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N Wong

Publications and source records attributed to N Wong.

At least 37 records · Page 2Linked to original sources
PubMed2000

Germline BRCA1/2 mutations and p27(Kip1) protein levels independently predict outcome after breast cancer.

PURPOSE: Decreased levels of the cyclin-dependent kinase inhibitor p27(Kip1) in breast cancer are associated with a poor outcome. The prognostic significance of BRCA1/2 mutations is less clear, and the relationship between BRCA1/2 mutation status, p27(Kip1) protein levels, and outcome has not been studied. PATIENTS AND METHODS: Pathology blocks from 202 consecutive Ashkenazi Jewish women with primary invasive breast cancer were studied. Tumor DNA was tested for the three common BRCA1/2 founder mutations present in Ashkenazi Jews, and p27(Kip1) expression was evaluated by immunohistochemistry. The median follow-up was 6.4 years. RESULTS: Thirty-two tumors (16%) were positive for a BRCA1/2 mutation. Low p27(Kip1) expression was seen in 110 tumors (63%) and was significantly associated with BRCA1/2 mutations (odds ratio, 4.0; 95% confidence interval [CI], 1.4 to 11.1; P =.009). BRCA1/2 mutation carriers had a significantly worse 5-year distant disease-free survival (DDFS) compared with women without BRCA1/2 mutations (58% v 82%; P =.003). Similar results were seen for women whose tumors expressed low levels of p27(Kip1), compared with those with high levels (5-year DDFS, 68% v 93%; P<.0001). In a multivariate analysis, both BRCA1/2 mutation and low p27(Kip1) expression were associated with a shorter DDFS (relative risk [RR], 2.1; 95% CI, 1.0 to 4.3; P =.05; and RR, 3.9; 95% CI, 1.4 to 11.1; P =.01, respectively). CONCLUSION: In this study, we showed that BRCA1/2 mutations were associated with low levels of p27(Kip1) in breast cancer. Both BRCA1/2 and p27(Kip1) status were identified as independent prognostic factors.

Adult↗
PubMed2000

Compliance of the respiratory system in newborn and adult rats after gestation in hypoxia.

We hypothesized that hypoxia during gestation modifies the compliance of the respiratory system of newborn and adult rats. Pregnant rats were placed in a hypobaric chamber at an inspired oxygen pressure of 86 mmHg (equivalent to 12% O2 in normobaria) from day 4 of gestation until day 2 post-partum. Three-day-old rat pups were smaller than controls, with higher hematocrit; the lungs were also small, with less protein and DNA content. The pressure (x-axis)-volume (y-axis) curve of the respiratory system was displaced to the right of the control curve, and the compliance of the respiratory system, measured on the inflation or deflation limb of the pressure-volume curve, was decreased by approximately 20-25%, depending upon the normalization procedure (per body mass or per dry lung weight). In 50-day-old rats exposed to hypoxia during gestation, body weight, hematocrit, lung mass and DNA content were normal; the compliance of the respiratory system, measured at ventilation frequencies between 20 cpm and 100 cpm, was higher than in controls by approximately 20%. It is concluded that the effects of prenatal hypoxia on the compliance of the respiratory system can vary with age. In the rat the process of alveolar formation initiates postnatally. Hence, in the newborn the effects of the prenatal hypoxia on the compliance of the respiratory system are likely to be dominated by the hypoxic pulmonary hypoplasia and hypertension, which decrease the compliance of the respiratory system. In the adult, the effects of the decreased alveolar formation are the prevailing ones, increasing the compliance of the respiratory system.

Age Factors↗
PubMed2000

Frequent c-myc and Int-2 overrepresentations in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a commonly occurring tumor in southern China. Although several causative factors have now been recognized, the genetic basis underlying its tumorigenesis is still unclear. To identify potential chromosomal aberrations for further investigations, comparative genomic hybridization (CGH) analysis was applied to the study of genomic imbalances in 10 NPC biopsy specimens. Before CGH analysis, the tumor cell content within the biopsy specimens was enriched by tissue microdissection, and universal genome amplification was performed on the recovered DNA. Recurrent chromosomal gains were detected on 1q (6 of 10 cases), 2q (5 of 10 cases), 3q (7 of 10 cases), 6p (8 of 10 cases), 6q (5 of 10 cases), 7q11.2 (4 of 10 cases), 8q (6 of 10 cases), 11q13, 12, and 15q (8 of 10 cases each), 17q (6 of 10 cases), and 20q (5 of 10 cases). Common losses were identified on 3p (5 of 10 cases), 9p (5 of 10 cases), 11q14-qter (8 of 10 cases), and 14q (5 of 10 cases). Among these aberrations, 7, 8, and 11 gains were further investigated on a series of NPC tissue samples, by interphase fluorescent in situ hybridization (FISH), for the incidence of alpha-satellites: 7, 8, and 11 c-myc and Int-2. Low-level increases of alpha-satellite 7 (9 of 34 cases; 26.5%), alpha-satellite 8 (15 of 34 cases; 44%), and alpha-satellite 11 (8 of 32 cases; 25%) were detected, whereas high-level copy gains of c-myc (21 of 34 cases; 62%) and Int-2 (26 of 34 cases; 76.5%) were more frequently found. Our series is the first to identify genomic overrepresentations of c-myc and Int-2 in NPC. The high incidence of Int-2 amplifications strongly suggests a role of this proto-oncogene in the pathogenesis of NPC.

Adult↗
PubMed2000

A comprehensive karyotypic analysis on a newly developed hepatocellular carcinoma cell line, HKCI-1, by spectral karyotyping and comparative genomic hybridization.

A continuously growing human hepatocellular carcinoma (HCC) cell line was established from a Chinese male, carrier of the hepatitis B virus (HBV). This cell line, designated HKCI-1, grows as an adhering monolayer of polygonal epithelial cells that embody one or more nuclei. HKCI-1 secretes alpha-fetoprotein but shows no evidence of HBV carriage. Conventional banding analysis of the short-term cultured primary tumor and the propagated HKCI-1 revealed a chromosome modal number of near-triploidy. It was, however, impossible to derive their complete karyotype due to the complex nature of chromosomal rearrangements and many marker chromosomes of uncertain origin. Spectral karyotyping (SKY) is a newly developed molecular cytogenetic technique that allows the unprecedented discernment of chromosomal abnormalities. Spectral karyotyping analysis on HKCI-1 and the primary tumor elucidated all aberrant chromosomes and revealed complex karyograms. Recurring aberrations detected in both primary tumor and HKCI-1 included der(X)t(X;11)(q10;p10), der(1)t(1;10)(q10;?pq), der(4)t(4;16)(p10;q10), i(5p), del(5)(q13), der(7)t(7;21)(q32q10::q10), der(8)t(8;17)(q10;p10), and der(9)t(9;22)(q34;?pq). Comparative genomic hybridization (CGH) was employed to monitor the culture evolution in vitro. Genomic imbalances in HKCI-1 involved chromosomal losses on 4q, 5q13-qter, 8p, 9pter-q33, 10q, 11q, 13q, 16q, 17q12-qter, and 22, and low-level gains on 6pter-q22, 7p, 8q, 9q34, 10p, 11p, 12, 17pter-q11.2, 18, 19, 20, 21, and Y. High-level amplifications were also detected on 5pter-q12, 7q11.2-qter, and Xq. The corresponding CGH finding on the primary tumor indicated similar imbalances. TP53 mutational analysis showed that both HKCI-1 and the primary tumor had the aflatoxin-associated mutation in codon 249 and an additional TP53 polymorphism in codon 72. Our present study demonstrates the value of combined SKY and CGH study in defining complex rearrangements and identifying cryptic translocations, and provides a comprehensive analysis on the chromosomal abnormalities in HKCI-1.

Adult↗
PubMed2000

Primary node negative breast cancer in BRCA1 mutation carriers has a poor outcome.

BACKGROUND: The association between BRCA1 germ-line mutations and breast cancer prognosis is controversial. A historical cohort study was designed to determine the prognosis for women with axillary lymph node negative hereditary breast cancer. PATIENTS AND METHODS: We tested pathology blocks from 118 Ashkenazi Jewish women with axillary lymph node negative breast cancer for the presence of the two common BRCA1 founder mutations, 185delAG and 5382insC. Patients were followed up for a median of 76 months. Somatic TP53 mutations were screened for by immunohistochemistry, and direct sequencing was performed in the BRCA1-positive tumours. RESULTS: Sixteen breast cancer blocks (13.6%) carried a BRCA1 mutation. Young age of onset, high nuclear grade, negative estrogen receptor status and over-expression of p53 were highly associated with BRCA1-positive status (P-values all <0.01). BRCA1 mutation carriers had a higher mortality than non-carriers (five-year overall survival, 50% and 89.6%, respectively, P = 0.0001). Young age of onset, estrogen receptor negative status, nuclear grade 3, and over-expression of p53 also predicted a poor outcome. Cox multivariate analyses showed that only germ-line BRCA1 mutation status was an independent prognostic factor for overall survival (P = 0.01). Among nuclear grade 3 tumours, the BRCA1 mutation carrier status was a significant prognostic factor of death (risk ratio 5.8, 95% confidence interval: 1.5-22, P = 0.009). Sequencing of BRCA1-related breast cancers revealed one TP53 missense mutation not previously reported in breast cancer. CONCLUSIONS: Using a historical cohort approach, we have identified BRCA1 mutation status as an independent prognostic factor for node negative breast cancer among the Ashkenazi Jewish women. Those managing women carrying a BRCA1 mutation may need take these findings into consideration. Additionally, our preliminary results, taken together with the work of others suggest a different carcinogenic pathway in BRCA1-related breast cancer, compared to non-hereditary cases.

Adult↗
PubMed2000

Chromosomal translocations are common in natural killer-cell lymphoma/leukemia as shown by spectral karyotyping.

Natural killer (NK)-cell lymphoma/leukemia is a group of rare but highly aggressive neoplasms. The associated genetic aberrations, as defined by conventional cytogenetics, include 6q deletion and chromosome X copy gain, while translocations have been suggested to be uncommon. In this study, three cases of NK cell lymphoma/ leukemia were investigated by spectral karyotyping (SKY). SKY permitted reinterpretation of the chromosomal alterations defined by G-banding and identified several cryptic translocations. In agreement with G-band, 6q deletion was detected in all 3 cases. Structural rearrangement involving chromosome X was observed in 2 cases, and fluorescence in situ hybridization (FISH) analysis indicated that both translocations involved Xp21-pter. Chromosome 8 translocation was also identified in 2 cases and shared a common breakpoint, 8p23. The present study shows the value of SKY in providing additional information on karyotypic abnormalities. The novel findings of recurring Xp21-pter rearrangements and 8p23 translocation should provide basis for further investigations into the tumorigenesis of NK cell lymphoma/leukemia.

Chromosome Banding↗
PubMed2000

A comprehensive karyotypic study on human hepatocellular carcinoma by spectral karyotyping.

The current paucity of cytogenetic information on hepatocellular carcinoma (HCC) reflects the difficulties in culturing hepatocytes in vitro. Here, we report on the successful culture of 15 HCC cases. Chromosome aneuploidy ranging from a near-diploid to hyperhexaploid karyotype was found, but their complete karyotypic interpretations were hampered by the presence of many unidentifiable rearrangements. Spectral karyotyping (SKY) was used to elucidate structural changes in these HCC samples and 3 liver cancer cell lines (PLC/PRF/5, Hep3B, and HepG2). Frequent structural abnormalities were found on chromosomes 1 (13 of 15 cases; 3 of 3 cell lines), 8 (10 of 15 cases; 2 of 3 cell lines), 17 (9 of 15 cases; 3 of 3 cell lines), and 19 (9 of 15 cases; 1 of 3 cell lines). In particular, the chromosome regions 1p13-q21, 8p12-q21, 17p11-q12, 17q22, and 19p10-q13.1 were involved in multiple rearrangements. SKY analysis also suggested several previously undescribed breakpoints in HCC. These breakpoints, predominantly pericentromeric, clustered around the chromosome bands 2q33-q34, 3p13-q12, 4p14-q12, 5p10-q11, 7p12-q11, 10q10-q11, 11q10, 11q13-q21, 12q10-q13, 12q22-q23, 13q10-q14, 15q10, 16q10-q13, 18p11-q11, 20p11-q13.1, 21q10, and 22q10. When tumor sizes were compared, a significantly higher number of structural abnormalities was found in tumors larger than 4 cm (P =.007). Rearrangements such as t(1;8), t(1;11), t(1;19), and t(17;21) that were identified in both primary tumors and cell lines might represent markers that reflect proliferative advantages. Although SKY analysis did not indicate consistent translocations, it suggested nonrandom breakpoints, predominantly in the pericentromeric region, on a number of chromosomes. These breakpoint clusters may thus prove to be more important in the liver carcinogenesis and targets for further molecular investigations.

Adult↗
PubMed2000

Hypertension and its treatment in postmenopausal women: baseline data from the Women's Health Initiative.

Little is known about the patterns of treatment and adequacy of blood pressure control in older women. The Women's Health Initiative, a 40-center national study of risk factors and prevention of heart disease, breast and colorectal cancer, and osteoporosis in postmenopausal women, provides a unique opportunity to examine these issues in the largest, multiethnic, best-characterized such cohort. Baseline data from the initial 98 705 women, aged 50 to 79 years, enrolled were analyzed to relate prevalence, treatment, and control of hypertension to demographic, clinical, and risk-factor covariates, and logistic regression analyses were performed to estimate odds ratios after adjusting for multiple potential confounders. Overall, 37.8% of the women had hypertension, which is defined as systolic blood pressure >/=140 mm Hg and/or diastolic blood pressure >/=90 mm Hg or being on medication for high blood pressure; 64.3% were treated with drugs, and blood pressure was controlled in only 36.1% of the hypertensive women, with lower rates of control in the oldest group. After adjustment for multiple covariates, current hormone users had higher prevalence than did nonusers (odds ratio 1.25). Hypertensive women had more comorbid conditions than did nonhypertensive women, and women with comorbidities were more likely to be treated pharmacologically. Diuretics were used by 44.3% of hypertensives either as monotherapy or in combination with other drug classes. As monotherapy, calcium channel blockers were used in 16%, angiotensin-converting enzyme inhibitors in 14%, beta-blockers in 9%, and diuretics in 14% of the hypertensive women. Diuretics as monotherapy were associated with better blood pressure control than any of the other drug classes as monotherapy. In conclusion, hypertension in older women is not being treated aggressively enough because a large proportion, especially those most at risk for stroke and heart disease by virtue of age, does not have sufficient blood pressure control.

Age Factors↗
PubMed2000

Differential gene expression of hepatocellular carcinoma using cDNA microarray analysis.

A cDNA microarray technique, which allows simultaneous analysis of differential expression of mRNA of over 4000 known human genes, was utilized to study the gene expression in 10 pairs of HCC and nontumorous tissues from ethnic Chinese patients in Hong Kong. A total of 211 genes were found to be highly expressed and 147 genes were downregulated in more than 1 out of 10 of the HCC pairs. The results were significant by two-tailed Wilcoxon test (P < or = 0.05 with 95% confidence) on the intensity of each DNA spot of the 10 HCC pairs. Six genes were highly expressed and 10 genes were downregulated in more than 30% of HCC pairs. Results are consistent with other published reports using traditional differential display, subtractive hybridization, or immunohistochemical staining methods. We also detected that beta-actin and glyceraldehyde 3-phosphate dehydrogenase (G3PDH), which have been commonly used as an internal standard control in mRNA expression studies, were highly expressed in HCC when compared with nontumorous tissue. It is concluded that cDNA microarray analysis is an effective method in the detection of differential gene expression in HCC.

Actins↗
PubMed2000

Importance of phenylalanine 107 in agonist recognition by the 5-hydroxytryptamine(3A) receptor.

The 5-hydroxytryptamine (5-HT)(3) receptor is a member of the ligand-gated ion channel receptor family with significant homology to the nicotinic acetylcholine, gamma-aminobutyric acid(A), and glycine receptors. In this receptor class, the agonist binding site is formed by parts of the extracellular amino-terminal region. This study examines the effects of altering phenylalanine 107 (F107) of the 5-HT(3AL) subunit, obtained from NG108-15 cells, using site-directed mutagenesis. The wild-type (WT) and mutant receptors were expressed in HEK 293 cells and characterized using both whole-cell patch-clamp and radioligand binding. The tyrosine mutant F107Y exhibits a significantly lower affinity for the agonist 5-HT (K(i) = 203 versus 15.6 nM) and an increase of similar magnitude in the EC(50) value (10.6 versus 1.2 microM) compared with WT. The activation kinetics of the maximal currents generated by 5-HT with this mutant were markedly slower than those of the WT receptor, but application of supramaximal concentrations of the agonist markedly decreased the time to half-peak. The asparagine mutant F107N displayed a significantly higher affinity for 5-HT than the WT receptor (1.62 versus 15.6 nM), which was mirrored in direction and magnitude by changes in the EC(50) value for this agonist (0.2 versus 1.2 microM). In contrast to the WT receptor, the mutant F107N was activated by acetylcholine (EC(50) = 260 microM). The response to acetylcholine was blocked by the 5-HT(3) receptor antagonist renzapride with a similar IC(50) value as that determined against currents generated by 5-HT in the WT receptor. These data suggest that F107 is an important determinant of agonist recognition at the 5-HT(3) receptor.

Animals↗
PubMed2000

Genomic aberrations in human hepatocellular carcinomas of differing etiologies.

We sought to assess whether genetic abnormalities in hepatocellular carcinoma differed in geographic locations associated with different risk factors. Comparative genomic hybridization (CGH) was applied to the genome-wide chromosomal analysis in 83 tumor samples from four different geographic origins. Samples were obtained from regions that differed in aflatoxin exposure: China (Hong Kong with low aflatoxin exposure and Shanghai with moderate aflatoxin exposure), Japan, and the United States (negligible aflatoxin exposure). Cases from Hong Kong and Shanghai were all hepatitis B virus (HBV) related, those from Japan were hepatitis C virus related, and those from the United States were HBV negative. In parallel, the mutational pattern of the whole p53 gene (exons 1-11) was also investigated in these cases. CGH revealed a complex pattern of chromosomal gains and losses, with the commonest aberration in each geographic location being chromosome 1q copy number gain (38-60%). Shanghai cases displayed the highest number of total aberrations per sample, with significant copy losses on 4q (75%), 8p (70%), and 16q (65%). Hepatitis C virus-related samples from Japan had a characteristically high incidence of 11q13 gain. p53 mutation(s) was detected in 23% of Hong Kong cases, 40% of Shanghai, 31% of Japan, but only 6% of the United States cases. The "aflatoxin-associated" codon 249 mutation was, however, identified only in samples from China (13% Hong Kong and 20% Shanghai). This finding, together with the highly aberrant pattern of genetic changes detected in the Shanghai series, is suggestive of the genotoxic effects of aflatoxin being more broadly based. It is also likely that there is a synergistic effect of HBV infection and high aflatoxin exposure in promoting hepatocellular carcinoma development. It appears from our CGH study that individual risk factors are indeed associated with distinct genetic aberrations, although changes in 1q gain appear common to all.

Adolescent↗
PubMed1999

Nasopharyngeal carcinoma cell line (C666-1) consistently harbouring Epstein-Barr virus.

We have established a cell line (C666-1) from undifferentiated nasopharyngeal carcinoma (NPC). This cell line consistently carries the Epstein-Barr virus (EBV) in long-term cultures. C666-1 is a subclone of its parental cell line, C666, derived from an NPC xenograft of southern Chinese origin. It grows as an adherent culture and lacks contact inhibition. In addition, it is tumorigenic in athymic nude mice. The cells consistently express EBV-encoded RNAs and are positively stained for cytokeratin, an epithelial marker. In addition, they express EBNA1 protein, LMP1 and LMP2 transcripts and thus resemble the EBV latency II pattern. The virus genotype is EBV-1 with the latent membrane protein 1 gene showing a 30-bp deletion at the carboxyl terminus, both consistent with findings in southern Chinese NPC tumours. Cytogenetic analysis revealed a sub-diploid status with a chromosomal modal number of 45. C666-1 is unique among NPC cell lines in that it carries EBV. These cells may serve as a good investigative tool as the viral latency pattern and genotype are observed in the majority of primary NPC biopsies from Chinese patients.

Animals↗
PubMed1999

Detection of recurrent chromosomal gains and losses in primary nasopharyngeal carcinoma by comparative genomic hybridisation.

Nasopharyngeal carcinoma (NPC) is a common cancer in Southern China but rare in Western countries. To search for genetic alterations in NPC, we examined a series of 20 primary tumours with comparative genomic hybridisation. The identified common chromosomal alterations included gain of chromosomes 1q, 8, 12, 19 and 20 as well as loss of chromosomes 1p, 3p, 9p, 9q, 11q, 13q, 14q and 16q. In concordance with our previous loss of heterozygosity studies in primary NPC, a high incidence of loss was detected on chromosomes 3p (75%), 11q (70%) and 14q (65%). Losses of 9q (60%), 13q (50%) and 16q (40%) were also identified. Novel chromosomal gains were observed on chromosome 12, with a high frequency (70%). Current analysis has revealed a comprehensive profile of the chromosomal regions showing losses and gains in primary NPC. Our findings may provide an entry point for conducting further investigations to locate the putative tumour-suppresser genes and oncogenes that may be involved in the tumourigenesis of NPC.

Chromosome Deletion↗
PubMed1999

Expression of glial cell line-derived neurotrophic factor and its mRNA in the nigrostriatal pathway following MPTP treatment.

Striatal glial cell line-derived neurotrophic factor (GDNF) mRNA levels in both young (2-month old) and old (11-month old) C57BL/6J mice were quantified at 3, 7 and 21 days following 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment. MPTP did not alter the expression of GDNF mRNA in these animals. Immunoreactive staining of GDNF in the substantia nigra and the striatum was also unchanged. In conclusion, MPTP-induced dopaminergic neurotoxicity does not elicit any changes in the expression of endogenous GDNF or its mRNA in the adult mouse brain.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1999

Chromosomal aberrations during progression of chronic myeloid leukemia identified by cytogenetic and molecular cytogenetic tools: implication of 1q12-21.

To study the genomic abnormality underlying the acute transformation of chronic myeloid leukemia (CML), 15 CML patients in blast crisis (BC), 3 in accelerated phase (AP), and 20 in chronic phase (CP) were analyzed by conventional cytogenetics, comparative genomic hybridization (CGH), and dual-color chromosomal painting. Philadelphia (Ph) chromosome was identified in every case studied. Only 5 among 20 CP patients had additional abnormalities while 13 of 18 patients with disease progression (BC + AP) showed extra numerical and/or structural chromosomal aberrations. Cytogenetically, the most common chromosome gains during BC and AP were double or triple Ph chromosomes (5 of 14 cases) and trisomy 8 (5 of 14 cases). Trisomies 7 and 17 (1 of 14 cases each) were also observed. CGH analysis detected genetic imbalances in eight cases. Gains of chromosome 20 (3 cases) and 17q (2 cases) were observed, respectively. The recurrent chromosome loss was the deletion of the short arm of chromosome 17, seen in one case with i(17)(q10) and one case with an unbalanced translocation (1;17). In one case, a very complex chromosomal rearrangement, del(3),del(6),der(6)t(17;3;6),der(17)t(6;17), was seen. A novel finding of this work is the involvement of chromosome 1(q12-21qter) in CML disease progression. Overrepresentation of 1(q12-21qter) region was detected by CGH in one case which had a derivative chromosome 17. This abnormal chromosome was later confirmed by fluorescence in situ hybridization (FISH) painting to be a fusion between chromosome 1 and 17 to form the der(17)t(1;17) (q12-21;p11). Two other cases showed the same region being involved in translocations, t(1;10)(q12-21;q26) and t(1;11)(q12-21;p15). It is possible that one or more genes residing on chromosome 1q12-21 may be important in the acute transformation of CML. In conclusion, we find that the combined use of CGH, chromosome painting, and classic cytogenetic analysis allows a better evaluation of the genomic aberration involved in CML blastic transformation, and offers new directions for its further molecular investigations.

Adult↗
PubMed1999

Detection of aberrant p16 methylation in the plasma and serum of liver cancer patients.

We have studied the feasibility of detecting tumor-associated aberrant p16 methylation in the circulation of patients with hepatocellular carcinoma (HCC). We extracted DNA from the tumor tissues and peripheral blood plasma or serum of 22 HCC patients. p16 methylation was found in 73% (16 of 22) of HCC tissues using methylation-specific PCR. Among the 16 cases with aberrant methylation in the tumor tissues, similar changes were also detected in the plasma/serum samples of 81% (13 of 16) of the cases. No methylated p16 sequences were detected in the peripheral plasma/serum of the six HCC cases without these changes in the tumor, in 38 patients with chronic hepatitis/cirrhosis, or in 10 healthy control subjects. These results suggest that circulating liver tumor DNA may be detected using tumor-associated DNA methylation changes. Because methylation abnormalities have been found in many other genes and tumor types, this approach may have implications for the noninvasive detection of a wide variety of cancers.

Adult↗
PubMed1999

Screening for hypercholesterolaemia in 10,000 neonates in a multi-ethnic population.

UNLABELLED: An immunoassay was developed for the detection of hypercholesterolaemia in dried blood spots collected from 6-day-old neonates. Blood spot samples (9,673) were subjected to immunoturbidimetric assay to determine the levels of apolipoprotein B (apoB), an index of plasma low density lipoprotein, and of apolipoprotein A-1 (apoA-1), an index of plasma high density lipoprotein. Infants with raised apoB or a reduced apoA-1/apoB ratio were recalled, retested and, if appropriate, referred to the Vascular Risk Clinic at King's College Hospital for medical management. A total of 189 were recalled for further testing; of whom 82 (45%) attended the recall clinic. A group of 16 families (24 individuals) had abnormal lipid profiles; of these, 7 families (14 individuals) had lipid profiles consistent with inherited hypercholesterolaemia. CONCLUSION: Neonatal screening for hypercholesterolaemia using blood spot apolipoprotein measurements is feasible but ethnic variations in disease prevalence must be considered in the design of a screening programme.

Adult↗