Akio Noma

Transient changes of serum lipoprotein(a) as an acute phase protein

Serum lipoprotein(a) (Lp(a)) was serially determined after acute attacks of myocardial infarction and after surgical operations. Acute phase proteins, such as C-reactive protein, alpha 1-acid glycoprotein, alpha 1-antitrypsin and haptoglobin, increased rapidly and markedly after the episodes. Initial values of serum Lp(a) concentrations were almost the same in both groups. Increases in serum Lp(a) levels were also observed during the first few days, with a return to the initial levels after more than 1 month. The periods for reaching maximal levels of acute phase proteins were similar in both groups of patients. On the contrary, the period required for Lp(a) to reach the maximal level in the myocardial infarction group was significantly longer than in the post-operative group. The present study suggests that Lp(a) has the characteristics of an acute phase reactant and may play an important role in recovery from tissue damage.

A new colorimetric micro-determination of free fatty acids in serum

Abstract A colorimetric micromethod, based on the formation of FFA-Cu soaps, was described for the determination of free fatty acids (FFA) in 100 μl of serum. FFA was extracted with chloroform-heptane-methanol. Phospholipids were scarcely extracted by this solvent system. 2-(2-thiozolylazo)-p-cresol was chosen for the colorimetric determination of copper. These modifications rendered the method more sensitive and stable than other available colorimetric methods. Results obtained with the proposed method were in reasonable agreement with those obtained with other colorimetric methods.

Lipopolysaccharide induction of indoleamine 2,3‐dioxygenase is mediated dominantly by an IFN‐γ‐independent mechanism

Indoleamine 2,3‐dioxygenase (IDO) is a rate‐limiting enzyme in the L‐tryptophan‐kynurenine pathway, which converts an essential amino acid, L‐tryptophan, to N‐formylkynurenine. It has been speculated that IFN‐γ is a dominant IDO inducer in vivo. The present study used IFN‐γ or TNF‐α gene‐disrupted mice and IFN‐γ antibody‐treated mice to demonstrate that lipopolysaccharide (LPS)‐induced systemic IDO is largely dependent on TNF‐α rather than IFN‐γ. IFN‐γ‐independent IDO induction was also demonstrated in vitro with LPS‐stimulated monocytic THP‐1 cells. These findings clearly indicate that there is an IFN‐γ‐independent mechanism of IDO induction in addition to the IFN‐γ‐dependent mechanism.

Plasma Fas Ligand, an Inducer of Apoptosis, and Plasma Soluble Fas, an Inhibitor of Apoptosis, in Patients With Chronic Congestive Heart Failure

OBJECTIVES This study sought to examine plasma levels of soluble Fas/APO-1 receptor (sFas), an inhibitor of apoptosis, and soluble Fas ligand (sFas-L), an inducer of apoptosis, and their relation to each other and to other clinical variables, such as New York Heart Association functional class, tumor necrosis factor (TNF) and interleukin-6 (IL-6) in congestive heart failure (CHF). BACKGROUND It has been recently reported that apoptotic cell death occurs in myocytes of dogs with CHF. Hypoxia is frequently seen in advanced CHF and can stimulate Fas/APO-1 receptors (Fas) to induce apoptosis in cultured myocytes. Fas and Fas ligand (Fas-L) are cell-surface proteins and representative apoptosis-signaling molecules. Fas on the cell membrane induces apoptosis when it binds Fas-L or sFas-L. However, plasma sFas, a molecule lacking the transmembrane domain of Fas, blocks apoptosis by inhibiting binding between Fas and Fas-L or sFas-L on the cell membrane. At present, it is unknown whether plasma sFas-L and plasma sFas increase in the presence of cardiac disease. METHODS The study included 70 patients (mean [+/-SEM] age 65 +/- 2 years, range 21 to 93) with chronic CHF (coronary artery disease in 28, dilated cardiomyopathy in 27, valvular heart disease in 15) and 62 age- and gender-matched normal control subjects. Plasma levels of sFas, sFas-L, TNF-alpha and IL-6 were measured by enzyme-linked immunosorbent assays using monoclonal anti-human antibodies. RESULTS There was no significant difference in sFas-L levels between normal subjects and patients in functional classes I to IV; however, sFas increased with severity of functional classification, independent of the underlying disease. sFas levels were significantly higher even in patients in functional class II than in normal subjects and those in functional class I, and were highest in patients in functional class IV (normal subjects; 2.2 +/- 0.1 ng/ml; functional class I: 2.2 +/- 0.2 ng/ml; functional class II: 3.1 +/- 0.2 ng/ml; functional class III: 3.9 +/- 0.3 ng/ml; functional class IV: 5.1 +/- 0.6 ng/ml). Plasma sFas levels were significantly higher in patients with elevated pulmonary artery wedge pressure and a decresed cardiac index than in those with values in the normal range. In patients in functional class IV, there was no significant difference in plasma sFas levels between the survivors and non-survivors during 6-month follow-up. However, plasma levels of sFas tended to decrease in nine patients with clinical improvement (baseline sFas: 5.2 +/- 0.8 ng/ml; 6-month sFas: 4.3 +/- 0.5 ng/ml, p = 0.07) but were similar in patients with no change in functional class. TNF-alpha and IL-6 were increased significantly only in patients in functional class IV, as previously reported, but were not related to sFas. CONCLUSIONS We found elevated levels of plasma sFas and no increase in plasma sFas-L in human CHF. The increase in sFas may play an important role in the pathophysiologic mechanisms of CHF.

Quantitation of serum apolipoprotein A-I, A-II, B, C-II, C-III and E in healthy Japanese by turbidimetric immunoassay : reference values, and age- and sex-related differences

Serum apolipoproteins (Apo) A-I, A-II, B, C-II, C-III and E were determined in healthy Japanese subjects (male 1,603, female 1,800, aged 4-95 yr) by the turbidimetric immunoassay, with six kinds of automated instruments, and the commercial reagent kits with standards. There was a high degree of interlaboratory comparability of analytical values among the 15 participating laboratories. The reference values were calculated for adult males and females (male 677, female 467, aged 21-60 yr). Apo A-I and E levels were significantly higher and Apo C-II and C-III were significantly lower in females than in males. Furthermore, serum Apo A-I and A-II tended to decrease, and Apo B to increase with age. Apo C-II, C-III and E tended to decrease after 60 yr of age.

Prevention of restenosis after percutaneous transluminal coronary angioplasty by reducing lipoprotein (a) levels with low-density lipoprotein apheresis

This study was designed to test the hypothesis that high plasma lipoprotein (a) (Lp[a]) levels are associated with an increase incidence of restenosis after angioplasty. Elective transluminal coronary angioplasty was performed in 66 patients (58 men and 8 women) aged 57 +/- 9 years (mean +/- SD). Two days before and 5 days after angioplasty, all patients underwent low-density lipoprotein (LDL) apheresis with a dextran sulfate cellulose column as an Lp(a) absorbent; 39 patients also received 10 mg of pravastatin and 1,500 mg of niacin daily. Restenosis was defined as a recurrent luminal stenosis of > or = 50% in a previously dilated segment. Median Lp(a) levels were reduced from 23.3 mg/dl before apheresis to 10.9 mg/dl after apheresis (p < 0.0001). Angiography performed 2 to 9 months after angioplasty revealed restenosis in at least 1 site in 38% of the 137 control patients and in 32% of the 66 patients who underwent apheresis. Restenosis also occurred in 37% of the patients who underwent apheresis alone and in 28% of the patients who also received pravastatin and niacin in combination with LDL apheresis. The restenosis rate was 21% in the 42 patients whose Lp(a) levels were significantly reduced > or = 50%, and in 50% of the 24 patients whose Lp(a) levels were significantly reduced < 50% (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

3-Hydroxyanthranilic acid, an L-tryptophan metabolite, induces apoptosis in monocyte-derived cells stimulated by interferon-γ

3-Hydroxyanthranilic acid (3-HAA), a metabolite of L-tryptophan, accumulates in monocyte-derived cells (THP-1),but not in other celllines tested(MRC9, H4, U373MG, Wil-NS), following immune stimulation that induces indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme in the L-tryptophan-kynurenine pathway. We examined whether metabolites of the L-tryptophan-kynurenine pathway act to induce apoptosis in monocytes/macrophages. Of the L-tryptophan metabolites tested, only 3-HAA at a concentration of 200µmol/L was found to induce apoptosis in THP-1 and U937 cells. The addition of ferrous or manganese ions further enhanced apoptosis and free radical formation by 3-HAA in these two types of cells. The apoptotic response induced by 3-HAA was significantly attenuated by the addition of antioxidant, α-tocopherol or Trolox (a water-soluble analogue of vitamin E), and the xanthine oxidase inhibitor, allopurinol. In addition, the 3-HAA-induced apoptotic response was slightly attenuated by catalase, but not by superoxide dismutase (SOD), indicating that generation of hydrogen peroxide is involved in this response. Interferon-γ (IFN-γ), an inducer of IDO, potently induced apoptosis in THP-1 cells, but not in U937 cells, in the presence of ferrous or manganese ions. This different susceptibility to apoptosis inducer between THP-1 and U937 cells may depend on the capacity of the cells for 3-HAA synthesis following IDO induction by IFN-γ. Furthermore, apoptosis was suppressed by cycloheximide in THP-1 cells, suggesting that newly synthesized proteins may be essential for apoptotic events. These results suggest that 3-HAA induces apoptosis in monocytes/macrophages under inflammatory or other pathophysiological conditions.

Serum lipid and apolipoprotein levels in patients with psoriasis

Although there have been extensive studies of serum lipid levels in psoriasis, the data are conflicting. In the present study, 38 male psoriatic patients and 40 age‐matched male control subjects were studied. In addition, a 75 g oral glucose tolerance test (OGTT) was performed in 28 patients and 28 age‐matched control subjects, in order to exclude subjects with abnormal OGTT values from the study. Twenty‐two patients and 26 control subjects had normal OGTT values. There was a tendency for psoriatic patients with normal glucose tolerance to have increased triglyceride levels, but this was not statistically significant. Total cholesterol and high‐density lipoprotein‐cholesterol levels in patients were normal. However, serum apo B (P<0.005), C‐II (P <0.005) and C‐III (P <0.005) levels in patients were significantly elevated compared with control subjects. When control subjects and patients with abnormal OGTT values were also included, a significant increase in triglyceride and apo E levels, and a significant decrease in the apo A‐I level were observed in psoriatic patients. These findings suggest that psoriasis per se is associated with increases in apo B, C‐II and C‐III levels, but that this does not profoundly affect lipid levels. The abnormal lipoprotein metabolism may be related to the high incidence of atherosclerosis in psoriasis.

Cerebrospinal fluid apo E and apo A-I concentrations in early- and late-onset Alzheimer's disease

We compared cerebrospinal fluid (CSF) apolipoprotein (apo) A-I and apo E concentrations in early- and late-onset Alzheimers disease (EOAD (n = 11), LOAD (n = 15), respectively) with those in control subjects (n = 23). CSF apo A-I levels in both EOAD and LOAD were consistent with control subjects. However, CSF apo E levels were significantly lower in EOAD group (mean +/- SD; 2.65 +/- 1.69 mg/l, P < 0.05) and higher in LOAD group (5.90 +/- 1.94 mg/l, P < 0.01) than those in control group (4.16 +/- 1.69 mg/l). In addition, the epsilon4 allele frequency was not different between EOAD and LOAD groups. Although the reason for the difference in CSF apo E concentrations between two groups is unknown, CSF apo E concentration seems to be associated with the pathogenesis of EOAD and LOAD. The rate of apo E production and/or catabolism in the brain may be different between them.

Lp(a) : An acute phase reactant?

The present study was designed to confirm the transient increases of plasma Lp(a) levels as an acute-phase reactant and to clarify the significance of these increases with the use of patients with acute myocardial infarction and patients subjected to surgical operations. Although interleukin 6, C-reactive protein and alpha 1 antitrypsin reached the maximal levels 1-2 days, 3 days and 4-5 days, respectively, after the episodes, the peak time of Lp(a) levels was delayed some extent in both patient groups. Studying the transient increases of Lp(a) levels as a function of apo(a) isoforms analyzed by density-gradient ultracentrifugation and SDS-PAGE, the higher-density Lp(a) particles preferentially containing high-molecular-weight apo(a) isoforms increased more than the lower-density Lp(a) particles containing low-molecular-weight apo(a) after the episodes. The immunohistochemical findings suggest that Lp(a) may play an important role as an acute-phase reactant in the repair of tissue injury, especially in the process of angiogenesis.