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1.
Ann R Coll Surg Engl ; 100(2): 129-134, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29046089

RESUMO

Introduction The incidence of deep neck space infection (DNSI) is rising and appears to be related to falling rates of tonsillectomy. The purpose of this study was to assess demographics of patients presenting with DNSI and the financial burden to the National Health Service (NHS). Methods Data were collected retrospectively on patients aged over 16 years admitted to NHS Greater Glasgow and Clyde with DNSI between 2012 and 2016. Demographics, aetiology and use of hospital resources were reviewed. The cost of hospital admissions was calculated using data from NHS Scotland's Information Services Division, the local diagnostics division and the British National Formulary. Results Seventy-four patients were admitted with DNSI during the study period. Forty (54%) were male. The mean age was 44.0 years (range: 16-86 years). The most frequent source of infection was the tonsil (n=30, 40.5%). The most common infective organism was Streptococcus constellatus (n=9, 12.2%). The mean length of stay was 11 days. Fifty-five patients (74.3%) required operative intervention. The mean cost of admission per patient was £5,700 (range: £332-£46,700). Conclusions This study highlights the high cost burden of DNSI to the NHS. The incidence of DNSI in Glasgow has risen over the study period; contributing factors may include the reduced tonsillectomy rate and a reduction in antibiotic prescribing. As the incidence of DNSI continues to rise, there will be an increase in cost to the NHS, which must be planned for.


Assuntos
Tempo de Internação , Pescoço/cirurgia , Doenças Faríngeas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Tempo de Internação/economia , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Doenças Faríngeas/complicações , Doenças Faríngeas/economia , Doenças Faríngeas/epidemiologia , Doenças Faríngeas/cirurgia , Estudos Retrospectivos , Tonsilectomia/economia , Tonsilectomia/estatística & dados numéricos , Adulto Jovem
2.
J Laryngol Otol ; 129(2): 174-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25684337

RESUMO

BACKGROUND: Branchial cleft cysts occur because of a failure of involution of the second branchial cleft. However, as well-differentiated squamous cell carcinoma can mimic branchial cleft cysts, there is a lack of consensus on the appropriate management of cystic neck lumps. OBJECTIVE: To report our experience of fine needle aspiration cytology and frozen section examination in the management of cystic neck lumps. METHOD: Retrospective case note review of patients managed in the Southern General Hospital, Scotland, UK. RESULTS: The sensitivity of fine needle aspiration cytology and frozen section for detecting branchial cleft cysts was 75 per cent and 100 per cent respectively. Two patients who did not undergo intra-operative frozen section examination were either over- or under-treated, which is discussed. CONCLUSION: Adult patients subjected to surgical excision of a suspected branchial cyst should undergo intra-operative frozen section analysis regardless of clinical suspicion for malignancy. This part of management is critical to ensure patients are offered appropriate treatment.


Assuntos
Biópsia por Agulha Fina/métodos , Branquioma/patologia , Secções Congeladas/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Branquioma/diagnóstico , Branquioma/terapia , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Diagnóstico Diferencial , Feminino , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias de Cabeça e Pescoço/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Carcinoma de Células Escamosas de Cabeça e Pescoço , Adulto Jovem
4.
J Laryngol Otol ; 125(1): 3-9, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20950510

RESUMO

OBJECTIVE: To review the aetiopathogenesis, clinical characteristics, immunohistochemical profile, prognosis and treatment options for primary thyroid squamous cell carcinoma, and to compare it with squamous cell carcinoma metastatic to the thyroid, thus providing the reader with a framework for differentiating primary and secondary disease. METHOD: Review of English language literature from the past 25 years. SEARCH STRATEGY: A search of the Medline, Embase and Cochrane databases (April 1984 to April 2009) was undertaken to enable a comprehensive review. RESULTS: After applying strict criteria for the diagnosis of primary thyroid squamous cell carcinoma, 28 articles were identified reporting 84 cases. When reviewing secondary thyroid squamous cell carcinoma, we only analysed cases of squamous cell carcinoma metastatic to the thyroid gland, and found 28 articles reporting 78 cases. CONCLUSION: It is possible to differentiate between primary and secondary thyroid squamous cell carcinoma, on the basis of combined evidence from clinical examination and endoscopic, pathological and radiological evaluation. Such differentiation is important, as the prognosis for primary squamous cell carcinoma is uniformly poor irrespective of treatment, and the most suitable option may be supportive therapy. Treatment for secondary squamous cell carcinoma of the thyroid varies with the site and extent of spread of the primary tumour.


Assuntos
Carcinoma de Células Escamosas , Neoplasias da Glândula Tireoide , Obstrução das Vias Respiratórias/etiologia , Obstrução das Vias Respiratórias/cirurgia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/secundário , Terapia Combinada , Diagnóstico Diferencial , Progressão da Doença , Endoscopia , Humanos , Imageamento por Ressonância Magnética , Cuidados Paliativos/métodos , Prognóstico , Taxa de Sobrevida , Neoplasias da Glândula Tireoide/mortalidade , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/secundário , Tomografia Computadorizada por Raios X
5.
Br Dent J ; 207(8): 361-2, 2009 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-19851377

RESUMO

Foreign body ingestion in dental and ENT practice is a commonly encountered emergency. In most cases, particularly in adults, there is a definite history of its ingestion, the nature of the foreign body is usually identifiable and the patient almost always presents immediately. We report an unusual case of an elderly patient with a six month history of progressive dysphagia referred to us by the physicians after investigations which were highly suggestive of a hypopharyngeal malignancy. Surprisingly when a biopsy was attempted, the hypopharyngeal mass turned out to be a dental plate. Dentists and otolaryngologists should be aware that pharyngeal foreign bodies can present without a positive history and can have a clinical presentation mimicking malignancy. A history of head injury, dementia, alcohol and drug abuse should be specifically excluded. A routine examination of a patient with dysphagia should include eliciting a specific history of wearing dentures and examination of teeth. In future designs for dental plates, bridges and crowns the use of a radio opaque material should be considered.


Assuntos
Transtornos de Deglutição/etiologia , Bases de Dentadura , Corpos Estranhos , Hipofaringe , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Corpos Estranhos/complicações , Corpos Estranhos/diagnóstico , Humanos , Neoplasias Hipofaríngeas/diagnóstico , Masculino
6.
Cell Death Differ ; 16(4): 593-602, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19136942

RESUMO

Transforming growth factor-beta (TGF-beta) potently induces apoptosis in Burkitt's lymphoma (BL) cell lines and in explanted primary human B lymphocytes. The physiological relevance and mechanism of TGF-beta-mediated apoptosis induction in these cells remains to be determined. Here we demonstrate the requirement for TGF-beta-mediated regulation of BIK and BCL-X(L) to activate an intrinsic apoptotic pathway in centroblastic BL cells. TGF-beta directly induced transcription of BIK and a consensus Smad-binding element identified in the BIK promoter recruits TGF-beta-activated Smad transcription factor complexes in vivo. TGF-beta also transcriptionally repressed expression of the apoptosis inhibitor BCL-X(L). Inhibition of BCL-X(L) sensitised BL cells to TGF-beta-induced apoptosis whereas overexpression of BCL-X(L) or suppression of BIK by shRNA, diminished TGF-beta-induced apoptosis. BIK and BCL-X(L) were also identified as TGF-beta target genes in purified normal human centroblast B cells and immunohistochemical analyses of tonsil tissue revealed widespread TGF-beta receptor-regulated Smad activation and a focal pattern of BIK expression. Furthermore, using a selective inhibitor of the TGF-beta receptor we provide evidence that autocrine TGF-beta signalling through ALK5 contributes to the default apoptotic programme in normal human centroblasts undergoing spontaneous apoptosis. Our data suggests that TGF-beta may act as a physiological mediator of human germinal centre homoeostasis by regulation of BIK and BCL-X(L).


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Proteína bcl-X/metabolismo , Proteínas Reguladoras de Apoptose/genética , Linfócitos B/citologia , Linfócitos B/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Ensaio de Desvio de Mobilidade Eletroforética , Citometria de Fluxo , Humanos , Immunoblotting , Imuno-Histoquímica , Técnicas In Vitro , Proteínas de Membrana/genética , Proteínas Mitocondriais , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteína bcl-X/genética
8.
J Laryngol Otol ; 117(9): 739-40, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14561369

RESUMO

Ectopic submandibular thyroid tissue is a rare entity and poses difficult diagnostic and management problems. The first case of ectopic submandibular thyroid with a normotopic multinodular goitre is presented


Assuntos
Coristoma/diagnóstico , Bócio Nodular/diagnóstico , Glândula Tireoide , Idoso , Biópsia por Agulha Fina , Coristoma/complicações , Coristoma/cirurgia , Feminino , Bócio Nodular/complicações , Bócio Nodular/cirurgia , Humanos , Pescoço/diagnóstico por imagem , Tireoidectomia , Tomografia Computadorizada por Raios X
9.
J Am Geriatr Soc ; 49(7): 941-7, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11527486

RESUMO

OBJECTIVE: To test the hypothesis that performance on a clock-drawing test in a mailed survey to an older cohort is associated with known and potential risk and protective factors for Alzheimer's disease. DESIGN: The Leisure World Cohort Study is an ongoing study, begun in 1981, of nearly 14,000 older adults. In November 1992, the 8,406 living cohort members were mailed a follow-up questionnaire. SETTING: Leisure World Laguna Hills, a southern California retirement community. PARTICIPANTS: The study population is a predominantly white, well-educated, upper-middle-class community; approximately two-thirds are women. Data from 4,843 cohort members (mean age 80 years; range 52-101) were analyzed. MEASUREMENTS: The questionnaire included a clock-drawing task: a predrawn circle 3 1/4 inches (8.3 cm) in diameter was provided with instructions "In the circle below, draw in the numbers as on a clock face. Make no erasures." Clocks were scored on 7 items: all numbers 1-12 present without adding extra or omitting numbers, sequencing of numbers, position of numbers, orientation of numbers to circle, consistent number style (either Arabic or Roman), tilt of numbers, and superfluous marks. A total clock score was calculated by summing the number of correct individual items (0-7). We also classified individuals as cognitively impaired by a previously suggested method: individuals were affected if they did not have three numbers drawn in the upper left quadrant of the clock face. RESULTS: Ninety percent or more of the participants across all ages placed the numbers 1 to 12 on their clocks without omissions or additions; 35% completed the clock drawing without error. The mean total clock scores decreased with each successive 5-year age group in both men and women. Regression analysis indicated a significant effect for age (b = -0.15, P <.0001), education (b = 0.05, P =.0001), smoking (b = 0.13, P =.03), and female gender (b = -0.05, P =.05) and a marginally significant effect of nonrheumatoid arthritis (b = 0.05, P =.07) on total clock score. No other measured variable had a significant effect. Cognitively impaired individuals were more likely to be female and older. After adjusting for age and gender, they were also more likely to be hypertensive and to have taken blood pressure medication and less likely to be college graduates, have glaucoma or arthritis, and to have taken vitamin supplements. CONCLUSION: The clock-drawing task is an appealing measure of cognitive function for large epidemiological studies because it is a simple, self-administered test that is easily adapted to mail surveys and correlates with more-detailed and more-time-consuming cognitive screens. Although it is relatively free of influence by language, cultural, or ethnic factors, our study shows that even in a highly educated population, clock drawing is influenced by educational level and other known risk factors for Alzheimer's disease. Thus a clock-drawing task may help predict cognitive frailty and future disability in older people. Such determination can direct high-risk individuals to earlier diagnosis, potential therapies, and better management.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/etiologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Avaliação Geriátrica , Testes Neuropsicológicos/normas , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/classificação , Doença de Alzheimer/prevenção & controle , Anti-Inflamatórios não Esteroides/efeitos adversos , Transtornos Cognitivos/classificação , Transtornos Cognitivos/prevenção & controle , Depressão/complicações , Escolaridade , Feminino , Seguimentos , Habitação para Idosos , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores de Risco , Sensibilidade e Especificidade , Distribuição por Sexo , Inquéritos e Questionários
10.
J Exp Bot ; 52(358): 1129-33, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11432930

RESUMO

The effect of water stress on the early seedling growth of onions was studied by placing newly-germinated seedlings in vermiculite equilibrated at different water potentials. Roots and shoots elongated more at -0.29 than at -0.64 MPa, but did not elongate at -1.66 MPa. However, roots and shoots of seedlings that had been incubated in vermiculite at -1.66 MPa for up to 35 d resumed elongation when subsequently placed on wet filter boards. This suggests that water stress can induce quiescence in newly-germinated seedlings.


Assuntos
Allium/crescimento & desenvolvimento , Água/metabolismo , Silicatos de Alumínio , Germinação , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/crescimento & desenvolvimento , Sementes
11.
J Exp Bot ; 52(354): 167-71, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11181726

RESUMO

Roots of 3-d-old pea seedlings (Pisum sativum L.) were mechanically impeded using a sand core apparatus, which allowed mechanical impedance to be varied independently of aeration and water status. Turgor of root cortical cells was then measured using a pressure probe. In seedlings grown in sand cores for 1 d, impedance had little effect on turgor, but in seedlings grown in the sand cores for 2 d, impedance increased turgor by 0.18 MPa in the apical 6 mm.


Assuntos
Pisum sativum/fisiologia , Fenômenos Biomecânicos , Raízes de Plantas/fisiologia , Pressão , Dióxido de Silício
12.
Breast Cancer Res Treat ; 60(2): 167-72, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10845279

RESUMO

BACKGROUND: Tamoxifen is an oral anti-estrogen used in the treatment of breast cancer and recently approved to reduce the incidence of breast cancer in high risk women. As a large clinical trial of tamoxifen has reported an increased risk of cataract, we conducted a study of women with breast cancer to evaluate the association of tamoxifen with cataracts and other eye problems. METHODS: We attempted to recruit previously interviewed patients who were cases in a population-based case-control study of 2653 women with primary breast cancer diagnosed between 1987 and 1996 at ages 55-72 years in Los Angeles County, California, USA. In November 1997, each case was mailed a questionnaire to ascertain self-reported incidence of eye diseases and Amsler grid test scores. Information from 1297 women aged 57-75 years of age was analyzed. Women reporting treatment with tamoxifen were categorized as standard-term users (4-5 years), short-term users (<4 years), or long-term users (6+ years) and compared to non-users. All p-values, relative risks, and confidence intervals for differences in eye problems and grid test results are adjusted for age and stage of disease at diagnosis. FINDINGS: Standard-term and long-term users of tamoxifen more frequently reported developing cataracts than non-users (18.2%, 21.4% vs. 14.8%). The relative risk was 1.40 (95% confidence interval 0.94-2.10) for standard-term users and 1.70 (1.11-2.59) for long-term users. Tamoxifen use was unrelated to frequency of glaucoma or macular degeneration or to Amsler grid test results. INTERPRETATION: Our study suggests that five or more years of tamoxifen use increases risk of cataracts. Healthy women considering tamoxifen use to reduce risk of breast cancer should be advised of the possibility of cataract development. Women choosing such therapy should be diligent about receiving regular ocular exams.


Assuntos
Antineoplásicos Hormonais/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Catarata/induzido quimicamente , Tamoxifeno/efeitos adversos , Idoso , Antineoplásicos Hormonais/uso terapêutico , Catarata/epidemiologia , Oftalmopatias/induzido quimicamente , Oftalmopatias/epidemiologia , Feminino , Seguimentos , Humanos , Incidência , Pessoa de Meia-Idade , Medição de Risco , Tamoxifeno/uso terapêutico , Fatores de Tempo
13.
Resuscitation ; 44(2): 109-17, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10767498

RESUMO

This paper describes an initiative to build a multimedia computer-based teaching package for cardiopulmonary resuscitation. The project resulted from a perceived gap in the undergraduate medical curriculum allied to concern from medical students. The software application was designed to be networked and used as an adjunct to taught life support courses for undergraduate medical students. The package comprises tutorials and test questions in basic and advanced life support. It incorporates sound, video, graphics and animation to illustrate the techniques involved and is distributed on CD ROM for the PC. The content is based on the 'Advanced Life Support Manual', produced by the Resuscitation Council (UK) and incorporates all changes to the guidelines made during 1997 and 1998. The basic life support section has been networked locally, and has been tested on more than 60 third year medical students attending a local basic life support course. It was found that students who used the package performed significantly better in theoretical assessments than those who did not.


Assuntos
Reanimação Cardiopulmonar/educação , Instrução por Computador , Educação de Graduação em Medicina , Feminino , Humanos , Masculino , Materiais de Ensino
14.
Breast Cancer Res Treat ; 64(2): 165-76, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11194452

RESUMO

BACKGROUND: Tamoxifen is an anti-estrogen used in the treatment of breast cancer and to reduce the incidence of breast cancer in high risk women. Although the brain is an estrogen target organ and several studies have found a beneficial effect of estrogen on cognitive function, the effect of tamoxifen on cognition has not been reported. Therefore, we initiated a follow-up study of women who had participated in a study of breast cancer to assess the effect of tamoxifen treatment on cognitive function. METHODS: We recruited previously interviewed patients who were cases in a population-based case-control study of 2,653 women with primary breast cancer diagnosed between 1987 and 1996 at ages 55-72 years in Los Angeles County, California, USA. In November 1997, each case was mailed a follow-up questionnaire. Cognitive function was assessed by (1) clock drawing. (2) copying a box drawing, and (3) narrative writing to describe a pictured scene. Women reporting treatment with tamoxifen were categorized as standard-term users (4-5 years), short-term users (< 4 years) or long-term users (6 + years) and compared to never users. Tamoxifen users were also classified as past or current users. Differences in the mean cognitive test scores were tested after adjusting for age, age at diagnosis, stage of disease, radiation therapy, chemotherapy, race, education, marital status, previous use of oral contraceptives, type of menopause, age at last menstrual period, previous use of hormone replacement therapy, and depressive symptoms using analysis of covariance. All p-values for differences in the proportion of women who had errors on the tests are 2-sided and adjusted for age, stage of disease at diagnosis, and chemotherapy. FINDINGS: Information from 1,163 women aged 57-75 years of age was analyzed; 710 had taken tamoxifen. There was little difference between women who had used tamoxifen for the standard five years and never users on the three cognitive tests. However, more women who had used tamoxifen for the standard term reported seeing their physician for memory problems than non-users (3.8% vs 1.5%, p = 0.04). This was especially true for current users of standard-term (8.0%, p = 0.003). Current users also had a significantly lower mean complexity score (p = 0.03) on the narrative writing task. No differences were seen between past users and non-users. INTERPRETATION: Our study suggests that current use of tamoxifen may adversely effect cognition. Further study of tamoxifen and cognition is needed so that healthy women considering tamoxifen for the primary prevention of breast cancer have comprehensive information about the side effects of the treatment.


Assuntos
Antineoplásicos Hormonais/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Transtornos Cognitivos/induzido quimicamente , Tamoxifeno/efeitos adversos , Idoso , Antineoplásicos Hormonais/uso terapêutico , Feminino , Seguimentos , Humanos , Memória/efeitos dos fármacos , Pessoa de Meia-Idade , Tamoxifeno/uso terapêutico
15.
Cancer Res ; 59(9): 2038-40, 1999 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10232582

RESUMO

Approximately 50% of immortal human keratinocyte lines show loss of heterozygosity of chromosome region 4q33-q34, and the reintroduction of chromosome 4 into one such line, BICR 6, causes proliferation arrest and features of replicative senescence. Recently, a candidate gene, mortality factor 4 (MORF4), was identified in this region and sequenced in 21 immortal keratinocyte lines. There were no mutations or deletions, and two of the seven lines that showed loss of heterozygosity at 4q33-q34 were heterozygous for MORF4 itself. Furthermore, the transfer of a chromosomal segment containing the entire MORF4 gene did not mimic the senescence effect of chromosome 4 in BICR 6. These results suggest that the inactivation of MORF4 is not required for human keratinocyte immortality.


Assuntos
Senescência Celular/genética , Queratinócitos/citologia , Fatores de Transcrição/fisiologia , Linhagem Celular Transformada , Cromossomos Humanos Par 4/genética , Fibroblastos/citologia , Genótipo , Humanos , Perda de Heterozigosidade , Reação em Cadeia da Polimerase , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Fatores de Transcrição/genética , Células Tumorais Cultivadas
16.
Mol Cell Biol ; 19(2): 1479-85, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9891081

RESUMO

Based on the dominance of cellular senescence over immortality, immortal human cell lines have been assigned to four complementation groups for indefinite division. Human chromosomes carrying senescence genes have been identified, including chromosome 4. We report the cloning and identification of a gene, mortality factor 4 (MORF 4), which induces a senescent-like phenotype in immortal cell lines assigned to complementation group B with concomitant changes in two markers for senescence. MORF 4 is a member of a novel family of genes with transcription factor-like motifs. We present here the sequences of the seven family members, their chromosomal locations, and a partial characterization of the three members that are expressed. Elucidation of the mechanism of action of these genes should enhance our understanding of growth regulation and cellular aging.


Assuntos
Senescência Celular/genética , Fatores de Transcrição/genética , Sequência de Aminoácidos , Sequência de Bases , Divisão Celular/genética , Linhagem Celular , Núcleo Celular/metabolismo , Expressão Gênica , Teste de Complementação Genética , Humanos , Dados de Sequência Molecular , Família Multigênica , Sondas de Oligonucleotídeos/genética , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/metabolismo
17.
Oncogene ; 14(16): 1955-64, 1997 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-9150362

RESUMO

Human keratinocyte immortality is genetically recessive to the normal phenotype of limited replicative lifespan and appears to require the dysfunction of p53 and the cyclin D-Cdk inhibitor p16. In order to test for the inactivation of other candidate replicative lifespan genes in the immortal cells of human tumors, we developed a series of mortal and immortal keratinocyte cultures derived from neoplastic lesions of the head and neck which were amenable to molecular genetic analysis by the loss of heterozygosity (LOH) technique. The results indicate that keratinocyte immortalization in head and neck squamous cell carcinoma (SCC-HN) development involves the inactivation of at least two further pathways to senescence and four in all. Chromosomes 1, 4 and 7 carry genes representing immortality complementation groups C, B and D respectively and immortal keratinocytes showed LOH at either 4q32-q34 between D4S1554 and D4S171 (group B) or 7q31 (group D) but never 1q25 (group C). These results tentatively suggest that the genes responsible for the immortality complementation groups encode proteins on the same pathway to senescence. In addition, all of the immortal keratinocyte lines possessed high levels of telomerase activity and a suppressor of telomerase activity has been mapped to the short arm of chromosome 3p. Five out of eight lines showed LOH at 3p21.2-p21.3, a region which may carry a gene capable of suppressing SCC-HN telomerase. However, alternative mechanisms of telomerase reactivation were also suggested by our results. None of the above genetic alterations were seen in seven senescent neoplastic keratinocyte cultures. Other loci harbouring antiproliferative genes implicated in replicative lifespan showed few or no alterations and any alterations seen were additional to those described above.


Assuntos
Carcinoma de Células Escamosas/genética , Deleção Cromossômica , Mapeamento Cromossômico , Neoplasias de Cabeça e Pescoço/genética , Queratinócitos/patologia , Carcinoma de Células Escamosas/patologia , Sobrevivência Celular , Senescência Celular , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 3 , Cromossomos Humanos Par 4 , Cromossomos Humanos Par 7 , Genes Supressores , Teste de Complementação Genética , Marcadores Genéticos , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Telomerase/biossíntese , Telomerase/genética , Células Tumorais Cultivadas , Cromossomo X
18.
Br J Cancer ; 70(4): 591-5, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7917902

RESUMO

Around 60% of oral squamous cell carcinomas (SCCs) have been shown to harbour p53 mutations, and other studies have demonstrated mutant p53 genes in normal and dysplastic squamous epithelium adjacent to these SCCs. In line with these earlier studies we show here that DOK, a keratinocyte cell line derived from a dysplasia, displays elevated levels of p53 protein and harbours a 12 bp in-frame deletion of the p53 gene spanning codons 188-191. In contrast, the coding region of the p53 gene was normal in a series of six benign recurrent laryngeal papillomas and a series of four premalignant oral erythroplakia biopsies and their cell cultures. All but one of these lesions were free of malignancy at the time of biopsy, in contrast to the premalignant lesions studied by previous investigators, but keratinocytes cultured from these lesions all displayed a partially transformed phenotype that was less pronounced than that of DOK. Since three out of four of the erythroplakia patients developed SCC within 1 year of biopsy, these lesions were by definition premalignant. The availability of strains of partially transformed keratinocytes from premalignant erythroplakias which possess normal p53 genes should enable us to test the role of mutant p53 in the progression of erythroplakia to SCC. The premalignant tissues and cultures were also tested for the presence of human papillomavirus (HPV), which is known to inactivate p53 function in some cases. Only the benign papillomas were shown to contain high levels of either HPV 6 or HPV 11 E6 DNA, but not both, and none of the samples contained detectable levels of HPV 16, HPV 18 or HPV 33 E6 DNA or L1 DNA of several other HPV types. There was therefore no evidence to suggest that p53 was being inactivated by a highly oncogenic HPV in these samples.


Assuntos
Carcinoma de Células Escamosas/genética , Genes p53 , Neoplasias de Cabeça e Pescoço/genética , Queratinócitos/fisiologia , Papiloma/genética , Lesões Pré-Cancerosas/genética , Biópsia , Carcinoma de Células Escamosas/microbiologia , Carcinoma de Células Escamosas/patologia , Células Cultivadas , Éxons , Neoplasias de Cabeça e Pescoço/microbiologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Queratinócitos/citologia , Queratinócitos/microbiologia , Mutação , Papiloma/microbiologia , Papiloma/patologia , Papillomaviridae , Fenótipo , Lesões Pré-Cancerosas/microbiologia , Lesões Pré-Cancerosas/patologia
19.
Cancer Res ; 54(19): 5045-9, 1994 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-7923114

RESUMO

Human chromosomes 1,4,6, and 9 harbor genes which induce cellular senescence in vitro but a role for their inactivation in human tumors is not established. To investigate this we searched for loss of heterozygosity (LOH) on these chromosomes in keratinocyte cultures obtained from different stages of human squamous cell carcinoma progression. There was consistent LOH between markers D9S171 and D9S157 in 9 of 9 (100%) informative immortal cultures and in one line which entered crisis, but 0 of 7 informative senescent cultures showed LOH. These results suggest that inactivation of a gene at 9p21 is important but insufficient for human squamous cell carcinoma keratinocyte immortalization.


Assuntos
Carcinoma de Células Escamosas/genética , Deleção Cromossômica , Cromossomos Humanos Par 9 , Neoplasias de Cabeça e Pescoço/genética , Queratinócitos/ultraestrutura , Proteínas S100 , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/fisiologia , Células Cultivadas , Humanos , Fenótipo , Proteína A4 de Ligação a Cálcio da Família S100
20.
Eur J Cancer B Oral Oncol ; 30B(5): 335-7, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7703803

RESUMO

The occurrence of mutations within the coding sequence of the p53 tumour suppressor gene is now well documented for squamous cell carcinomas of the head and neck region. However, evidence that these mutations are required for the maintenance and progression of squamous tumours is still formally lacking. To test this we have examined whether p53 mutations detected in primary squamous cell carcinomas of the tongue are also detected in the corresponding lymph node metastases. Three different p53 mutations were detected in each of three primary tongue squamous cell carcinomas (SCC), and in each case the same mutation was detected in a lymph node metastasis excised from the same patient. Although the sample number is small, the chance of obtaining the same p53 mutation independently in both the primary and metastatic tumour of each patient is at least 10(-4), therefore the results indicate that keratinocytes harbouring these p53 mutations possess a selective advantage throughout SCC progression.


Assuntos
Carcinoma de Células Escamosas/genética , Genes p53/genética , Mutação Puntual/genética , Neoplasias da Língua/genética , Carcinoma de Células Escamosas/secundário , Progressão da Doença , Deleção de Genes , Humanos , Metástase Linfática , Reação em Cadeia da Polimerase
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