RESUMO
BACKGROUND: Primary and incisional ventral hernia trials collect unstandardized inconsistent data, limiting data interpretation and comparison. This study aimed to create two minimum data sets for primary and incisional ventral hernia interventional trials to standardize data collection and improve trial comparison. To support these data sets, standardized patient-reported outcome measures and trial methodology criteria were created. METHODS: To construct these data sets, nominal group technique methodology was employed, involving 15 internationally recognized abdominal wall surgeons and two patient representatives. Initially a maximum data set was created from previous systematic and panellist reviews. Thereafter, three stages of voting took place: stage 1, selection of the number of variables for data set inclusion; stage 2, selection of variables to be included; and stage 3, selection of variable definitions and detection methods. A steering committee interpreted and analysed the data. RESULTS: The maximum data set contained 245 variables. The three stages of voting commenced in October 2019 and had been completed by July 2020. The final primary ventral hernia data set included 32 variables, the incisional ventral hernia data set included 40 variables, the patient-reported outcome measures tool contained 25 questions, and 40 methodological criteria were chosen. The best known variable definitions were selected for accurate variable description. CT was selected as the optimal preoperative descriptor of hernia morphology. Standardized follow-up at 30 days, 1 year, and 5 years was selected. CONCLUSION: These minimum data sets, patient-reported outcome measures, and methodological criteria have allowed creation of a manual for investigators aiming to undertake primary ventral hernia or incisional ventral hernia interventional trials. Adopting these data sets will improve trial methods and comparisons.
Assuntos
Ensaios Clínicos como Assunto/normas , Hérnia Ventral/cirurgia , Herniorrafia/métodos , Hérnia Incisional/cirurgia , Laparoscopia/métodos , Guias de Prática Clínica como Assunto , Telas Cirúrgicas , Parede Abdominal/cirurgia , Feminino , Humanos , Masculino , Recidiva , Resultado do TratamentoRESUMO
OBJECTIVE: To compare the safety and efficacy of 10% sinecatechins (Veregen® ) ointment against placebo in the treatment of usual type vulvar intraepithelial neoplasia (uVIN). DESIGN: A Phase II double-blind randomised control trial. SETTING: A tertiary gynaecological oncology referral centre. POPULATION: All women diagnosed with primary and recurrent uVIN. METHODS: Eligible patients were randomised 1:1 to receive either sinecatechins or placebo ointment (applied three times daily for 16 weeks) and were followed up at 2, 4, 8, 16, 32 and 52 weeks. MAIN OUTCOME MEASURES: The primary outcome measure, recorded at 16 and 32 weeks, was histological response (HR). Secondary outcome measures included clinical (CR) response, toxicity, quality of life and pain scores. RESULTS: There was no observed difference in HR between the two arms. However, of the 26 patients who were randomised, all 13 patients who received sinecatechins showed either complete (n = 5) or partial (n = 8) CR, when best CR was evaluated. In placebo group, three patients had complete CR, two had partial CR, six had stable disease and two were lost to follow up. Patients in the sinecatechins group showed a statistically significant improvement in best observed CR as compared with the placebo group (P = 0.002). There was no difference in toxicity reported in either group. CONCLUSION: Although we did not observe a difference in HR between the two treatment arms, we found that 10% sinecatechins application is safe and shows promise in inducing clinical resolution of uVIN lesions and symptom improvement, thus warranting further investigation in a larger multicentre study. TWEETABLE ABSTRACT: A randomised control study indicating that sinecatechins ointment may be a novel treatment for uVIN.
Assuntos
Camellia sinensis , Carcinoma in Situ , Catequina/análogos & derivados , Neoplasias Vulvares , Adulto , Antineoplásicos/farmacologia , Carcinoma in Situ/tratamento farmacológico , Carcinoma in Situ/patologia , Catequina/administração & dosagem , Catequina/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Pomadas/administração & dosagem , Pomadas/efeitos adversos , Extratos Vegetais/farmacologia , Resultado do Tratamento , Neoplasias Vulvares/tratamento farmacológico , Neoplasias Vulvares/patologiaAssuntos
COVID-19 , Colo/cirurgia , Recuperação Pós-Cirúrgica Melhorada/normas , Fidelidade a Diretrizes/tendências , Padrões de Prática Médica/tendências , Reto/cirurgia , Inglaterra , Humanos , Avaliação de Resultados em Cuidados de Saúde , Guias de Prática Clínica como Assunto , Padrões de Prática Médica/normas , Estudos RetrospectivosRESUMO
INTRODUCTION: Subcostal hernias are categorized as L1 based on the European Hernia Society (EHS) classification and frequently involve M1, M2, and L2 sites. These are common after hepatopancreatic and biliary surgeries. The literature on subcostal hernias mostly comprises of retrospective reviews of small heterogenous cohorts, unsurprisingly leading to no consensus or guidelines. Given the limited literature and lack of consensus or guidelines for dealing with these hernias, we planned for a Delphi consensus to aid in decision making to repair subcostal hernias. METHODS: We adopted a modified Delphi technique to establish consensus regarding the definition, characteristics, and surgical aspects of managing subcostal hernias (SCH). It was a four-phase Delphi study reflecting the widely accepted model, consisting of: 1. Creating a query. 2. Building an expert panel. 3. Executing the Delphi rounds. 4. Analysing, presenting, and reporting the Delphi results. More than 70% of agreement was defined as a consensus statement. RESULTS: The 22 experts who agreed to participate in this Delphi process for Subcostal Hernias (SCH) comprised 7 UK surgeons, 6 mainland European surgeons, 4 Indians, 3 from the USA, and 2 from Southeast Asia. This Delphi study on subcostal hernias achieved consensus on the following areas-use of mesh in elective cases; the retromuscular position with strong discouragement for onlay mesh; use of macroporous medium-weight polypropylene mesh; use of the subcostal incision over midline incision if there is no previous midline incision; TAR over ACST; defect closure where MAS is used; transverse suturing over vertical suturing for closure of circular defects; and use of peritoneal flap when necessary. CONCLUSION: This Delphi consensus defines subcostal hernias and gives insight into the consensus for incision, dissection plane, mesh placement, mesh type, and mesh fixation for these hernias.
Assuntos
Consenso , Técnica Delphi , Herniorrafia , Telas Cirúrgicas , Humanos , Herniorrafia/métodosRESUMO
Expression profiling using DNA microarrays holds great promise for a variety of research applications, including the systematic characterization of genes discovered by sequencing projects. To demonstrate the general usefulness of this approach, we recently obtained expression profiles for nearly 300 Saccharomyces cerevisiae deletion mutants. Approximately 8% of the mutants profiled exhibited chromosome-wide expression biases, leading to spurious correlations among profiles. Competitive hybridization of genomic DNA from the mutant strains and their isogenic parental wild-type strains showed they were aneuploid for whole chromosomes or chromosomal segments. Expression profile data published by several other laboratories also suggest the use of aneuploid strains. In five separate cases, the extra chromosome harboured a close homologue of the deleted gene; in two cases, a clear growth advantage for cells acquiring the extra chromosome was demonstrated. Our results have implications for interpreting whole-genome expression data, particularly from cells known to suffer genomic instability, such as malignant or immortalized cells.
Assuntos
Aneuploidia , Cromossomos Fúngicos , Saccharomyces cerevisiae/genética , DNA Fúngico/análise , Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos/métodosRESUMO
Computed tomography (CT) scanning is the imaging modality of choice when planning the overall management and operative approach to complex abdominal wall hernias. Despite its availability and well-recognised benefits there are no guidelines or recommendations regarding how best to read or report such scans for this application. In this paper we aim to outline an approach to interpreting preoperative CT scans in abdominal wall reconstruction (AWR). This approach breaks up the interpretive process into 4 steps-concentrating on the hernia or hernias, any complicating features of the hernia(s), the surrounding soft tissues and the abdominopelvic cavity as a whole-and was developed as a distillation of the authors' collective experience. We describe the key features that should be looked for at each of the four steps and the rationale for their inclusion.
Assuntos
Parede Abdominal , Hérnia Ventral , Hérnia Incisional , Cirurgia Plástica , Humanos , Parede Abdominal/cirurgia , Hérnia Ventral/cirurgia , Hérnia Incisional/cirurgia , Herniorrafia/métodos , Tomografia Computadorizada por Raios X/métodosRESUMO
BACKGROUND: Reconstruction of massive contaminated abdominal wall defects associated with enteroatmospheric fistulation represents a technical challenge. An effective technique that allows closure of intestinal fistulas and reconstruction of the abdominal wall, with a good functional and cosmetic result, has yet to be described. The present study is a retrospective review of simultaneous reconstruction of extensive gastrointestinal tract fistulation and large full-thickness abdominal wall defects, using a novel pedicled subtotal thigh flap. METHODS: The flap, based on branches of the lateral circumflex femoral artery, was used to reconstruct the abdominal wall in six patients who were dependent on artificial nutritional support, with a median (range) of 4·5 (3-23) separate intestinal fistulas, within open abdominal wounds with a surface area of 564·5 (204-792) cm2. Intestinal reconstruction was staged, with delayed closure of a loop jejunostomy. Median follow-up was 93·5 (10-174) weeks. RESULTS: Successful healing occurred in all patients, with no flap loss or gastrointestinal complications. One patient died from complications of sepsis unrelated to the surgical treatment. All surviving patients gained complete nutritional autonomy following closure of the loop jejunostomy. CONCLUSION: Replacement of almost the entire native abdominal wall in patients with massive contaminated abdominal wall defects is possible, without the need for prosthetic material or microvascular free flaps. The subtotal pedicled thigh flap is a safe and effective method of providing definitive treatment for patients with massive enteroatmospheric fistulation.
Assuntos
Parede Abdominal/cirurgia , Fístula Cutânea/cirurgia , Fístula Intestinal/cirurgia , Sepse/cirurgia , Retalhos Cirúrgicos , Adulto , Fístula Cutânea/complicações , Feminino , Humanos , Fístula Intestinal/complicações , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Músculo Quadríceps/transplante , Estudos Retrospectivos , Coxa da Perna , Transplante Autólogo , Resultado do Tratamento , CicatrizaçãoRESUMO
We describe here a method for drug target validation and identification of secondary drug target effects based on genome-wide gene expression patterns. The method is demonstrated by several experiments, including treatment of yeast mutant strains defective in calcineurin, immunophilins or other genes with the immunosuppressants cyclosporin A or FK506. Presence or absence of the characteristic drug 'signature' pattern of altered gene expression in drug-treated cells with a mutation in the gene encoding a putative target established whether that target was required to generate the drug signature. Drug dependent effects were seen in 'targetless' cells, showing that FK506 affects additional pathways independent of calcineurin and the immunophilins. The described method permits the direct confirmation of drug targets and recognition of drug-dependent changes in gene expression that are modulated through pathways distinct from the drug's intended target. Such a method may prove useful in improving the efficiency of drug development programs.
Assuntos
Calcineurina/genética , Ciclosporina/farmacologia , Regulação Fúngica da Expressão Gênica , Imunofilinas/genética , Imunossupressores/farmacologia , Saccharomyces cerevisiae/genética , Tacrolimo/farmacologia , Desenho de Fármacos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Genótipo , Modelos Biológicos , Mutação , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/efeitos dos fármacos , Transdução de SinaisRESUMO
PURPOSE: Porcine acellular dermal matrix (PADM) has been promoted as a suitable material for the reinforcement of the abdominal wall in Ventral Hernia Working Group (VHWG) Grade 3/4 wounds by Ventral Hernia Working Group et al. (Surgery 148(3):544-548). We describe our experience of, and assess the mechanisms for the failure of PADM (PermacolTM) in intestinal and abdominal wall reconstruction (AWR) for enterocutaneous fistulation (ECF). METHODS: All patients referred to our unit who had PADM used for AWR and ECF were studied from a prospectively maintained database. Follow-up data until 31/12/2018 were analysed. PADM was explanted at further surgery and examined histologically. RESULTS: 13 patients, (median age-58.5 years) underwent AWR with PADM reinforcement. Twelve of these (92%) patients had developed abdominal wall defects (AWD) and ECF following complications of previous surgery. Six patients underwent fistula takedown and AWR with PADM, of which 5(83%) refistulated. Seven patients referred to us had already undergone similar procedures in their referring hospitals and had also refistulated. Median (range) time to fistulation after AWR with PADM was 17 (7-240) days. In all cases, PADM had been used to bridge the defect and placed in direct contact with bowel. At reconstructive surgery for refistulation, PADM was inseparable from multiple segments of small intestine, necessitating extensive bowel resection. Histological examination confirmed that the PADM almost completely integrated with the seromuscular layer of the small intestine. CONCLUSION: PADM may become inseparable from serosa of the human small intestinal serosa when it is left in the abdomen during reconstructive surgery. This technique is associated with recurrent intestinal fistulation and intestinal failure and should be avoided if at all possible.
Assuntos
Derme Acelular/efeitos adversos , Colágeno/efeitos adversos , Hérnia Ventral/cirurgia , Herniorrafia/efeitos adversos , Fístula Intestinal/etiologia , Parede Abdominal/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Herniorrafia/métodos , Humanos , Fístula Intestinal/cirurgia , Intestino Delgado/cirurgia , Masculino , Pessoa de Meia-Idade , Procedimentos de Cirurgia Plástica/efeitos adversos , Procedimentos de Cirurgia Plástica/métodos , Recidiva , Reoperação , Estudos Retrospectivos , Telas Cirúrgicas/efeitos adversosRESUMO
Simplified meteorological models and pollutant source configurations were used to demonstrate the types of pollutant patterns that might be encountered in the Washington, D.C.-Boston megalopolitan corridor. A semirealistic source distribution and source intensity of carbon dioxide were used in this demonstration. The results of the computations suggest that local increases in quantities of pollutants may at times require regional rather than local source consideration.
Assuntos
Poluição do Ar , Dióxido de Carbono/análise , Modelos Teóricos , Tempo (Meteorologia) , Computadores , District of Columbia , Estados UnidosRESUMO
BACKGROUND: Increasing evidence indicates that combined mechanical and oral antibiotic bowel preparation reduces the infectious complications of colorectal surgery. Anecdotal evidence suggests the combination is rarely used in the UK and Europe. AIM: To establish colorectal surgeons' current use and awareness of the benefits of such bowel preparation, and to identify decision-making influences surrounding preoperative bowel preparation. METHOD: An electronic survey was emailed to all members of the Association of Coloproctology of Great Britain and Ireland, and promoted via Twitter. FINDINGS: A total of 495 respondents completed the survey: 413 (83.2%) UK, 39 (7.9%) other European, 43 (8.7%) non-European. Respondents used oral antibiotics for 12-20% of cases. Mechanical bowel preparation (MBP), phosphate enema, and no preparation, respectively, ranged between 9 and 80%. Combined MBP and oral antibiotic bowel preparation ranged between 5.5 and 18.6%. Fifty-three percent (260/495) agreed that combined mechanical and oral antibiotic bowel preparation reduces surgical site infection; 32% (157/495) agreed that the combination reduces risk of anastomotic leak. Kappa statistics between 0.06 and 0.27 indicate considerable incongruity between surgeons' awareness of the literature, and day-to-day practice. Twenty-four percent (96/495) believed MBP to be incompatible with enhanced recovery after surgery (ERAS); 41% (204/495) believed that MBP delays return to normal intestinal function. CONCLUSIONS: Few UK and European colorectal surgeons use mechanical and oral antibiotic bowel preparation, despite evidence of its efficacy in reducing infectious complications. The influence of ERAS pathways and UK and European guidelines may explain this. In contradiction to the UK and Europe, North American guidelines recommend incorporating combined mechanical and oral antibiotic bowel preparation into ERAS programmes. This study suggests that future UK and European guidelines incorporate combined mechanical and oral antibiotic bowel preparation into the ERAS pathway.
Assuntos
Antibacterianos/administração & dosagem , Cirurgia Colorretal/efeitos adversos , Enema/métodos , Padrões de Prática Médica , Cuidados Pré-Operatórios/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Humanos , Irlanda , Inquéritos e Questionários , Reino UnidoRESUMO
Tris(chloropropyl)phosphate (TCPP) is an organophosphorus flame retardant (OPFR) and plasticizer increasingly used in consumer products and as a replacement for brominated flame retardants. Commercially available TCPP is a mixture of four structural isomers the most abundant of which is tris(1-chloro-2-propyl)phosphate (TCPP-1). Although there is a widespread use of TCPP and potential for human exposure, there is limited data on the safety or toxicity of TCPP. The National Toxicology Program is conducting long-term studies to examine the toxicity of the TCPP in rats after lifetime exposure, including perinatal oral exposure. Quantitative estimates of internal dose are essential to interpret toxicological findings in rodents. To aid in this, a method was fully validated to quantitate the most abundant isomer, TCPP-1, in female Harlan Sprague Dawley (HSD) rat and B6C3F1 mouse plasma with partial validation in male rat plasma, and male and female mouse plasma. The method used protein precipitation using trichloroacetic acid followed by the extraction with toluene, and analysis by gas chromatography with flame photometric detection. The performance of the method was evaluated over 5-70 ng TCPP-1/mL plasma. The method was linear (r ≥ 0.99), accurate (inter-day relative error: ≤ ± -7.2) and precise (inter-batch relative standard deviation: ≤27.5%). The validated method has lower limits of quantitation and detection of ~5 and 0.9 ng/mL, respectively, in female HSD rat plasma and can be used on samples as small as 50 µL demonstrating the applicability to plasma samples from toxicology studies.
Assuntos
Cromatografia Gasosa/métodos , Retardadores de Chama/análise , Organofosfatos/sangue , Fotometria/métodos , Plastificantes/análise , Animais , Calibragem , Cromatografia Gasosa/normas , Feminino , Ionização de Chama , Limite de Detecção , Masculino , Camundongos , Fotometria/normas , Ratos Sprague-Dawley , Padrões de Referência , Reprodutibilidade dos TestesRESUMO
It is increasingly accepted that survival alone is an inadequate measure of the success of childhood brain tumour treatments. Consequently, there is growing emphasis on capturing quality of survival. Ependymomas are the third most frequently occurring brain tumours in childhood and present significant clinical challenges. European Society of Paediatric Oncology Ependymoma II is a comprehensive international program aiming to evaluate outcomes under different treatment regimens and improve diagnostic accuracy. Importantly, there has been agreement to lower the age at which children with posterior fossa ependymoma undergo focal irradiation from three years to either eighteen months or one year of age. Hitherto radiotherapy in Europe had been reserved for children over three years due to concerns over adverse cognitive outcomes following irradiation of the developing brain. There is therefore a duty of care to include longitudinal cognitive follow-up and this has been agreed as an essential trial outcome. Discussions between representatives of 18 participating European countries over 10 years have yielded European consensus for an internationally accepted test battery for follow-up of childhood ependymoma survivors. The 'Core-Plus' model incorporates a two-tier approach to assessment by specifying core tests to establish a minimum dataset where resources are limited, whilst maintaining scope for comprehensive assessment where feasible. The challenges leading to the development of the Core-Plus model are presented alongside learning from the initial stages of the trial. We propose that this model could provide a solution for future international trials addressing both childhood brain tumours and other conditions associated with cognitive morbidity.
Assuntos
Assistência ao Convalescente/métodos , Neoplasias Encefálicas/radioterapia , Ensaios Clínicos como Assunto/métodos , Cognição/efeitos da radiação , Ependimoma/radioterapia , Adolescente , Sobreviventes de Câncer/psicologia , Criança , Pré-Escolar , Irradiação Craniana/efeitos adversos , Europa (Continente) , Feminino , Humanos , Lactente , Masculino , MorbidadeRESUMO
Starvation for amino acids induces Gcn4p, a transcriptional activator of amino acid biosynthetic genes in Saccharomyces cerevisiae. In an effort to identify all genes regulated by Gcn4p during amino acid starvation, we performed cDNA microarray analysis. Data from 21 pairs of hybridization experiments using two different strains derived from S288c revealed that more than 1,000 genes were induced, and a similar number were repressed, by a factor of 2 or more in response to histidine starvation imposed by 3-aminotriazole (3AT). Profiling of a gcn4Delta strain and a constitutively induced mutant showed that Gcn4p is required for the full induction by 3AT of at least 539 genes, termed Gcn4p targets. Genes in every amino acid biosynthetic pathway except cysteine and genes encoding amino acid precursors, vitamin biosynthetic enzymes, peroxisomal components, mitochondrial carrier proteins, and autophagy proteins were all identified as Gcn4p targets. Unexpectedly, genes involved in amino acid biosynthesis represent only a quarter of the Gcn4p target genes. Gcn4p also activates genes involved in glycogen homeostasis, and mutant analysis showed that Gcn4p suppresses glycogen levels in amino acid-starved cells. Numerous genes encoding protein kinases and transcription factors were identified as targets, suggesting that Gcn4p is a master regulator of gene expression. Interestingly, expression profiles for 3AT and the alkylating agent methyl methanesulfonate (MMS) overlapped extensively, and MMS induced GCN4 translation. Thus, the broad transcriptional response evoked by Gcn4p is produced by diverse stress conditions. Finally, profiling of a gcn4Delta mutant uncovered an alternative induction pathway operating at many Gcn4p target genes in histidine-starved cells.
Assuntos
Aminoácidos/biossíntese , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica/genética , Proteínas Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Aminoácidos/genética , Amitrol (Herbicida)/farmacologia , Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/genética , Genes Reporter/genética , Glicogênio/metabolismo , Metanossulfonato de Metila/farmacologia , Mitocôndrias/genética , Mitocôndrias/metabolismo , Modelos Teóricos , Mutagênicos/farmacologia , Análise de Sequência com Séries de Oligonucleotídeos , Peroxissomos/genética , Peroxissomos/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas Quinases/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/fisiologia , Transativadores/genética , Transativadores/metabolismoRESUMO
PURPOSE: Use the ID(50) (infectious dose to 50% of experimental animals) to quantify the most effective prophylactic dosing regimen to use with gatifloxacin 0.3% (Zymar) for the prevention of keratitis in a rabbit laser in situ keratomileusis model of Staphylococcus epidermidis infection. SETTING: University Laboratory, University of Arizona, Tucson, Arizona, USA. METHODS: Two groups of rabbits were compared in each of 2 experiments that were separated by 12 months. In the first experiment, rabbits receiving no postoperative antibiotic therapy (Group 1) were compared with rabbits receiving postoperative antibiotic therapy (Group 2). In the second experiment, postoperative antibiotic therapy (Group 3) was compared with preoperative and postoperative antibiotic therapy (Group 4). All antibiotic regimens used gatifloxacin 0.3%. Before antibiotic therapy began, corneal pockets were created in the right eye of each rabbit and all rabbits received balanced salt solution (BSS) only or BSS and S epidermidis inoculations in the corneal pocket. Rabbits were monitored for corneal infiltrates after surgery. RESULTS: The ID(50) of the first, second, third, and fourth groups of rabbits was 10(2), 10(4), 10(5), and 10(7) organisms, respectively. The data showed a statistically significant difference between rabbits receiving BSS only and most rabbits receiving BSS plus inoculate at each postoperative measurement (P<.05). CONCLUSIONS: The findings suggest that the use of both preoperative and postoperative antibiotic therapy may be most effective in preventing infection. Postoperative antibiotic therapy increased the number of S epidermidis necessary to cause infection by at least 100-fold over no antibiotic intervention. Preoperative plus postoperative antibiotic therapy increased the number of bacteria necessary to cause infection by at least 100-fold over postoperative therapy alone and by more than 10000-fold over no antibiotic intervention.
Assuntos
Anti-Infecciosos/uso terapêutico , Antibioticoprofilaxia , Úlcera da Córnea/prevenção & controle , Infecções Oculares Bacterianas/prevenção & controle , Fluoroquinolonas/uso terapêutico , Ceratomileuse Assistida por Excimer Laser In Situ/efeitos adversos , Infecções Estafilocócicas/prevenção & controle , Staphylococcus epidermidis/crescimento & desenvolvimento , Animais , Contagem de Colônia Microbiana , Úlcera da Córnea/microbiologia , Modelos Animais de Doenças , Infecções Oculares Bacterianas/microbiologia , Gatifloxacina , Coelhos , Infecções Estafilocócicas/microbiologiaRESUMO
Topoisomerase II alpha is an essential nuclear enzyme involved in DNA replication and a target for many of the clinically useful antineoplastic agents. In a mitoxantrone-selected human leukemia cell line, HL-60/MX2, cellular topoisomerase II (topo II) catalytic activity is decreased, in association with the finding of reduced nuclear topo II alpha and beta protein levels. In addition, HL-60/MX2 cells contain a novel M(r) 160,000 topo II alpha-related protein that localizes predominantly to the cell cytoplasm (W. G. Harker et al., Biochemistry, 30: 9953-9961, 1991). In these studies, we have investigated the molecular mechanisms underlying the altered expression of the topo II alpha protein(s) in these cells. Three topo II alpha mRNAs, 7.2, 6.3, and 4.8 kb, were identified in the HL-60/MX2 cells, with the 6.3 and 4.8 kb transcripts being present in roughly equivalent amounts, while the 7.2-kb mRNA represents < 7% of the total topo II alpha-specific mRNA. Portions of the 3'-coding and 3'-untranslated regions were found to be missing from the 7.2- and 4.8-kb topo II alpha mRNAs by Northern blot analysis. Sequences encoding the 3' regions of the normal and truncated forms of the topo II alpha enzyme were obtained from the HL-60/MX2 cells through the use of a 3'-rapid amplification of cDNA ends strategy. Approximately 1321 nucleotides are missing from the 3'-coding and 3'-untranslated regions of the 4.8-kb mRNA and are replaced by 122 nucleotides that contain an in-frame stop codon and consensus polyadenylation signal. The translation product of the truncated 4388-bp topo II alpha transcript would have a predicted M(r) of 157,850, with 108 COOH-terminal amino acids being replaced by 13 novel residues. Immunoblot analysis confirmed that amino acids in the COOH-terminal region of topo II alpha were missing from the M(r) 160,000 HL-60/MX2 protein, and antisera generated to a synthetic peptide representing the 13 unique amino acids identified a M(r) 160,000 protein in nuclear extracts from these cells. PCR evaluation of the organization of the 3' region of the topo II alpha gene revealed that the 4.8-kb mRNA found in HL-60/MX2 cells diverges from that of the 6.3-kb mRNA at a consensus exon-intron splice donor site. The 122-bp novel nucleotides identified in the truncated transcript appear to originate from an adjacent intron as a result of altered RNA processing. These studies suggest that as a result of the disruption of the carboxy terminus of the topo II alpha protein and the putative nuclear targeting sequences identified therein, cellular localization of the protein is altered, which may confer a growth advantage for the HL-60/MX2 cells in the presence of mitoxantrone.
Assuntos
Códon de Terminação , DNA Topoisomerases Tipo II , DNA Topoisomerases Tipo II/genética , Íntrons , Isoenzimas/genética , Mitoxantrona/farmacologia , Poli A/genética , Poli A/metabolismo , RNA Mensageiro/genética , Sequência de Aminoácidos , Antígenos de Neoplasias , Sequência de Bases , Northern Blotting , Citoplasma/metabolismo , DNA Topoisomerases Tipo II/biossíntese , Proteínas de Ligação a DNA , Resistencia a Medicamentos Antineoplásicos , Células HL-60/efeitos dos fármacos , Células HL-60/metabolismo , Humanos , Isoenzimas/biossíntese , Dados de Sequência Molecular , Transdução de Sinais/fisiologiaRESUMO
A multidrug-resistant variant of the human HL-60 promyelocytic leukemia cell line (HL-60/MX2) has been isolated in vitro by subculturing these cells in progressively increasing concentrations of mitoxantrone. The MX2 cells are cross-resistant to etoposide, teniposide, bisantrene, dactinomycin, 4'-(9-acridinylamino)methanesulfon-m-anisidide, and the anthracyclines daunorubicin and doxorubicin but retain sensitivity to the Vinca alkaloids melphalan and mitomycin C. In addition, the MX2 cells display slight collateral sensitivity to bleomycin. Despite being 30-35-fold less sensitive to mitoxantrone, net [14C]mitoxantrone accumulation at 60 min was reduced by only 10% in the mitoxantrone-resistant cells compared to the parental line. Furthermore, at later time points, e.g., 120 and 180 min, mitoxantrone accumulation in the MX2 cells exceeded that in HL-60 cells by 8.5 and 6.4%, respectively. No significant differences were observed between the sensitive and resistant cell lines in the initial (first 60 s) accumulation of mitoxantrone, and only minor (3-6%) enhancement of mitoxantrone efflux was detected in the resistant cell type. Monoclonal antibodies to P-glycoprotein had no detectable reactivity with membrane vesicles from either the sensitive or resistant cell types as determined by standard immunoblotting techniques. The mitoxantrone-resistant cells displayed a reciprocal translocation [rcpt(1;3)-(q21;p23)] not found in the sensitive parent, but there were no demonstrable double minute chromosomes or homogeneous staining regions in cells from either line. Thus, these mitoxantrone-resistant human leukemia cells display many features which are atypical for the "classic" multidrug resistance phenotype and should provide a useful model for the study of multidrug resistance which is not mediated by P-glycoprotein.
Assuntos
Amplificação de Genes , Cariotipagem , Leucemia/genética , Glicoproteínas de Membrana/genética , Mitoxantrona/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Antineoplásicos/metabolismo , Resistência a Medicamentos , Humanos , Leucemia/metabolismo , Leucemia/patologia , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologiaRESUMO
A human HL-60 leukemia cell line selected for resistance to mitoxantrone, HL-60/MX2, displays cross-resistance only to agents whose cytotoxicities result from interaction with the nuclear enzyme DNA topoisomerase II (topo II). The topo II catalytic activity is reduced 2-fold in the drug-resistant cell line in association with the absence of the M(r) 180,000 isoform of topo II and the finding of novel M(r) 160,000 topo II alpha-related immunoreactive protein in these cells by immunoblot. The topo II alpha (M(r) 170,000) protein levels in nuclear extracts from the HL-60/MX2 cells were noted on average to be approximately 40% lower than in comparable HL-60 nuclei. Studies of the subcellular localization of topo II by immunohistochemical and fractional extraction techniques demonstrated that the M(r) 160,000 topo II alpha-related protein is primarily localized in the cytoplasm. Levels of the 6.3-kilobase topo II alpha mRNA were noted to be reduced 2-fold in the HL-60/MX2 cells in association with the finding of a novel 4.8-kilobase topo II alpha-related mRNA transcript that was present in HL-60/MX2 but not HL-60 cells. The absence of topo II beta protein in nuclear and whole cell extracts from the HL-60/MX2 cells was associated with the virtual absence of detectable topo II beta mRNA in those cells by Northern blot analysis. Using a reverse transcription-PCR assay we were able to demonstrate the presence of very low levels of topo II beta mRNA in HL-60/MX2 cells, representing < 1% of that found in the HL-60 cells. In contrast, the nuclear catalytic activity and cellular mRNA levels of the related nuclear enzyme DNA topoisomerase I were nearly identical in the two cell types. Southern blot analysis of DNA extracted from the drug-sensitive and drug-resistant cells revealed a structural alteration in one topo II alpha allele in the HL-60/MX2 cells, but there was no evidence of rearrangement or hypermethylation of the topo II beta locus. These results indicate that the reduced levels of topo II alpha and beta isoenzymes observed in mitoxantrone-resistant HL-60/MX2 cells are related to changes in the levels of their respective mRNA transcripts. The identification of structural changes in one topo II alpha allele in the HL-60/MX2 cell line suggests that the altered allele may serve as the source of the unique 4.8-kilobase topo II alpha-related mRNA transcript and the M(r) 160,000 protein discovered in those cells.
Assuntos
DNA Topoisomerases Tipo II/biossíntese , Expressão Gênica , Mitoxantrona/toxicidade , Sequência de Bases , Linhagem Celular , Primers do DNA , DNA Topoisomerases Tipo II/análise , DNA Topoisomerases Tipo II/metabolismo , DNA de Neoplasias/isolamento & purificação , DNA de Neoplasias/metabolismo , Resistência a Medicamentos , Humanos , Isoenzimas/análise , Isoenzimas/biossíntese , Isoenzimas/metabolismo , Cinética , Leucemia Promielocítica Aguda , Metilação , Dados de Sequência Molecular , Peso Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , Mapeamento por Restrição , Frações Subcelulares/enzimologia , Transcrição Gênica , Células Tumorais CultivadasRESUMO
OBJECTIVES: To establish that conventional protocols often do not provide an adequate framework for managing interstitial cystitis, and to describe the special role of the urologic caregiver in developing a collaborative relationship with interstitial cystitis (IC) patients that can allay fears and provide hope that this devastating disease can be managed effectively. METHODS: Epidemiologic studies and a decade of experience of IC patients and their physicians are utilized in developing a rationale for a collaborative relationship between urologic caregivers and IC patients. RESULTS: The symptoms of interstitial cystitis-pain, urgency, and urinary frequency-can have a profoundly disruptive effect on patients' lives and present unique challenges to physicians as urologic caregivers. The impact of IC on patients' lives needs to be accounted for empathetically, and appropriate referrals for depression, sexuality, or relationship problems should be made. Pain should be managed aggressively, and patients who have had delayed diagnosis or who have not responded to the traditional treatments should be educated about the array of medical, complementary/alternative, and self-help modalities available. CONCLUSIONS: A successful treatment paradigm requires that physicians and patients be knowledgeable about the array of medical and complementary/alternative therapies and that these be applied in a systematic but creative way. Through empathic support, information, and a flexible treatment protocol, patients will learn to trust the medical process and take an active part in the management of IC.