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Biomedical subjects

T Wakasugi

Publications and source records attributed to T Wakasugi.

70 records · Page 4Linked to original sources

Causes of death in patients with familial hypercholesterolemia.

Five out of 15 homozygotes and 41 out of 527 heterozygotes of familial hypercholesterolemia (FH) died during the past 10 years. Sudden death or heart failure was the cause of death in each of the 5 deceased homozygotes. Twenty heterozygotes died of myocardial infarction, 9 of sudden death, and 1 died after AC bypass surgery. Thus, 30 heterozygotes (73.2%) died of coronary heart disease (CHD). The mean age of death was significantly younger in male heterozygotes (54 years) than in the females (68 years). Rate of death from CHD in heterozygotes was 11 times higher than in the general population in Japan. Rate of death from pancreas cancer in FH was significantly higher than in the general population. These results suggest that FH is highly associated with pancreas cancer as well as CHD.

Adolescent↗

Genes for the eight ribosomal proteins are clustered on the chloroplast genome of tobacco (Nicotiana tabacum): similarity to the S10 and spc operons of Escherichia coli.

The nucleotide sequence of a tobacco (Nicotiana tabacum) chloroplast gene cluster that encodes eight proteins homologous to Escherichia coli ribosomal proteins L23, L2, S19, L22, S3, L16, L14, and S8 has been determined. RNA gel blot hybridization revealed that all eight coding regions are expressed in the chloroplasts. The arrangement of the eight genes resembles that found in the E. coli S10 and spc operons. Among the eight genes, the L2 and L16 genes contain 666- and 1020-base-pair introns, respectively. These intron boundary sequences are consistent with the conserved boundary sequences of the chloroplast group III introns [Shinozaki, K., Deno, H., Sugita, M., Kuramitsu, S. & Sugiura, M. (1986) Mol. Gen. Genet. 202, 1-5].

Amino Acid Sequence↗

ApoVLDL of the Watanabe Heritable Hyperlipidemic rabbit and the cholesterol-fed rabbit.

The Watanabe Heritable Hyperlipidemic rabbit (WHHL rabbit) and the cholesterol-fed rabbit have been reported to show elevations of very low density (VLDL), intermediate density (IDL), and low density lipoproteins (LDL), and a broad-beta band on agarose-gel electrophoresis. We have studied the lipid and lipoprotein composition of WHHL rabbits and cholesterol-fed rabbits using ultracentrifugal analysis and isoelectric focusing. The total cholesterol (TC)/triglyceride (TG) ratios of VLDL, IDL, and LDL in WHHL rabbits were slightly elevated, but almost normal compared with those of cholesterol-fed rabbits, whose TC/TG ratios were markedly elevated compared with normolipidemic rabbits. ApoVLDL of WHHL rabbits showed no compositional changes in apoE and apoC isoforms, and no marked changes in the apoE/apoC ratios. But apoVLDL of cholesterol-fed rabbits showed a significant decrease of apoC-III, a significant increase of apoC-V, and marked elevation of the apoE/apoC ratio. We conclude that serum lipoprotein compositions in the WHHL rabbit were normal, while the lipoprotein lipid and apolipoprotein composition in the WHHL rabbit are different from those in cholesterol-fed rabbits.

Animals↗

Reduction of serum cholesterol in heterozygous patients with familial hypercholesterolemia. Additive effects of compactin and cholestyramine.

We studied the effects of the bile acid sequestrant cholestyramine, alone and in combination with the experimental agent compactin (ML-236B), a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, on serum levels of lipoproteins in 10 heterozygous patients with familial hypercholesterolemia. After cholestyramine treatment alone for 2 to 16 months, serum total and low-density lipoprotein cholesterol decreased by 20 and 28 per cent, respectively. With the addition of compactin for 12 weeks there was a 39 per cent total decrease in serum cholesterol from the control value--from 356 +/- 14 to 217 +/- 10 mg per deciliter (9.27 +/- 0.36 to 5.64 +/- 0.26 mmol per liter [mean +/- S.E.M.]; P less than 0.001)--and a 53 per cent decrease in low-density lipoprotein cholesterol--from 263 +/- 13 to 125 +/- 10 mg per deciliter (6.84 +/- 0.34 to 3.25 +/- 0.26 mmol per liter; P less than 0.001). High-density lipoprotein cholesterol, which had increased during cholestyramine treatment, remained at its higher level. No adverse effects were observed. If long-term safety can be demonstrated, the compactin-cholestyramine regimen may prove useful in heterozygous familial hypercholesterolemia. prove useful in heterozygous familial hypercholesterolemia.

Adult↗

Effects of an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase on serum lipoproteins and ubiquinone-10-levels in patients with familial hypercholesterolemia.

We studied the effects of ML-236B, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, on serum levels of lipoproteins and ubiquinone-10-in seven heterozygous patients with familial hypercholesterolemia. ML-236B was given at doses of 30 to 60 mg per day for 24 weeks. Serum cholesterol decreased from 390 +/- 9 to 303 +/- 8 mg per deciliter (101 +/- 0.2 to 7.88 +/- 0.2 mmol per liter, mean +/- S.E.M.; p less than 0.001) and serum triglyceride decreased from 137 +/- 18 to 87 +/- 9 mg per deciliter (1.55 +/- 0.20 to 0.98 +/- 0.01 mmol per liter; p less than 0.05). Intermediate-density-lipoprotein (DL) cholesterol, IDL triglyceride, low-density-lipoprotein (LDL) cholesterol, and LDL triglyceride decreased significantly (p less than 0.01, P less than 0.001, and P less than 0.001, respectively). However, there were no significant changes in very-low-density-lipoprotein (VLDL) cholesterol and triglyceride or high-density-lipoprotein (HDL) cholesterol. Serum ubiquinone-10 levels did not change, and LDL levels of ubiquinone-10 decreased by 50 per cent, from 0.39 +/- 0.07 to 0.20 +/- 0.01 microgram per milliliter (P less than 0.05). No adverse effects were observed. We conclude that ML-236B is effective in lowering serum cholesterol without lowering serum ubiquinone-10 in heterozygous patients with familial hypercholesterolemia.

Adult↗

Effects of ML-236b (compactin) on sterol synthesis and low density lipoprotein receptor activities in fibroblasts of patients with homozygous familial hypercholesterolemia.

We studied biochemical genetics of low density lipoprotein (LDL) receptor mutations in fibroblasts from six homozygous and five heterozygous patients with familial hypercholesterolemia (FH). Three of six homozygotes are receptor-negative type and the other three homozygotes are receptor-defective type. In the cells from three receptor-negative homozygotes, the receptor binding, internalization, and degradation of (125)I-LDL were 0.5+/-0.3 ng/mg protein (mean+/-SEM), 14+/-8 and 8+/-6 ng/mg protein per 6 h (four normal cells; 44+/-3, 386+/-32, and 1,335+/-214 ng/mg protein per 6 h), respectively. In the cells from three receptor-defective homozygotes, the receptor binding, internalization, and degradation of (125)I-LDL were 6+/-2, 29+/-8, and 90+/-32 ng/mg protein per 6 h, respectively. In these six homozygotes, two pairs of siblings are included. Two siblings in the same family were classified as receptor-negative and two siblings in another family were classified as receptor-defective. The receptor-negative phenotypes and the receptor-defective phenotypes bred true in individual families. The cells from five heterozygotes showed approximately 46% of the normal activities of receptor.ML-236B, competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase), completely inhibited the incorporation of [(14)C]acetate into digitonin-precipitable sterols in fibroblasts from normal subjects and heterozygous and homozygous patients with FH with the concentration of 0.5 mug/ml. However, at 0.05 mug/ml of ML-236B sterol synthesis in fibroblasts from homozygotes was not completely suppressed in contrast to normal and heterozygous cells. Moreover, after preincubation with 0.05 mug/ml of ML-236B for 24 h in medium containing lipoproteins, sterol synthesis in the cells from receptor-negative homozygote showed 75% of the initial activity compared with that of 25% without preincubation. In the cells from a normal subject and a heterozygote, sterol synthesis was inhibited even after preincubation. These results suggest that (a) the inhibitory effect of ML-236B is overcome in homozygote cells by their high intracellular levels of HMG-CoA reductase and (b) that a higher dose of ML-236B may be required to lower serum cholesterol levels in FH homozygotes than in heterozygotes.

Anticholesteremic Agents↗

Comparative analysis of RNA editing sites in higher plant chloroplasts.

Transcripts of land plant chloroplast genomes undergo C-to-U RNA editing. Systematic search disclosed 31 editing sites in tobacco, 27 in maize, and 21 in rice. Based on these identified sites, potential editing sites have been predicted in the transcripts from four angiosperm chloroplast genomes which have been completely sequenced. Most RNA editing events occur in internal codons, which result in amino-acid substitutions. The initiation codon AUG was found to be created from ACG by RNA editing in the transcripts from rpl2, psbL, and ndhD genes. Comparison of editing patterns raises a possibility that many editing sites were acquired in the evolution of angiosperms.

Binding Sites↗

Serum lipids, lipoprotein lipids and coronary heart disease in patients with xanthelasma palpebrarum.

Serum lipids and lipoprotein lipids were studied in 53 patients (21 males and 32 females) with xanthelasma palpebrarum and 40 age-matched normal controls (20 males and 20 females). Patients were subdivided into patients with normolipidemia, hyperlipidemia or familial hypercholesterolemia (FH). In both male and female patients with hyperlipidemia or FH, the serum cholesterol (Chol) levels were significantly higher than in normal controls. In both male and female patients with normolipidemia or hyperlipidemia, the VLDL-Chol levels were significantly higher than in normal controls. Male patients with FH showed significantly higher levels of VLDL-Chol than normal controls. Both male and female patients with normolipidemia, hyperlipidemia or FH showed significantly higher levels of LDL-Chol, lower HDL-Chol levels and lower HDL-Chol/LDL-Chol ratios than normal controls. In both male and female patients with hyperlipidemia and in male patients with FH, the serum triglyceride (TG) levels were significantly higher than in normal controls. Both male and female hyperlipidemic patients showed significantly higher levels of VLDL-TG than normal controls. In male patients with FH, the VLDL-TG levels were significantly above the control levels. In male patients with normolipidermia, the LDL-TG levels were significantly higher than in normal controls. In both male and female patients with hyperlipidemia or FH, the LDL-TG levels were significantly higher than in normal controls. The HDL-TG levels in patients with normolipidemia (males) or FH (females) were significantly lower than in normal controls. The prevalence of coronary heart disease in patients with normolipidemia, hyperlipidemia or FH was 29.4%, 24.0% and 45.4%, respectively.

Adult↗

New variant of low density lipoprotein receptor gene. FH-Tonami.

A new variant of the low density lipoprotein receptor (LDLR) gene was ascertained through Southern blotting analysis of LDLR genes of 35 unrelated Japanese patients with heterozygous familial hypercholesterolemia (FH). This mutant gene had a 6 kilobase deletion which had eliminated only exon 15, an exon that encodes the O-linked sugar domain. The mutation was recognized in two patients with heterozygous FH. We refer to these patients as 'FH-Tonami', since they were both born in the Japanese district of Tonami. Although there is no evidence of a relation between families, the possibility of a common ancestor with FH does exist. Neonatal diagnosis of FH in two fetuses from one family was possible through analyses of their LDLR genes in cord blood samples at delivery.

Genes↗

An asymptomatic, normotensive sipple syndrome patient with glucose intolerance and hypercholesterolemia, and her kindred.

The proband, a 42-year-old woman without any symptoms or hypertension, was admitted for examination of accidentally discovered bilateral adrenal masses. Physical examination disclosed bilateral nodular goiter and mild sinus tachycardia. Pheochromocytomas and medullary thyroid carcinomas were revealed by biochemical and histopathological examinations. Hypercholesterolemia and abnormal glucose metabolism returned to normal after bilateral total adrenalectomy and thyroidectomy. Screening examination showed four affected family members. Three of them were also asymptomatic and normotensive. In pheochromocytoma patients, normotension, hypercholesterolemia, and impaired glucose metabolism might be signs of excess secretion of epinephrine rather than norepinephrine.

Adrenal Gland Neoplasms↗

A study of the clinical significance of lipoprotein (a) in nephrotic syndrome.

Lipoprotein (Lp)(a) concentrations were measured in eight patients with nephrotic syndrome in the age range of 8 to 69 yrs. Mean (+/- SE) levels of serum Lp(a) were elevated in the nephrotic patients compared to controls (76.5 +/- 19.7 vs 18.6 +/- 0.9 mg/dl, p less than 0.001). After treatment with prednisolone, Lp(a) concentrations were decreased from 85.2 +/- 21.6 to 42.2 +/- 14.0 mg/dl. During the treatment, serum total cholesterol showed a negative correlation with serum albumin concentration. However, no correlation was noted between Lp(a) and serum albumin concentration. There were no significant correlations between Lp(a) and other lipoprotein lipid and apolipoprotein levels. It was concluded that hyperLp(a)aemia may be an independent risk factor in the development of premature atherosclerosis in patients with nephrotic syndrome.

Adolescent↗