Reference values of plasma lipoprotein (a) in newly classified apolipoprotein(a) phenotype groups in the Japanese population.

We tried to establish the reference values of plasma lipoprotein (a) [Lp(a)] concentration in phenotype groups of apoliprotein(a) [apo A] classified by a new criterion. Lp(a) concentration was determined by latex agglutination immunoassay, and apo A was analysed by electrophoresis in sodium dodecyl sulphate-polyacrylamide gel and a Western blotting technique. According to the relative mobility to the apo B-100 band, apo A was classified into 11 isoforms, i.e. F, B, and S1-S9, and the phenotype was defined by their apparent combination. The frequency ratio of single-band versus double-band was approximately 2:1. In 382 cases of single-band, the most frequent phenotype was S5 (24.3%), followed by S4 (17.3%), S6 (15.4%) and S3 (14.4%). In 181 cases of double-band, S5/S6 phenotype was observed most frequently (12.2%). followed by S4/S5 (10.5%) and S3/S6 (7.2%). The reference value was determined between antilogs of the mean +/- 1.96 standard deviation by logarithmic transformation of all observed values for individual phenotype cases. These results suggest that the reference values shown to be variable with apo A phenotypes should be useful for evaluating Lp(a) values in diagnosis of atherosclerosis.

Surgical treatment for dissecting aneurysm of the aorta using a double ringed graft.

Since 1978 we have been using a new double ringed graft for the treatment for dissecting aneurysm of the aorta. This prosthesis is a segment of a woven Dacron graft with two stainless steel rings, fixed and sutured in place, 10 or 12 mm apart, at each end of the graft. The operative procedure is as follows: the graft is tied into the true lumen of the dissected aorta; tape is ligated around the aorta and fixed between the two rings; and suturing of the aortic layers is done over the inserted graft. This technique has been applied in 11 cases of dissecting aneurysm. Eight patients survived, and 3 died soon after surgery due to complications. The safety of this method was ascertained by experimental and pathohistological studies.

[Beta(+)-thalassemia (-31CapA-->G) homozygosity discovered on the mass medical examination: diagnosis for beta-thalassemia and DNA analysis].

A 44-year-old Japanese male showed a high value of HbF (14.3%) in an assay of glycated Hb (HbA1c) by use of HLC-723GHb II system. The proband was asymptomatic although he was found to be anemic ten years ago. The hematological examination revealed microcytosis, hypochromia and slight reticulocytosis (3.7%). Serum iron level was high (245 g/dl). Blood smear revealed aniso-poikilocytosis with scattered target cells. Hb analysis showed a remarkable increase of HbA2 (8.6%) as well as the high HbF cited above, but no abnormal Hb was detected. The beta/alpha ratio of globin biosynthesis in reticulocytes was decreased to 0.25. DNA sequencing of the beta-globin gene disclosed that the proband was homozygous for beta (+)-thalassemia mutation-31CapA-->G. This mutation was linked to A gamma T gene and haplotype -(-)+2(-)+2-. His parents and two daughters were heterozygous for the mutation. They were anemic and had increased HbA2 levels of 4.36-5.43%. The beta/alpha ratios of globin biosynthesis were 0.61-0.81.

[Establishment of a reference interval for highly sensitive CRP by exclusion of individuals with abnormal values in related laboratory tests].

In November, 1999, U.S. Food and Drug Administration approved a highly sensitive CRP(hs-CRP) assay that could assist medical doctors to predict the risk of cardiovascular accidents. Many doctors are now interested in the assay and trying to elucidate the relationship between serum CRP levels and cardiovascular diseases. In the past, it was difficult to establish a valid reference interval of serum CRP because of the poor analytical sensitivity and difficulty in sampling reference individuals. We have established a reference interval of serum CRP for the hs-CRP assay(Dade Behring). The study population consisted of 7,224 individuals(21-81 years old) who received a regular medical check-up. Potentially abnormal samples were excluded, depending on the results of other laboratory tests related to serum CRP variation. The upper limit of the reference interval was 0.15 mg/dl. The serum CRP was higher in smokers than in non-smokers, especially in men.

Parameter optimization technique using the response surface methodology.

We propose a parameter optimization technique using the response surface methodology (RSM) for the accurate biological cell simulation which calculates cell behavior by numerically integrating the differential equation and generates action potentials, intracellular Ca transient, contraction, and intracellular ATP consumption by using parameter values of major ion permeability and amplitude of Ko dependency. Since most of these parameters cannot be directly measured by experiment, these are searched for by applying an optimization technique, that is, by minimizing an objective function defined as a difference between a measured and a calculated waveform of action potentials in a cardiac myocyte. We employ the RSM as the optimization technique. In the RSM, a quadratic polynomial is used in general, and a mathematical technique is used to calculate the extreme points. Because our parameter space cannot be approximated by a single quadratic polynomial surface, we adopt a recursive subdivision technique and use the coefficient of multiple determination to representing a response surface in each subspace for a criteria of the subdivision. We confirmed the effectiveness of the proposed technique by searching for parameters which are determined in advance.

Severe pulmonary vascular disease consisting of ventricular septal defect and patent ductus arteriosus. A case diagnosed as the indication for total correction by the hemodynamic study.

A 12-year-old girl with ventricular septal defect, patent ductus arteriosus and pulmonary hypertension was hemodynamically diagnosed as the indication for total correction by the initial cardiac catheterization. However, histologic assessment by lung biopsy revealed the terminal stage of plexogenic pulmonary arteriopathy, i.e. plexiform lesions, dilatation lesions and fibrinoid necrosis of the media which denied the possibility of corrective surgery. We would like to stress that the open lung biopsy should be performed when the hemodynamic study indicates marginal operability, especially in older children and adults in order to investigate the grade of occlusive pulmonary vascular disease.