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Biomedical subjects

K Nustad

Publications and source records attributed to K Nustad.

At least 91 records · Page 5Linked to original sources
PubMed1976

Rat submandibular gland kallikreins: purification and cellular localization.

1 Four submandibular gland kallikreins (E.C.3.4.21.8) were isolated by chromatography on DEAE-Sephadex A-50 and hydroxyapatite, followed by gel filtration and electrofocusing. The pI values were 3.87, 3.96, 4.07 and 4.16, and a common molecular weight of 34,000 was found. 2 The kallikreins were localized by direct immunofluorescence with an antibody to rat urinary kallikrein, to the granular tubules, striated duct cells and some main duct cells in the submandibular gland, and to striated duct cells in the sublingual gland. Kallikrein was not found in acini and stroma. 3 Several non-kallikrein esterases present in the submandibular gland reacted with the antibody to rat urinary kallikrein. The antibody was made monospecific for kallikrein by absorption with the crossreacting esterases. 4 We suggest that kallikrein is produced in striated duct cells. Granular tubules, which are differentiated from striated duct cells, have preserved the ability to produce kallikrein. These cells also store large quantities of kallikrein.

Animals↗
PubMed1975

Synthesis of kallikreins by rat kidney slices.

1 Four radioactive akllikreins were isolated from rat kidney slices incubated with (3H)-L-leucine. 2 The kallikreins were purified by procedures previously used for the isolation of rat urinary kallikreins (Nustad & Pierce, 1974), and by affinity chromatography on a column of insolubilized anti-rat urinary kallikrein. 3 The kidney kallikreins resembled the urinary kallikreins in their relative amounts, isoelectric points and electrophoretic mobilities on polyacrylamide disc gels. 4 The data indicate that the kidney synthesizes four kallikreins which are released into urine. The kallikreins are not changed by passage through the lower urinary tract.

Animals↗
PubMed1975

Cellular localization of kallikreins in rat submandibular and sublingual salivary glands: immunofluorescence tracing related to histological characteristics.

Immunohistochemical localization of rat salivary gland kallikrein was related to glandular structures in tissue processed and stained by various methods. In the submandibular gland, most of the kallikrein was located to cytoplasmic granules of the granular tubules. Cells of the striated ducts showed a faint cytoplasmic staining with a bright luminal rim that occasionally was seen also in the excretory ducts. Minor amounts of kallikrein was found in the interstitial tissue. In the sublingual gland, kallikrein was found in the cytoplasm of the striated duct cells and as a luminal rim in the main ducts. Acini were negative in both glands. Fixation in Helly's fluid preserved cytoplasmic granules and was thus superior for intracellular localization of kallikrein, whereas ethanol fixation, due to absence of non-specific background staining, afforded the most sensitive method for detection of small amounts of antigen. In the submandibular gland, best identification of granular tubules and striated ducts was achieved with DMAB-nitrite staining for tryptophan and counterstaining with Mayer's haemalum on sections of tissue fixed in Helly's fluid. In the sublingual gland, the duct system was best demonstrated by haematoxylin-eosin staining.

Animals↗
PubMed1970

The relationship between kidney and urinary kininogenase.

1. Rat kidneys which were perfused with saline contained both kininogenase (KGA) and kininase activity. These activities were separated by gel filtration on a Sephadex G-100 column. The kininase activity was excluded from the column whereas the KGA activity was retained. Kidney KGA activity was primarily found in the sedimentable fraction of the homogenate.2. The kidney KGA activity was compared with the urinary KGA activity, and the following properties were found to be the same: molecular dimension, pH optimum, effect of inhibitors, and ability to liberate kinins from kininogens.3. A urinary sample collected over 24 h contained about 8 times the KGA activity found in the corresponding kidneys at the end of the collection period. The urine: kidney ratio for alkaline phosphatase was about 0.01.4. The ability of kidney and urinary samples to hydrolyse N-alpha-benzoyl-L-arginine ethyl ester (BAEE) at pH 8.5 paralleled the KGA activity.

Alkaline Phosphatase↗
PubMed1970

Localization of kininogenase in the rat kidney.

1. The rat kidney kininogenase (KGA) activity was located mainly in the kidney cortex.2. Differential centrifugation of kidney cortex homogenate revealed that the microsomal fraction contained more KGA activity per unit of protein than the other subcellular fractions.3. Subfractionation of the microsomal fraction showed that the KGA activity was recovered in a subfraction also containing high specific activity of both alkaline phosphate and glucose-6-phosphatase. It is suggested that the KGA activity is localized in the plasma membrane and/or endoplasmic reticulum membranes of kidney cortical cells.4. Hydrolysis of N-alpha-benzoyl-L-arginine ethyl ester at pH 8.5 paralleled the KGA activity.

Alkaline Phosphatase↗
PubMed1970

Subcellular localization of renin and kininogenase in the rat kidney.

1. The distribution of enzymatic activities was determined in subcellular fractions of rat kidney cortex homogenates after various homogenization procedures. The specific activities of kininogenase (KGA), BAEE esterase (pH 8.5), alkaline phosphatase and glucose-6-phosphatase were, on average, 3.4 times higher in the microsomal fraction than in the whole homogenate. The total amount of these activities in the microsomal fraction after gentle, ordinary and forced homogenization were about 15, 40 and 65% of total recovered activities, respectively. These results confirmed the localization of KGA in the microsomal fraction.2. Renin activity was primarily recovered in the heavy mitochondrial fraction. When the force of the homogenization was increased some renin activity was shifted to the soluble fraction.3. When a mixture of renin and purified urinary KGA was given intravenously to an anaesthetized rat, a hypotensive response due to the KGA was followed by a hypertensive renin response. Over a certain range of concentrations KGA and renin could be measured simultaneously. In fractions of kidney homogenates, however, KGA activity was too low to be measured by this method.

Acid Phosphatase↗
PubMedDate not supplied

Automated immunofluorometric assay for MUC1.

The aim of the present study was to establish a robust, reliable and fully automated immunofluorometric assay for the breast cancer serum marker MUC1. This would further serve as a prototype assay for evaluation of other MUC1 assays based on new antibody combinations. Using time-resolved fluorescence as tracer signal we developed an automated immunofluorometric assay for MUC1 (MUC1 IFMA). This assay was compared with two commercial assays. The CA15-3 EIA (CanAg) which use the same antibodies as the MUC1 IFMA, and the ETI-CA-15-3 K (Sorin) which use the original antibodies defining the CA 15-3 assay. The three assays showed comparable results. The coefficient of variation was below 10% from 9 to 2,400 kU/l for the MUC1 IFMA, from 15 to 250 kU/l for the CA15-3 EIA, and from 25 to 200 kU/l for the ETI-CA-15-3 K assay. At a specificity of 0.94 the overall diagnostic sensitivities for the MUC1-IFMA, CA15-3 EIA and ETI-CA-15-3 K assays were 0.40, 0.37, and 0.38, respectively. When applied to metastatic breast cancer, all assays had sensitivities close to 0.80. There was a close correlation (Spearman rank = 0.99) between results from the new assay and the CA15-3EIA. The new automated assay was not strictly immunometric as we could not achieve conditions where solid phase or tracer antibodies were in apparent excess. However, the assay performed well at a wide range of assay conditions. The automation, which minimizes imprecision in pipetting and handling of samples, and the high capacity of the AutoDELFIA instrument enabling measurement of all samples in a single run, were important aspects for establishing a reliable assay. The principle of the new automated immunofluorometric assay will be used as a rapid and reliable evaluation of a wide range of monoclonal antibody combinations in our search for the optimal MUC1 assay. This new automated immunofluorometric assay will be useful in the rapid and reliable evaluation of a wide range of monoclonal antibody combinations in our search for the optimal MUC1 assay.

Adult↗
PubMedDate not supplied

New immunoassays for MUC1 in breast cancer.

Eleven experimental immunofluorometric assays (IFMAs) were made using antibodies previously tested for epitope specificities. These assays were compared with six commercially available immunoassays. The clinical performance of these experimental assays was evaluated by analysing sera from 138 breast cancer patients and 105 female blood donors. The clinical performance of these assays was evaluated at a set specificity of 0.94. The highest overall sensitivity (0.56) was observed in the experimental assay with the antibody BC2 as solid phase and GP1.4 as the tracer antibody. This combination also showed the highest sensitivity in stage I/II breast cancer. The Truquant assay (Biomira) had an overall sensitivity of 0.51, and the highest sensitivity in stages III and IV at 0.65 and 0.94, respectively. The remaining commercial assays, with sensitivity ranging from 0.67 to 0.79, were below the top five experimental assays that showed sensitivity values between 0.79 and 0.85. The findings from our current study suggest that further development in MUC1 immunoassays could improve the detection of relapse in breast cancer patients.

Adult↗
PubMedDate not supplied

Elevated CA125 in breast cancer--A sign of advanced disease.

The serum tumor markers CA 125, MUC1 and CEA were measured in 221 breast cancer patients over a period of 2 years. Patients examined on at least three occasions were included in the study. Thirty-three patients had increasing or continuously high concentrations of CA 125. Thirty (91%) of these had involvement of the pleura, either as pleural metastasis or metastasis in surrounding tissue i.e. bone structures in the thorax cavity or lung parenchyma. MUC1 and CEA were elevated in 27 (82%) and 24 (73%) of the 33 patients, respectively. Increased concentrations of these two markers did not relate to the site of metastasis. However, the three tumor markers complemented each other in detecting early metastases. Increased CA 125 was associated with metastasis in or near the pleura, and in stage IV breast cancer it was related to poor prognosis.

Adult↗
PubMedDate not supplied

CA 125: the end of the beginning.

CA 125, a high-molecular-weight mucin, was first defined in 1981 by the monoclonal antibody OC125. Until recently, it has defied many attempts to purify it from a variety of sources, although many research groups have successfully raised antibodies that bind to CA 125. Nevertheless, CA 125 has demonstrated its considerable value as a marker in monitoring patients with ovarian cancer. This year, two research groups have succeeded in cloning the high-molecular-weight mucin CA 125. Their findings are summarized and the significance discussed in light of existing data from the human genome.

CA-125 Antigen↗