ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS

摘要:

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumor. It is usually asymptomatic in the early stages and tends to be intravascularly and intrabiliary invasive. Therefore, most patients present with incurable disease at the time of detection and early diagnosis of HCC is critical for a good prognosis.The imaging-based diagnosis of small tumors is relatively inaccurate, as cirrhotic and dysplastic nodules mimic HCC radiologically. The availability of a suitable serological marker to distinguish between HCC and benign liver lesions would, therefore, be very useful for early diagnosis. The only serological marker currently widely used for the diagnosis of HCC is alphafetoprotein (AFP). However, the sensitivity of this marker is limited (41–65%). Given the high heterogeneity of HCC, it is currently thought that an optimal serological test for HCC will be based on the simultaneous measurement of two or three highly specific serological markers.Several laboratories have recently reported that glypican-3 (GPC3), a membrane-bound proteoglycan, is expressed by a large proportion of HCCs, but is undetectable in normal hepatocytes and non-malignant liver disease. Furthermore, various studies demonstrated that GPC3 could be used as a serological test for the diagnosis of patients with HCC. Although the specificity of the test was very high in the context of a population with chronic liver disease, the sensitivity was limited (within the same range as AFP). Interestingly, in most cases, elevated GPC3 values did not correlate with elevated AFP values. As a consequence, the serological level of at least one of the two markers was elevated in a large majority of HCC patients. These results suggest that the sensitivity of the diagnostic test can be significantly improved without compromising specificity with the simultaneous measurement of both GPC3 and AFP.

ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS

摘要:

BackgroundFluorescencein situhybridization (FISH) can identify chromosomal translocations on fixed archival tissue, but studies cross-validating the utility of FISH on lesions of different cell lineages that harbor similar translocations (e.g. those involving anaplastic lymphoma kinase [ALK]) have not been published.AimOur objective was to define the diagnostic utility, performance characteristics, and limitations of a commercially available, split-signal, FISH probe forALKgene rearrangements on fixed, archived tissue from lesions of diverse cell lineage.Study designThe sensitivity, specificity, and positive and negative predictive values of the Vysis®ALKFISH probe were compared with those of the ALK-1 antibody (Dako®) in a series of 101 cases, comprising 43 hematolymphoid neoplasms, 4 reactive lymphoid controls, 50 non-hematolymphoid (including neuroectodermal, epithelial, myofibroblastic, and germ cell) lesions, and 4 early-trimester aborted fetuses that served as neuroblastic controls.MethodsThe study involved a predominantly (72%) Singaporean Chinese population aged between 9 months and 88 years (excluding the aborted fetal controls). All cases were reviewed both histologically and immunohistochemically with a wide panel of antibodies using the standard protocols in order to diagnose them according to the latest WHO classification systems. A positive cut-off value was determined, both by comparison with diagnostic categories with and withoutALKtranslocations, as well as with negative controls.ResultsTheALKFISH probe suffered a 33% non-informative rate, but in informative cases it showed 94% concordance with the ALK-1 immunostain. A minimum cut-off value of 5 in 200 informative cells was adopted to make a positive call in each case. Of the ALK-1 immunoreactive lesions, nine lymphomas were concordantlyALKtranslocation-positive but one vesical inflammatory myofibroblastic tumor was discordantly FISH-negative. Among the ALK-1-immunonegative lesions, one case each of anaplastic lymphoma and pulmonary mycobacterial spindle cell pseudotumor were discordantlyALKFISH-positive, while a case each of intestinal myeloblastic tumor and ganglioglioma showed initial – but not reproducible – positive FISH readings. The remaining cases were concordantly negative.DiscussionThe discrepancies betweenALKFISH results and well-established immunomorphological parameters indicate that interpretation is not always straightforward. Notably, the derivation of threshold cut-off values for positive calls on FISH assays has seldom been addressed in the literature, and has raised issues in interpreting cases with borderline positivity in this study. The factors that may influence such cut-off values are extensively reviewed.ConclusionsWe propose the term ‘conditional threshold positivity’ to encourage the adoption of different cut-off values for making positive calls in lesions of different origin.

ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS

摘要:

AimSARS-associated coronavirus (SARS-CoV) has been confirmed as the pathogen for severe acute respiratory syndrome (SARS). The aim of our study was to construct a sensitive and specific real-time quantitative fluorescent (QF) reverse transcriptase (RT)-PCR method for the detection ofSARS-CoVRNA.MethodsStored blood specimens from 44 patients with confirmed SARS were used along with blood samples from two sets of controls, 30 healthy volunteers who had no contact with SARS patients, and 30 healthy doctors and nurses who had contact with SARS patients but were without symptoms of SARS. Two pairs of primers were synthesized by the Shanghai Sangon Company according to SARS-CoV BJ01 strain sequence (AY278488), and then a pair of primers were designed and compared with a pair of primers published by WHO.ResultsUsing serial dilutions ofSARS-CoV, the 44 blood samples from SARS patients specimens were tested. Using a 0.01% dilution ofSARS-CoV, all 44 clinical samples tested positive in our assay. In comparison, using a 0.1% dilution ofSARS-CoV, 26 of the 44 samples tested positive using the WHO primers. In the QF-RT-PCR assay, there was a linear amplification from 100 copies to 108copies of the control RNA per RT-PCR and at least 10 copies, and sometimes even 1 copy, of target RNA tested positive in our assay.ConclusionThe primer we developed is sufficiently sensitive and specific to diagnose symptomaticSARS-CoVinfections and for monitoring virus load.

ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS

摘要:

IntroductionGenetic testing is increasingly being used to evaluate susceptibility to hereditary diseases because it is a cost effective screening method. Predictive testing for retinoblastoma can help to save the vision and avoid unnecessary (and invasive) eye examinations for probands and their close relatives. This study was undertaken to evaluate the cost effectiveness of the retinoblastoma genetic screening strategy established in our hospital.Study designCytogenetic study of peripheral blood, mutational, and methylation analyses from the tumor DNA of 25 patients with retinoblastoma was undertaken. The cost for retinoblastoma (RB1) gene screening was calculated based on the cost of the chemicals and consumables used and the clinical examination charges at our hospital. A comparison was made between the cost of genetic screening and clinical testing for retinoblastoma. Retinoblastoma patients underwent clinical management and genetic testing at Sankara Nethralaya, Chennai, India.ResultsBy adopting a genetic screening strategy, a 3.5-fold cost saving was seen for a proband while a 6-fold saving was seen for a family with two sibs compared to the cost of clinical examination. The clinical examination fee and cost of genetic screening for a proband was $US536 and $US152, respectively, while for a nuclear family with two sibs the costs were $US1071 and $US175, respectively.DiscussionSavings for a family will be higher if indirect costs, such as savings in travel times to and from the hospital and labor savings, were taken into account. Cost will be a major factor in determining the implementation of genetic screening forRB1gene in the clinical practice.ConclusionIn our study in India, genetic screening for retinoblastoma was cheaper than conventional screening and was useful in the genetic counseling of the families.

ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS

摘要:

IntroductionGenetic factors in the immune system are widely suspected to have a role in the etiology of glaucoma. In this study, we evaluated the association between primary open-angle glaucoma (POAG) and the transporter associated with antigen processing (TAP) gene polymorphisms. TheTAPgene polymorphisms we evaluated were TAP1-1 codon 333 A/G (Ile-Val), TAP1-2 codon 637 (Asp-Gly), TAP2-1 codon 379 (Val-Ile), TAP2-2 codon 665 (Thr-Ala) and codon 687 (Stop-Gln), and TAP2-3 codon 565 (Ala-Tht). Due to the lack of predictive markers for glaucoma, many glaucoma patients are only diagnosed when their visual acuity and visual field has irreversibly deteriorated. Our aim was to confirm whether or not the TAP1 and TAP2 genes can be used to identify suspectability to glaucoma.MethodsSixty-six patients with POAG and 105 healthy volunteers were enrolled in this case-control study. We resolved theTAP1andTAP2gene polymorphisms by PCR-based analysis.ResultsThere was a significant difference in the distribution of TAP1-1 codon 333 and TAP1-2 codon 637 gene polymorphisms (p = 0.0375 and 0.01, respectively) between POAG patients and healthy controls. However, there was no significant difference between the two groups in TAP2-1 codon 370, TAP2-2 codon 665, and TAP2-3 codon 565 (p = 0.273, 0.19, and 0.131, respectively). In TAP1-1 codon 333, there was a significant difference between the “GG” homozygote and “GA” heterozygote (OR 4.32; 95% CI 1.336, 13.969). In TAP1-2 codon 637, there was a significant difference between the “GG” homozygote and “GA” heterozygote (OR 15; 95% CI 1.733, 129.860). There was also a significant difference between “GG” homozygote and “AA” homozygote (OR 10.8; 95% CI 1.286, 91.880). Therefore, TAP1-1 codon 333 and TAP1-2 codon 637 gene polymorphisms were useful genetic markers of POAG. The prevalence of the TAP1-2 “GG” homozygote differs significantly between POAG patients and healthy controls, although in the alleles of the bothTAPgenes, there were no significant differences between the two groups.ConclusionThe immune system acts as an arbiter to help determine whether under stress a neuronal cell will survive or sacrifice itself to injuries. TAP1-1 and TAP1-2 play an important role in the immune system.TAP1-1 andTAP1-2 gene polymorphisms may, by way of post-transcriptional changes and altered regulation of gene expression, be involve the immune system in the development of POAG.

ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS

摘要:

IntroductionLymph node status in patients with cutaneous malignant melanoma is the most important prognostic factor. Patients with clinically positive nodes (stage III) should undergo therapeutic lymphadenectomy; however, the surgical approach to the regional disease in patients with negative clinical examination (stage I and II) is still controversial. Selective lymphadenectomy consists of the intraoperative identification of the first node in the nodal basin, the sentinel lymph node (SLN). Routine examination, serial sectioning, and immunohistochemistry may underestimate the presence of tumor cells. PCR is a molecular biology technique that may be useful for the detection of malignant melanoma nodal metastases in the SLN.AimThe aim of this study was to use tyrosinase messenger RNA (mRNA) amplification for the detection of micrometastases in fresh frozen SLNs.Methods46 hematoxylin-eosin (HE)-negative sentinel node samples from 42 patients with malignant melanoma were included in this study. Formalin-fixed paraffin-embedded sections were immunostained with S-100 protein and HMB-45. A central portion of the node was submitted for PCR. This method was accomplished with a combination of reverse transcription and amplification of the tyrosinase complementary DNA and double- round PCR (nested reverse transcriptase [RT]-PCR).ResultsIn 1 of the 42 SLN-negative patients, immunohistochemistry stains allowed the detection of micrometastases. With molecular biology, 14 of the 42 SLN patients were positive (33%); in another 12 (29%), only the nested RT-PCR was positive. Of the 42 patients, 24 were put into 3 groups and followed for a 5-year period with 1, 7, and 16 patients, respectively, in the groups. The first group involved 1 patient who had provided 2 SLN samples that were found to be SLN-positive using both techniques, immunohistochemistry stains and nested RT-PCR (he had hepatic metastasis and died 24 months after diagnosis). The second group, with only nested RT-PCR positive SLN samples, included 7 of 12 patients who were followed and had a median survival of 37 months; 4 died of widespread metastatic disease, the other 3 patients had event-free survival, but 1 consented to undergo a therapeutic lymphadenectomy as a result of a positive test. The last group consisting of 16 of 32 patients, with complete 5-year survival, who were SLN-negative with both techniques, immunohistochemistry stains and nested RT-PCR. Fourteen of the 16 (88%) were event-free survival during the follow-up, and 2 had local relapse.ConclusionTyrosinase mRNA amplification may be a negative prognostic factor for the detection of micrometastases in fresh frozen SLNs using molecular biology techniques.

ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS

摘要:

AimThe purpose of this study was to evaluate the validity of the combined use of micromanipulation and quantitative fluorescent (QF)-PCR assay for the identification of fetal elements in transcervical cell (TCC) samples collected in early pregnancy.MethodsTCC samples were obtained by intrauterine lavage (IUL) in 113 pregnant women who were between 7 and 12 weeks pregnant before termination of pregnancy. All IUL samples were screened under an inverted microscope, at which time the isolation of fetal cells by micromanipulation was attempted. QF-PCR assay, using 9 small tandem repeat (STR) markers for chromosomes 13, 18, 21, X, and Y, was performed in all specimens to identify fetal cells in TCC samples and the corresponding placental tissue and blood specimens. TCC samples from male fetuses in which either the micromanipulation or QF-PCR analysis were unsuccessful, were studied with fluorescentin situhybridization (FISH), using probes for X and Y chromosomes.ResultsIsolation of supposed fetal material from IUL samples was carried out by means of micromanipulation in 93 cases (82.3%), where discernible chorionic villous filaments or cell clumps of probable trophoblastic origin were present. The QF-PCR analysis was performed in all 93 IUL samples and paternal peaks could be documented in 88 cases (94.6%) thus confirming the presence of fetal cells. Thirteen cases negative to micromanipulation and derived from male fetuses and four male cases not informative with QF-PCR analysis, after micromanipulation, were then tested with FISH assay using probes for sexual chromosomes. In six samples, rare (2–3%) male fetal cells were detected. Considering the combined results obtained from QF-PCR and FISH assays, the overall fetal sexing was correct in 83.2% of cases (94 of 113).ConclusionThis study provides evidence that fetal cells are present in a high proportion of IUL samples. Micromanipulation appears to be an extremely efficient method for the isolation of trophoblastic elements. This study also confirms the potential of IUL as a possible alternative to the traditional prenatal diagnostic procedures for the recovery of fetal cells in precocious stage of gestation, and validates the combination of the isolation of such fetal elements by means of micromanipulation and analysis with the QF-PCR assay for the identification of the most frequent prenatal chromosomal aneuploidies.

ISSN:1084-8592    

出版商:ADIS    

年代:2004

数据来源: ADIS