We have identified a non-insulin-dependent diabetic patient with fasting hyperinsulinemia (90 ,uU/ml), an elevated insulin:C-peptide molar ratio (1.68; normal, 0.05-0.20

Two recombinant mutants of porcine kidney D-amino acid oxidase [EC 1.4.3.3, DAO], in which Tyr(228) and His(307) are replaced with Phe and Leu, respectively, have been expressed in Escherichia coli and purified to apparent homogeneity. The molecular size and amino-terminal sequence of the two mutants were the same as those of the native DAO. Kinetic analysis revealed that the Michaelis constants of the Phe-228 and Leu-307 mutants for D-alanine were 71- and 10-fold and the inhibition constants for benzoate, a potent competitive inhibitor, were 1,189- and 18-fold greater than those of the native DAO, respectively. The maximum velocities of the Phe-228 and Leu-307 mutants were 66 and 58% that of the native DAO. The kinetically estimated dissociation constant of the Leu-307 mutant for FAD was 28-fold greater than that of the native DAO, whereas the value of the Phe-228 mutant was comparable to that of the native DAO. The Leu-307 mutant and the recombinant wild-type DAO were inactivated by D-propargylglycine (D-PG), a suicide substrate. However, the Phe-228 mutant was resistant to the inactivation. Absorption peaks of the Phe-228 mutant were blue-shifted about 10 nm from the corresponding peaks of the wild-type DAO, and the oxidized form was fully reduced by D-alanine without appearance of the purple intermediate.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of simvastatin on the lipid profile of hemodialysis patients.hibit dyslipidemia, which is thought to be one of the Background. Simvastatin, a 3-hydroxy 3-methylglutaryl co-

Rat gene for renin-binding protein (RnBP) was shown to be expressed in the kidney, adrenal gland, brain, lung, spleen, ovary, testis, and heart. On sodium depletion and captopril administration, the rat showed a marked increase in the adrenal RnBP mRNA level and a slight decrease in the kidney RnBP mRNA level. In two-kidney, one clip hypertensive rats, the RnBP mRNA levels of the clipped and contralateral kidneys were unchanged and also its adrenal mRNA level was maintained at the control level. The recombinant rat RnBP was synthesized in Escherichia coli cells and purified to apparent homogeneity. The RnBP existed as a homodimer and formed a heterodimer with rat renin to inhibit renin activity extensively. Intravenous injection of the RnBP into rats resulted in a rapid and strong inhibition of plasma renin activity, which persisted at least for 2 h. These results suggest that the expression of RnBP gene in the kidney and adrenal gland is regulated independently, and the function of RnBP is related to electrolyte homeostasis, probably through the interaction with renin.

One of the side effects by interferon ribavirin (I/R) treatment is haemolytic anemia, causing some patients to discontinue I/R treatment. The exact mechanism of I/R-induced anemia is unknown. The aim of this study is to evaluate the effects of I/R treatment on the serum lipid and red blood cell (RBC) membrane lipid profiles of patients with chronic hepatitis C (CHC) and the association between changes of RBC membrane lipids and haemolytic anemia by I/R treatment. Fourteen patients with CHC were treated with I/R and their serum lipid profiles were studied. In addition, in seven of the 14 patients, the RBC membrane lipid profiles were analysed. In the RBC membrane lipid composition, the total cholesterol, total phospholipids and cholesterol/phospholipids (C/PL) ratio were significantly increased. Phosphatidylcholine (PC) and the phosphatidylcholine/ sphingomyelin (PC/SM) ratio were significantly decreased and other phospholipid fractions were significantly increased. Changes in the serum lipids and RBC membrane lipid profiles of patients with CHC treated with I/R were shown. Especially, a decrease in the RBC deformability and membrane fluidity by changes in these RBC membrane lipids was supposed and it is suggested that those changes may result in haemolytic anemia by I/R treatment.

Local hyperthermia is one of the heat therapies for cancer patients. The effect of this therapy is recognized to affect the immune function. On the other hand, researchers have recently suggested that vitamin E has not only antioxidant but also other functions including the immune function. However, the association between local hyperthermia therapy and vitamin E level is not yet well understood. Comparing plasma alpha and gamma tocopherol levels before and after the therapy, the basal levels of both tocopherols in the cancer patients did not significantly differ from those in healthy subjects. However, the interindividual difference in the basal levels was very wide in the cancer patients. After long-term local hyperthermia (more than 70 days), the levels of both tocopherols were significantly higher than the basal levels. This result suggests that long-term local hyperthermia therapy influences plasma tocopherol level in cancer patients; thus, an increase in vitamin E level may play an important role in the therapy of cancer patients.

Very little information is available related to possible differences in immunological character istics of IDDM among Asian populations, though it has been reported that IDDM is associated with Bw54-DR4 and B17-DR3 in Japanese and Chinese, respectively. There is virtually no report related to comparative studies on Bf-DM association among Asian populations, while Bf-DM association is reported to be stronger than HLA-DM association in Caucasians. In the present paper, the results of our studies on anti-thyroid antibodies (ATA) of IDDM in Japanese, Chinese and Filipinos are presented. In Japanese, the incidence of ATA positive was higher in IDDM with a duration of less than one year (35.7%) than that in the patients with a duration of one year or more (12.5%). But, there was no such a duration depen dent decrease in the incidences of ATA among Chinese or Filipino IDDM. The frequency of BfSS in Filipinos is lower than in Japanese or Chinese. However, no association was found between Bf phenotypes and IDDM in Asian populations. These results indicate that autoimmunity is transient in Japanese IDDM, but persistent in Chinese and Filipinos, and that it is too early to postulate in general that Bf-IDDM association in general populations is stronger than HLA-IDDM association.IDDM, HLA, immunological characteristics.

We describe a family from Japan displaying the mutant insulin syndrome with hyperinsulinaemia and an increased insulin:C-peptide molar ratio. Serum insulin isolated from several family members showed reduced in vitro biological activity, and analysis by high performance liquid chromatography revealed a peak co-eluting with human insulin and a second species of increased hydrophobicity co-migrating with the previously reported Insulin Wakayama. The insulin genes from the propositus were cloned and sequenced, revealing one normal allele; the second allele, encoding a leucine for valine amino acid substitution at position 3 of the insulin A chain, was similar to that previously described for Insulin Wakayama. Synthesized [Leu A3] insulin showed 0.14% of receptor binding activity on rat adipocytes and a 10-fold prolonged half-life in a somatostatin-infused dog compared with human insulin. The finding of the same mutant gene in two unrelated Japanese families suggests that Insulin Wakayama may be discovered in additional Japanese families with hyperinsulinaemia and/or diabetes.