Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Reverse Survival Method”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2004

Prognostic model of pulmonary adenocarcinoma by expression profiling of eight genes as determined by quantitative real-time reverse transcriptase polymerase chain reaction.

PURPOSE: Recently, several expression-profiling experiments have shown that adenocarcinoma can be classified into subgroups that also reflect patient survival. In this study, we examined the expression patterns of 44 genes selected by these studies to test whether their expression patterns were relevant to prognosis in our cohort as well, and to create a prognostic model applicable to clinical practice. PATIENTS AND METHODS: Expression levels were determined in 85 adenocarcinoma patients by quantitative reverse transcriptase polymerase chain reaction. Cluster analysis was performed, and a prognostic model was created by the proportional hazards model using a stepwise method. RESULTS: Hierarchical clustering divided the cases into three major groups, and group B, comprising 21 cases, had significantly poor survival (P =.0297). Next, we tried to identify a smaller number of genes of particular predictive value, and eight genes (PTK7, CIT, SCNN1A, PGES, ERO1L, ZWINT, and two ESTs) were selected. We then calculated a risk index that was defined as a linear combination of gene expression values weighted by their estimated regression coefficients. The risk index was a significant independent prognostic factor (P =.0021) by multivariate analysis. Furthermore, the robustness of this model was confirmed using an independent set of 21 patients (P =.0085). CONCLUSION: By analyzing a reasonably small number of genes, patients with adenocarcinoma could be stratified according to their prognosis. The prognostic model could be applicable to future decisions concerning treatment.

Adenocarcinoma↗
PubMed2004

Detection of melanoma cells in the lymphatic drainage after lymph node dissection in melanoma patients by using two-marker reverse transcriptase-polymerase chain reaction assay.

BACKGROUND: The aim of this study was to evaluate the role of melanoma gene expression as a marker of the presence of melanoma cells in lymphatic drainage routinely collected after lymphadenectomy and to correlate reverse transcriptase-polymerase chain reaction (RT-PCR) assay results with recurrence, survival, and prognostic factors. METHODS: We collected 24-hour postoperative lymphatic drainage samples (between days 2 and 4) from 93 patients with stage III melanoma who underwent radical lymphadenectomy between May 2002 and November 2003. We used RT-PCR assays with primers specific for the tyrosinase and MART-1 (Melan-A) genes. The samples were considered positive if at least one marker was expressed. Median follow-up time was 12.8 months. RESULTS: In 18 (19.4%) of 93 patients, the RT-PCR assay results were positive: in 8 of 18 for tyrosinase only, in 7 of 18 for MART-1 only, and in 3 of 18 for both markers. We observed a significantly higher recurrence rate in patients with positive RT-PCR results (15 of 18; 83%) than negative results (26 of 75; 35%; P = .0001). Positive results of RT-PCR correlated with the number of involved lymph nodes (P = .0001) and extracapsular extension of nodal metastases (P = .03). We observed significant differences in overall and disease-free survival for RT-PCR-positive and -negative patients in univariate and multivariate analyses. CONCLUSIONS: We observed positive RT-PCR assay results for melanoma cells in the lymphatic drainages of approximately 20% of patients after lymphadenectomy. This correlated significantly with early recurrence and shorter survival. These results may suggest that the RT-PCR assay could be useful for routinely analyzing postoperatively collected lymphatic drainage in stage III melanoma patients and for predicting disease progression.

Adult↗
PubMed2001

[Reconstruction of heel by reversed island fibular musculocutaneous flap].

OBJECTIVE: To explore the anatomical basis of blood supply and heel reconstruction by reversed island fibular musculocutaneous flap. METHODS: The blood supply of fibular musculocutaneous flap and the biomechanical characteristics of heel were studied by anatomical examination. One case with right heel full defect because of explosion injury was repaired by transfer of reversed island fibular vessels. The fibular flap was 14 cm in length with part of peroneus muscle and long flexor muscle of great toe. RESULTS: The lower part of fibular artery had plentiful anastomosis with anterior tibial artery and posterior tibial artery, which could provide ideal reversed blood supply. The rotatory point of vessel pedicle could be chosen according to the need of operation. The lowest site might be above 6 cm to lateral malleolus, and the vessel pedicle was 20 cm in length. The morphological feature of the reversed island fibular musculocutaneous flap was suitable to the biomechanical character of heel. The patient achieved satisfactory clinical result, the musculocutaneous flap survived well for 10 months of follow-up. CONCLUSION: The reversed island fibular musculocutaneous flap provide a new method for repairing the severe heel defect, especially in full defect of calcaneus and cuboid bone.

Adult↗
PubMed1998

cDNA cloning of a third human C2-domain-containing class II phosphoinositide 3-kinase, PI3K-C2gamma, and chromosomal assignment of this gene (PIK3C2G) to 12p12.

Phosphoinositide (PI) 3-kinases have been shown to have critical roles in signaling pathways that regulate proliferation, oncogenic transformation, cell survival, cell migration, and intracellular protein trafficking. We have previously used reverse-transcription polymerase chain reaction methods to identify novel PI 3-kinase isoforms in normal human breast and in lymph nodes containing metastatic breast cancer. Here we report the cDNA cloning of a Class II PI 3-kinase found in normal breast tissue. This gene (PIK3C2G) encodes the third distinct protein of the human Class II PI 3-kinase family, PI3K-C2gamma. PIK3C2G was mapped to chromosome 12 at 12p12 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed2006

Multidrug resistance in locally advanced breast cancer.

BACKGROUND: Advanced breast cancer cases can still be encountered resulting in poor prognosis. The primary treatment for these patients is chemotherapy, and multidrug resistance (MDR) is a serious obstacle in the treatment. Detecting drug resistance before first-line chemotherapy may increase the patient's survival. In this study, the role of MDR is evaluated in locally advanced breast cancer patients. METHODS: Reverse transcriptase polymerase chain reaction was used for the detection of MDR genes, ABCB1 and ABCC1. Immunohistochemistry was used for the detection of MDR proteins, P-glycoprotein (Pgp) and MDR-associated protein 1. RESULTS: Breast tissues from 25 patients both before and after chemotherapy were examined. Five patients were unresponsive to chemotherapy. Four had ABCB1 gene expression induced by chemotherapy, and Pgp positivity was detected in 9 patients after chemotherapy. Both the induction of ABCB1 gene expression (p < 0.001) and Pgp positivity (p < 0.001) during chemotherapy were significantly related with clinical response. Although 80% of the clinically unresponsive patients had ABCC1 gene expression, the relation between ABCC1 expression and clinical drug response was not significant. CONCLUSION: In locally advanced breast cancer, ABCB1 gene expression during chemotherapy contributes to clinical unresponsiveness. However, ABCC1 gene expression did not correlate strongly with the clinical response.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1999

Neurotrophins and Trk receptors in primitive neuroectodermal tumor cell lines.

OBJECTIVE: Primitive neuroectodermal tumors (PNETs) are thought to be derived from early central nervous system precursors. Therefore, we hypothesized that the neurotrophins (nerve growth factor, brain-derived neurotrophic factor, and neurotrophin-3) and their receptors (TrkA, TrkB, and TrkC), which are involved in the proliferation, differentiation, and survival of neuronal cells, might be important in regulating tumor growth. METHODS: Using ribonucleic acid (RNA) blotting and reverse transcription-polymerase chain reaction analysis, we investigated the expression of these ligands and their receptors in six PNET cell lines (Daoy, PFSK, D283 Med, UW288-1, CHP707m, and D341 Med). Neurotrophin protein levels were measured using enzyme-linked immunosorbent assay procedures. Receptor function was demonstrated by autophosphorylation. Induction of c-Fos expression and effects on cell proliferation were assessed after the addition of exogenous neurotrophin. RESULTS: Three cell lines expressed messenger RNA for all neurotrophins, whereas the other three expressed two of the three neurotrophins. Neurotrophin protein levels were low. All cell lines expressed trkA messenger RNA. Five expressed the amino terminus of trkB, but three of these did not express the carboxyl terminus. All cell lines contained trkC messenger RNA, but the receptor was truncated in two cell lines. No cell line contained message for a receptor containing an insertion in the tyrosine kinase domain. The addition of neurotrophin to PNET cells resulted in phosphorylation of a protein that was immunoprecipitated with an anti-pan-Trk antibody. c-Fos expression and cell growth were increased by preincubation with neurotrophins, but only in the cell lines expressing the relevant full-length receptors. CONCLUSION: The expression of neurotrophins and neurotrophin receptors by PNET cell lines is variable. The presence of activated Trk receptors in these cell lines may be required for rapid growth, via an autocrine loop mechanism. This will require further investigation.

Brain Neoplasms↗
PubMed2006

Glial-derived neurotrophic factor modulates enteric neuronal survival and proliferation through neuropeptide Y.

BACKGROUND & AIMS: Glial-derived neurotrophic factor (GDNF) promotes the survival and proliferation of enteric neurons. Neuropeptide Y (NPY) is an important peptide regulating gastrointestinal motility. The role of NPY on the survival and proliferation of enteric neurons is not known. We examined the effects of GDNF on the expression and release of NPY from enteric neurons and the role of NPY in promoting enteric neuronal proliferation and survival. METHODS: Studies were performed in primary enteric neuronal cultures and NPY knockout mice (NPY(-/-)). GDNF-induced expression of NPY was assessed by reverse-transcription polymerase chain reaction (RT-PCR), immunocytochemistry, and enzyme-linked immunosorbent assay. Using NPY-siRNA and NPY-Y1 receptor antagonist, we examined the role of NPY in mediating the survival and proliferation effects of GDNF. Gastrointestinal motility was assessed by measuring gastric emptying, intestinal transit, and isometric muscle recording from intestinal muscle strips. RESULTS: GDNF induced a significant increase in NPY messenger RNA and protein expression in primary enteric neurons and the release of NPY into the culture medium. NPY (1 mumol/L) significantly increased proliferation of neurons and reduced apoptosis. In the presence of NPY-siRNA and NPY-Y1 receptor antagonist or in enteric neurons cultured from NPY(-/-) mice, GDNF-mediated neuronal proliferation and survival was reduced. NPY increased the phosphorylation of Akt, a downstream target of the PI-3-kinase pathway. In NPY(-/-) mice, there were significantly fewer nNOS-containing enteric neurons compared with wild-type (WT) mice. NPY(-/-) mice had accelerated gastric emptying and delayed intestinal transit compared with WT mice. CONCLUSIONS: We demonstrate that NPY acts as an autocrine neurotrophic factor for enteric neurons.

Animals↗
PubMed1983

In situ femoropopliteal and distal vein bypass for limb salvage--experience of 50 cases.

The aim of this paper is to assess the in situ technique of saphenous vein femoropopliteal (and femorotibial) bypass for limb salvage, and to compare it with the reversed vein method of bypass. In our 3-year study, we have operated on 50 cases resulting in a graft patency and limb salvage rate of 78 per cent at 18 months and 72 per cent overall. There was a 2 per cent perioperative and 10 per cent overall mortality. Graft thrombosis was associated with a variety of factors, mostly notably a small vein (les than 4 mm), a low calf vessel anastomosis, wound sepsis and progressive proximal (inflow) disease. However, the strongest correlation was that between graft thrombosis and the extent of distal disease, as 11 of 12 cases with thrombosed grafts had grade 2 or 3 run-off. In our experience the in situ technique offers haemodynamic and technical advantages over the reversed vein method of performing straightforward femoropopliteal bypass. Moreover, the in situ technique has wider application in that it allows a smaller vein (greater than 2.5 mm) to be used and also makes anastomosis to a small calf vessel easier. In this series, 16 per cent of cases would have been considered unsuitable for the reversed vein method if 4 mm was accepted as the lower limit of size for a reversed vein graft.

Aged↗
PubMed2002

Ritonavir plus saquinavir versus single protease inhibitor therapy in protease inhibitor-naive HIV-infected patients: the Swiss HIV Cohort Study.

OBJECTIVES: To compare the response to ritonavir (RTV) plus saquinavir (SQV) with single protease inhibitor (PI) therapies among PI-naive HIV-1 infected individuals. METHODS: Response to treatment was analysed according to the intent-to-treat principle in a prospective observational cohort study of 177 patients who between May 1995 and March 2000 started a double PI therapy with RTV and SQV (nonboosting dosages) plus at least one nucleoside reverse transcriptase inhibitor (NRTI) and 2,214 patients with a single PI therapy plus two NRTIs. We used survival analysis and Cox's proportional hazard regression methods. The primary endpoint was the time to a plasma viral load of < 400 copies/mL. Secondary endpoints were taken as a gain in the CD4 count of >100 cells/microL, and change of initial PI for any reason. RESULTS: Baseline characteristics in both treatment groups were balanced. Median follow-up in both groups was 10.4 months. Time to an HIV-1 viral load of < 400 copies/mL and an increase in the CD4 count of >100 x 10(6) cells/L was shorter for RTV plus SQV compared with single PI regimens (log rank test for each endpoint P < 0.05). The adjusted hazard ratios of RTV plus SQV compared with single PI regimens were 1.21 (95% confidence interval 0.99-1.47) for achieving an HIV-1 viral load of < 400 copies/mL, 1.12 (0.88-1.42) for an increase in the CD4 count of > 100 cells/microL, and 0.90 (0.73-1.11) for change of first PI regimen. CONCLUSIONS: Treatment with RTV plus SQV compared with single PI regimens appeared to give similar results for virological or immunological response.

Adolescent↗
PubMed1994

Effects of stepwise cryodilution prior to freezing and stepwise post-thaw rehydration on viability of ovine embryos.

Ovine embryos were exposed to 3 methods of stepwise cryodilution (1, 3 or 5 steps) prior to deep freezing. After 6 to 10 mo of frozen storage, the embryos were thawed and rehydrated using a reversal of each stepwise prefreezing method to remove the oryoprotectant. All embryos were cultured for 48 h, and survival was microscopically evaluated at 0, 14, 24, 38 and 48 h. Survival of embryos in culture was assessed by progressive normal development such as increased cell mass and integrity of morula or blastulation and hatching. There was no significant difference in post-thaw survival and development between 1 and 3-step treatment groups. Embryos frozen and thawed using the 5-step method had lower viability (P < 0.05) at 24 h of culture than either the 1- or 3-step method.

Journal Article↗
PubMed2003

Regulation of apoptosis by lethal cytokines in human mesothelial cells.

BACKGROUND: Dysregulation of peritoneal cell death may contribute to the complications of peritoneal dialysis (PD). Chronic peritoneal dialysis and acute peritonitis are both associated with loss of mesothelial cells. In addition, acute peritonitis is characterized by sudden changes in the number of peritoneal leukocytes. However, the factors regulating peritoneal cell survival are poorly understood. METHODS: Peritoneal effluent cells and mesothelial cells cultured from peritoneal dialysis patients were studied. Reverse transcriptase-polymerase chain reaction (RT-PCR) and flow cytometry were used to assess the expression of FasL and Fas mRNA and protein. Western blot was used to assess FasL and tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL). RT-PCR was used to study TRAIL and TRAIL receptor mRNA. Apoptosis was quantified by flow cytometry of DNA content and confirmed by morphology. RESULTS: Apoptotic cells, including apoptotic mesothelial cells, were present in the peritoneal effluent of stable peritoneal dialysis patients and patients with bacterial peritonitis. The lethal cytokines FasL and TRAIL were expressed by peritoneal effluent cells, while cultured mesothelial cells expressed FasL, Fas, and TRAIL receptors. Cultured mesothelial cells were sensitive to FasL-induced apoptosis. IFNgamma increased the cell surface expression of Fas and the sensitivity of mesothelial cells to FasL-induced apoptosis. In contrast to the effect of FasL, TNFalpha and TRAIL did not induce apoptosis in human mesothelial cells from peritoneal dialysis patients. CONCLUSION: Lethal cytokines, such as FasL, may contribute to peritoneal cell turnover and the loss of mesothelium in peritoneal dialysis. The role of other cytokines, such as TRAIL, remains undefined. Approaches in limiting mesothelial cell injury that interferes with apoptosis should be considered.

Aged↗
PubMed1998

A comparative analysis of FISH, RT-PCR, and cytogenetics for the diagnosis of bcr-abl-positive leukemias.

Philadelphia (Ph) chromosome-positive leukemias, with the bcr-abl gene translocation, have a dismal prognosis. The identification of Ph-positive patients is vitally important because only aggressive therapeutic approaches, such as allogeneic bone marrow transplantation, may result in long-term disease-free survival. Routine diagnostic methods, such as Southern blot analysis and cytogenetics, may lead to false-negative results. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis is considered the most sensitive tool for the detection of the bcr-abl translocation, and it is widely used alone or in combination with karyotyping or Southern blot analysis to identify Ph-positive cases. In this study, we used fluorescence in situ hybridization (FISH) with BCR and ABL double-color probes for detecting Ph-positive leukemias. The FISH results were compared with the results of cytogenetic and RT-PCR analyses in 75 patients with leukemia or other myeloproliferative syndromes (chronic myeloid leukemia, 30; acute lymphoblastic leukemia, 24; acute myelogenous leukemia, 6; essential (hemorrhagic) thrombocythemia, 12; chronic myelomonocytic leukemia, 2; and polycythemia vera, 1). FISH analysis proved to be simple, extremely reliable and sensitive; bcr-abl fusion detection was successful in the presence of all types of molecular junctions i.e., (b2a2, b3a2, and e1a2). Furthermore, a Ph-positive case that proved fusion negative by RT-PCR was identified as positive by FISH. The sensitivity of RT-PCR and FISH related to Ph-positive cases were 97% and 100%, respectively. Regarding specificity, in 4 (5%) of 75 patients, RT-PCR provided false-positive results. Cross-contamination was identified because a new specimen was harvested and reanalyzed when FISH, cytogenetics, and RT-PCR results were contradictory. We believe FISH is an optimal diagnostic method to detect bcr-abl translocation that can be used alone or to validate the results of RT-PCR analysis.

Bone Marrow↗
PubMed1977

Cerebral edema.

Great strides have been made in understanding the pathogenesis of cerebral edema. Treatment is usually successful, particularly with the newer modes of management (mannitol, steroids, hyperventilation); however, cerebral edema is occasionally resistant to all modes of therapy. At that point, no treatment is effective; even if the patient does survive, he is left with a major severe neurological deficit. Future research must be directed toward methods of reversing this presently untreatable state.

Adrenal Cortex Hormones↗
PubMed2000

Deregulated expression of promyelocytic leukemia zinc finger protein in B-cell chronic lymphocytic leukemias does not affect cyclin A expression.

INTRODUCTION: The promyelocytic leukemia zinc finger (PLZF) gene encodes a transcription factor expressed in myeloid, lymphoid and CD34(+) progenitor cells. Structurally related to BCL-6, which is involved in human lymphoma, PLZF may have a role in proliferation, differentiation and survival of hematopoietic cells, that could be mediated by transcriptional repression of the cyclin A gene. MATERIALS AND METHODS: Quantitative competitive reverse transcription-polymerase chain reaction was used to measure the levels of expression of PLZF and cyclin A in normal leukocyte subsets (including CD19(+) lymphocytes, n=21) and malignant B lymphocytes (including B-chronic lymphocytic leukemias [B-CLL], n=63). Results obtained with this method were confirmed by Western and Northern blot analysis. Transactivation assays were performed using an expression construct for PLZF and two cyclin A promoter luciferase reporters in an Epstein-Barr virus (EBV)-transformed B-cell line. Cyclin A expression, cell growth kinetics, and cell cycle were analysed in stable clones of the Burkitt lymphoma (BL) B-cell line DG75 with inducible expression of PLZF, generated using the tetracycline-regulated expression system. RESULTS: Expression of PLZF was 100-fold downregulated in 90% B-CLL (56/63) compared to normal B lymphocytes (P<0.001). B-CLL patients with the highest levels of PLZF had a poorer survival (P<0.013). In transactivation assays, PLZF inhibited the activity of the cyclin A reporters by 50%, demonstrating that PLZF can repress cyclin A expression in non-malignant B lymphocytes. However, in B-CLL patients, the level of cyclin A expression was found to be within the normal range. Altered PLZF function in B lymphoid malignancies was further corroborated in the PLZF-regulatable DG75 clones, where induction of PLZF expression did not significantly alter the levels of cyclin A expression, the cell growth kinetics, or the cell cycle phase distribution. CONCLUSION: The lower survival of patients with the highest levels of PLZF suggests that this protein may be a marker of progression in B-CLL. The absence of co-ordinated regulation of PLZF and cyclin A genes in B-CLL and in a malignant B-cell line may indicate a loss of cyclin A control by PLZF in B-CLL and other B-cell disorders. Deregulation of PLZF could thus play a role in B-cell malignancy.

Antigens, CD↗
PubMedDate not supplied

Effect of mitomycin C dissolved in reversible thermo-setting gel on the outcome of filtering surgery in the rabbit.

PURPOSE: Based on our previous report that showed enhanced transfer of mitomycin C to the sclera and the conjunctiva by dissolving the agent into a reversible thermo-setting gel, we conducted a study to investigate the efficacy of mitomycin C gel in the rabbit. METHODS: We subconjunctivally injected 0.1 mL of the mitomycin C gel solution containing several different amounts of the agent. Trephination was performed in the injected region 24 hours later. Intraocular pressure measurement, photography, and ultrasound biomicroscopic examination of the filtering bleb were conducted 1, 2, and 4 weeks postoperatively. RESULTS: The gel containing 3.0 microg or more mitomycin C significantly enhanced bleb formation and reduction in the intraocular pressure. CONCLUSIONS: The reversible thermo-setting gel seems to help the filtering bleb to survive in the rabbit and deserves further investigation as a new method of mitomycin C application.

Animals↗
PubMed2007

A five-gene signature and clinical outcome in non-small-cell lung cancer.

BACKGROUND: Current staging methods are inadequate for predicting the outcome of treatment of non-small-cell lung cancer (NSCLC). We developed a five-gene signature that is closely associated with survival of patients with NSCLC. METHODS: We used computer-generated random numbers to assign 185 frozen specimens for microarray analysis, real-time reverse-transcriptase polymerase chain reaction (RT-PCR) analysis, or both. We studied gene expression in frozen specimens of lung-cancer tissue from 125 randomly selected patients who had undergone surgical resection of NSCLC and evaluated the association between the level of expression and survival. We used risk scores and decision-tree analysis to develop a gene-expression model for the prediction of the outcome of treatment of NSCLC. For validation, we used randomly assigned specimens from 60 other patients. RESULTS: Sixteen genes that correlated with survival among patients with NSCLC were identified by analyzing microarray data and risk scores. We selected five genes (DUSP6, MMD, STAT1, ERBB3, and LCK) for RT-PCR and decision-tree analysis. The five-gene signature was an independent predictor of relapse-free and overall survival. We validated the model with data from an independent cohort of 60 patients with NSCLC and with a set of published microarray data from 86 patients with NSCLC. CONCLUSIONS: Our five-gene signature is closely associated with relapse-free and overall survival among patients with NSCLC.

Aged↗
PubMed1996

The p53 gene in breast cancer: prognostic value of complementary DNA sequencing versus immunohistochemistry.

BACKGROUND: Mutations in the p53 tumor suppressor gene (also known as TP53) have been detected in a wide variety of human cancers. In breast cancer, the presence of p53 gene alterations has been associated with worse prognosis. PURPOSE: We compared a complementary DNA (cDNA)-based sequencing method and an immunohistochemical (IHC) method for their abilities to detect p53 mutations in breast cancer specimens. In addition, we determined the prognostic value of information obtained when these two methods were used. METHODS: Specimens from 316 primary breast tumors were evaluated for the presence of mutant p53 protein by use of the mouse monoclonal antibody Pab 1801 (that recognizes both wild-type and mutant forms of p53) and standard IHC methods. In addition, the entire coding region of p53 genes expressed in these tumors was screened for mutations by combining reverse transcription, the polymerase chain reaction, and DNA sequencing. Probabilities for overall survival (OS), breast cancer-corrected survival (BCCS; death from breast cancer is the considered event), and relapse-free survival (RFS) were estimated by use of the Kaplan-Meier method, and survival curves for different patient subgroups were compared by use of the logrank method. All reported P values are from two-sided tests. RESULTS: Sixty-nine (22%) of 316 tumors had p53 gene mutations detected by the cDNA-based sequencing method; only 31 (45%) of these mutations were located in evolutionarily conserved portions of the p53 coding region. Sixty-four tumors (20% of the total) had elevated levels of p53 protein as detected by IHC, suggesting the presence of mutations. Of the sequencing-positive tumors (i.e., p53 mutant), 23 exhibited negative IHC reactions, indicating that IHC failed to detect 33% of the mutations. Furthermore, 19 of the IHC-positive tumors were sequencing negative (i.e., p53 wild-type), suggesting a 30% false-positive frequency with IHC. Four tumors (1.3% of the total) could not be analyzed by the cDNA-based sequencing method, and three tumors (1% of the total) could not be analyzed by IHC. The 5-year estimates for RFS, BCCS, and OS were significantly shorter for patients with p53 sequencing-positive tumors than for patients with sequencing-negative tumors (P = .001, P = .01, and P = .0003, respectively). Patients with IHC-positive tumors showed reduced survival in all three categories when compared with those with IHC-negative tumors, but the differences were not statistically significant. CONCLUSIONS: Use of a cDNA-based sequencing method to determine the status of the p53 gene in primary breast cancers yielded better prognostic information than IHC performed with the Pab 1801 monoclonal antibody.

Adult↗
PubMed2001

Survival of poliovirus in New Zealand green-lipped mussels, Perna canaliculus, on refrigerated and frozen storage.

Poliovirus survival in live and frozen mussels during storage was assessed by both viral culture and molecular methods. Live New Zealand green-lipped mussels were incubated overnight at 20 degrees C in an aerated tank of filtered seawater seeded with the poliovirus 2 (PV2) vaccine strain. An extraction and concentration method that preserved viral infectivity was used to recover PV2 taken up by the mussels at day 0, at day 2 after storage at 4 degrees C, and at days 7, 14, and 28 after storage at -20 degrees C. This method allowed both culture and molecular analysis to be carried out. Presence of intact PV2 in each batch of mussels was determined by a pan-enterovirus specific reverse transcription-polymerase chain reaction (RT-PCR) and confirmed by dot-blot hybridization. Survival of infectious PV2 was determined by the monolayer plaque assay. After 48 h at 4 degrees C, infectious PV2 levels were 81% of the original level detected in the mussels. Infective virus levels then declined to 66, 53, and 44% after storage at -20 degrees C for 7, 14, and 28 days, respectively. Generic RT-PCR methods were 10 times more sensitive than cell culture techniques for virus detection but did not give information on virus infectivity. The survival of infectious pathogenic viruses in fresh and frozen mussels on storage constitutes a potential health risk and so is a major concern for public health authorities.

Animals↗