyme, suggesting that this mutation had greatly elevated the oxygenase:carboxylase ratio.


Asunto(s)
Cianobacterias/enzimología , Ribulosa-Bifosfato Carboxilasa/química , Serina/química , Alanina/química , Secuencia de Aminoácidos , Sitios de Unión , Cianobacterias/química , Cianobacterias/genética , Cisteína/química , Activación Enzimática , Cinética , Mutagénesis Sitio-Dirigida , Unión Proteica , Serina/genética , Especificidad por Sustrato , Treonina/química
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