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Biomedical subjects

T M Cao

Publications and source records attributed to T M Cao.

18 recordsLinked to original sources
PubMed2006

Incidence of enterohemorrhagic Escherichia coli, Escherichia coli O157, Salmonella, and Listeria monocytogenes in retail fresh ground beef, sprouts, and mushrooms.

The objective of this study was to determine the prevalence of enterohemorrhagic Escherichia coli (EHEC), E. coli O157, Salmonella, and Listeria monocytogenes in retail food samples from Seattle, Wash. A total of 2,050 samples of ground beef (1,750 samples), mushrooms (100 samples), and sprouts (200 samples) were collected over a 12-month period and analyzed for the presence of these pathogens. PCR assays, followed by culture confirmation were used to determine the presence or absence of each organism. Of the 1,750 ground beef samples analyzed, 61 (3.5%) were positive for EHEC, and 20 (1.1%) of these were positive for E. coli O157. Salmonella was present in 67 (3.8%) of the 1,750 ground beef samples. Of 512 ground beef samples analyzed, 18 (3.5%) were positive for L. monocytogenes. EHEC was found in 12 (6.0%) of the 200 sprout samples, and 3 (1.5%) of these yielded E. coli O157. Of the 200 total sprout samples, 14 (7.0%) were positive for Salmonella and none were positive for L. monocytogenes. Among the 100 mushroom samples, 4 (4.0%) were positive for EHEC but none of these 4 samples were positive for E. coli O157. Salmonella was detected in 5 (5.0%) of the mushroom samples, and L. monocytogenes was found in 1 (1.0%) of the samples.

Agaricales↗
PubMed2003

Plasmablastic lymphoma presenting in a human immunodeficiency virus-negative patient: a case report.

Plasmablastic lymphoma (PBL), an aggressive non-Hodgkin's lymphoma that carries a poor prognosis, previously has been identified almost exclusively in patients infected with the human immunodeficiency virus (HIV). We present a case of a 42-year-old HIV-negative patient presenting with an isolated nasal cavity mass, the typical presentation for PBL. The patient was given systemic chemotherapy, central nervous system prophylaxis, and consolidative locoregional radiotherapy and achieved a complete clinical response. This case suggests PBL should be considered in HIV-negative patients with characteristic findings.

Adult↗
PubMed2001

Rapid engraftment after allogeneic transplantation of density-enriched peripheral blood CD34+ cells in patients with advanced hematologic malignancies.

BACKGROUND: Acute graft versus host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. Preclinical studies have suggested that a T-cell subset with a CD4-/CD8- double-negative (DN) T-cell phenotype is capable of suppressing GVHD. Double-negative T cells can be mobilized into the peripheral blood with granulocyte colony-stimulating factor (G-CSF) and enriched by density centrifugation. The current study was performed to study the feasibility and safety of applying a density gradient separation technique for enrichment of CD34+ and DN T cells, while depleting CD4+ and CD8+ single-positive (SP) T cells from peripheral blood progenitor cells (PBPCs) for the purpose of allogeneic transplantation. METHODS: Twenty-five patients with advanced hematologic malignancies were treated with a myeloablative preparative regimen consisting of fractionated total body irradiation, etoposide, and cyclophosphamide. Human leukocyte antigen identical donors were mobilized with G-CSF PBPC collected by apheresis. The apheresis product was applied to a single-step density gradient, and the low-density cell population was collected. The low-density cell population was infused as the sole source of allogeneic cells after myeloablative therapy. Graft versus host disease prophylaxis consisted of cyclosporine with or without prednisone. RESULTS: CD34 cell recovery was efficient with a median 72% yield, providing for a median CD34+ cell dose of 6.5 x 10(6)/kg (range,1.0- 13.9 x 10(6)/kg). CD3+CD4+ or CD3+CD8+ SP T cells were depleted by a median of 94.4% (range, 58.8- 99.2%), and the ratio of CD34+:SP T cells increased 10-fold. Double-negative T cells were depleted by 92% (range, 18.8- 99.4%), thus the ratio of DN:SP T cells increased less than 2-fold in 71% of apheresis samples tested. Hematopoietic engraftment was rapid, and there was no occurrence of graft failure in examinable patients. Median time to absolute neutrophil count greater than 0.5 x 10(9)/L and platelet count greater than 20 x 10(9)/L was 10.5 and 12 days, respectively. The incidence of Grade 2-4 acute GVHD was 26% (95% confidence interval [CI], 6-45%), although not all patients were examinable due to an unexpectedly high nonrecurrence mortality that at Day 180 was 62% (95% CI, 40-83%). CONCLUSIONS: These data suggest that T-cell subset manipulation via density gradient separation is a safe procedure and allowed rapid hematopoietic recovery. Selective enrichment of a donor DN T-cell subset was observed in only a few and was not associated with a reduced incidence of GVHD. However, the low-density selected cells still resulted in GVHD, and there was a high treatment-related mortality.

Adult↗
PubMed2001

High-dose therapy and autologous hematopoietic-cell transplantation for follicular lymphoma beyond first remission: the Stanford University experience.

A retrospective analysis was performed to investigate the outcome of high-dose therapy (HDT) and autologous hematopoietic cell transplantation in patients with follicular lymphomas beyond first remission. Ninety-two patients with primary induction failure or relapsed follicular low-grade lymphoma (FLGL), follicular large cell lymphoma (FLCL), and transformed follicular lymphoma (TFL) were treated with myeloablative therapy consisting of etoposide (60 mg/kg), cyclophosphamide (100 mg/kg), and either carmustine (BCNU;15 mg/kg) or fractionated total body irradiation (FTBI; 1200 cGy) followed by transplantation of purged autologous bone marrow or peripheral blood hematopoietic cells. For the 49 patients with relapsed FLGL, the median age was 49 years and the median interval from diagnosis to HDT was 30 months. The 4-year estimate of overall survival (OS) was 60% (95% confidence interval [CI], 45%-75%) and of disease-free survival (DFS) was 44% (95% CI, 29%-59%). Treatment with the FTBI-containing HDT regimen was associated with significantly longer DFS (P = .04) and OS (P = .04) in our multivariate analysis. OS was also significantly longer among those treated with 3 or fewer chemotherapy regimens. For the 26 FLCL patients, the median age was 51 years and in 31% the indication for HDT was primary induction failure. For FLCL patients, the 4-year estimate of OS was 58% (95% CI, 37%-79%) and of DFS was 51% (95% CI, 30%-72%). Among the 17 patients with TFL, 13 (76%) transformed at first relapse, and only 6 patients (35%) achieved complete remission with salvage therapy prior to HDT. For TFL patients, the 4-year estimate of OS was 50% (95% CI, 24%-76%) and of DFS 49% (95% CI, 20%-78%). There were 3 occurrences of myelodysplasia (1 after treatment with TBI, 2 after BCNU treatment), yielding an estimated incidence of 7% (95% CI, 0%-16%) at 56 months. This analysis shows that relapsed FLGL patients treated with 3 or fewer different chemotherapy regimens show inferior survival. The HDT regimen containing FTBI appears to be superior to the BCNU-based regimen for relapsed FLGL, although longer follow-up is needed to evaluate late effects. Lastly, patients with TFL or induction failure and relapsed FLCL can achieve survival outcome comparable to those observed with the indolent follicular lymphomas.

Adult↗
PubMed2001

[Clinical study on long-term treatment of ankylosing spondylitis with integrated Traditional Chinese and Western medicine].

OBJECTIVE: To seek for the new method of integrated traditional Chinese and western medical treatment (TCM-WM) for ankylosing spondylitis (AS) to control the disease development, shorten the therapeutic course and reduce disability rate. METHODS: Patients of AS enrolled in this study were 106 patients in group A, who were persistently treated with TCM-WM for over 10 months, 48 patients in group B treated with western medicine and 34 in group C treated with non-steroidal anti-inflammatory and analgesic agents. They were followed-up for 2 years. RESULTS: (1) Short-term effect: the markedly effective rate in the three groups was 73.58%, 47.92% and 5.88% respectively, and the total effective rate was 96.23%, 87.50% and 41.18% respectively. The comparisons of group A to group B and C showed significant difference, the effect in group A was superior to that in group B and group C (chi 2 = 10.58, P < 0.01 and chi 2 = 67.76, P < 0.01 respectively). (2) Results of 2-year follow-up: the recurrence rate in group A was 18.37% (9/49), it was insignificantly different from that in group B (7/23 = 30.43%, chi 2 = 1.32, P > 0.05), but significantly different from that in group C (8/12 = 66.67%, chi 2 = 11.19, P < 0.01). CONCLUSION: Long-term TCM-WM therapy, which concentrated on the advantages of traditional Chinese and western medicine, was a practical method in treating AS with reliable effect, few side-reaction, therefore, is worth spreading.

Adolescent↗
PubMed2000

Pulmonary toxicity syndrome in breast cancer patients undergoing BCNU-containing high-dose chemotherapy and autologous hematopoietic cell transplantation.

We performed a retrospective review to investigate pulmonary toxicity syndrome (PTS) in a cohort of breast cancer patients undergoing BCNU-containing high-dose chemotherapy (HDC). Our aim was to characterize presentation, identify risk factors, determine outcome following therapy, and find any association with differences in survival. We reviewed the data of 152 patients with stage II or III or metastatic breast cancer treated with cyclophosphamide 5625 mg/m2, cisplatin 165 mg/m2, and BCNU 600 mg/m2 followed by autologous peripheral blood hematopoietic cell transplantation. During follow-up, PTS was diagnosed when the following criteria were met: (1) presentation with typical clinical symptoms of PTS, (2) an absolute carbon monoxide diffusion capacity (DLCO) decline of 10% compared with pre-HDC DLCO, and (3) no clinical evidence of active pulmonary infection. Patients were then treated with a course of corticosteroid therapy. The incidence of PTS for all 152 patients was 59%, with a median onset at 45 days (range, 21-149 days) post-HDC. The median absolute DLCO decrement was 26% (range, 10%-73%) at diagnosis of PTS. There was no significant correlation between patient age, stage of breast cancer, pre-HDC chemotherapy regimen, pre-HDC chest wall radiotherapy, tobacco use, prior lung disease, or baseline pulmonary function test results and the development of PTS. We did observe an interesting association between PTS and the development of a noncholestatic elevation of transaminases. Of PTS patients treated with prednisone therapy for a median of 105.5 days (range, 44-300 days), 91% achieved resolution of their PTS without pulmonary sequelae. At 3 years, the overall survival (OS) of stage II or III patients who developed PTS was 84% (95% confidence interval [CI], 73%-95%); of metastatic breast cancer patients with PTS, the OS was 58% (95% CI, 38%-78%). These values were not significantly different from those of patients who did not develop PTS (91% [95% confidence interval [CI], 81%-100%] and 53% [95% CI, 32%-74%], respectively). No significant differences in disease-free or event-free survival were observed between patients with and without PTS. The incidence of PTS in breast cancer patients treated with a BCNU-containing HDC regimen can be remarkably high. Treatment with a course of corticosteroid therapy is successful in the vast majority.

Adult↗
PubMed1994

Identification of partial complementary DNA clones encoding a 59-kd protein with characteristics of a unique oncofetal antigen.

BACKGROUND: Oncofetal antigens (OFAs) are conserved tumor-associated autoantigens or transplantation antigens present on the surface of all major classes of rodent and human tumors and on midgestational fetal cells but not on normal neonatal or adult human and rodent tissues. A syngeneically derived monoclonal antibody, MAb-115, recognizes murine OFAs of 44 and 200 kd in molecular mass. PURPOSE: Our goal was to clone and characterize the complementary DNAs (cDNAs) that encode these murine OFAs. METHODS: Rabbit antiserum raised against purified 44-kd OFA glycoprotein was used to screen a mouse embryo cDNA-lambda phage expression library. Recombinant phage clones positive for the expression of OFAs were detected by immunohistochemical staining, then isolated and plaque purified. The presence of an OFA-encoding sequence in the recombinant phage was confirmed by specific reaction of the expressed protein with MAb-115. Recombinant fusion protein was purified from the extracts of corresponding lysogens. Rabbit antiserum against purified recombinant fusion protein was raised, and the capacity of this antiserum to detect the expression of OFA on rodent tumor and fetal cells was determined by flow cytometry. In addition, immunoreactivity of tumor bearer and hyperimmune murine sera to bacterially expressed recombinant OFA protein was evaluated by enzyme-linked immunosorbent assay. The OFA-expressing insert DNA from plaque-purified lambda clones was subcloned into phagemid vectors for sequencing analysis. RESULTS: Antiserum derived against the isolated recombinant mouse embryo polypeptide mimicked MAb-115 in its specific binding to all OFA-positive rodent tumor and fetal cell lines tested and likewise did not show reactivity to normal adult tissues. This antiserum specifically recognized the native 44- and 200-kd OFAs in extracts of murine lymphocytic lymphoma. Furthermore, sera of tumor-bearing mice or mice immunized with purified OFA or intact, irradiated OFA-positive lymphocytic lymphoma cells also reacted with the recombinant fusion protein. The characterization of the isolated clone included nucleotide sequence information followed by analysis of the deduced primary structure of the protein. CONCLUSIONS: These data suggest that the isolated cDNA clones encode a distinct gene product which is widely expressed on the surface of tumor and fetal cells and represents the first characterized sequence of a true OFA. IMPLICATIONS: The availability of this cDNA, encoding a protein expressed only on tumor and fetal cells, provides a direct means to assess biological characteristics of malignant tissue which can be assayed by biochemical, histochemical, and molecular methods.

Amino Acid Sequence↗
PubMed1994

[Study on efficacy of adult primary nephrotic syndrome with TCM-WM therapy and its hemorheologic effects].

The efficacy of TCM-WM therapy in treating adult primary nephrotic syndrome in comparing with using Western medicine alone and its influence on patient's hemorheology was investigated. The results showed that with the therapy of combined therapy the clinical remission rate and total effective rate were 65.4% and 88.5%, while that of Western medicine alone were 37.0% and 59.3% respectively. There was significant difference between the above-mentioned two groups (P < 0.01). Adverse effect scores with combined therapy were much lower than that of WM alone (P < 0.01). The recurrence rate of the illness with TCM-WM and WM therapy were 7.25% and 53.13% respectively (P < 0.01). Furthermore, the combined treatment of TCM-WM could remarkably improve the blood viscosity and reduce the content of fibrinogen. It was suggested that Syndrome Differentiation with the administration of steroid could not only ameliorate the adverse effects of steroid but promote the efficacy and reduce the recurrence of the disease. Besides, the addition of blood-activating and stasis-removing herbs could also improve the blood viscosity and the impaired fibrinolysis.

Adult↗
PubMed1983

Molecular processing of adenovirus proteins.

Late in adenovirus infection, a virus-encoded protease processes several viral structural proteins. The maturation cleavages are a prerequisite for full viral infectivity. The peptide fragment removed during processing is located at the amino end of the major core protein VII. The structure of the precursor peptide sequence was determined by both protein and nucleotide sequencing. Two processing events were elucidated. First, during protein biosynthesis, the initiator methionyl residue is removed and the penultimate seryl residue is acetylated. Second, the resulting NH2-terminal 23-residue fragment is removed during virus assembly. The specificity of the viral endoprotease was investigated by isolating and characterizing another viral proprotein precursor, Pro-VI. The propeptide of VI was also found to be extended at the amino end of the molecule. Comparison of the two propeptide sequences at the cleavage site revealed a consensus amino acid sequence of Gly-Gly-Ala. In addition, there is extensive similarity in the precursor sequences of both proteins. The analogous constitution of the precursor fragments in Pro-VI and Pro-VII suggests that a common mechanism is implicated in controlling the reorganization of VI and VII during virion assembly.

Adenoviruses, Human↗
PubMed1983

Gene and protein sequences of adenovirus protein VII, a hybrid basic chromosomal protein.

The sequences of both the gene and the corresponding protein of adenovirus major core protein VII have been determined. The precise location of this gene is between 43.37 and 44.90 map coordinates on the viral genome. Protein VII is 173 residues long and has a molecular weight of 19,258. Detailed analysis of its sequence has revealed four basic domains separated by several predicted alpha helices. It is proposed that intrachain folding of protein VII is driven by hydrophobic interactions of the alpha helices, leaving the basic domains of the protein to interact with DNA phosphates. Protein monomers may further associate with each other in the formation of hexameric nucleosome-like particles. The displacement and replacement of protein VII during the viral infectious cycle in the host cell appears to mimic the biology of nucleoprotamine during the processes of spermatogenesis and fertilization. The presence of a protamine-like domain affirms a hybrid histone/protamine molecular structure for protein VII, although it may resemble the protamine in function.

Adenoviruses, Human↗
PubMed1982

Ultraviolet light induced preferential cross-linking of histone H3 to deoxyribonucleic acid in chromatin and nuclei of chicken erythrocytes.

Histones have been cross-linked to DNA in chicken erythrocyte nuclei and chromatin by using ultraviolet light irradiation at 254 nm. Following irradiation, cross-linked histone-DNA adducts were isolated and purified by hydroxylapatite chromatography, and the DNA component was subjected to acid hydrolysis. Of several hydrolysis techniques investigated, trichloroacetic hydrolysis of the DNA component of the adducts was found to be most effective. Histones isolated from hydrolyzed histone-DNA adducts were characterized by gel electrophoresis and fingerprint analysis. No histone-histone protein adducts were observed. All histone fractions have been shown to cross-link DNA in nuclei or chromatin by utilizing the technique employed, but with different propensities. The order of observed cross-linking, deduced from kinetic experiments, is H1 + H5, H3 greater than H4 greater than H2A much greater than H2B. The preferential binding of the core histone H3, as compared to the other core histones, is discussed in light of recent data concerning histone-DNA interactions and nucleosome structure. The use of the ultraviolet light technique as a conformational probe to study chromatin is also discussed.

Animals↗
PubMed1978

The in vitro interaction of the carcinogens, 4-nitroquinoline-N-oxide and its metabolite 4-hydroxylaminoquinoline-N-oxide, with intact rat liver mitochondria.

The inhibition of rat liver mitochondrial respiration caused by rotenone, is relieved by the 2 carcinogens, 4-nitroquinoline-N-oxide (NQO) and its metabolite 4-hydroxylaminoquinoline-N-oxide (HAQO). Thus these agents cause reducing equivalents to circumvent the first coupling site of the respiratory chain. This is another example of the experimental confluence between oxidative phosphorylation and chemical carcinogenesis.

4-Nitroquinoline-1-oxide↗