Hemodiafiltration Improves Low Levels of Health-Related Quality Of Life (Qol) and Nutritional Conditions of Hemodialysis Patients

We compared the effects on the nutritional condition and health-related quality of life (HR-QoL) of the treatment of patients with on-line hemodiafiltration (OL-HDF) and conventional hemodialysis (CHD) using a superflux dialyzer. In total, 47 maintenance (M) HD patients were treated by CHD with a high-flux dialyzer for the first 4 months (1st CHD) and were then switched to predilution OL-HDF for the next 4 months (OL-HDF), after which CHD was resumed for the last 4 months (2nd CHD). We assessed the clinical parameters, fat mass value, muscle mass value, and HR-QoL. In patients with low serum albumin levels, these levels significantly (p < 0.05) increased in the OL-HDF period. Moreover, the fat mass values significantly (p < 0.05) increased in patients with decreased fat mass values in the OL-HDF period. Although there was no significant difference in the patients with higher scores of physical functioning, role physical, vitality, and social functioning, patients with lower scores in the 1st CHD period had significantly increased (p < 0.05) in the OL-HDF period. In this crossover study, we revealed that OL-HDF treatment significantly improved the nutritional conditions and HR-QoL scores compared with the improvement observed after CHD with a superflux dialyzer, especially for maintenance hemodialysis patients with malnutrition and a low QoL.

An alpha2-macroglobulin-serine proteinase complex from human carcinomatous ascites and pleural effusion: isolation, monoclonal antibody preparation, and immunohistochemical study

A protein with the apparent molecular mass of 720 kDa which hydrolyzes anilide substrates of p-guanidino-L-phenylalanine was purified from ascites and pleural effusion of patients with pulmonary, breast, gastric, and ovarian cancers by chromatographic techniques. When this protein was separated on SDS-PAGE on nonreducing conditions, two bands corresponding to 720 and 360 kDa were seen to have gelatin-digestive activity in zymography assay. Moreover, when it separated by SDS-PAGE on reducing conditions, it migrated as several bands up to 180 kDa. The N-terminal amino acid sequence and immunoreactivity of anti-alpha2-macroglobulin polyclonal antibody revealed that the 180-kDa band was intact alpha2-macroglobulin. The hydrolytic activity of this complex was completely inhibited by diisopropyl fluorophosphate (DFP) and p-amidinophenylmethanesulfonyl fluoride. In addition, the 65-kDa protein observed under reducing conditions bound 3H-labeled DFP. These results suggest that the purified protein is a complex of the plasma proteinase inhibitor alpha2-macroglobulin and a serine proteinase. Several monoclonal antibodies were obtained when the purified complex was used as an antigen. One of these antibodies, which was immunoreactive to this complex but not to alpha2-macroglobulin, gave a positive band corresponding to 65 kDa on SDS-PAGE under reducing conditions. Use of this antibody in immunohistochemical studies revealed immunoreactivities in numerous neoplastic tissues with strong activity in advanced gastric cancers (e.g., poorly differentiated adenocarcinoma). In addition, strong cross-reactivity was detected in glandular cells of the fetus intestine.

[An approach to home therapy for cancer pain patients]

Recently, in consideration of cost performance and improvement in quality of life (QOL) of the patient, the significance of home care and outpatient treatment has also been recognized in Japan. A terminal cancer patient who had local recurrence in the pelvic region after surgery for rectum carcinoma, was treated for cancer pain by us with a continuous epidural infusion of morphine by means of a prolonged operating continuous infusion device. The treatment made home therapy possible and allowed the patient to return to normal social activities. Based on this case, the significance of and issues regarding home therapy are discussed in this study.

The conformation of the lysyl side chain of substrates at the active center of trypsin

In order to study the conformation of the side chain of lysine substrates bound to the active center of trypsin, two lysine analogs, cis- and trans-2,6-diamino-4-hexenoic acids (4,5-dehydrolysines) were synthesized and kinetic parameters for the hydrolysis of benzoyl methyl esters and phenylthiazolones of these analogs by this enzyme were compared with those of the corresponding lysine derivatives. The derivatives of cis-4,5-dehydrolysine were hydrolyzed much more slowly than those of lysine, owing largely to the small kcat values for the former. On the other hand, the derivatives of the trans-isomer were hydrolyzed at about the same rates as those of lysine and the values of both Km and kcat of the former are also similar to those of the latter. These results indicate that the conformation of the side chain of the lysine derivatives hydrolyzed by trypsin is such that the beta- and epsilon-carbons are in a trans-like conformation, as suggested by X-ray crystallographic studies of inhibitor-trypsin complex.

Interactions of derivatives of guanidinophenylalanine and guanidinophenylglycine with Streptomyces griseus trypsin

The rates of hydrolysis of the ester, amide and anilide substrates of p-guanidino-L-phenylalanine (GPA) by Streptomyces griseus trypsin (S. griseus trypsin) were compared with those of arginine (Arg) substrates. The specificity constant (kcat/km) for the hydrolysis of GPA substrates by the enzyme was 2-3-times lower than that for arginine substrates. The kcat and Km values for the hydrolysis of N alpha-benzoyl-p-guanidino-L-phenylalanine ethyl ester (Bz-GPA-OEt) by S. griseus trypsin are in the same order of magnitude as those of N alpha-benzoyl-L-arginine ethyl ester (Bz-Arg-OEt), although both values for the former when hydrolyzed by bovine trypsin are higher by one order of magnitude than those for the latter. The specificity constant for the hydrolysis of Bz-GPA-OEt by S. griseus trypsin is much higher than that for N alpha-benzoyl-p-guanidino-L-phenylglycine ethyl ester (Bz-GPG-OEt). As with the kinetic behavior of bovine trypsin, low values in Km and kcat were observed for the hydrolysis of amide and anilide substrates of GPA by S. griseus trypsin compared with those of arginine substrates. The rates of hydrolysis of GPA and arginine substrates by S. griseus trypsin are about 2- to 62-times higher than those obtained by bovine trypsin. Substrate activation was observed with S. griseus trypsin in the hydrolysis of Bz-GPA-OEt as well as Bz-Arg-OEt, whereas substrate inhibition was observed in three kinds of N alpha-protected anilide substrates of GPA and arginine. In contrast, no activation by the amide substrate of GPA could be detected with this enzyme.

A new beta-naphthylamide substrate of p-guanidino-L-phenylalanine for trypsin and related enzymes

N alpha-Benzyloxycarbonyl-p-guanidino-L-phenylalanine beta-naphthylamide (Z-GPA-beta NA) was synthesized and the susceptibility of this compound to trypsin and related enzymes was compared with that of N alpha-benzyloxycarbonyl-L-arginine beta-naphthylamide (Z-Arg-beta NA). Both Z-GPA-beta NA and Z-Arg-beta NA were rapidly and almost completely hydrolyzed by trypsin and pronase. Z-Arg-beta NA was hydrolyzed slowly by thrombin, while Z-GPA-beta NA was not susceptible to this enzyme at all. The rate of hydrolysis of Z-GPA-beta NA by papain was slower than that of Z-Arg-beta NA. Neither beta-naphthylamide substrate was hydrolyzed by alpha-chymotrypsin. The specificity constant (kcat/Km) for the hydrolysis of Z-GPA-beta NA by trypsin was somewhat larger than that for the hydrolysis of Z-Arg-beta NA. Contributions of the benzene ring in the side chain of Z-GPA-beta NA to good binding of this substrate to the specificity site of this enzyme and to the poor fit of the scissile bond in the substrate molecule to the active serine residue are presumed from comparison of the individual kinetic parameters (Km and kcat) for the two beta-naphthylamide substrates. Z-GPA-beta NA was ascertained to be a useful substrate in the study of the binding and catalytic specificities of various trypsin-like enzymes.

A new serine protease which preferentially recognizes p-guanidino-L-phenylalanyl residue in ascitic plasma from Ehrlich ascites tumor-bearing mice

A new enzyme which hydrolyzes anilide substrates of p-guanidino-L-phenylalanine in preference to those of arginine was found in the ascitic plasma from Ehrlich ascites tumor-bearing mice. The activity of this enzyme on N alpha-benzyloxycarbonyl-p-guanidino-L-phenylalanine p-nitroanilide was strongly inhibited by diisopropyl fluorophosphate and phenylmethanesulfonyl fluoride but not by sulfhydryl-reactive reagents and metal chelating agents. Peptide substrates containing p-guanidino-L-phenylalanine were hydrolyzed by this enzyme much faster than those containing arginine. These results suggest that this enzyme is a different type of serine protease from trypsin and thrombin. This enzyme was also found in the human gastric and colon cancer cells and their surrounding ascitic plasmas.

Kinetics of hydrolysis of amide and anilide substrates of p-guanidino-L-phenylalanine by bovine and porcine trypsins

The rates of hydrolysis of N alpha-benzoyl-p-guanidino-L-phenylalaninamide (Bz-GPA-NH2) and N alpha-substituted p-nitroanilides (pNA) of GPA (benzyloxycarbonyl(Z)-GPA-pNA, benzoyl(Bz)-GPA-pNA and acetyl(Ac)-GPA-pNA) by bovine and porcine trypsins were compared with those of arginine (Arg) substrates. The amide type substrates of GPA were hydrolyzed as fast as those of Arg by the two enzymes with much the same kcat/Km values, though significant differences were found between the kcat and Km values of GPA derivatives and those of Arg derivatives. The kinetic behavior of porcine trypsin toward GPA substrates was almost the same as that of the bovine enzyme. The ratio of the kcat value for Bz-GPA-OEt to that for Bz-GPA-NH2 was much larger than that for the ester to amide substrates of arginine, suggesting that the conformational change of the active site of trypsin induced by a benzene ring in the side chain of Bz-GPA-OEt specifically increases the velocity of the deacylation process of the ester substrate. Remarkably low values of both kcat and Km were found for the tryptic hydrolysis of Z-GPA-pNA and Ac-GPA-pNA, as well as on that of Bz-GPA-pNA (Tsunematsu, H., et al. (1983) J. Biochem. 94, 123-128). Z-GPA-pNA is the best substrate for the two trypsins among the three N alpha-substituted anilide substrates of GPA.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics of hydrolysis of phenylthiazolones of arginine, homoarginine, norarginine, and canaavanine by trypsin

Phenylthiazolones (PTAs) of arginine and its homologs and analogs, homoarginine, norarginine (alpha-amino-gamma-guanidinobutyric acid), canavanine, and gamma-hydroxyarginine, were prepared. A steady-state kinetic analysis of the trypsin [EC 3.4.21.4]-catalyzed hydrolysis reactions was carried out and the kinetic parameters for these internal thioesters were compared with those for normal linear ester substrates. PTA-gamma-hydroxyarginine was so labile that hydrolysis by the enzyme could not be followed. PTA-arginine has a specificity constant (Kcat/Km) comparable to that for the Nalpha-unblocked arginine ester substrate, though the value is about 0.1% of that for a specific ester substrate, Nalpha-tosylarginine methyl ester. PTA derivatives of canavanine and homoarginine were hydrolyzed with Kcat/Km walues of the same order of magnitude as that for PTA-arginine. However, PTA-noraginine was much less susceptible to tryptic hydrolysis that PTA-homoarginine, while the linear esters of norarginine are known to be more susceptible than those of homoarginine.