The Formation of 2,6-Dihydroxy-phenylacetic Acid from Phenylacetic Acid by Various Fungi

Two principal toxins of diarrhetic shellfish poisoning, okadaic acid and dinophysistoxin-1, were esterified with 9-anthryldiazomethane in methanol. After cleaning with a Sep-pak silica cartridge column, the fluorescent esters were analyzed on a Develosil ODS column with MeCN- MeOH-H₂0 (8:1:1). The fluorescence intensities of both toxin derivatives measured at an excitation of 365 nm and an emission of 412 nm showed good linearity in the range 1 ~ 80ng.     

Simultaneous determination of residual veterinary drugs in bovine, porcine, and chicken muscle using liquid chromatography coupled with electrospray ionization tandem mass spectrometry

A simple and rapid method using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC/MS/MS) for the simultaneous determination of 130 veterinary drugs and their metabolites in bovine, porcine, and chicken muscle was developed. The drugs (1 to 10 ng/g, in muscle) were extracted from bovine, porcine, or chicken muscles with acetonitrile-methanol (95:5, v/v), and the extracts were delipidated with n-hexane saturated with acetonitrile. The extracts were evaporated, dissolved with methanol, analyzed by liquid chromatography with gradient elution on a C18 column, and determined by electrospray ionization tandem mass spectrometry. The detection limits ranged from 0.03 to 3 ng/g. The quantitation limits ranged from 0.1 to 10 ng/g. One hundred eleven, 122, and 123 drugs from bovine, porcine, and chicken muscle respectively showed recoveries between 70 and 110%.     

Effect of exercise on iron metabolism in horses

We investigated the effect of exercise on iron metabolism in horses. Four horses were walked on a mechanical walker for 1 wk (pre-exercise). They then performed moderate exercise on a high-speed treadmill in the first week of the exercise and relative high in the second week and high in the third week. Serum iron was significantly lower in the third week of exercise than in the pre-exercise. Transferrin saturation (TS) was significantly lower in the first and third weeks of exercise than in the pre-exercise. Serum haptoglobin was significantly lower in the first week of exercise than in the pre-exercise and further significantly lower in the second and third weeks than in the first. The packed cell volume did not change during the experiment. The exercise significantly increased the apparent absorption of iron. Urinary iron excretion did not change throughout the experiment. Sweat iron loss did not change during the exercise. The exercise significantly increased iron balance. We considered that hemolysis is induced by moderate exercise and is further enhanced by heavy exercise, which decreases serum iron and TS. However, the increase in iron absorption compensates for the adverse effect of exercise on iron status. Therefore, exercise does not induce anemia in horses.     

Alteration of renal adrenomedullin and its receptor system in the severely hypertensive rat: effect of diuretic

OBJECTIVE: We investigated the pathophysiological role of the renal adrenomedullin (AM) system, including the ligand, receptor, and amidating activity, in severe hypertensive rats. METHOD: We studied three groups: control Wistar Kyoto rats (WKY), spontaneously hypertensive stroke-prone rats (SHR-SP), and diuretic-treated SHR-SP. We measured AM-mature, active form, and AM-total (active form+inactive form) in plasma and renal tissues, and mRNA levels of AM and AM receptor system components such as calcitonin receptor-like receptor (CRLR), receptor activity-modifying protein (RAMP) 2, and RAMP3 in renal tissues. RESULTS: SHR-SP had higher blood pressure, plasma neurohumoral factors, and lower renal function than WKY. SHR-SP had higher AM-mature and AM-total levels in plasma and renal tissues than WKY. Although the plasma AM-mature/AM-total ratio was similar in the two groups, AM-mature/AM-total ratio in renal tissues was higher in SHR-SP than in WKY. In addition, mRNA levels of AM in the renal cortex and medulla and the mRNA levels of CRLR, RAMP2, and RAMP3 in the renal cortex were higher in SHR-SP than in WKY. Chronic diuretic treatment decreased blood pressure and improved kidney function and neurohumoral factors, with reductions in plasma and renal AM system. CONCLUSION: Upregulation of circulating and renal AM system may modulate pathophysiology in SHR-SP.     

Isolation and Identification of a New Analogue of Aspergillic Acid Derived from Valine and Isoleucine

The biological activities of zinc and cadmium on Euglena gracilis grown in zinc deficient and sufficient media were examined- Cadmium was neither involved in the normal cell metabolism of E. gracilis under zinc deficient conditions, nor did not replace zinc, which is essential for the normal growth. More cadmium was incorporated into cells grown in zinc deficient media than in zinc sufficient ones, resulting in more toxic effects in zinc deficient media than in zinc sufficient ones. Cadmium effectively provoked abnormal cells under zinc deficient conditions, suggesting that the normal process of cell division was interrupted by cadmium.