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1.
Case Rep Hematol ; 2018: 4832619, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30186642

RESUMO

Gamma heavy chain disease (γ-HCD) is a rare lymphoproliferative disorder characterised by the production of a truncated immunoglobulin heavy chain. Fewer than 200 cases have been reported in the literature. In some cases, γ-HCD occurs with other lymphoid neoplasms. This study reports clinical, biochemical, haematological, and histological findings in two cases of γ-HCD. We describe newer biochemical diagnostic tools (HevyLite measurement, capillary electrophoresis, and immunotyping) that can aid in the characterisation of γ-HCD. The first case is an 88-year-old woman with γ-HCD. The second case is an 81-year-old woman who developed γ-HCD during treatment for Waldenstrom's macroglobulinemia. In the second patient, histopathology identified a separate clone responsible for the secretion of the gamma heavy chain. Studies on the clonal evolution of the disease may provide insight into therapeutic implications and the genomic complexity of the disease.

2.
Intern Med J ; 37(3): 201-4, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17316345

RESUMO

As a society and as specialists involved in the diagnosis and management of cancer, we must begin to find new cost-effective ways to provide equitable access to the innovative, effective and expensive drugs that may begin to make cancer a chronic rather than rapidly lethal disease. Drugs such as trastuzumab and gefitinib are safer 'targeted therapies' that only attract government subsidies after the pathologist identifies the target present in a minor subset of patients. Nonetheless, funding for pathological identification of these targets remains a challenge. To illustrate, gefitinib may produce 'Lazarus' responses and prolonged survival among patients with epidermal growth factor receptor mutation-positive non-small-cell lung cancer. Many such examples will enter the clinical domain in the coming years. As we enter this era of personalized medicine, we argue that the use of expensive targeted therapies should be limited to pathologically proven indications because truly effective drugs are best applied to those individuals who would most benefit. It follows that medical oncologists should be trained properly to use targeted therapies. Then a new generation of oncologists would be empowered to participate in the iterative cycles of research between bench and bedside that are necessary for optimal use of biotherapies and their integration into multimodality cancer treatment programmes. We propose that cancer pathology be made available as a training option in the postgraduate education of medical oncologists. Oncologists and pathologists may jointly administer and mutually accredit the training module, which may also contribute towards the award of a higher degree.


Assuntos
Competência Clínica , Educação de Pós-Graduação em Medicina , Oncologia/educação , Oncologia/tendências , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Humanos
3.
Histol Histopathol ; 21(8): 813-21, 2006 08.
Artigo em Inglês | MEDLINE | ID: mdl-16691533

RESUMO

An unsupervised method for megakaryocyte detection and analysis is proposed, in order to validate supplementary tools which can be of help in supporting the pathologist in the classification of Philadelphia negative chronic myeloproliferative disorders with thrombocytosis. The experiment was conducted on high power magnification photomicrographs taken from hematoxylin-and-eosin 3 micrometer thick sections of formalin fixed, paraffin embedded bone marrow biopsies from patients with reactive thrombocytosis or chronic myeloproliferative disorders. Each megakaryocyte has been isolated in the photos through an image segmentation process, mainly based on mathematical morphology and wavelet analysis. A set of features (e.g. area, perimeter and fractal dimension of the cell and its nucleus, shape complexity via elliptic Fourier transform, and so on) is used to characterize the disorders and discriminate between essential thrombocythemia and idiopathic myelofibrosis. Features related to the general contour of the cell like cytoplasmic area and perimeter are good markers in distinguishing between normal or reactive and pathologic megakaryocytes while nuclear features and global circularity are helpful in the differential diagnosis between ET and prefibrotic IMF. The method proposed should be considered as a fast preprocessing tool for the diagnostic phase and its use can be extended to solve different object recognition problems.


Assuntos
Células da Medula Óssea/patologia , Processamento de Imagem Assistida por Computador/métodos , Megacariócitos/patologia , Transtornos Mieloproliferativos/diagnóstico , Software , Trombocitose/patologia , Humanos , Fotomicrografia , Estudos Retrospectivos
4.
Leukemia ; 17(12): 2401-9, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14523461

RESUMO

We analyzed molecular responses in 55 newly diagnosed chronic-phase chronic myeloid leukemia (CML) patients enrolled in a phase 3 study (the IRIS trial) comparing imatinib to interferon-alfa plus cytarabine (IFN+AraC). BCR-ABL/BCR% levels were measured by real-time quantitative RT-PCR and were significantly lower for the imatinib-treated patients at all time points up to 18 months, P<0.0001. The median levels for imatinib-treated patients continued to decrease and had not reached a plateau by 24 months. A total of 24 IFN+AraC-treated patients crossed over to imatinib. Once imatinib commenced, the median BCR-ABL/BCR% levels in these patients were not significantly different to those on first-line imatinib for the equivalent number of months. The incidence of progression in imatinib-treated patients, defined by hematologic, cytogenetic or quantitative PCR criteria, was significantly higher in the patients who failed to achieve a 1 log reduction by 3 months or a 2 log reduction by 6 months, P=0.002. A total of 49 patients were screened for BCR-ABL kinase domain mutations. Mutations were detected in two imatinib-treated patients who crossed over from IFN+AraC and both lost their imatinib response. In conclusion, first-line imatinib-treated patients had profound reductions in BCR-ABL/BCR%, which significantly exceeded those of IFN+AraC-treated patients and early measurements were predictive of subsequent response.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Antineoplásicos/administração & dosagem , Citarabina/administração & dosagem , Interferon-alfa/administração & dosagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Piperazinas/administração & dosagem , Pirimidinas/administração & dosagem , Benzamidas , Medula Óssea/metabolismo , Estudos Cross-Over , Citogenética , Análise Mutacional de DNA , Proteínas de Fusão bcr-abl/sangue , Proteínas de Fusão bcr-abl/química , Proteínas de Fusão bcr-abl/genética , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Fosfotransferases/química , Fosfotransferases/genética , Prognóstico , Estrutura Terciária de Proteína , Resultado do Tratamento
5.
Aliment Pharmacol Ther ; 16 Suppl 2: 128-36, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11966533

RESUMO

BACKGROUND: Cancers characterized by microsatellite instability may be biologically different from their counterparts with stable microsatellite sequences. Circulating cancers cell present in blood prior to surgery may constitute an adverse prognostic finding. AIM: To correlate these two phenomena with morphological features and survival in advanced gastric cancer. METHODS: We examined 76 cases of resected sporadic, advanced gastric cancer by means of routine morphology and a panel of microsatellite markers. Sixty-six cases were screened for presence of cancer cells circulating in blood prior to the surgery using combined morphological and immunocytochemical approach. RESULTS: Twenty-one (27.6%) cases demonstrated microsatellite instability in at least one locus. Among them 11 (14.5%) showed microsatellite instability in more than 30% (4/12) examined loci, and they were therefore designated as replication error positive (RER+). Circulating cancer cells were detected in 2/19 microsatellite instability and in 11/47 remaining cases (difference not significant). The survival of the microsatellite instability cases was significantly better. The presence of circulating cancer cells did not correlate with survival. CONCLUSION: It is possible that the microsatellite instability status, but not circulating cancer cells, constitutes a prognostic predictive factor in advanced gastric carcinoma. Confirmation of this hypothesis requires continuation of patient follow-up.


Assuntos
DNA de Neoplasias/genética , Repetições de Microssatélites/genética , Células Neoplásicas Circulantes , Neoplasias Gástricas/sangue , Neoplasias Gástricas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Marcadores Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Gástricas/mortalidade , Taxa de Sobrevida
6.
Pol Arch Med Wewn ; 105(4): 311-5, 2001 Apr.
Artigo em Polonês | MEDLINE | ID: mdl-11761803

RESUMO

Two cases of systemic mastocytosis with different clinical course were described. The first of them manifested with returning attacks of tachycardia with raise of blood pressure, followed by its drop and loss of consciousness. Abdominal pain and persistent diarrhea characterized the second one. The common signs in both cases were skin changes of urticaria pigmentosa, presence of Darier's symptom, very high blood levels of tryptase and prostaglandin D2 and rise in urinary LTE4 concentration. Differential diagnostic is discussed and histopathology bone marrow biopsies are presented.


Assuntos
Mastocitose/genética , Mastocitose/metabolismo , Adulto , Feminino , Humanos , Leucotrienos/metabolismo , Masculino , Mastocitose/diagnóstico , Pessoa de Meia-Idade , Mutação Puntual/genética , Prostaglandinas D/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , Serina Endopeptidases/metabolismo , Índice de Gravidade de Doença , Triptases
7.
Pol J Pathol ; 52(4): 225-30, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11915186

RESUMO

The authors present brief overview of problems associated with analysis of microsatellite sequences in DNA from archival paraffin-embedded tissue. This methodology can serve several diagnostic and research purposes provided appropriate precautions are taken to extract DNA of acceptable quality with small admixture of contaminants. Also PCR amplification step requires some modifications compared to routine reactions involving DNA from fresh or freshly-frozen tissues.


Assuntos
DNA/análise , Repetições de Microssatélites/genética , Eletroforese em Gel de Ágar , Humanos , Inclusão em Parafina , Reação em Cadeia da Polimerase/métodos
8.
Haemophilia ; 6(6): 693-5, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11122398

RESUMO

Anaphylaxis to factor IX (FIX) in patients with haemophilia B is a rare and life-threatening complication that has been reported to occur in association with the development of inhibitors to FIX. Management of these patients is difficult. This report presents an 18-month-old boy with a frame-shift mutation of the FIX gene and FIX coagulant level of <1% who developed anaphylactoid reactions to low and high purity plasma-derived FIX concentration infusions and an inhibitor measuring 1.0 BU mL(-1). The patient was managed with simple plasmapheresis, a short course of corticosteroids and high-dose antigen exposure, which successfully induced long-lasting immune tolerance to FIX concentrates.


Assuntos
Anafilaxia/imunologia , Anafilaxia/prevenção & controle , Antígenos/imunologia , Fator IX/imunologia , Hemofilia B/imunologia , Plasmaferese , Anafilaxia/etiologia , Fator IX/administração & dosagem , Fator IX/efeitos adversos , Hemofilia B/tratamento farmacológico , Humanos , Tolerância Imunológica , Lactente , Masculino
9.
Br J Haematol ; 109(3): 635-7, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10886215

RESUMO

An atypical BCR-ABL transcript in a patient with Philadelphia (Ph)-positive chronic myeloid leukaemia (CML) was detected using a long polymerase chain reaction technique. Sequence analysis revealed a joining of BCR exon e8 and ABL exon a2, with a 55-base pair (bp) insert of an inverted sequence of ABL intron 1b between them, giving rise to an in frame e8a2 BCR-ABL transcript. This is the first report of a BCR-ABL transcript with the insertion of an inverted sequence. The long PCR technique is a useful screen for atypical BCR-ABL transcripts not detected by standard techniques.


Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Fusão Gênica Artificial , Eletroforese em Gel de Ágar , Éxons , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica
10.
Breast Cancer Res Treat ; 60(2): 135-42, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10845276

RESUMO

Microsatellite markers may provide evidence of faulty DNA mismatch repair (MMR) via the detection of microsatellite instability (MSI). The choice of microsatellite markers may impact on the MSI detection rate. In hereditary non-polyposis colon cancer (HNPCC), several informative microsatellite markers have been recommended. Two of these, BAT 25 and BAT 26, are quasi-homozygous, enabling analysis of tumour DNA in the absence of paired normal DNA. Sixty-six breast cancer patients under 45 years of age at diagnosis were examined for MSI at BAT 25 and BAT 26. Tumour DNA was extracted from paraffin-embedded tissue. No MSI was detected at the BAT 25 or BAT 26 loci. An additional five microsatellite markers, known to be informative for HNPCC, were examined for MSI in these patients. Apparently-normal profiles were achieved. A tabulated survey of 306 microsatellite markers used to detect MSI in breast cancer revealed that only 35.5% of markers detected MSI at an average rate of 2.9%. The MSI detection rate at the specific HNPCC markers varied from 0% to 10% in breast cancer, with D175250 and TP53 being the HNPCC markers most suitable for analysis of breast cancer. The size of the microsatellite marker's repeat unit did not impact on MSI detection rates. Compiled data from large studies (n > 100) revealed D115988 as the marker with the highest MSI detection rate. Genomic instability pathways of carcinogenesis, characterised by MMR defects and MSI, appear to play a role in the genesis of some breast cancer types.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/genética , DNA de Neoplasias/genética , Repetições de Microssatélites/genética , Mutação , Adulto , Idade de Início , Neoplasias da Mama/patologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Feminino , Humanos , Pessoa de Meia-Idade , Sensibilidade e Especificidade
11.
Br J Haematol ; 107(3): 560-2, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10583258

RESUMO

About one third of cases of haemophilia A have no family history of the disorder, and 20% are thought to be due to a new mutation. In the family reported here, a 3 bp deletion was detected in DNA from the proband at the 3' end of exon 15. Direct sequencing of genomic DNA prepared from blood and buccal cells of the grandfather revealed both normal and mutant sequences, suggesting that he is a mosaic for this mutation. This highlights the usefulness of mutation detection, both for accurate genetic counselling and to determine the origin of new mutations of haemophilia.


Assuntos
Hemofilia A/genética , Mosaicismo/genética , Mutação/genética , Triagem de Portadores Genéticos , Aconselhamento Genético , Humanos , Linhagem
12.
Br J Haematol ; 107(3): 587-99, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10583264

RESUMO

We have developed a rapid real-time quantitative PCR method for measuring BCR-ABL mRNA levels in peripheral blood in chronic myeloid leukaemia (CML). The technique was used to monitor minimal residual disease for the early detection of relapse and as an assessment of treatment response. Normal BCR mRNA was quantitated to control for RNA degradation and the results reported as a percentage of BCR-ABL/BCR. Every patient measured at diagnosis (n = 21) had increased expression of BCR-ABL of up to 5-fold above the normal BCR levels. With effective treatment the BCR-ABL levels decreased. The molecular data was correlated with Philadelphia chromosome levels in bone marrow and a good correlation was found when treatment induced a cytogenetic response (Spearman correlation = 0.94, P < 0.0001, n = 67 samples). In patients receiving interferon-alpha therapy we found a significant difference in the BCR-ABL levels between cytogenetic response groups. The method was sensitive, reproducible, and readily detected a change in BCR-ABL transcript levels in serial blood samples. Sample throughput was high because post PCR processing was unnecessary. We conclude that real-time quantitative PCR monitoring of peripheral blood can be used to reliably monitor disease response in CML.


Assuntos
Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/metabolismo , Antineoplásicos/uso terapêutico , Sequência de Bases , Transplante de Medula Óssea/métodos , Genes abl/genética , Humanos , Interferon-alfa/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Dados de Sequência Molecular , Neoplasia Residual/diagnóstico , Cromossomo Filadélfia , Polimorfismo Genético , Transplante Homólogo
13.
Hum Mutat ; 13(5): 413, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10338100

RESUMO

Beta-thalassemia major is one of the commonest genetic disorders in South-East Asia. The spectrum of beta-thalassemia mutations in the various ethnic sub-populations on the island of Borneo is unknown. We studied 20 Dusun children from the East Malaysian state of Sabah (North Borneo) with a severe beta-thalassemia major phenotype, using a combination of Southern analysis, polymerase chain reaction analysis and direct sequencing. We found the children to be homozygous for a large deletion, which has a 5' breakpoint at position -4279 from the cap site of the beta-globin gene (HBB) with the 3' breakpoint located in a L1 family of repetitive sequences at an unknown distance from the beta-globin gene. This was similar to a recent finding of a large deletion causing beta-thalassemia first described in unrelated beta-thalassemia heterozygotes of Filipino descent. This report describes the first 20 families with homozygosity of the deletion causing a severe phenotype. It provides the first information on the molecular epidemiology of beta-thalassemia in Sabah. This finding has implications for the population genetics and preventative strategies for beta-thalassemia major for nearly 300 million individuals in South-East Asia.


Assuntos
Deleção de Genes , Globinas/genética , Talassemia beta/genética , Southern Blotting , Humanos , Malásia , Fenótipo , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
14.
Int J Colorectal Dis ; 14(6): 277-81, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10663894

RESUMO

Over past three decades in Poland we have seen a steady increase in the incidence of colorectal cancer. It is unclear whether this phenomenon is associated with changes in biology of the disease. In the present study we compared basic clinical data and pathological features of colorectal carcinomas submitted as resection specimens to a single institution in 1975 (n=76) and 1995 (n=106). We found a significant increase in sigmoid tumors (15.8% in 1975, 34.9% in 1995, P=0.0028), a decline in the frequency of mucinous carcinomas (22.4% in 1975, 7.5% in 1995, P=0.0041), and reversed distribution of low- and high-grade tumors (more high-grade than low-grade carcinomas in 1975, the opposite in 1995). We observed trends toward more pronounced peritumoral desmoplastic response, less prominent chronic peritumoral inflammatory infiltrate, and more frequent perineural invasion. The 1995 patients were on average significantly older at surgery (59 years in 1975, 64 years in 1995, P=0.02) and had smaller tumors (max. diameter=5.49 cm in 1975, 4.27 cm in 1995, P=0.0018). There were no differences in distribution of tumor stage, patient's sex, type of infiltrating margin formed by carcinomas, relative amount formed by the solid tumor component, invasion of veins and lymphatics, or presence of an adenoma contiguous with a carcinoma. Differences between 1975 and 1995 cases observed in our material probably reflect the changing biology of colorectal carcinoma in Poland. Mucinous, high-grade, proximal tumors, surrounded by prominent chronic inflammatory infiltrate, diagnosed in relatively younger subjects are associated with familial and sporadic cancers due to widespread genomic instability (replication error positive or RER(+) phenotype). We conclude that in Poland the APC/K-ras/p-53 carcinogenesis pathway is becoming even more important than the carcinogenesis characterized by RER(+) tumors. This study is a starting point for further investigations aimed at confirming this hypothesis.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/patologia , Distribuição por Idade , Idoso , Biópsia por Agulha , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Incidência , Masculino , Pessoa de Meia-Idade , Polônia/epidemiologia , Prevalência , Sistema de Registros , Distribuição por Sexo
15.
Clin Chem Lab Med ; 36(8): 641-4, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9806477

RESUMO

We have shown the impact of molecular diagnostics related to mutation detection in an extensive family with a strong history of colorectal cancer. The nature and presentation of the cancers suggested that hereditary nonpolyposis colorectal cancer was the most likely cause. The strategies employed have enabled the detection and characterisation of the causative mutation in the proband and predictive testing in the remaining relatives where requested. Using the chemical cleavage of mismatches technique and direct sequencing, the MSH2 and MLH1 genes of the proband were investigated. A single base substitution, C-->T at nucleotide 350, codon 117, of the MLH1 gene was identified. Across the family pedigree at specific points, 22 other relatives have been tested for the mutation by direct DNA sequencing from genomic DNA. Of the total of 23 patients tested to date, 11 have the mutation. In conjunction with appropriate genetic counselling, this service has clarified the genetic status of many individuals within this family. Predictive information provided prior to the development of symptoms enables individuals to make informed choices regarding disease management and the future, removing the anxiety associated with the unknown.


Assuntos
Neoplasias Colorretais/diagnóstico , Proteínas de Ligação a DNA , Proteínas Adaptadoras de Transdução de Sinal , Sequência de Bases , Proteínas de Transporte , Neoplasias Colorretais/genética , Primers do DNA , Feminino , Aconselhamento Genético , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Masculino , Proteína 1 Homóloga a MutL , Proteína 2 Homóloga a MutS , Proteínas de Neoplasias/genética , Proteínas Nucleares , Linhagem , Proteínas Proto-Oncogênicas/genética
17.
Mol Pathol ; 50(2): 57-71, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9231152

RESUMO

CD44 is a family of transmembrane glycoproteins that act mainly as a receptor for hyaluronan. It can also bind some other extracellular matrix ligands (chondroitin sulphate, heparan sulphate, fibronectin, serglycin, osteopontin) with lower affinity. CD44 is encoded by a single gene containing 20 exons, 10 of which (v1-v10) are variant exons inserted by alternative splicing. The standard, ubiquitously expressed isoform of CD44, does not contain sequences encoded by these variant exons. Numerous variant isoforms of CD44 containing different combinations of exons v1-v10 inserted into the extracellular domain can be expressed in proliferating epithelial cells and activated lymphocytes. CD44 plays a significant role in lymphocyte homing. Both alternative splicing and glycosylation influence receptor function of the molecule, usually reducing its affinity to hyaluronan. The cytoplasmic domain of CD44 communicates with the cytoskeleton via ankyrin and proteins belonging to the ezrin-moesin-radixin family. Relatively little is known about the intracellular events following interactions of CD44 with its ligands. Some variant isoforms, especially those containing sequences encoded by v6-v10, are overexpressed in both human and animal neoplasms. In a rat pancreatic adenocarcinoma model one of the variant CD44 isoforms was proved to be determinant in the metastatic process. For some human neoplasms (carcinomas of the digestive tract, non-Hodgkin's lymphomas, thyroid carcinomas, and others) correlations have been made between the particular pattern of CD44 variants produced by neoplastic cells and clinicopathological parameters of tumours, such as grade, stage, presence of metastases, and survival. In vitro studies indicate that modifications of CD44 expression result in different ligand recognition and influence cell motility, invasive properties, and metastatic potential of experimental tumours. Investigation of CD44 neoexpression can be useful both in early cancer diagnosis and in predicting tumour behaviour. It can also contribute to better understanding of molecular mechanisms leading to neoplastic transformation.


Assuntos
Adesão Celular/fisiologia , Receptores de Hialuronatos/fisiologia , Neoplasias/patologia , Processamento Alternativo , Animais , Carcinoma/metabolismo , Carcinoma/patologia , Carcinoma/fisiopatologia , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/fisiopatologia , Citoesqueleto/fisiologia , Humanos , Receptores de Hialuronatos/química , Receptores de Hialuronatos/genética , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/química , Ácido Hialurônico/fisiologia , Ligantes , Linfócitos/metabolismo , Linfócitos/fisiologia , Linfoma/metabolismo , Linfoma/patologia , Linfoma/fisiopatologia , Mamíferos , Melanoma/metabolismo , Melanoma/patologia , Melanoma/fisiopatologia , Camundongos , Invasividade Neoplásica/fisiopatologia , Metástase Neoplásica/fisiopatologia , Neoplasias/metabolismo , Neoplasias/fisiopatologia , Ratos
18.
Exp Mol Pathol ; 64(2): 114-25, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9316589

RESUMO

CD44 glycoprotein is the main extracellular receptor for hyaluronic acid. The CD44 gene is composed of 20 exons and encodes a variety of isoforms generated by alternative splicing of 10 variant exons. Overexpression of discrete CD44 isoforms containing products of variant exons have been implicated in the progression of cancer, including human colon carcinoma. The pattern of CD44 transcripts changes during early colorectal carcinogenesis, and their relation to CD44 protein expression remains to be defined under experimental conditions. In the current study we investigated CD44 expression in a murine model of human colon adenoma/carcinoma. Colon tumors were induced in 19 ICR/Ha mice by 1,2-dimethylhydrazine injections and CD44 expression was studied by RT-PCR/ Southern blot analysis as well as immunohistochemistry. CD44 transcripts were strongly overexpressed in tumors compared to normal colon. Both neoplastic and normal colon samples exhibited the same species of CD44 transcript representing standard and variant isoforms. Seventy-five percent of neoplasms contained foci of CD44-positive tumor cells, whereas in normal colon the epithelial immunoreactivity was confined to the crypt base. Immunostaining of neoplastic cells was heterogeneous and there was a significant tendency toward the progressive loss of CD44 immunoreactivity in large invading tumors. It is concluded that early events in murine colorectal carcinogenesis are characterized by a marked global overexpression of standard and variant CD44 transcripts.


Assuntos
Neoplasias do Colo/imunologia , Receptores de Hialuronatos/biossíntese , 1,2-Dimetilidrazina/toxicidade , Animais , Carcinógenos/toxicidade , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Receptores de Hialuronatos/genética , Masculino , Camundongos , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo
19.
Br J Haematol ; 94(2): 400-6, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8759905

RESUMO

A subgroup of patients with haemophilia A who have a familial discrepancy between the one-stage and two-stage factor VIII:C results has previously been described. These patients show factor VIII:C levels by one-stage assay that are 2-7-fold higher than their two-stage results. We have studied 10 such families and identified six different mutations in the factor VIII gene in this group. The chemical cleavage method and DNA sequencing was used to identify mutations in factor VIII gene fragments generated by reverse transcription and PCR. All available family members were tested to confirm the presence of the mutation in affected individuals. These patients were found to have one of six single point substitutions causing a missense mutation and alteration to one codon in exons 7, 11, 14 or 18. The mutations comprise three that have not previously been described (Ala284Glu. Arg698Leu. Leu1932Phe) and three that have been previously described (Ser289Leu, Arg531His, Arg698Trp). Alterations to the amino acid composition of the A1, A2 and A3 domains of factor VIII are predicted by these molecular studies. In contrast, a control group of 23 mild haemophilia families with equivalent factor VIII:C results by one-stage and two-stage assays did not have any of the above mutations. Detailed studies in seven of these latter families identified four mutations affecting the A3, C1 and C2 domains of factor VIII. These findings suggest a genetic basis to the unusual factor VIII phenotype but do not explain the mechanism of the discrepant factor VIII activity.


Assuntos
Fator VIII/genética , Hemofilia A/genética , Mutação Puntual , Éxons , Haplótipos , Humanos , Linhagem , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
20.
Aust N Z J Med ; 26(2): 195-205, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8744618

RESUMO

BACKGROUND: Haemophilia A is a sex-linked bleeding disorder carried by unaffected females. Currently, the two main methods used for the determination of carrier status in women from families with haemophilia A are bioassays and DNA-based assays using restriction fragment length polymorphisms (RFLP). AIM: The aim of this paper was to assess the current usefulness of these two methods. METHODS: Bioassays measured factor VIII coagulation activity by a two-stage coagulation assay and von Willebrand antigen by immunoelectrophoresis. RFLP were determined with two intragenic probes (p114 and p486) and two linked probes (St14 and DX13). Data were analysed using a Bayesian analysis to allow for all possible recombination events. We also incorporated an estimate for the risk of mosaicism into calculations in isolated haemophilia families. Both bioassays and RFLP were used to determine carrier status in 63 women, 31 from known haemophilia families and 32 from families of isolated cases. The techniques were assessed for their ability to classify the patients as normal (p < 0.2) or carrier (p > 0.7). Where applicable, intron 22 inversion was also tested. RESULTS: In the known families, six women could not be classified after bioassay, but all could be classified by RFLP. Of the 32 women from families of isolated cases, eight were unclassified by bioassay and 12 were not definitely classified using RFLP. However, RFLP was useful in determining that a recent mutation had occurred in six of the eight families in which DNA from the grandparents was available. CONCLUSION: For diagnosis of carriers of haemophilia, RFLP is the preferred method in familial haemophilia, but is less useful in isolated haemophilia.


Assuntos
Hemofilia A/sangue , Hemofilia A/genética , Heterozigoto , Polimorfismo de Fragmento de Restrição , Testes de Coagulação Sanguínea , Diagnóstico , Estudos de Avaliação como Assunto , Fator VIII/genética , Feminino , Humanos , Imunoeletroforese , Mutação , Linhagem , Probabilidade , Austrália do Sul , Fator de von Willebrand/análise , Fator de von Willebrand/genética
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