We previously noted fibrinogen concentrations were spuriously elevated when determined simultaneously with antithrombin III activity on a Hitachi 705 analyzer. In the current manuscript, we suggest the interference is caused by thrombin-α₂ macroglobulin complex in the fibrinogen antiserum (used for immunoturbidimetric fibrinogen assay) that hydrolyzes chromogenic substrate from the antithrombin III activity assay.

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A hybridoma secreting monoclonal anti-human lgA antibody was subcloned and adapted to serum serum-free medium. The cells have stably grown and produced an antibody. The monoclonal antibody (MoAb) thus produced in this serum-free mediumw as simply purified by precipitation.
Characteristics of the antibody was comparable to that obtained from mouse ascitic tumor. It was also demonstratetd to be utilized in an automated turbidimetric assay.
MoAbs produced by serum-free Cell culture system may offer great potential for the immunodiagnostic reagents.

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Non-activated polymorphonuclear leukocytes did not degrade apo A proteins in high density lipoproteins in vitro, although it affected amyloid A proteins significantly. In contrast, leukocytes activated by phorbol myristate acetate metabolized all kinds of apoproteins in the lipoprotein, whether they had amyloid A proteins or not. The metabolic rates of amyloid A proteins and apo C-III were very rapid compared with those of apo A proteins.In contrast, lipid moieties of high density lipoproteins were hardly affected, with the exception of triglycerides, from incubation with either non-activated leukocytes and then lipoprotein particles were considered to become lipid-rich.
These results suggest the possibility that high density lipoproteins could be metabolized in acute phases by activated leukocytes in circulating blood as well as through usual metabolic pathways.

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An automated determination of cyclosporins in serum by column-switching highperformance liquid chromatography (HPLC) is described. To increase the analytical recoveries of cyclosporins in serum, serum was diluted to 4 times with a solution containing 10% of 1, 1, 3, 3-tetramethylurea and 0.05 % of sodium dodecylsulfate. A 1000-μl of the mixture was directly injected onto a TSK precolumn PW. After washing the precolumn with water for 10 min, the precolumn-connection was switched to introduce the retained substances onto an analytical column, TSKgel OH-100RP. Cyclosporins were separated with acetonitrile/water (40: 60.v/v) within 30 min. The column temperatures were at room temperature for the precolumn and at 70° for the analytical column. By the present method, the analytical recovery (70%), detection limit (20ng/m1), and within-run reproducibility (5.7% for 250ng/ml, 3.4% for 500ng/ml, 1.2% for 1000ng/ml) were sufficient for therapeutic monitoring of cyclosporin A.

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Non-defatted portion of each lyophilized human and experimental atherosclerotic aortae were fractionated sequentially into glycosaminoglycan, glycoprotein, collagen and elastin, a modified method of directly non-dellpidemic elastin fractionation (Kramsch's method). The cholesterol contents, composition of fatty acids of cholesterol ester and the lipid composition in the nondelipidated fractions were determined. The following results were observed: 1) The accumulation of cholesterol in the arch, thoracic and abdominal aortic elastin fraction (fr.) accounted for 60-90% of the sum of the total cholesterol content of each connective tissue. 2) The elasin-bound fr. was digested by treatment of Pancreatic elastase, and fractionated into supernatant (sup.) and precipitate (ppt.). and then the ratio of digested cholesterol value (sup. /sup. ppt.) was found to be about 70-90%. 3) The intimal elastin fr. and collagen fr. from atherosclerotic plaques contained mach more cholesterol ester than other fractions. While other frs.(glycosaminoglycan fr. and glycoprotein fr.) from various layers contained free fatty acids as the most lipid constituent. 4) Characteristic feature of fatty acid moieties of cholesterol ester in the elastin fr. may be in that the ratios of C_{18: 2}, C_{18: 1} and C_{18: 2} are markedly changed, while C_{16: 0} remains constant. 5) The mode of lipid deposition in the arterial elastin fr. obtained from the experimental animals (rabbits and rats) was similar to the phenomenon of lipid accumulation in the human atherosclerotic aorta. The present method allowed estimation of lipid deposition in a small sample of aorta (about 10-20 mg of dry weight), and the cholesterol content of the connective tissue fraction may thus be used as one of the biochemical atherosclerotic indices, proving the degree of severity together with histopatho-logical methods.

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We investigated the multiformity of the sugar chain (s) of carcinoembryonic antigen (CEA) in various subjects by using serial lectin affinity chromatographies. This technique revealed a possible structure of sugar chain (s) of tumor-associated CEA. The sugar chain (s) of serum CEA from normal adult and the patients with benign disease had biantennary complex type without the fucose residue and hybrid type without the internal fucose residue. The sugar chain (s) of serum CEA from cancer patients without distant metastasis had biantennary complex type and hybrid type without the internal fucose residue. But, besides those of sugar chain (s), the increase of multiantennary complex type and high mannose type sugar chain (s) were observed in the sugar chain (s) of CEA in the patients with distant metastasis. These results suggested that the tumor-associated CEA may relate to the fucoslylation of the sugar chain (s) and/or the increasing of sugar chain (s) with bisecting GIcNAc, as in a case of α-fetoprotein. Thus, the measurement of CEA subfractions may be useful for diagnosis of a patient with distant metastasis of cancer.

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Sodium azide is a well-known bacteriostatic reagent, and is conventionally added to buffer for enzyme immunoassay. Since, however, sodium azide inhibits the peroxidase activity, we cannot use it for enzyme immunoassay with peroxidase conjugate.
In the present study, we found that phenolic group substances of low molecular weight as tyrosine, phenol red, and phenol blocked the interference by sodium azide.

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