Unique heparan sulfate from shrimp heads exhibits a strong inhibitory effect on infections by dengue virus and Japanese encephalitis virus.

The structure and biological activities of a highly sulfated heparan sulfate (HS) extracted from shrimp (Penaeus brasiliensis) heads were characterized. Structurally the shrimp HS was more heterogenous than heparin, although it is still highly sulfated. The molecular mass of the shrimp HS preparation was determined to be 32.3 kDa by gel filtration HPLC. Analysis by surface plasmon resonance demonstrated that various growth/differentiation factors specifically bound to the shrimp HS with comparable affinity. Notably, the shrimp HS had a greater inhibitory effect against infections by dengue virus type 2 as well as Japanese encephalitis virus than heparin. Experiments on anticoagulant activity indicated that the shrimp HS exhibited significant anti-thrombin activity, but less than the commercial heparin. Hence, the HS preparation from shrimp heads, an industrial waste, is a prospective agent for a variety of clinical applications.

[Study of preparation of the calibration standard for the crustacean protein detection method].

We examined the preparation method of the calibration standard for an ELISA kit for measuring crustacean protein in food products. The initial extract of the calibration standard was stabilized by addition of protease inhibitor to the extracting solution and heating at 100 degrees C for 10 min. In accordance with the preparation procedure for calibrators, we prepared 3 lots of initial extract of calibration standard and analyzed the protein concentration and SDS-electrophoretic pattern. Single bands at 160, 41, 37 kDa and 4 bands in the range of 16-20 kDa were observed on SDS-PAGE. The range of protein concentration of the initial extract of the calibration standard was 2.74-4.10 mg/mL.

Lipocalin-type prostaglandin D synthase is a powerful biomarker for severity of stable coronary artery disease.

Lipocalin-type prostaglandin D synthase (L-PGDS), which is responsible for the biosynthesis of prostaglandin (PG) D(2), has been found to be present in the atherosclerotic plaque of the human coronary artery and also to be detectable in human serum. This multicenter cooperative study was designed to establish the diagnostic value of measuring serum L-PGDS for coronary artery disease. The study included 1013 consecutive patients suspected of having stable coronary artery disease who underwent diagnostic coronary angiography. Peripheral blood was collected prior to angiography. The serum level of L-PGDS, as determined by a sandwich ELISA, was 58.1 +/- 2.2, 62.0 +/- 1.8 and 80.6 +/- 2.6 microg/dl for patients with no stenotic lesion (N, n=241), single-vessel coronary artery disease (S, n=351), and multi-vessel coronary artery disease (M, n=421), respectively (N vs. S; P<0.001, S vs. M; P<0.01, N vs. M; P<0.001). Multiple regression analysis indicated that the most powerful independent predictor of the coronary severity score (Gensini Score) was the L-PGDS level (R=0.55, P<0.0001). The serum L-PGDS level is suitable to evaluate the severity of coronary artery disease. The measurement of serum L-PGDS can be a strategy for screening of stable coronary artery disease prior to coronary angiography.

A reliable and sensitive immunoassay for the determination of crustacean protein in processed foods.

Among food allergens, crustacea such as shrimps, crabs, and lobsters are a frequent cause of adverse food reactions in allergic patients. The major allergen has been identified as a muscular protein, tropomyosin. A novel sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of crustacean protein in processed foods was developed using the sample dilution buffer that is added to porcine tropomyosin. The sandwich ELISA method was highly specific for the Decapoda group, apart from minor cross-reactivities to other crustacea and mollusks. The recovery ranged from 85 to 141%, while the intra- and interassay coefficients of variation were less than 2.8 and 8.4%, respectively.

Lipocalin-type prostaglandin D synthase (beta-trace) in cerebrospinal fluid: a useful marker for the diagnosis of normal pressure hydrocephalus.

Lipocalin-type prostaglandin D synthase (PGDS) is considered to be mainly produced in the leptomeninges and secreted into cerebrospinal fluid (CSF). We found PGDS levels in CSF of patients with normal pressure hydrocephalus (NPH) (8.99+/-2.59 microg/ml, mean+/-S.D., n=14) to be significantly lower than levels in a control (15.29+/-5.17, n=14, P<0.0001) and other dementia group (19.14+/-4.34, n=7, P=0.0003). Thus, PGDS level in CSF is a useful marker for the differential diagnosis of NPH from other diseases with dementia.