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1.
Clin Chem Lab Med ; 2015 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-26351956

RESUMEN

The College of American Pathologists (CAP) has maintained the highest standards for laboratory medicine through education, evaluation, and certification. One form of External Quality Assurance - proficiency testing (PT) - is the centerpiece of that mission. Over 500 medical and scientific experts oversee CAP PT programs which include more than 600 tests performed by 22,000 laboratories in over 100 countries. It is the most comprehensive laboratory peer-review comparison program in the world. The CAP offers four urine sediment PT products tailored to the needs of different laboratories. Each includes three or four digital images, shipped twice a year. The program is overseen by the Hematology and Clinical Microscopy Resource Committee. Images are graded if there is 80% or greater consensus of either referee or participant laboratories. Failing laboratories must analyze the reasons for the failure, report the results, and initiate corrective action. Over the years, there has been a progressive decline in the number of errors, demonstrating that education and regulatory oversight are major contributors to improved PT performance and, by extension, patient care. The PT urine sediment image databank is a unique resource, representing the consensus of many laboratories. Participant and referee responses identify which morphologic variants are unambiguous and which are more difficult to classify. The PT challenges include discussions of disease pathophysiology and key morphologic features. This teaching component is what helps to set the CAP's program apart. The discussions formed the basis for the Color Atlas of Urinary Sediment published by the CAP in 2010.

3.
Ann Coloproctol ; 39(5): 395-401, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35417955

RESUMEN

PURPOSE: Anastomotic leak (AL) is an uncommon but potentially devastating complication after rectal resection. We aim to provide an updated assessment of bowel function and quality of life after AL, as well as associated short- and long-term outcomes. METHODS: A retrospective audit of all rectal resections performed at a colorectal unit and associated private hospitals over the past 10 years was performed. Relevant demographic, operative, and histopathological data were collected. A prospective survey was performed regarding patients' quality of life and fecal continence. These patients were matched with nonAL patients who completed the same survey. RESULTS: One hundred patients (out of 1,394 resections) were included. AL was contained in 66.0%, not contained in 10.0%, and only anastomotic stricture in 24.0%. Management was antibiotics only in 39.0%, percutaneous drainage in 9.0%, operative abdominal drainage in 19.0%, transrectal drainage in 6.0%, combination of percutaneous drainage and transrectal drainage in 2.0%, and combination abdominal/transrectal drainage in 1.0%. The 1-year stoma rate was 15.0%. Overall, mean Fecal Incontinence Severity Instrument scores were higher for AL patients than their matched counterparts (8.06±10.5 vs. 2.92±4.92, P=0.002). Patients with an AL had a mean EuroQol visual analogue scale (EQ-VAS) of 76.23±19.85; this was lower than the matched mean EQ-VAS for non-AL patients of 81.64±18.07, although not statistically significant (P=0.180). CONCLUSION: The majority of AL patients in this study were managed with antibiotics only. AL was associated with higher fecal incontinence scores in the long-term; however, this did not equate to lower quality of life scores.

4.
J Med Chem ; 45(12): 2512-9, 2002 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-12036359

RESUMEN

Oxytocin is a neurohypophyseal peptide hormone that induces labor and lactation in mammals. An inverse gamma-turn mimetic corresponding to the tripeptide Ile-Val-Asn has been synthesized and incorporated instead of residues 3-5 of oxytocin to probe the hypothesis that a gamma-turn involving these residues is found in the receptor bound conformation of oxytocin. In the turn mimetic, residues i and i + 1 are connected by a psi[CH(2)O] isostere while a covalent methylene bridge replaces the hydrogen bond that is often found between residues i and i + 2 in gamma-turns. The turn mimetic was assembled from three types of building blocks: an azido epoxide, an alpha-bromo acid, and a protected beta-amino alcohol. The oxytocin analogue did not induce contractions of the uterus nor did it inhibit oxytocin-induced contractions. It is suggested that the loss of bioactivity is mainly due to the presence of a psi[CH(2)O] isostere instead of an amide bond between residues i and i + 1 in the turn mimetic.


Asunto(s)
Oxitocina/análogos & derivados , Oxitocina/síntesis química , Péptidos Cíclicos/síntesis química , Animales , Femenino , Técnicas In Vitro , Contracción Isométrica , Espectroscopía de Resonancia Magnética , Imitación Molecular , Oxitocina/química , Oxitocina/farmacología , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Estructura Secundaria de Proteína , Ratas , Ratas Sprague-Dawley , Estereoisomerismo , Relación Estructura-Actividad , Útero/efectos de los fármacos , Útero/fisiología
5.
Pathology ; 34(2): 148-56, 2002 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12009097

RESUMEN

AIMS: Serous oligocystic adenoma of the pancreas is an uncommon benign neoplasm and is a recently described entity. To date, there are 19 adult cases of this tumour. We report three additional cases, two with macrocystic and one with unilocular types. We describe their clinicopathological, immunohistochemical and ultrastructural findings and review the world's literature. METHODS: For a 10-year period, we reviewed all benign cystic lesions of the pancreas with emphasis on serous oligocystic adenoma. We characterised serous oligocystic adenoma as an ill-demarcated or encapsulated mass, composed largely or exclusively of macrocysts (cysts measuring 20mm or more) but few in number (oligolocular). Grossly, it may contain only a single cyst (unilocular) of any size with a few satellite cysts observed on histological examination. Special stains and immunohistochemistry as well as electron microscopy were performed on three and two cases of serous oligocystic adenoma, respectively. RESULTS: Between 1990 and 2000, we collected 26 benign cystic lesions of the pancreas, three of which were serous oligocystic adenomas (two with macrocystic and one with unilocular types). Many of the cells lining the cysts showed PAS positivity. There was negative staining for PAS with diastase digestion, Alcian blue and mucicarmine. All cases showed positive staining for CAM5.2, AE1/AE3, EMA and CK7. The proliferation index marker was low. There was negative staining for CK20, insulin, glucagon, somatostatin, synaptophysin, chromogranin A, CEA and p53. Ultrastructural studies on two cases revealed similar findings. The single row of uniform epithelial cells lining the cysts was composed of simple cuboidal to flat cells which rested on a thin basal lamina. Their nuclei were round to ovoid. Glycogen granules were identified in the cytoplasm. Short microvilli emerged from the epithelial apical surface. Adjacent tumour cells were connected by microfilaments. CONCLUSIONS: Serous oligocystic adenomas of the pancreas are uncommon benign tumours. Prior to this study, 19 adults with these lesions were reported in the world's literature. No correct pre-operative diagnosis was carried out on all 22 cases. The 20 patients with follow-up ranging from 2 months to 5 years did not show tumour recurrence or malignant transformation.


Asunto(s)
Cistadenoma Seroso/patología , Neoplasias Pancreáticas/patología , Adolescente , Adulto , Anciano , Biomarcadores de Tumor/análisis , Estructuras Celulares/ultraestructura , Cistadenoma Seroso/química , Cistadenoma Seroso/cirugía , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/química , Neoplasias Pancreáticas/cirugía , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
7.
Org Biomol Chem ; 5(16): 2599-605, 2007 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-18019535

RESUMEN

A series of 2,4-disubstituted pyridine derivatives has been designed, synthesised and evaluated as thrombin inhibitors. A Grignard exchange reaction was used to introduce various benzoyl substituents in position 4 of the pyridine ring, where they serve as P3 residues in binding to thrombin. In position 2 of the pyridine ring, a para-amidinobenzylamine moiety was incorporated as P1 residue by an SNAr reaction using ammonia as nucleophile followed by a reductive amination. A crystal structure obtained for one of the compounds in the active site of thrombin revealed that the basic amidine group of the inhibitor was anchored to Asp 189 at the bottom of the S1 pocket. A comparison with melagatran, bound in the active site of thrombin, revealed a good shape match but lack of hydrogen bonding possibilities in the S2-S3 region for the thrombin inhibitors reported in this study.


Asunto(s)
Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Piridinas/síntesis química , Piridinas/farmacología , Trombina/antagonistas & inhibidores , Cristalografía por Rayos X , Diseño de Fármacos , Inhibidores Enzimáticos/química , Modelos Moleculares , Estructura Molecular , Piridinas/química , Relación Estructura-Actividad , Trombina/química
8.
Org Biomol Chem ; 4(3): 416-23, 2006 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-16446799

RESUMEN

A cyclic Leu-enkephalin mimetic containing a 7-membered ring, and two linear analogues, has been prepared on solid phase. In the cyclic mimetic the intramolecular (1-4) hydrogen bond found in crystalline Leu-enkephalin has been replaced by an ethylene bridge. In addition, the amide bond between Tyr1 and Gly2 has been replaced by a methylene ether isostere and Gly3 has been deleted. The two linear analogues both contain the methylene ether isostere instead of the Tyr1-Gly2 amide bond and the shorter of the two lacks Gly3. The three compounds, and a beta-turn mimetic analogous to the 7-membered turn mimetic but with Gly3 included, were evaluated for specific binding to micro- and delta-opioid receptors in rat brain membranes. With the exception of the beta-turn mimetic the three other Leu-enkephalin analogues all bound with varying affinity to the micro- and delta-opioid receptors. From the results it could be concluded that Leu-enkephalin binds in a turn conformation to the opiate receptors, but that this conformation is not a (1-4) beta-turn.


Asunto(s)
Materiales Biomiméticos/síntesis química , Materiales Biomiméticos/farmacología , Encefalina Leucina/análogos & derivados , Encefalina Leucina/química , Animales , Materiales Biomiméticos/química , Materiales Biomiméticos/metabolismo , Encéfalo/citología , Ciclización , Ligandos , Estructura Molecular , Ratas , Receptores Opioides delta/metabolismo , Receptores Opioides mu/metabolismo
9.
J Org Chem ; 69(10): 3500-8, 2004 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-15132562

RESUMEN

A beta-turn mimetic in which the four amino acids of a beta-turn have been replaced by a 10-membered ring has been designed, synthesized, and subjected to conformational studies. In the mimetic, the intramolecular CO(i)-HN(i)(+3) hydrogen bond that is often found in beta-turns has been replaced by an ethylene bridge. In addition, the amide bond between residues i and i + 1 was exchanged for a methylene ether isoster. Such a beta-turn mimetic, based on the first four residues of Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu), was prepared in 15 steps. The synthesis relied on a beta-azido alcohol prepared in five steps from Cbz-Tyr(tBu)-OH as a key, i-position building block. tert-Butyl bromoacetate, glycine, and a Phe-Leu dipetide were then used as building blocks for positions i + 1, i + 2, and i + 3, respectively. Conformational studies based on (1)H NMR data showed that the beta-turn mimetic was flexible, but that it resembled a type-II beta-turn at low temperature. This low energy conformer closely resembled the structure determined for crystalline Leu-enkephalin.


Asunto(s)
Encefalina Leucina/síntesis química , Aminoácidos/química , Encefalina Leucina/química , Enlace de Hidrógeno , Espectroscopía de Resonancia Magnética , Imitación Molecular , Estructura Molecular , Conformación Proteica , Estructura Secundaria de Proteína
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