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1.
J Laryngol Otol ; 137(8): 925-929, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36651334

RESUMO

OBJECTIVE: A standard lateral neck dissection should yield at least 18 lymph nodes. The goal of the present study was to examine what factors might influence the number of lymph nodes retrieved during a neck dissection. METHODS: This was a retrospective cohort study in a tertiary academic referral centre for head and neck oncology. Two hundred and nineteen consecutive neck dissections were examined. Age of the patient and primary site were recorded, along with tumour histology, previous radiotherapy and final nodal count. RESULTS: The mean age was 62.2 ± 13.0 years. The most common primary site was the oral cavity (38.8 per cent). The mean number of lymph nodes was 30.63 ± 13.9. In total, 17.8 per cent had undergone previous radiotherapy. The mean number of lymph nodes was 33.26 ± 13.27 in patients with no previous radiation exposure and 18.47 ± 9.46 in those with previous radiation treatment. CONCLUSION: Lymph node yield from a neck dissection is likely multi-factorial in nature. Previous radiotherapy, the only significant contributor, led to a mean reduction of lymph node yield from 33.3 to 18.5.


Assuntos
Neoplasias de Cabeça e Pescoço , Esvaziamento Cervical , Humanos , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Linfonodos/cirurgia , Linfonodos/patologia , Neoplasias de Cabeça e Pescoço/cirurgia , Neoplasias de Cabeça e Pescoço/patologia , Pescoço/patologia , Estadiamento de Neoplasias
2.
Int J Oral Maxillofac Surg ; 50(8): 999-1002, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33317906

RESUMO

The purpose of this study was to investigate whether the time delay between 'out of house' proprietary virtual surgical planning (OH-VSP) of the mandibular resection for oral cancer and the actual surgery results in compromised margins and oncological disadvantage for the patient. Outcomes of patients who had OH-VSP of their mandibular resection and reconstruction were compared with those of patients who had the same surgery using a conventional non-VSP approach. The groups were similar in patient demographics, tumour stage and size, nodal status, and reconstruction complexity. VSP resulted in a significant reduction in operating time (P<0.01). VSP did not affect bony (P=0.49) or soft tissue (P=0.22) margin status. In summary, VSP reduced the operating theatre time, and despite the time interval between bony resection planning and surgery, there was no compromise to the oncological safety of the operation.


Assuntos
Retalhos de Tecido Biológico , Reconstrução Mandibular , Neoplasias Bucais , Cirurgia Assistida por Computador , Fíbula , Humanos , Mandíbula/cirurgia , Neoplasias Bucais/cirurgia
3.
Aust Dent J ; 66(2): 205-211, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32990942

RESUMO

The neurofibromatoses [NF 1, NF 2 and schwannomatosis] are a group of genetic disorders that lead to the development of nervous system tumours and have diverse dermatologic, neurologic, ophthalmic, skeletal and vascular effects. The most common is NF 1 (Neurofibromatosis 1) also known as von Recklinghausen's disease, which is one of the most common human genetic diseases. Oral manifestations of NF 1 are reported in 72% of cases and in one of our cases precipitated attendance at a general dental practitioner (GDP), subsequent diagnosis and genetic screening for family members. This disease may go undiagnosed due to its variable expressivity of symptoms. The pivotal importance of a GDP in the discovery and early referral to an oral or oral and maxillofacial surgeon for further investigation and diagnosis of this condition is highlighted. Knowledge of the most common features of neurofibromatosis can facilitate the speedy referral and subsequent diagnosis of generalized neurofibromatosis, local surgical management of benign neoplasms and long term management of its other clinical features. Dentists should be aware of the classic symptoms of this condition and of their role in long-term care in view of the risk of local recurrence and malignant transformation.


Assuntos
Neurofibromatoses , Neurofibromatose 1 , Odontólogos , Humanos , Recidiva Local de Neoplasia , Neurofibromatoses/diagnóstico , Neurofibromatose 1/complicações , Neurofibromatose 1/diagnóstico , Papel Profissional
4.
J Hosp Infect ; 105(4): 589-592, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32590011

RESUMO

The role of the hospital environment in the transmission of infection is well described. With an emerging infection whose mode of transmission is under investigation, strict infection prevention and control measures, including patient isolation, hand hygiene, personal protective equipment that is doffed on exiting the patient room, and environmental cleaning should be implemented to prevent spread. Environmental testing demonstrated that COVID-19 patients contaminated the patient area (11/26, 42.3% of tests) but contamination of general ward areas was minimal (1/30, 3%) and the virus was detected after cleaning on one item only (1/25, 4%) which was noted to be in disrepair.


Assuntos
Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Surtos de Doenças/prevenção & controle , Hospitais/estatística & dados numéricos , Controle de Infecções/métodos , Controle de Infecções/estatística & dados numéricos , Pandemias/prevenção & controle , Quartos de Pacientes/estatística & dados numéricos , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Betacoronavirus , COVID-19 , Monitoramento Ambiental/métodos , Monitoramento Ambiental/estatística & dados numéricos , Humanos , Irlanda , SARS-CoV-2
5.
Ir Med J ; 112(10): 1017, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-32081194

RESUMO

Aim: To undertake a retrospective analysis of the use of a diagnostic pathology service, to determine the source of oral biopsies submitted for histological analysis, and to examine the range and frequencies of histologically diagnosed oral lesions in an Irish population. Methods: A retrospective analysis was carried out on all oral biopsies submitted for histological analysis to an oral and maxillofacial diagnostic pathology service from June to December 2015. Results: In total 724 oral biopsies were submitted. The majority of diagnoses were benign (80.3%) and the remaining diagnoses were made up of malignancies (6.7%) and potentially malignant disorders (PMDs), histologically characterised by epithelial dysplasia (13%). Less than 1% of biopsies were submitted from general dentists in primary care. Conclusion: This study showed that oral biopsies are not submitted from the primary care setting, but rather from hospital-based specialist units or referral-based specialist practitioners. There was a broad range of histological diagnoses, the majority of which were benign.


Assuntos
Odontologia Geral/estatística & dados numéricos , Doenças da Boca/diagnóstico , Patologia Bucal/estatística & dados numéricos , Padrões de Prática Odontológica/estatística & dados numéricos , Biópsia/estatística & dados numéricos , Unidade Hospitalar de Odontologia/estatística & dados numéricos , Feminino , Humanos , Masculino , Neoplasias Bucais/diagnóstico , Encaminhamento e Consulta/estatística & dados numéricos , Estudos Retrospectivos
6.
Endocr Pathol ; 29(3): 231-235, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29978374

RESUMO

The aim of this study was to determine the number of cases of papillary thyroid carcinoma (PTC) which could be reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) in our institute over a 10-year period, document their clinical status and assess the number of slides that had to be reviewed per case to exclude NIFTP. The histopathology reports for thyroid resections for all papillary carcinoma over a 10-year period (2007-2016) were reviewed. Five hundred forty-five histopathology reports were reviewed, and 71 cases were identified as potential cases of NIFTP. Forty-nine (69%) cases had been referred from external departments and the slides were not available for review. Of the remaining 22 (31% of 71) cases, 5 were reclassified as NIFTP. The 17 cases that were not reclassified as NIFTP required review of 114 of 356 slides (median 5.5 slides per case) was required to exclude NIFTP. For the 5 NIFTP cases, 58 slides were reviewed (median 12 slides per case). We found that review of the histology reports alone was adequate for exclusion in most cases, e.g. classic PTC or EVPTC cases with documented lymphovascular invasion or capsular invasion. As a single exclusion criterion is required for exclusion from reclassification as NIFTP, this can be achieved efficiently. Two of the five patients received radioactive iodine [RAI] as per standard treatment at time of diagnosis, on the basis of tumour size. None have recurrent or metastatic disease with mean follow-up of 5.8 years.


Assuntos
Adenocarcinoma Folicular/classificação , Patologia Clínica , Câncer Papilífero da Tireoide/classificação , Neoplasias da Glândula Tireoide/classificação , Carga de Trabalho , Adenocarcinoma Folicular/patologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Adulto Jovem
7.
Head Neck Pathol ; 3(3): 246-8, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20596979

RESUMO

While most head and neck squamous carcinoma (HNSCC) occurs in older people, an increasing number of young patients are being affected worldwide, with up to 5.5% <40. These are predominantly oral and oropharyngeal cancers. Some patients have heavy exposure to the usual risk factors, but an increasing number do not. Part of this trend appears to be due to rising numbers of HPV associated tonsil carcinoma, particularly in males (smokers and non-smokers). A subset of young patients, however, is non-smoking females usually with tongue cancers, not related to HPV, the aetiology of which is unclear. Various mechanisms may be at work here: the variation in ability to detoxify the products of smoke and alcohol varies in individuals, which may explain why environmental exposure to smoke seems to play a role in some non-smokers with HNSCC. The role of marijuana remains possible but uncertain, and it may be that anaemia is a co-factor. There is an increased risk of HNSCC in first degree relatives of HNSCC patients, and while inherited syndromes associated with HNSCC are rare, elucidation of their genetics may help to develop our understanding the disease in these young patients without recognised risk factors.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/etiologia , Neoplasias de Cabeça e Pescoço/epidemiologia , Neoplasias de Cabeça e Pescoço/etiologia , Adulto , Idade de Início , Feminino , Humanos , Masculino , Fatores de Risco
8.
Head Neck Pathol ; 3(3): 249-51, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20596980

RESUMO

A recent increase in the number of young patients (often nonsmokers) developing head and neck squamous cell carcinoma (HNSCC) has been documented, however, there remains no clear evidence to support the significance of any single determinant. The typical HNSCC arises as a result of a multistep process and the progression model involving multiple genetic and epigenetic events is thought to be relatively consistent. While the progression model itself may be consistent, detection methods used in genomic studies are variable and all have their limitations. This article reviews changes at a molecular level in the typical HNSCC patient (the over 40 year old male smoker) and compares the profile to that of the young adult with HNSCC. Human papillomavirus infection with high risk types 16 and 18 has widely been reported as one of the prominent mechanisms behind the development of oropharyngeal cancer. A review of recent studies in relation to HPV and HNSCC is undertaken in this article, in an effort to examine the role that HPV plays in the development of HNSCC in young adults.


Assuntos
Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/virologia , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/virologia , Infecções por Papillomavirus/complicações , Adulto , Carcinoma de Células Escamosas/epidemiologia , Hibridização Genômica Comparativa , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Neoplasias de Cabeça e Pescoço/epidemiologia , Humanos , Masculino
9.
Virchows Arch ; 450(3): 249-60, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17252232

RESUMO

The most common sub-variant of papillary thyroid carcinoma (PTC) is the so-called follicular variant (FVPTC), which is a particularly problematic lesion and can be challenging from a diagnostic viewpoint even in resected lesions. Although fine needle aspiration cytology is very useful in the diagnosis of PTC, its accuracy and utility would be greatly facilitated by the development of specific markers for PTC and its common variants. We used the recently developed Applied Biosystems 1700 microarray system to interrogate a series of 11 benign thyroid lesions and conditions and 14 samples of PTC (six with classic morphology and eight with follicular variant morphology). TaqMan(R) reverse transcriptase-polymerase chain reaction was used to validate the expression portfolios of 50 selected transcripts. Our data corroborates potential biomarkers previously identified in the literature, such as LGALS3, S100A11, LYN, BAX, and cluster of differentiation 44 (CD44). However, we have also identified numerous transcripts never previously implicated in thyroid carcinogenesis, and many of which are not represented on other microarray platforms. Diminished expression of metallothioneins featured strongly among these and suggests a possible role for this family as tumour suppressors in PTC. Fifteen transcripts were significantly associated with FVPTC morphology. Surprisingly, these genes were associated with an extremely narrow repertoire of functions, including the major histocompatibility complex and cathepsin families.


Assuntos
Adenocarcinoma Folicular/genética , Adenocarcinoma Papilar/genética , Biomarcadores Tumorais/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/metabolismo , Adenocarcinoma Folicular/patologia , Adenocarcinoma Papilar/metabolismo , Adenocarcinoma Papilar/patologia , Biomarcadores Tumorais/metabolismo , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Reação em Cadeia da Polimerase/métodos , Estudos Prospectivos , RNA Mensageiro/metabolismo , Taq Polimerase/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Tireoidectomia
10.
Int J Oral Maxillofac Surg ; 36(3): 259-62, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17113753

RESUMO

INTRODUCTION: Insulin-like growth factor (IGF) possesses mitogenic properties promoting cellular proliferation and inhibiting cellular apoptosis. Reported evidence suggests that cancer (non-oral) is associated with high circulating levels of IGF-1 and low levels of IGFBP-3. AIMS: This study measured circulating levels of IFG-1 and IGFBPs -1, -2 and -3 in oral cancer patients. METHODOLOGY: Blood was collected from surgical patients and controls. Samples were assayed for IGF-1 and IGFBPs -1, -2, -3, using commercially available enzyme-linked immunosorbant assays (ELISA; R&D Systems Europe, Oxon, UK). RESULTS: Twenty-seven oral cancer and 31 age- and sex-matched patients were recruited. Mean IGF-1 and IGFBP-3 levels were significantly lower in cancer patients than controls (85.3 ng/ml and 2008 ng/ml versus 191 ng/ml and 2935 ng/ml, P<0.001). In contrast, levels of IGFBPs 1 and 2 were significantly higher in cancer patients than in controls. No significant association was demonstrated with tumour size or nodal metastases. DISCUSSION: This study has shown that in contrast to other cancers, circulating levels of IGF-1 and IGFBP-3 may both be lowered in patients with head and neck cancer.


Assuntos
Biomarcadores Tumorais/sangue , Carcinoma de Células Escamosas/sangue , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/sangue , Fator de Crescimento Insulin-Like I/análise , Neoplasias Bucais/sangue , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
Br J Oral Maxillofac Surg ; 44(3): 203-6, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16005553

RESUMO

Classically, squamous cell carcinoma (SCC) of the head and neck is a disease of older adults, but recently there have been reports of an increasing incidence in young people. This study of patients in the Republic of Ireland compares sex distribution, sites, risk factors, stage and grade of tumour, and nodal status of 130 patients with SCC of the head and neck, 30 of whom were less than 40 years old. There was a highly significant association between age, smoking status, and site of tumour. For the first time to our knowledge in a study such as this, the preoperative haematological status of the patients was assessed, and although 15% were anaemic there was no significant difference in the occurrence of anaemia between the younger and the older patients. We think that it is possible that the biology of SCC of the head and neck in young people differs from that in older people.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Neoplasias de Cabeça e Pescoço/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Feminino , Humanos , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Distribuição por Sexo , Fumar/efeitos adversos
12.
Int J Oral Maxillofac Surg ; 34(6): 674-7, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16053893

RESUMO

The objective of this study was to examine the histological features of apparently normal oral mucous membrane adjacent to lesions of oral lichen planus. Twenty-six patients attending an oral medicine unit with clinical lesions typical of oral lichen planus had biopsies of lesional and perilesional sites. Biopsies were examined for histopathological features of oral lichen planus. Twenty-two (85%) of lesional biopsies and 12 (46%) of the perilesional biopsies were reported as either typical or showing some features of lichen planus. Twelve of these 22 cases (55%) had both lesional and perilesional biopsies reported as either typical or showing some features of lichen planus. These 12 cases represented 46% of all cases. In four cases (15%) neither the lesional nor the adjacent perilesional biopsy was reported as lichen planus. The inflammatory process in oral lichen planus may extend beyond the confines of the clinical lesion into adjacent mucous membrane of normal appearance.


Assuntos
Líquen Plano Bucal/patologia , Mucosa Bucal/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
Br J Oral Maxillofac Surg ; 43(4): 281-4, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15993279

RESUMO

We examined the records of two cohorts of patients who were seen from 1960 to 1999 with a diagnosis of squamous cell carcinoma (SCC) of the mouth and throat, one series being retrospective (n=400) and the other prospective (n=213) to find out about delays in diagnosis. The median delay in both cohorts was 3 months and the patients were responsible for the delay in most cases (n=319, 81% and n=160, 78%, respectively). Half the patients in each cohort had delayed diagnoses (n=217, 54% and n=119, 56%, respectively) and similar percentages (n=110, 53% and n=172, 47%) presented with advanced disease (stage III or IV). These were not the same patients for there was no correlation between delay and stage or survival. Logistic regression analysis showed that non-white race (p=0.01) and high-grade histology (p=0.002) predicted advanced disease. The proportion of patients presenting with advanced disease had not changed in 40 years despite public education. We suggest that some tumours may be silent and that initial symptoms do not reliably predict early disease.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias Bucais/diagnóstico , Neoplasias Faríngeas/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
14.
Int J Surg Pathol ; 13(1): 1-8, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15735849

RESUMO

The purpose of this study was to assess BRAF mutation rates in various thyroid tissues and to investigate if concomitant mutations with ret/PTC activation occurred in inflammatory and neoplastic lesions. To this end, we developed a novel Taqman based screening assay for the common T1799A BRAF mutation. Heterozygous T1799A mutations were detected in 13 of 34 (44%) papillary thyroid carcinomas (PTCs) tested. No such mutations were detected in the other tissue types tested. Concomitant presence of both oncogenes was reported in 5 of the 34 PTCs. A significant temporal trend was observed, with ret/PTC chimera detected for the most part before 1997 and BRAF mutations being more prevalent after 1997. The results suggest that some environmental/etiological agent(s) may have influenced the pathobiology of thyroid tumor development, among the population examined, over time.


Assuntos
Carcinoma Papilar/genética , Mutação , Proteínas de Fusão Oncogênica/genética , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias da Glândula Tireoide/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/epidemiologia , Carcinoma Papilar/patologia , Estudos de Coortes , DNA de Neoplasias/análise , Feminino , Humanos , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Proteínas Tirosina Quinases , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/patologia , Tireoidite Autoimune/genética , Tireoidite Autoimune/patologia
15.
Oral Oncol ; 40(3): 348-52, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14747068

RESUMO

Although hyalinizing clear cell carcinoma (HCCC) had been previously illustrated by several authors, it was not until 1994 that this tumour was characterized by Milchgrub et al. [Am J Surg Pathol (1994),18,74] and separated from the heterogeneous group of clear cell carcinomas described in the literature. HCCC is a distinctive infiltrative low-grade, monomorphic, glycogen-rich clear cell carcinoma with prominent stromal hyalinization occurring most often in the minor salivary glands of adult women. A case of hyalinizing clear cell carcinoma arising in the tongue of an adult female is described with special reference to the presence of minor foci of mitotic activity, necrosis and anaplasia in this otherwise typical low-grade carcinoma. Widespread metastases and death within a year of initial presentation in this case suggests that there may be a subset of this indolent tumour in which these features are associated with a poor prognosis.


Assuntos
Adenocarcinoma de Células Claras/patologia , Neoplasias das Glândulas Salivares/patologia , Neoplasias da Língua/patologia , Adenocarcinoma de Células Claras/secundário , Evolução Fatal , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico
16.
Br Dent J ; 196(2): 79-81, 2004 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-14739958

RESUMO

Necrotizing sialometaplasia is a self-limiting, variably ulcerated benign process affecting minor salivary glands. Accurate histological diagnosis is paramount, as it has been mistaken for malignancy, which has resulted in excessively aggressive and unnecessary radical surgery. A unique case of bilateral necrotizing sialometaplasia, presenting with anaesthesia of the greater palatine nerves, is described. An attempt at active therapy with intralesional steroids had no effect on the course of the condition.


Assuntos
Sialometaplasia Necrosante/patologia , Adulto , Diagnóstico Diferencial , Feminino , Glucocorticoides/uso terapêutico , Humanos , Hipestesia/etiologia , Injeções Intralesionais , Palato/inervação , Triancinolona/uso terapêutico
17.
Artigo em Inglês | MEDLINE | ID: mdl-11709690

RESUMO

The giant cell granuloma of the jaws is a benign osteolytic lesion that may be treated by curettage, intralesional corticosteroids, or calcitonin. These medical treatments may be particularly useful when lesions arise in the immature facial skeleton, recur, or enlarge very rapidly-the last two situations being recognized complications of pregnancy. In this study, a patient is presented with a central giant cell lesion of the maxilla that switched from a relatively indolent growth pattern to become a rapidly enlarging and destructive lesion in the maxilla almost immediately after the patient became pregnant. Although calcitonin treatment is normally avoided in pregnancy, it proved highly effective, caused no obstetric or fetal side effects, and was not contraindicated by renal failure due to lupus nephritis. Histologically, the lesion was converted to a fibro-osseous lesion-like appearance. On the basis of the results of this case, calcitonin appears to be a safe, effective, and conservative treatment for giant cell granulomas that enlarge rapidly during pregnancy.


Assuntos
Calcitonina/uso terapêutico , Granuloma de Células Gigantes/tratamento farmacológico , Doenças Maxilares/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Adulto , Biópsia , Matriz Óssea/patologia , Calcitonina/administração & dosagem , Feminino , Fibrose , Células Gigantes/patologia , Granuloma de Células Gigantes/patologia , Humanos , Injeções Subcutâneas , Doenças Maxilares/patologia , Gravidez , Complicações na Gravidez/patologia
19.
Nucleic Acids Res ; 25(3): 491-6, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9016586

RESUMO

The antitumor agent cis-diamminedichloroplatinum(II) (cisplatin) introduces cytotoxic DNA damage predominantly in the form of intrastrand crosslinks between adjacent purines. Binding assays using a series of duplex oligonucleotides containing a single 1,2 diguanyl intrastrand crosslink indicate that human cell extracts contain factors that preferentially recognise this type of damage when the complementary strand contains T opposite the 3', and C opposite the 5'guanine in the crosslink. Under the conditions of the band-shift assay used, little binding is observed if the positions of the T and C are reversed in the complementary strand. Similarly, duplexes containing CC or TT opposite the crosslink are recognised relatively poorly. The binding activity is absent from extracts of the colorectal carcinoma cell lines LoVo and DLD-1 in which the hMutSalpha mismatch recognition complex is inactivated by mutation. Extensively purified human hMutSalpha exhibits the same substrate preference and binds to the mismatched platinated DNA at least as well as to an identical unplatinated duplex containing a single G.T mismatch. It is likely, therefore, that human mismatch repair may be triggered by 1,2 diguanyl intrastrand crosslinks that have undergone replicative bypass.


Assuntos
Adenosina Trifosfatases , Cisplatino , Adutos de DNA , Reparo do DNA , Proteínas de Ligação a DNA , Proteínas de Escherichia coli , Proteínas de Bactérias/metabolismo , Extratos Celulares , Humanos , Proteína MutS de Ligação de DNA com Erro de Pareamento , Células Tumorais Cultivadas
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