Biomedical subjects

T C Chen

Publications and source records attributed to T C Chen.

At least 55 records · Page 3Linked to original sources

PubMed2001

Angiomyolipoma of the liver: case report.

Hepatic angiomyolipoma is a rare benign mesenchymal tumor of the liver. Most multiple hepatic angiomyolipomas have appeared in patients with renal angiomyolipoma and tuberous sclerosis. A 38-year-old female patient without chronic hepatitis B or C was hospitalized because of epigastric fullness for 2 months. Radiologic studies showed a large solid tumor with a small daughter nodule in the right hepatic lobe. Upon intravenous bolus injection of contrast medium, both tumors showed weak heterogeneous enhancement in the delayed phase. Although hepatocellular carcinoma was suspected by the findings of computed tomography, percutaneous transhepatic ultrasound-guided biopsy was performed for the large tumor. The histopathology showed many mature fat cells intermingled with thick-walled blood vessels, and epithelioid cells with eosinophilic cytoplasm; the epithelioid cells stained positively for HMB-45 and smooth muscle actin. Angiomyolipoma of the liver was confirmed. The main tumor enlarged considerably during a follow-up period of 3 years. Surgical resection was performed due to persistent symptoms. She had an uneventful postoperative recovery and was well when followed up 10 months after surgery. We should be aware that a hepatic angiomyolipoma can change in size during its natural course, and this finding does not necessarily indicate malignancy.

Adult↗

PubMed2001

Prostate cancer and spinal cord compression.

Prostate cancer metastasis to the spine is an extremely difficult clinical problem to treat. However, it occurs commonly, and all clinicians--not only oncologists--should undertake to understand its pathogenesis, diagnosis, clinical presentation, and current treatment options. This review emphasizes the surgical treatment of prostate cancer metastasis to the spine. The goals of this article are to (1) present an overview of the pathophysiology of this disease, with an emphasis on the mechanisms of metastasis and invasion, (2) provide a general overview of the clinical presentation and diagnosis of metastatic prostate carcinoma, and (3) discuss currently available treatment options. Such options include best medical management, nonsurgical treatments (radiation, chemotherapy), and surgical treatment of newly diagnosed and previously irradiated metastatic prostate carcinoma to the spine. Algorithms for the treatment of this disease are presented.

Algorithms↗

PubMed2000

Constitutive activation of nuclear factor kappaB in hepatocellular carcinoma.

BACKGROUND: Nuclear factor kappaB (NF-kappaB) is a transcription factor that plays important roles in cell proliferation and in immunity against viral infections. NF-kappaB is a dimer of Rel proteins that is sequestered in the cytoplasm as an inactive form through interaction with an inhibitory kappaB (IkappaB) protein. When IkappaB is degraded, the NF-kappaB dimer will enter the nucleus to activate the target genes. Chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection may activate NF-kappaB and, thus, may modulate cell apoptosis and may be associated with oncogenesis. The role of NF-kappaB in hepatocellular carcinoma (HCC) has not yet been explored. METHODS: Immunohistochemical staining to search for active nuclear RelA and nuclear IkappaBalpha proteins were done on formalin fixed liver tissues from 65 patients with HCC and from 9 normal control participants. Nuclear extracts of fresh-frozen tumor and nontumor liver tissues from 37 patients with HCC and from 7 normal controls were tested for NF-kappaB-DNA binding activity by electrophoretic mobility shift assay. The RelA and IkappaBalpha protein expressions were studied by Western blot analysis. RESULTS: Nuclear NF-kappaB stainings were significantly more abundant in HBV-infected or HCV-infected tumors as well as nontumor parts of HCC compared with normal controls. Nuclear NF-kappaB DNA binding activity and nuclear RelA protein expression were greater in tumor tissue compared with nontumor tissue, whereas cytosolic IkappaBalphs protein expression was generally greater in nontumor tissue compared with tumor tissue. CONCLUSIONS: Constitutive activation of NF-kappaB was found more frequently in tumor tissue compared with nontumor tissue. It is possible that NF-kappaB overexpression accompanied by dysregulation of IkappaBalpha may play a role in the hepatocarcinogenesis of HBV or HCV infection.

Adult↗

PubMed2000

Surgical outcome for thoracic disc surgery in the postlaminectomy era.

In this article the author reviews outcomes of thoracic disc surgery reported in the literature. Care was taken to include only series in which none or a few patients underwent laminectomy for the treatment of thoracic disc lesions. The author found that thoracic discectomy may be performed in an efficacious and safe manner via the transthoracic, lateral extracavitary, transpedicular, or endoscopic approach. In the vast majority of patients, preoperative symptoms of pain (radiculopathy or axial loading pain) and myelopathy were improved after surgery. Measurements of operative time, blood loss, length of hospital stay, and patient satisfaction were often inadequately reported. Complications (systemic and neurological) were well documented and were not common. A plea is made for uniformity in documenting outcome in future series so that today's procedures for thoracic discectomy may be more accurately compared with future cases regardless of the inevitable advances in surgical techniques for removal of thoracic discs.

Diskectomy↗

PubMed2000

Aberrant transcripts of the cyclin-dependent kinase-associated protein phosphatase in hepatocellular carcinoma.

The cyclin-dependent kinase (Cdk)-associated protein phosphatase (KAP) is a human dual specificity protein phosphatase that dephosphorylates Cdk2 on threonine 160 in a cyclin-dependent manner. To investigate whether mutations of this enzyme occur in hepatocellular carcinoma (HCC), KAP mRNA was analyzed by reverse transcription-PCR (RT-PCR), followed by cloning and sequencing. Eight of 14 biopsy tissues obtained from advanced HCC, 6 of 13 surgically removed HCC tissues, and 2 of the adjacent noncancerous tissues contained aberrant KAP transcripts. Using the yeast two-hybrid system, five of seven representative KAP mutants were shown to be defective in interacting with Cdk2. These data suggest a possible role of KAP mutations in multiple-step hepatocarcinogenesis.

Amino Acid Sequence↗

PubMed2000

Second malignant tumors in patients with nasopharyngeal carcinoma and their association with Epstein-Barr virus.

Since previous published studies about second malignant tumors (SMTs) in nasopharyngeal carcinoma (NPC) patients usually included a limited sample size and did not attain consistent results, we conducted a large retrospective study in a cohort of 1,549 patients to assess the risk of SMT in NPC patients following radiotherapy (RT) in Taiwan. The follow-up period ranged from 2 to 16 years, with a median of 7 years. Thirty-nine patients developed SMTs during the 7,145 person-year follow-up [standardized incidence ratio (SIR): 2. 8; 95% confidence interval (CI): 2.0 to 3.9]. Increased risks of developing SMTs were observed for head and neck (H/N) cancer (SIR: 16.5; 95% CI: 10.0 to 26.8), gastric cancer (SIR: 5.5; 95% CI: 2.2 to 11.4) and leukemia (SIR: 9; 95% CI: 1.9 to 26.3). Paraffin-embedded specimens of secondary H/N cancer (11), secondary gastric cancer (6) and their corresponding NPC specimens were examined by EBER in situ hybridization to assess the association between Epstein-Barr virus (EBV) and these SMTs. Twenty-six primary H/N and 5 gastric cancer specimens were chosen as the control groups. In H/N cancer, EBV was detected in 3.8% of the primary cancers and 9.1% of the secondary cancers. All the positive specimens resulted from hypopharyngeal cancer. Of the secondary gastric cancers, only 1 case (16.6%) was associated with EBV. None of the primary gastric cancers was associated with EBV. Our results indicate an increased risk of developing SMTs, with a preference for head and neck cancer, gastric cancer and leukemia, in NPC patients after RT in Taiwan. Only a small proportion of the secondary H/N and gastric cancers was associated with EBV.

Adolescent↗

PubMed2000

Mutational analysis of the p27(kip1) gene in hepatocellular carcinoma.

p27(Kip1) is an inhibitor of cyclin-dependent kinase. It has been reported that reduced p27(Kip1) expression is present in human hepatocellular carcinoma. To determine the role of p27(Kip1) in hepatocarcinogenesis, 46 cases with hepatocellular carcinomas were studied. p27(Kip1) mutation was first screened by single strand conformation polymorphism, and direct DNA sequencing was then performed on those cases with mobility shifts. Two polymorphism sites were found. One is a previously described polymorphism at codon 109 (GTC-->GGC) which was found in two cases. The second polymorphism was identified at codon 55 (GCG-->GCA) in six of the 46 cases. However, the polymorphism at codon 55 was also present in seven of 93 healthy controls (7.5%), indicating that it is not associated with a predisposition for development of hepatocellular carcinoma (Fisher's exact test, 0.05). These results show that p27(Kip1) mutation is not a frequent event in human hepatocellular carcinoma, and suggest that it may be inactivated predominantly by transcriptional and/or posttranscriptional regulation rather than genomic aberrations.

Adult↗

PubMed2000

Dedifferentiation of human hepatocellular carcinoma up-regulates telomerase and Ki-67 expression.

HYPOTHESIS: Dedifferentiation of human hepatocellular carcinoma (HCC) may influence telomerase activation and Ki-67 expression. DESIGN: Laboratory study using human HCC specimens. SETTING: University hospital. PATIENTS: Twelve patients with HCC with specific morphologic patterns (nodule-in-nodule [n = 4] or confluent multinodular [n = 8] type) and histological heterogeneity and who had undergone curative hepatectomy were studied. Of these, 8 patients had 2 different histological grades of HCC cells distributed at various nodules but within the same tumor; 3 patients, 3 different histological grades; and 1 patient, all 4 different histological grades. INTERVENTION: Tissue samples were retrieved from each nodule of the tumor and not mixed with one another. A total of 42 cancerous tissues from different distinctive nodules of the 12 patients were taken for telomerase and Ki-67 study, and corresponding noncancerous counterparts (n = 12) served as healthy control samples. Telomerase activity was assayed by the telomerase repeat amplification protocol. Expression of messenger RNA (mRNA) by the human telomerase catalytic subunit human telomerase reverse transcriptase (hTERT) was determined using reverse transcription polymerase chain reaction. The relative telomerase activity and hTERT mRNA in each tissue sample was quantified using densitometry and expressed as a percentage of the standardized HeLa cell line. Immunostaining with anti-Ki-67 antibody was used to detect Ki-67 and was expressed as Ki-67 labeling index. MAIN OUTCOME MEASURES: Telomerase activity, hTERT mRNA, and Ki-67 labeling index stratified by different histological gradings in each patient was analyzed. The correlations between telomerase activity and hTERT mRNA and between telomerase activity and expression of Ki-67 were plotted. RESULTS: Telomerase activity increased from more to less differentiated foci of HCC cells in each case (generalized linear model, P<.001). Mean +/- SD expression of hTERT mRNA in 43 cancerous tissue samples, even those 4 with negative telomerase activity, was distinguishable from that of the noncancerous controls (0.84 + 0.23 vs 0.41 + 0.11; t test, P =.008). Telomerase activity was correlated to hTERT mRNA expression (Pearson correlation, r(2) = 0.56; P<.001). The Ki-67 labeling index increased from more to less differentiated foci of HCC in each case (generalized linear model, P<.001). Expression of Ki-67 correlated with telomerase activity within differently graded areas within individual tumors (Pearson correlation, r(2) = 0.38; P<. 001). CONCLUSION: Using the model of human HCC with histological heterogeneity, we determined that dedifferentiation of human HCC induces telomerase activation and Ki-67 expression.

Carcinoma, Hepatocellular↗

PubMed2000

Olone modulates the therapeutic effect of interferon to eliminate preferentially the hepatitis B virus precore stop mutant.

BACKGROUND/AIMS: The aim of this study was to understand the changes in the proportion of hepatitis B virus precore stop mutant during the course of prednisolone primed interferon (IFN) therapy. METHODS: Three groups of patients were included: patients receiving prednisolone-primed IFN treatment (Group I, n=31), IFN treatment only (Group II, n=29), and placebo (Group III, n=25). The proportion of precore stop mutant was measured by a quantitative amplification-created restriction site method. RESULTS: Distinct patterns of the progression of the proportion of mutant were found among these three groups. A steady increase in the proportion of mutant was observed only in Group III patients. In Group II patients, the presence of a higher percentage of mutant (> 25%) immediately before IFN treatment was predictive for the subsequent clearance of hepatitis B e antigen (HBeAg) (p<0.01), but not for complete anti-viral response (p>0.05). Prednisolone pretreatment resulted in an increase in the proportion of mutant in patients with initially low percentages (< or = 25%) of mutant. During the period of IFN treatment, both the relative and absolute amount of the precore stop mutant decreased significantly in Group I patients who cleared HBeAg. The presence of such a decrease in this group of patients was predictive for both HBeAg clearance and complete anti-viral response. CONCLUSIONS: Our data suggest that prednisolone serves as a modulator to enhance elimination of precore stop mutant by IFN, which advocates the benefit of corticosteroid pretreatment in an area where the precore mutants are prevalent.

Administration, Oral↗

PubMed2000

An evaluation of the biologic activity and vitamin D receptor binding affinity of the photoisomers of vitamin D3 and previtamin D3.

Skin is in the site of previtamin D3 and vitamin D3 synthesis and their isomerization in response to ultraviolet irradiation. At present, little is known about the function of the photoisomers of previtamin D3 and the vitamin D3 in skin cells. In this study we investigated the antiproliferative activity of the major photoisomers and their metabolites in the cultured human keratinocytes by determining their influence on 3H-thymidine incorporation into DNA. Our results demonstrated at both 10(-8) and 10(-6) M in a dose-dependent manner. Lumisterol, tachysterol3, 5,6-trans-vitamin D3, and 25-hydroxy-5,6-trans-vitamin D3 only induced significant inhibition at 10(-6) M. 25-Hydroxytachysterol3 was approximately 10- to 100-fold more active than tachysterol3. 7-Dehydrocholesterol was not active even at 10(-6) M. The dissociation constants of vitamin D receptor (VDR) for 25-hydroxytachysterol3, 25-hydroxy-5,6-trans-vitamin D3, and 5,6-trans-vitamin D3 were 22, 58, and 560 nM, respectively. The dissociation constants for 7-dehydrocholesterol, tachysterol, and lumisterol were greater than 20 microM. In conclusion, vitamin D3, its photoisomers and the photoisomers of previtamin D3 have antiproliferative activity in cultured human keratinocytes. However, the antiproliferative activity did not correlate with their binding affinity for VDR. The results suggest that some of the photoproducts may be metabolized to their 25-hydroxylated and 1 alpha,25-dihydroxylated counterparts before acting on VDR. Alternatively, a different receptor may recognize these photoproducts or another mechanism may be involved in modulating the antiproliferative activity of the photoisomers examined.

Calcitriol↗

PubMed2000

Aberrant expression of TSG101 in Taiwan Chinese breast cancer.

Functional inactivation of the tsg101 gene in mouse fibroblasts results in cell transformation and the ability to form metastatic tumors in nude mice. The human tsg101 gene was mapped to chromosome 11q15.1-2 and found to mutate in some cancer patients. To test the expression pattern of the tsg 101 gene in Chinese breast cancer patients, we analyzed the mRNA by RT-PCR in 51 breast cancer patients. The full-length tsg101 and 7 truncated transcripts were detected in both normal and matched tumor tissues. A short transcript with a deletion of nucleotides 154-1054 is frequently presented in late-stage breast cancers. TSG101 protein expression was also detected by Western blot analysis in 30 breast cancer patients. A predicted full-length 46 kDa and three proteins with smaller molecular weight were detected. The full-length 46 kDa protein was less expressed in tumor specimens. Immunohistochemical stains from 10 patients of each stage 0-4 revealed that TSG101 protein was predominantly present in the cytoplasm. Cell nuclei were occasionally immunopositive and the chromosomes were deeply stained during cell division. The intracellular location and the expression of TSG101 protein were both not stage-dependent in primary breast cancers. In addition, normal mammary glands were more homogenously immunopositive than invasive ductal carcinoma. These results support the notion that the aberrant expression of TSG101 in breast cancer is associated with altered cell growth.

Blotting, Western↗

PubMed2000

Dermatofibroma is a clonal proliferative disease.

Benign fibrous histiocytoma of the skin or dermatofibroma (DF) has been regarded as a fibrohistiocytic tumor. Whether DF is a neoplastic growth or a reactive process has not been settled. Since a neoplastic process is clonal in nature, clonal analysis of DF was conducted to see if DF is a clonal disease. Fresh specimens of 13 DFs and 2 hypertrophic scars obtained from female patients were studied. The adjacent nonlesional skin tissues served as controls. The clonal analysis was based on the methylation pattern of the polymorphic X-chromosome linked androgen-receptor gene (HUMARA). Eight DFs and 1 hypertrophic scar were heterozygous at the androgen receptor gene and could be analyzed. All 8 informative DFs showed a significant reduction in one of the allelic bands compared with the corresponding bands of the nonlesional tissue after Hha I digestion. Therefore, DF is a clonal proliferative disease. In contrast, 1 hypertrophic scar showed a polyclonal pattern of X-chromosome inactivation. We conclude that DF is a clonal disease favoring a neoplastic process.

Alleles↗

PubMed2000

Hexafluoro-1,25-dihydroxyvitamin D3 has markedly increased potency in inhibiting proliferation of cultured human keratinocytes compared with 1,25-dihydroxyvitamin D3.

BACKGROUND: Although topical 1,25-dihydroxyvitamin D3 (calcitriol, 1, 25(OH)2D3) and its analogues, calcipotriol and tacalcitol, are effective for patients with psoriasis, some patients show little or no response. There is a need to develop more potent analogues of 1, 25(OH)2D3. Hexafluoro-1,25(OH)2D3 (F6-1,25(OH)2D3) is at least 10 times more potent than 1,25(OH)2D3 on calcium metabolism. OBJECTIVES: We were interested in whether F6-1,25(OH)2D3 was also more potent than 1,25(OH)2D3 in inhibiting normal human and psoriatic keratinocyte proliferation. METHODS: The antiproliferative activity of F6-1,25(OH)2D3 and 1,25(OH)2D3 was determined by 3H-thymidine incorporation into keratinocyte DNA and by counting basal cells. RESULTS: F6-1,25(OH)2D3 was approximately 10-fold more active and had a longer lasting antiproliferative effect than 1,25(OH)2D3 on normal human keratinocytes, and was about 100-fold more potent than 1, 25(OH)2D3 on human psoriatic keratinocytes as determined by 3H-thymidine incorporation. F6-1,25(OH)2D3 also caused a dose-dependent decrease in the number of basal cells and was 100-fold more active than 1,25(OH)2D3. CONCLUSIONS: The increased potency and the long-lasting effects of F6-1,25(OH)2D3 suggest that F6-1,25(OH)2D3 may be a potent candidate agent for treating psoriasis.

Calcitriol↗

PubMed2000

The effects of repeated maximal voluntary isokinetic eccentric exercise on recovery from muscle damage.

This study investigated whether performing repeated bouts of maximal voluntary isokinetic eccentric exercise (MAX1) on 3 (MAX3) and 6 days (MAX6) after the initial bout would produce significant changes in the indirect markers of muscle damage and total work. A secondary purpose was to determine whether participants' psychological maximal effort was equivalent to the physiological maximal effort during muscle soreness. Male university students were assigned randomly to a control group (n = 12) and a group that repeated the exercise (EX; n = 12). The MAX1 was 3 x 10 repetitions of the nondominant elbow flexors on the Cybex 6000 system at a speed of 60 deg/s. The EX group performed the same exercise 3 days and 6 days after MAX1. The range of motion and maximal isometric force (MIF), muscle soreness index, plasma creatine kinase, and glutamic-oxaloacetate transaminase activities were measured before and every 24 hr for 9 days after MAX1 for both groups. MIF was also assessed once before and immediately after each MAX for the EX group. There were no significant changes (p > .05) between the groups for all criterion measures, except for total amount of work (p < .05). It is concluded that strenuous voluntary isokinetic eccentric exercise performed with damaged muscles does not appear to exacerbate damage or influence the recovery process. Although individuals could perform repeated MAXs, the total work performed was significantly reduced. This has practical implications in strength training for coaches and athletes during muscle damage.

Adult↗

PubMed2000

Decreased bioavailability of vitamin D in obesity.

BACKGROUND: Obesity is associated with vitamin D insufficiency and secondary hyperparathyroidism. OBJECTIVE: This study assessed whether obesity alters the cutaneous production of vitamin D(3) (cholecalciferol) or the intestinal absorption of vitamin D(2) (ergocalciferol). DESIGN: Healthy, white, obese [body mass index (BMI; in kg/m(2)) > or = 30] and matched lean control subjects (BMI </= 25) received either whole-body ultraviolet radiation or a pharmacologic dose of vitamin D(2) orally. RESULTS: Obese subjects had significantly lower basal 25-hydroxyvitamin D concentrations and higher parathyroid hormone concentrations than did age-matched control subjects. Evaluation of blood vitamin D(3) concentrations 24 h after whole-body irradiation showed that the incremental increase in vitamin D(3) was 57% lower in obese than in nonobese subjects. The content of the vitamin D(3) precursor 7-dehydrocholesterol in the skin of obese and nonobese subjects did not differ significantly between groups nor did its conversion to previtamin D(3) after irradiation in vitro. The obese and nonobese subjects received an oral dose of 50000 IU (1.25 mg) vitamin D(2). BMI was inversely correlated with serum vitamin D(3) concentrations after irradiation (r = -0.55, P: = 0.003) and with peak serum vitamin D(2) concentrations after vitamin D(2) intake (r = -0.56, P: = 0.007). CONCLUSIONS: Obesity-associated vitamin D insufficiency is likely due to the decreased bioavailability of vitamin D(3) from cutaneous and dietary sources because of its deposition in body fat compartments.

Adult↗

PubMed2000

Malignant glaucoma.

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Anterior Chamber↗

PubMed2000

Malignant perihilar biliary obstruction: magnetic resonance cholangiopancreatographic findings.

OBJECTIVE: We studied the efficacy of magnetic resonance cholangiopancreatography (MRCP) in the evaluation of malignant perihilar biliary obstructions, with reference to endoscopic retrograde cholangiopancreatography (ERCP). METHODS: A total of 40 patients with malignant perihilar biliary obstructions, who underwent both MRCP (Magnetom Vision; Siemens, Erlangen, Germany; projection technique and multislice plus maximum intensity projection) and ERCP examinations, were studied. The study group included hilar cholangiocarcinoma (Klatskin tumor) in 26 patients, icteric hepatocellular carcinoma in four patients, gallbladder carcinoma in five patients, and metastasis from other than hepatobiliary origin in five patients. Axial and coronal magnetic resonance (MR) images were added simultaneously to the MRCP. The mean serum bilirubin level on admission was 11.5 mg/ml (range, 2.8-28.5 mg/ml). The presence and extent of malignant biliary obstruction were determined with both MRCP and ERCP following the known criteria: an abrupt and irregular character of a distal narrow segment, a proportionally dilated biliary tree proximally, and an irregularly shaped intraluminal filling defect. The efficacy of the MRCP examination in detecting the presence of biliary obstruction, its anatomical extent, and the underlying cause, respectively, was compared to that of ERCP. RESULTS: MRCP examination was successfully performed on all patients, whereas ERCP examination was unsuccessful in two patients. Both MRCP and ERCP were very effective in detecting the presence of biliary obstructions (40 of 40 vs. 38 of 38, p = 1.0). MRCP was superior in its investigation of anatomical extent (34 of 40 vs. 24 of 38, p = 0.015) and the cause of the jaundice (31 of 40 vs. 22 of 38, p = 0.023) compared to ERCP. Specifically, the performance of MRCP is promising for the interpretation of cholangiocarcinoma (22 of 26) and gallbladder carcinoma (five of five), but is relatively ineffective for the interpretation of icteric HCC (two of four) and metastasis (two of five). CONCLUSION: MRCP represented an ideal noninvasive diagnostic tool for the evaluation of malignant perihilar biliary obstructions with reference to ERCP.

Bile Duct Neoplasms↗

PubMed2000

Real-time PCR for quantitative detection of Toxoplasma gondii.

The protozoan Toxoplasma gondii is one of the most common infectious pathogenic parasites and can cause severe medical complications in infants and immunocompromised individuals. We report here the development of a real-time PCR-based assay for the detection of T. gondii. Oligonucleotide primers and a fluorescence-labeled TaqMan probe were designed to amplify the T. gondii B1 gene. After 40 PCR cycles, the cycle threshold values (C(T)) indicative of the quantity of the target gene were determined. Typically, a C(T) of 25.09 was obtained with DNA from 500 tachyzoites of the T. gondii RH strain. The intra-assay coefficients of variation (CV) were 0.4, 0.16, 0.24, and 0.79% for the four sets of quadruplicate assays, with a mean interassay CV of 0.4%. These values indicate the reproducibility of this assay. Upon optimization of assay conditions, we were able to obtain a standard curve with a linear range (correlation coefficient = 0.9988) across at least 6 logs of DNA concentration. Hence, we were able to quantitatively detect as little as 0.05 T. gondii tachyzoite in an assay. When tested with 30 paraffin-embedded fetal tissue sections, 10 sections (33%) showed a C(T) of <40 and were scored as positive for this test. These results were consistent with those obtained through our nested-PCR control experiments. We have developed a rapid, sensitive, and quantitative real-time PCR for detection of T. gondii. The advantages of this technique for the diagnosis of toxoplasmosis in a clinical laboratory are discussed.

Animals↗