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Biomedical subjects

M Chen

Publications and source records attributed to M Chen.

At least 919 records · Page 51Linked to original sources
PubMed1982

The clinical significance of rheometric measurement of cervical mucus properties.

Rheometric properties of cervical mucus were studied with the Ovutimer in 26 women. 14 women had regular menstrual cycles, 12 had menstrual irregularities and received treatment to induce ovulation. In 21 women (80.7%) a significant correlation was found between the ovulation time as established by the luteinizing hormone surge, and ovulation time as established by the Ovutimer test. The instrument was found satisfactorily accurate in establishing the day of ovulation in almost all cases.

Anovulation↗
PubMed1982

Randomized study comparing doxorubicin, cyclophosphamide, vincristine, methotrexate with leucovorin rescue, and cytarabine (ACOMLA) with cyclophosphamide, doxorubicin, vincristine, prednisone, and bleomycin (CHOP-B) in the treatment of diffuse histiocytic lymphoma.

Two combination chemotherapy programs, ACOMLA (doxorubicin, cyclophosphamide, vincristine, methotrexate and leucovorin rescue, and cytarabine) and CHOP-B (cyclophosphamide, doxorubicin, vincristine, prednisone, and bleomycin), were evaluated in 29 prospective randomized patients with advanced diffuse histiocytic lymphoma. A complete response was achieved in 13 of the 15 patients (87%) treated with CHOP-B and in nine of the 14 patients (64%) treated with ACOMLA. The overall complete response rate was 75%. Two patients treated with ACOMLA and none of the CHOP-B-treated patients have relapsed. Median followup is 32 months for ACOMLA patients and 26 months for CHOP-B patients. Actuarial freedom from relapse at 2 years is 49.9% for ACOMLA and 93.3% for CHOP-B (P = 0.04). Toxicity was substantial, with eight nonfatal episodes of sepsis and three drug-related deaths. There have been no central nervous system relapses. Although patients treated with CHOP-B have a better response rate, the small numbers of patients treated to date preclude definitive conclusions.

Antineoplastic Agents↗
PubMed1982

Purification and characterization of cancer suppressive factor.

Cancer suppressive factor (CSF) has been purified thousandfold from the ascites of mice. The purified factor possesses an activity to kill the cancer cells in vitro but little affects the bone marrow cells. Only one protein band has been observed on the polyacrylamide gel electrophoretogram of CSF. Its molecular weight is about 4,000 daltons as estimated by ultrafiltration method.

Animals↗
PubMed1981

CT and angiographic correlates: surgical image of renal mass lesions.

Twenty-three consecutive patients with surgically proved renal mass lesions were examined preoperatively by means of computerized tomography (CT) and renal angiography. Histopathology of the 23 renal masses included the following: hypernephroma (17), transitional cell carcinoma (3), oncocytoma (2), benign cyst (1). Computed tomography was correct in the preoperative diagnosis of 21 of 23 masses (91 per cent); angiographic diagnosis was correct in 18 of 23 consecutive masses (78 per cent). Correlation of the findings on CT and angiography resulted in correct diagnosis in 22 of the 23 lesions (96 per cent). Independently, CT and angiography each contribute essential information for diagnosis and preoperative planning. CT discloses anatomic detail, tissue consistency, organ system relationships, and relatively precise estimates of tumor bulk. Angiography remains a necessary complement providing a surgical image of tumor vascularity and vessel origins.

Adenoma↗
PubMed1981

Expression in Escherichia coli of biologically active enzyme by a DNA sequence coding for the human plasminogen activator urokinase.

We have isolated clones of Escherichia coli strain K-12 that contain a hybrid pBR322 plasmid having a 4.2-kilobase insert of a DNA transcript of the mRNA of human plasminogen activator, urokinase. The bacterially produced enzyme has properties similar to those of urokinase from human fetal kidney cells. Both enzymes occur in discrete forms ranging from 32,000 to 150,000 daltons in size. They react with antibody to purified urokinase from human kidney cells, bind to a benzamidine-Sepharose column, and induce plasminogen-dependent lysis of a fibrin clot.

Base Sequence↗
PubMed1981

Influence of heme and vitamin B12 on growth and fermentations of Bacteroides species.

We examined the effects of heme on the growth and fermentations of Bacteroides species. Bacteroides fragilis ATCC 25285 required heme for growth and produced malate and lactate as major products of glucose fermentation when the concentration of heme was 1 ng/ml. With 1 microgram of heme per ml, malate was not formed, lactate production decreased, and succinate and acetate were the major fermentation products. B. eggerthii ATCC 27754 grew without heme, with the production of mainly malate and lactate from glucose. Its fermentation with 1 microgram of heme per ml was similar to that of B. fragilis grown with the same concentration of heme. B. splanchicus VPI 6842 grew without heme, with the production of mainly malate, acetate, and H2 from glucose. With 1 microgram of heme per ml, malate disappeared, H2 decreased significantly, and succinate, acetate, and butyrate were the major products. The addition of vitamin B12 to media containing 1 microgram of heme per ml caused all species to produce propionate at the expense of succinate and, with B. splanchnicus, also at the expense of butyrate. Thus, the concentration of heme and the presence of vitamin B12 significantly influenced the course of glucose fermentation by these bacteria.

Bacteroides↗
PubMed1981

Total myelography with metrizamide through the lumbar route.

Myelography of the entire spinal cord was performed in 64 consecutive patients using metrizamide via lumbar puncture. Adequate to good opacification of the cervical and thoracic subarachnoid space was obtained in 63 patients. The technical factors responsible for this success rate are patient cooperation, high iodine concentration, high iodine concentration (250 mg/ml), slow injection rate, delayed removal of the needle, minimal patient motion, and rapid performance. Side effects were minor and no more frequent than with lumbar metrizamide myelography alone. Adequate hydration before and after and upright position after seem to be important in minimizing adverse effects.

Adolescent↗
PubMed1980

Neonatal hypermagnesemia: effect on parathyroid hormone and calcium homeostasis.

Twenty pre-eclamptic mothers treated with MgSO4 and their newborn infants were studied prospectively to determine the clinical and biochemical effects of hypermagnesemia. Maternal serum magnesium concentration rose to 4.4 mg/dl at delivery and was accompanied by a fall in maternal serum calcium concentration during labor. Neonatal serum Mg concentration remained elevated for the first 72 hours of life (mean at 72 hours = 3.0 mg/dl). Serum Mg concentration was higher in premature infants and in babies with birth asphyxia and/or hypotonia. Serum Ca concentration was higher and serum PTH was lower in hypermagnesemic study infants when compared to a retrospectively selected, matched froup of control infants. We speculate that elevated serum Mg values in these infants result in a shift of Ca from bone to plasma, and that elevated Mg and Ca concentrations further suppress neonatal parathyroid function.

Calcium↗
PubMed1980

Native ribonucleoprotein is an efficient transcriptional complex of avian myeloblastosis virus.

A native ribonucleoprotein (RNP) complex of avian myeloblastosis virus was prepared under conditions that gave optimal cDNA synthesis. The complex was an autonomous transcriptional unit capable of synthesizing DNA complementary to the RNA virus genome in the absence of exogenous reverse transcriptase (RNA-dependent DNA nucleotidyltransferase), genomic RNA, and primer. The RNA of the RNP complex cannot be translated in an in vitro cell-free translational system. The RNP contains intact viral RNA, the two subunits of the reverse transcriptase (beta and alpha), the p32 polypeptide resulting from the cleavage of the beta subunit into the alpha subunit, and p12. The principal polypeptide constituent of the RNP complex is the highly basic protein p12, which occurs at a molar ratio of 40:1 in relation to the beta subunit of the polymerase. When examined by the electron microscope, the RNP complex appears similar to the beaded structure of chromatin fiber. A significant portion of these molecules are circular, with headlike structures attached. The circular nature of the proviral DNA and the ability of the RNP complex to generate large intact cDNA copies from the natural primer end suggest that the 5' and 3' ends of the viral RNA are in proximity when in the RNP complex.

Avian Leukosis Virus↗
PubMed1979

Discriminant analysis on cells from developing squamous cancer of the respiratory tract.

Cytologic preparations made from the tracheobronchial tree taken by the Schreiber catheter have been scanned by three color microphotometry. The digitized cell images were processed by the analytical cytodiagnostic programs of the TICAS system. Cells were sorted into two control groups and five groups of increasing atypia ranging from normal epithelium to invasive squamous cell carcinoma. Standard statistical tests, including Wilk's Lambda, Rao's V, and the Kruskal-Wallis tests are performed on these subsets of cell image features. This study demonstrates that discriminant analyses permit differentiation between normal cells and those from marked atypia or carcinoma and that the classification achieves a high degree of agreement with visual assignment.

Animals↗