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Biomedical subjects

T Sanner

Publications and source records attributed to T Sanner.

At least 91 records · Page 5Linked to original sources
PubMed1980

Role of circulating antibodies in the humoral leukocyte adherence inhibition response of lung and breast cancer patients.

A modified leukocyte adherence inhibition (H-LAI) assay has recently been developed in which 0.25% serum from the patient is added to the assay system in combination with the relevant antigen. Trypsinized leukocytes from control persons are used as indicator cells. In the present work, the nature of the humoral factor in serum from breast and lung cancer patients is studied. 3.5 M KCl extracts from the cell lines MCF-7 and Calu-1 were used as breast and lung cancer antigen, respectively. It was found that the humoral factor involved in the H-LAI response was precipitated from the sera by addition of ammonium sulphate to 50% saturation. This factor could be removed by passage through an affinity column with the relevant antigen bound to the matrix. Stable complexes were formed between the humoral factor and the relevant antigen, and could be precipitated by polyethylene glycol. When different anti-immunoglobulins were added to the sera, the humoral factor was specifically removed by addition of anti-IgG antibodies. The data presented indicate that the humoral factor in sera from patients with breast and lung cancer is antitumor antibodies of IgG nature.

Antibodies, Neoplasm↗
PubMed1980

Immune responses in lung cancer patients measured by a modified leukocyte adherence inhibition test using serum.

A modified leukocyte adherence inhibition (H-LAI) assay was used to study immunological factors in serum from lung cancer patients. In this test, 0.25% serum was added to the assay system, together with tumor antigen and trypsinized leukocytes from control persons. Extracts from a human lung cancer cell line (Calu-1) and a human breast cancer cell line (MCF-7) were used as antigens. The results obtained were compared with data found with the original hemocytometer (C-LAI) assay. Of 21 lung cancer patients studied, 20 (95%) gave a positive response in both the H-LAI and the C-LAI assay systems against Calu-1 antigen. Only 1 of the patients gave a positive response in the H-LAI system against MCF-7 antigen, while 3 patients (14%) responded in the C-LAI assay. None of the 14 control persons tested gave a positive response. While the C-LAI assay was limited to the use of fresh blood, the H-LAI system was performed on small amounts of serum. The serum could be stored in the frozen state for a long time period. The results indicate that the H-LAI assay possesses at least the same sensitivity and specificity as the original C-LAI test.

Antigens, Neoplasm↗
PubMed1979

Role of ions in the regulation of porcine lactate dehydrogenase.

Different ions affect the H4 and M4 isoenzymes of porcine lactate dehydrogenase (L-lactate: NAD+ oxidoreductase, EC 1.1.1.27) in the same way, inhibiting the enzyme at low pyruvate concentrations, whereas at high pyruvate concentrations, the activities were enhanced. The inhibition was competitive with regard to pyruvate and NADH. The enhancement of the enzyme activity at high pyruvate concentration is due to the increase in the Km value for pyruvate, implying that higher substrate concentrations are needed to obtain substrate inhibition. Sulphate behaved differently from the other ions. It inhibited in a noncompetitive manner with regard to pyruvate and did not activate the enzyme at high pryvuate concentration. The effect of ions increased with the size of the anion. The ionic strength was of less importance.

Animals↗
PubMed1979

Cellular antitumor immune response in women with risk factors for breast cancer.

The leukocyte adherence inhibition technique was used to study cell-mediated immunoactivity to breast adenocarcinoma. In a group of 74 patients with untreated breast cancer in Stages I and II, 69% showed a positive response, while 48% of the 25 patients in Stages III and IV had reactive leukocytes. Among 43 control persons, only 2 women showed positive responses. In a group of 161 women with benign breast diseases, 24% showed a positive reaction against breast carcinoma extract. The percentage of positive responses was higher than the average of women with benign disease among those who had a mother or a sister with breast cancer, who had previously had benign breast lumps removed, who had microcalcifications in their breasts, or for whom an increased intraductal epithelial proliferation was found in their biopsies. Twenty-eight women with benign breast diseases and two or more of the above factors were assigned to the high-risk group, in which 43% had reactive leukocytes. Of the 50 women with one risk factor, 34% showed a positive response, while of the 83 women in the low-risk group, with none of the above factors, only 11% had a positive reaction. The results suggest that the leukocyte adherence inhibition test may be used to identify groups of women who have a high risk for breast cancer.

Adenocarcinoma↗
PubMed1976

Variation in levels of enzymes related to energy metabolism in alternative developmental pathways of Blastocladiella emersonii.

The activities of phosphofructokinase (PFK), fructose diphosphatase (FDP), nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP)-linked isocitrate dehydrogenases (IDHNAD, IDHNADP), two NAD-linked glutamate dehydrogenases (GDH1, GDH2), and isocitrate lyase were studied during the development of the two phenotypes, ordinary colorless and resistant sporangia (OC and RS plants), of water mold Blastocladiella emersonii in synchronized liquid cultures. The OC plants had a generation time of about 12 h, whereas the RS plants required 3.5 days to reach maturity. All the enzymes were present throughout the development of both phenotypes. In zoospores, PFK, FDP, and GDH2 were localized in the cytosol. The IDHNADP activity was distributed with two-thirds in the soluble and one-third in the particulate fraction. GDH1 and IDHNAD showed the same distribution and were predominantly present in the particulate fraction, presumably in the mitochondria. Isocitrate lyase was found in the particulate fraction. The enzyme levels changed considerably during development. FDP and IDHNADP varied in a parallel manner. Similarly, the three enzymes PFK, IDHNAD and GDH1 showed parallel variations. The activity patterns for all enzymes were different for the OC and RS pathways. Isocitrate lyase exhibited the largest changes in activity during development. Thus, during OC plant formation, its activity decreased by a factor of 20. GDH2 varied similarly to PFK and IDHNADP during OC plant development, whereas it behaved like isocitrate lyase during RS plant development. The ratios between anabolic and catabolic enzymes were higher in mature plants than in zoospores and higher in RS plants than in OC plants. The results indicate that the variations in the enzyme levels are secondary to the critical changes involved in the transition from one developmental pathway to the other.

Blastocladiella↗
PubMed1976

Removal of inhibitors against RNA-directed DNA polymerase activity in human milk.

Milk from a number of species (e.g., man, mouse, rat, dog, and cow) contains inhibitors of the RNA-directed DNA polymerase. When attempts are made to isolate virions from the milk, part of the inhibitors follow the virions in the purification. The amount of inhibitors varies in different milk samples. These inhibitors can probably account for the large discrepancies reported in studies of the presence of oncornaviruses in human milk. Phosphatases bound to subcellular particles or fragments seem to be the most important inhibitors in the milk interfering with the RNA-directed DNA polymerase assay. It is shown that the inhibitory enzymes can be completely removed by sedimentation of the milk through a Metrizamide gradient.

Animals↗
PubMed1975

Formation of transient complexes in the glutamate dehydrogenase catalyzed reaction.

The reaction of glutamate dehydrogenase and glutamate (gl) with NAD+ and NADP+ has been studied with stopped-flow techniques. The enzyme was in all experiments present in excess of the coenzyme. The results indicate that the ternary complex (E-NAD(P)H-kg) is present as an intermediate in the formation of the stable complex (E-NAD(P)H-gl). The identification of the complexes is based on their absorption spectra. The binding of the coenzyme to (E-gl) is the rate-limiting step in the formation of (E-NAD(P)H-kg) while the dissociation of alpha-ketoglutarate (kg) from this complex is the rate-limiting step in the formation of (E-NAD(P)H-gl). The Km for glutamate was 20-25 mM in the first reaction and 3 mM in the formation of the stable complex. The Km values were independent of the coenzyme. The reaction rates with NAD+ were approximately 50% greater than those with NADP+. Furthermore, high glutamate concentration inhibited the formation of (E-NADH-kg) while no substrate inhibition was found with NADP+ as coenzyme. ADP enhanced while GTP reduced the rate of (E-NAD(P)H-gl) formation. The rate of formation of (E-NAD(P)H-kg) was inhibited by ADP, while it increased at high glutamate concentration when small amounts of GTP were added. The results show that the higher activity found with NAD+ compared to NADP+ under steady-state assay conditions do not necessarily involve binding of NAD+ to the ADP activating site of the enzyme. Moreover, the substrate inhibition found at high glutamate concentration under steady-state assay condition is not due to the formation of (E-NAD(P)H-gl) as this complex is formed with Km of 3 mM glutamate, and the substrate inhibition is only significant at 20-30 times this concentration.

Adenosine Diphosphate↗
PubMed1975

Properties of the highly reactive SH groups of phosphorylase b.

The reaction of rabbit muscle phosphorylase b with 5,5'-dithiobis(2-nitrobenzoic acid) (Nbs2) has been studied with stopped-flow spectrophotometry. Two highly reactive sulfhydryl groups per dimer reacted with Nbs2 within a few seconds, while the remaining SH groups needed several minutes and hours. Decomposition of the time curve revealed that the highly reactive SH groups can be divided into two subclasses: a fast type which reacted with a rate constant of 3 x 10-3 M-1 sec-1 and a more slowly reacting type disappearing with a rate constant of 0.3 x 10-3 M-1 sec-1. The reactivity of the slowly reacting type increased by a factor of about 2 in the presence of 1 mM AMP. Concurrently, the ratio between the fast reacting and the more slowly reacting subclasses decreased from 5.3 to 1.0. The AMP effect was greatly enhanced by glucose 1-phosphate. This enhancement was abolished in the presence of ATP. The finding that the ratio between the number of SH groups in the two subclasses of the highly reactive SH groups changed upon addition of ligand molecules indicates that the two subclasses reflect the different reactivities of the SH groups when the enzyme is present in different conformational states. It is suggested that the highly reactive SH group measured belong to the peptide: Gly-Cys-Arg-Asp.

Animals↗