RESUMEN
Cancer cell metabolism is often deregulated as a result of adaption to meeting energy and biosynthesis demands of rapid growth or direct mutation of key metabolic enzymes. Better understanding of such deregulation can provide new insights on targetable vulnerabilities, but is complicated by the difficulty in probing cell metabolism at different levels of resolution and under different experimental conditions. We construct computational models of glucose and glutamine metabolism with focus on the effect of IDH1/2-mutations in cancer using a combination of experimental metabolic flux data and patient-derived gene expression data. Our models demonstrate the potential of computational exploration to reveal biologic behavior: they show that an exogenously-mutated IDH1 experimental model utilizes glutamine as an alternative carbon source for lactate production under hypoxia, but does not fully-recapitulate the patient phenotype under normoxia. We also demonstrate the utility of using gene expression data as a proxy for relative differences in metabolic activity. We use the approach of probabilistic model checking and the freely-available Probabilistic Symbolic Model Checker to construct and reason about model behavior.
Asunto(s)
Glutamina , Neoplasias , Humanos , Glutamina/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Modelos Estadísticos , Hipoxia de la Célula , Glucosa/metabolismoRESUMEN
Many advances in wound healing have relevance to facial plastic surgery. We briefly highlight some of these advances, including new biological and synthetic products and other potential technologies to improve wound healing, as well as the literature describing them.
Asunto(s)
Traumatismos Faciales/terapia , Cicatrización de Heridas , Terapia por Estimulación Eléctrica , Traumatismos Faciales/fisiopatología , Fibrina/administración & dosificación , Fibrina/farmacología , Ondas de Choque de Alta Energía , Humanos , Oxigenoterapia Hiperbárica , Péptidos y Proteínas de Señalización Intercelular/administración & dosificación , Péptidos y Proteínas de Señalización Intercelular/farmacología , Terapia de Presión Negativa para Heridas , Plasma Rico en Plaquetas , Procedimientos de Cirugía Plástica , Piel Artificial , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/fisiologíaRESUMEN
OBJECTIVE: To determine the frequency, type of pathogen and clinical significance of bacterial colonization of double-J stents after pyeloplasty in children. PATIENTS AND METHODS: The medical files of 82 consecutive children (22 girls, 60 boys) who underwent pyeloplasty at a tertiary pediatric medical center in 2000-2007 were reviewed. Additional inclusion criteria were sterile urine preoperatively and placement of an indwelling double-J stent during surgery. Intravenous gentamicin was administered prior to pyeloplasty and stent removal; cephalexin was administered postoperatively until discharge. Children with a postoperative urinary tract infection (UTI) received full-dose antimicrobial treatment followed by prophylaxis until stent removal. RESULTS: Median patient age at surgery was 11 months (1 month-17.5 years). Forty-nine stents were inserted on the left side, 32 on the right, and one bilaterally. Cultures showed bacterial colonization in 58 cases (70.7%); 15 (25.8%) grew Staphylococcus (coagulase negative and positive). Eight children had febrile UTI postoperatively; in four the stent was colonized by Enterococci and in one by Proteus; three were sterile. There was no statistically significant association between positive stent culture and febrile UTI, patient age or sex, or stent laterality. The study was potentially limited by its observational design, small sample size, and the selective antibiotic treatment of patients with UTI which may have affected stent bacterial resistance. CONCLUSION: Bacterial colonization is not uncommon in double-J stents retained for several weeks after pyeloplasty, but is usually not clinically significant. Enterococcus is the most frequent pathogen.
Asunto(s)
Bacterias/aislamiento & purificación , Pelvis Renal/cirugía , Stents/microbiología , Obstrucción Ureteral/cirugía , Adolescente , Niño , Preescolar , Contaminación de Equipos , Diseño de Equipo , Femenino , Humanos , Lactante , Masculino , UréterRESUMEN
AIM: Development of a new chromatic (colorimetric/fluorescence) bacterial sensor, for rapid, sensitive and versatile detection of bacterial proliferation. METHODS AND RESULTS: We constructed agarose-embedded chromatic films which produce dramatic colour changes and fluorescence transformations in response to bacterial growth. The sensing constructs comprise glass-supported Langmuir-Schaeffer phospholipid/polydiacetylene films that undergo both blue-red transformations and induction of intense fluorescence following interactions with bacterially secreted amphiphilic compounds that diffuse through the agarose. The agarose matrix coating the sensor film further contains growth nutrients, facilitating signal amplification through promotion of bacterial culture proliferation. The agarose layer also constitutes an effective barrier for reducing background signals not associated with the bacteria. We demonstrate the applications of the new sensor for the detection of Gram-negative and Gram-positive bacteria, and for screening specimens of physiological fluids (blood and urine) and foods (meat) for bacterial contaminations. CONCLUSIONS: The experiments demonstrate that the new agarose-embedded film constructs are capable of bacterial detection through visible colour transitions and fluorescence emission recorded in conventional apparatuses. SIGNIFICANCE AND IMPACT OF THE STUDY: This work demonstrated a new simple chromatic platform for bacterial detection, based on the generation of easily recorded colour and fluorescence changes. The new bacterial detection scheme is highly generic and could be employed for varied practical uses, in which, rapid reporting on bacterial presence is required.
Asunto(s)
Bacterias/aislamiento & purificación , Microbiología de Alimentos , Adsorción , Materiales Biomiméticos , Colorimetría/métodos , Liposomas , Nanotecnología , Polímero Poliacetilénico , Polímeros , Poliinos , Sefarosa , Espectrometría de FluorescenciaRESUMEN
OBJECTIVES: Reimplantation of megaureters may be complicated by excessive bulk of tissue when plicated, or stenosis at the anastomosis site when excisional tapering is performed. Some urologists in our institution reimplant megaureters without tailoring, while others routinely tailor megaureters. Aiming to compare success rates, we report our experience in reimplanting obstructive megaureters with and without tailoring. MATERIALS: The medical records of 30 boys and four girls with primary obstructive megaureters (a total of 38 ureters) were reviewed. Median age at operation was 18 months (range 1 month to 8 years). Of the ureters, 16/38 were tailored and 22/38 were reimplanted without tailoring. RESULTS: Preoperative mean diameter (per ultrasound) of the 16 tailored ureters was 16.1mm (range 10-26 mm). Postoperative ultrasound showed resolution of hydronephrosis in 3/16 (19%), an improvement in 11/16 (69%), and no change in the degree of hydronephrosis in 2/16 (13%). Preoperative mean diameter of the non-tailored ureters was 14 mm (range 10-27 mm), and postoperative ultrasound showed resolution of hydronephrosis in 11/22 (50%), an improvement in 10/22 (45%), and no change in the degree of hydronephrosis in 1/22 (5%). Of the tailored ureters, 1/16 needed re-operation because of anastomotic stricture, and one girl had recurrent urinary tract infections. Of the non-tailored ureters, four had recurrent infection, of whom one boy underwent redo reimplantation because of grade 2 vesicoureteric reflux. CONCLUSION: In this series non-tailoring reimplantation was an equivalent option to tailoring in obstructive megaureters.
RESUMEN
PURPOSE: Urethral polyps in girls are included in the differential diagnosis of interlabial masses. Only 6 cases have been described in the English literature to date and etiology is uncertain. We present 5 more cases and review the literature. We also propose an etiology for urethral polyps in young girls and compare polyps between girls and boys as well as older females. MATERIALS AND METHODS: The medical records of prepubertal girls with urethral polyps seen at our hospital between 1980 and 2003, including operative reports and followup, were reviewed. A senior pathologist re-inspected the specimens to confirm the diagnosis. A MEDLINE search of urethral polyps was performed. RESULTS: We identified 5 girls 2 to 10 years old with urethral polyps. All girls presented with "vaginal" bleeding, 1 had recurrent urinary tract infections and vulvitis, 1 had urinary frequency, and 1 had painful voiding. The polyps were not site specific and were located in the distal, mid and proximal urethra. All polyps were excised and were found benign. Four girls were cured after 1 procedure, while in one girl the polyp reappeared. The patients were followed for 1 to 17 years and eventually became asymptomatic. CONCLUSIONS: Urethral polyps in prepubertal girls are probably benign. We suggest that the etiology of most of polyps in girls is similar to those in older females, that is a prolapsing urothelium that has evolved into a polyp.
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Pólipos/diagnóstico , Enfermedades Uretrales/diagnóstico , Niño , Humanos , Masculino , Pólipos/patología , Pólipos/cirugía , Enfermedades Uretrales/patología , Enfermedades Uretrales/cirugíaRESUMEN
OBJECTIVE: Pain management following bladder surgery in children is often complicated by bladder spasm. The overall severity of spasm can be reduced with opioids, anticholinergic medication and sedatives, although breakthrough spasms often occur. At the Royal Children's Hospital, Melbourne, intravesical bupivacaine has been used to manage postoperative bladder spasm to good effect. The administration of intravesical bupivacaine is analysed in this prospective audit of locally applied intravesical anaesthetic and compared with other methods. METHOD: From February to August 2003, histories of 58 patients who had intravesical bupivacaine were studied and compared with six other methods of management of postoperative bladder spasm. CONCLUSION: Data showed that epidural anaesthesia was the most effective treatment of pain, with a pain score reduction of 6.6, compared with a reduction of 6.1 with intravesical bupivacaine, and 4.5 using intravenous morphine. However, intravesical bupivacaine was the most effective method for the relief of bladder spasm.
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Anestésicos Locales/uso terapéutico , Bupivacaína/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Complicaciones Posoperatorias/tratamiento farmacológico , Espasmo/tratamiento farmacológico , Vejiga Urinaria/cirugía , Acetaminofén/uso terapéutico , Administración Intravesical , Analgésicos Opioides/uso terapéutico , Anestesia Epidural , Anestésicos Locales/administración & dosificación , Bupivacaína/administración & dosificación , Niño , Preescolar , Codeína/uso terapéutico , Femenino , Humanos , Masculino , Dimensión del Dolor , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Espasmo/clasificaciónRESUMEN
PURPOSE: The aim of this study was to investigate children presenting with malignant pelvic tumors obstructing the upper urinary tract. METHODS: Seventeen children with upper urinary tract obstruction by a malignant tumor were reviewed. A nephrostomy tube or Double J (DJ) stent was inserted into each obstructed urinary system and removed after tumor shrinkage and/or hydronephrosis regression. RESULTS: There were 9 boys and 8 girls in the study; the mean age and median follow-up were 5.7 years and 2.5 years, respectively. The most common obstructing tumor was rhabdomyosarcoma. Twelve children underwent diversion by nephrostomy tubes and 3 by DJ stents; 2 patients underwent resection of the tumors with ureteroureterostomy. Complications after the insertion of the stents included febrile urinary tract infections (UTI) or pyelonephritis in 4 of the children with DJ stents. In the nephrostomy group, febrile UTI developed in 3 and the tube fell out in 1, and was blocked in another. Of the 17 children, 9 have no evidence of disease, 2 are currently under treatment, and 6 died of cancer. CONCLUSIONS: The prognosis of children with malignant pelvic tumor obstructing the upper urinary system justifies urgent and optimal upper tract diversion, enabling chemotherapy to be started immediately.
Asunto(s)
Neoplasias Pélvicas/complicaciones , Obstrucción Ureteral/etiología , Obstrucción Ureteral/cirugía , Derivación Urinaria , Preescolar , Femenino , Estudios de Seguimiento , Humanos , MasculinoRESUMEN
PURPOSE: Endoscopic ureterocele decompression is a well established procedure in children. However, an accurate endoscopic incision may be challenging in large ectopic ureteroceles. We describe a percutaneously assisted technique to facilitate the ease of ureterocele incision and review other described methods. MATERIALS AND METHODS: We reviewed the medical records of 12 children with ectopic ureteroceles subtending a double collecting system who underwent endoscopic, percutaneously assisted incision. Six ureteroceles were on the left side, 5 were on the right side and 1 child had bilateral ureteroceles. Decompression results were evaluated by ultrasound and Tc-mercaptoacetyltriglycine imaging during a mean of 2.8 years of followup. RESULTS: There were 7 girls and 5 boys. Mean age at presentation was 11.6 months (range 1 week to 6 years). The decompression success rate was 84% (11 of 13 renal units), and improved renal function and drainage was noted in 5 of 12 patients (41.6%). Seven of 12 patients had vesicoureteral reflux, of whom 2 were asymptomatic at followup and, hence, were treated conservatively. Five children underwent surgery because of recurrent urinary tract infections. CONCLUSIONS: Although our results are similar to those of other methods, percutaneously assisted cystoscopic incision of ureterocele enables easier and more accurate decompression. However, when comparing the various techniques described, it seems that postoperative results mostly reflect the anatomical and functional characteristics of the urinary system rather than the technique used.
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Descompresión Quirúrgica/métodos , Ureterocele/cirugía , Ureteroscopía/métodos , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios RetrospectivosRESUMEN
Partial cDNAs of different isoforms of protein phosphatase 2Cbeta (PP2Cbeta or PPM1B) have been characterized in mammals. We disclose here the full cDNAs of two major PP2Cbeta isoforms from human, rat and mouse. These cDNAs (2.6 and 3.3 kb) are able to encode 53 kDa (PP2Cbetal) and 43 kDa (PP2Cbetas) polypeptides, respectively. The isoforms are co-expressed ubiquitously with the highest level in skeletal muscle, as assessed by Northern-blot analysis. Western and in situ analyses using monoclonal antibodies against PP2Cbeta confirmed the existence of two isoforms in the cytoplasm. Comparative sequence analysis revealed that both cDNAs consist of six exons with an alternate usage of the 3' exons that underlies the differences between them. The genomic structure of PP2Cbeta is similar to that of other PP2C paralogs and includes a non-coding first exon followed by a large intron and a large second exon that encoded most of the catalytic domain. Both variants of the ending exon include large non-coding regions. All non-translated regions (NTRs) are highly conserved between the orthologous genes, indicating their regulatory function. The 5'-NTR is long (379 bp), includes upstream start codons and is predicted to contain stable secondary structures. Such features inhibit translation initiation by the scanning mechanism. Introduction of this NTR element into a bi-luciferase expression-cassette enabled expression of the second cistron, suggesting that it might serve as an internal ribosome entry site, or it contains a cryptic promoter. Overexpression of PP2Cbeta under CMV-promoter in 293 cells led to cell-growth arrest or cell death.
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Empalme Alternativo/genética , Secuencia Conservada/genética , Fosfoproteínas Fosfatasas/genética , Proteínas de Saccharomyces cerevisiae , Transcripción Genética/genética , Animales , Secuencia de Bases , Dominio Catalítico , Muerte Celular , División Celular , Línea Celular , Clonación Molecular , Citoplasma/enzimología , Exones/genética , Etiquetas de Secuencia Expresada , Perfilación de la Expresión Génica , Humanos , Intrones/genética , Isoenzimas/análisis , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/inmunología , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Fosfoproteínas Fosfatasas/análisis , Fosfoproteínas Fosfatasas/química , Fosfoproteínas Fosfatasas/inmunología , Biosíntesis de Proteínas/genética , Proteína Fosfatasa 2 , Proteína Fosfatasa 2C , Transporte de Proteínas , ARN Mensajero/análisis , ARN Mensajero/biosíntesis , ARN Mensajero/genética , RatasRESUMEN
Protein phosphatase (PP2Calpha) is a member of the mammalian serine threonine-specific protein phosphatases family. We produced monoclonal antibodies against the recombinant PP2Calpha and evaluated the immunoreactivity of normal human tissues. The reactivity was strong in normal skin, the digestive tract, lung, kidney, breast, prostate, endocrine glands, and brain, while it was moderate in the ovary, testis, and liver. Epithelial cells revealed high levels of PP2Calpha expression, but stromal cells, including fibroblasts and endothelial cells, showed no or little PP2Calpha expression. Given the broad reactivity in endocrine and secreting epithelial cells, we propose that PP2Calpha expression might contribute to secretory cell function.
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Sistema Digestivo/enzimología , Células Epiteliales/enzimología , Fosfoproteínas Fosfatasas/análisis , Fosfoproteínas Fosfatasas/biosíntesis , Proteínas de Saccharomyces cerevisiae , Sistema Urogenital/enzimología , Anticuerpos Monoclonales/análisis , Encéfalo/citología , Encéfalo/enzimología , Mama/enzimología , Femenino , Humanos , Inmunohistoquímica/métodos , Pulmón/enzimología , Linfa/enzimología , Masculino , Miocardio/enzimología , Neuronas/enzimología , Proteína Fosfatasa 2 , Proteína Fosfatasa 2C , Piel/enzimología , Timo/enzimología , Glándula Tiroides/enzimologíaRESUMEN
1. Uptake of triglycerides and phosphoglycerides was demonstrated in ligated washed chick intestinal segments in situ. Mucosal uptake was observed both in the jejunum and ileum of chicks and was not accompanied by significant luminal hydrolysis of acylglycerides. 2. Brush border membrane vesicles were prepared and lipase and phospholipase activities were demonstrated. These activities were enriched in parallel to the increase in activity of maltase and gamma-glutamyl transpeptidase in all small intestinal areas. 3. In order to determine if the pancreatic and brush border membrane lipolytic activities were similar different properties of these activities were examined. The relative activities of pancreatic and brush border membranes towards triolein and phosphatidylcholine differed. The pH-triolein activity curve and the use of different additives showed some diverging effects between the activities. These differences were not, however, sufficient to conclude that the brush border activity towards triolein is distinct from that of pancreatic lipase. 4. Lipolytic activity in the brush border may play a role in acylglyceride digestion, uptake and transport in the small intestine of the chick.
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Pollos/metabolismo , Intestino Delgado/enzimología , Lipasa/metabolismo , Fosfolipasas/metabolismo , Animales , Concentración de Iones de Hidrógeno , Masculino , Microvellosidades/enzimología , Ácido Oléico/farmacocinética , Fosfatidilcolinas/farmacocinética , Trioleína/farmacocinéticaRESUMEN
Streptomyces griseus aminopeptidase is a zinc metalloenzyme containing 2 mol zinc/mol protein, similar to the homologous enzyme Aeromonas proteolytica aminopeptidase. In addition, a unique Ca2+-binding site has been identified in the Streptomyces enzyme, which is absent in the Aeromonas enzyme. Binding of Ca2+ enhances stability of the Streptomyces enzyme and modulates its activity and affinity towards substrates and inhibitors in a structure-dependent manner. Among the three hydrophobic 4-nitroanilides of alanine, valine and leucine, the latter displays the largest overall activation (increase in k(cat)/Km). Large enhancements in affinity (1/Ki) upon Ca2+ binding have been observed for inhibitors with flexible (leucine-like) residues at their N-termini and smaller enhancements for inhibitors with rigid (phenylalanine-like) residues.
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Aeromonas/enzimología , Aminopeptidasas/química , Calcio/farmacología , Péptidos , Streptomyces griseus/enzimología , Anilidas/metabolismo , Antibacterianos/farmacología , Proteínas Bacterianas/química , Sitios de Unión/fisiología , Inhibidores Enzimáticos/farmacología , Estabilidad de Enzimas/efectos de los fármacos , Cinética , Leucina/análogos & derivados , Leucina/farmacología , Metaloproteínas/química , Modelos Moleculares , Estructura Molecular , Unión Proteica , Estructura Terciaria de Proteína , Especificidad por SustratoRESUMEN
Tripeptide derivatives like 3-carboxypropanoylalanyl-alanyl-leucine 4-nitroanilide or 3-carboxypropanoyl-alanyl-alanyl-phenylalanine 4-nitroanilide are very sensitive substrates for neprilysin (k cat > 10(2)s(-1); k cat/Km > or = 10(6) s(-1) x M(-1)) and are widely employed in investigations of the enzyme. However, these compounds are also good substrates for the serine proteases chymotrypsin and subtilisin (k cat approximately 1s(-1)-34s(-1)). By substituting the N-terminal alanine of the substrates with proline, the catalytic efficiency of the enzymic reaction, by the serine proteases, is diminished by 2-3 orders of magnitude, whereas that by neprilysin and theromlysin decreases only slightly. These effects demonstrate that structural alterations in peptide substrates that impair secondary sub-site interactions with one class of peptidases may enhance the selectivity of the substrates towards another class of peptidases.
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Neprilisina/metabolismo , Oligopéptidos/metabolismo , Subtilisinas/metabolismo , Termolisina/metabolismo , Secuencia de Aminoácidos , Compuestos de Anilina/síntesis química , Compuestos de Anilina/química , Compuestos de Anilina/metabolismo , Quimotripsina/metabolismo , Cinética , Datos de Secuencia Molecular , Oligopéptidos/síntesis química , Oligopéptidos/química , Especificidad por SustratoRESUMEN
An abnormal circadian pattern of melatonin was found in a group of young adults with an extreme autism syndrome. Although not out of phase, the serum melatonin levels differed from normal in amplitude and mesor. Marginal changes in diurnal rhythms of serum TSH and possibly prolactin were also recorded. Subjects with seizures tended to have an abnormal pattern of melatonin correlated with EEG changes. In others, a parallel was evidenced between thyroid function and impairment in verbal communication. There appears to be a tendency for various types of neuroendocrinological abnormalities in autistics, and melatonin, as well as possibly TSH and perhaps prolactin, could serve as biochemical variables of the biological parameters of the disease.
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Trastorno Autístico/sangre , Ritmo Circadiano , Hidrocortisona/sangre , Melatonina/sangre , Prolactina/sangre , Tirotropina/sangre , Adolescente , Adulto , Humanos , Masculino , Melatonina/metabolismo , RadioinmunoensayoRESUMEN
A recent Ethiopian immigrant to Israel presented with pneumococcal sepsis, massive splenomegaly and lymph-adenopathy. Investigations revealed many features of both hairy cell leukaemia (HCL) and hyperreactive malarious splenomegaly (HMS). Proguanil therapy for HMS was followed by rapid, marked decrease in spleen size, disappearance of the tartrate-resistant acid phosphatase-positive cells characteristic of HCL, and increasing eosinophilia, but unchanged lymphadenopathy.