Simultaneous determination of amantadine, rimantadine, and memantine in processed products, chicken tissues, and eggs by liquid chromatography with tandem mass spectrometry

A simultaneous determination of amantadine, rimantadine, and memantine in processed products (deep-fried chicken, fried chicken, fried quail egg, and grilled chicken) with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. This new method was also applicable for chicken tissue (muscle, liver, and gizzard) and eggs. The chromatographic separation was performed on a Kinetex^® XB-C18 core-shell technology column using a mobile phase of acetonitrile and 0.1% formic acid in a 10mmol/L ammonium formate solution, resulting in the complete separation of isomers (rimantadine and memantine) and any other obstructive peaks from the sample matrices. Sample preparation was performed by a modified QuEChERS method using acetonitrile and a 0.1% acetic acid extraction solution and cleaned using an Oasis^® MCX cartridge. The sample matrix had no effect on the identification of the compounds. For quantification, an external solvent calibration curve was used. This new method exhibited good accuracy ranging from 79.9% to 91.5%. The relative standard deviation of repeatability (RSD_r) ranged from 1.2% to 3.6% and the relative standard deviation of within-laboratory reproducibility (RSD_WR) ranged from 1.3% to 6.0%. These standard deviations satisfied the criteria for Japanese validation guidelines. The limit of quantification (LOQ) was 1.0μg/kg for all samples. Analyte residues were not detected in 55 samples using the validated method.

[Determination of Amantadine in Poultry Tissues and Egg by LC-MS/MS]

An accurate and selective analytical method for amantadine, which is used as antiviral drug to treat influenza A virus infection, was developed using LC-MS/MS. Residual amantadine was extracted from 4 kinds of food sample (poultry muscle, liver, gizzard and egg) with acetonitrile-pH 3.0 McIlvaine buffer (7 : 3), then cleaned up with an Oasis® MCX mini-cartridge. An external standard calibration curve was used for quantification, after sample purification by the combination of a reverse-phase strong cation exchange mixed mode cartridge for cleanup and a HILIC column for HPLC. The method was validated by performing recovery tests in accordance with Japanese guidelines for the validation of analytical methods for residual agricultural chemicals in food. Recovery ranged from 79.3% to 91.7%, RSDs of repeatability were under 3.3%, and RSDs of within-laboratory reproducibility were under 8.4%. This new method was applied to samples of poultry and egg purehased in Tokyo, but residual amantadine was not detected at all.

Complementary medicine education in Japanese medical schools: a survey

OBJECTIVES

To evaluate the present state of complementary medicine (CM) education in Japanese medical schools.

DESIGN

This investigation consisted of two studies: (1) a telephone survey to curricular office workers in September 1998; and (2) a self-completed questionnaire to representatives of sponsoring departments in July 1999.

SETTINGS

All 80 medical schools for Western medicine.

MAIN OUTCOME MEASURES

Presence of a CM course and sponsoring department. Titles of courses and teaching methods.

RESULTS

The response rate to the telephone survey and self-completed questionnaire was 100 and 95%, respectively. Of 80 medical schools, CM was officially taught in 16 schools (20%). Of these 16 schools, there were 19 CM courses and the anesthesia department sponsored the most courses (six courses). All courses had oriental medicine titles such as acupuncture and Kampo except for one course.

CONCLUSION

Twenty per cent of Japanese Medical Schools taught CM with predominantly oriental medicine themes.

Seroprevalence of Bartonella henselae and Toxoplasma gondii infections among pet cats in Kanagawa and Saitama Prefectures

Seroprevalence of Bartonella henselae and Toxoplasma gondii was investigated among 471 pet cats obtained from seven private animal hospitals in Kanagawa and Saitama Prefectures during the period from May 1994 to June 1995. 'Furthermore, 67 randomly selected from the 471 serum samples were examined for the feline immunodeficiency virus (FIV) antibody and feline leukemia virus (FeLV) antigen. The antibody to B. henselae was examined by an indirect immunofluorescent antibody test. T. gondii, FIV and FeLV infections in cats were detected with respective commercial kits. Of the cat serum samples tested, 43 (9.1%) were found to be seropositive for B. henselae and 41 (8.7%) for T. gondii. The B. henselae-positive rate (12.9%) of male cats was significantly higher than that (5.2%) of female cats. On the other hand, T. gondii-positive rate was 9.1% in male and 8.7% in female cats and there was no significant difference in the positivity between sexes. The positive rate in each hospital varied from 0 to 19.5% for B. henselae and 4.9 to 18.8% for T. gondii. The ages of B. henselae- and T. gondii-positive cats were distributed from < 1-year-old to 14-year-old and the seropositivity increased with age of cats. Of the 67 cat serum samples, 16 and 6 cases were positive for FIV and FeLV, respectively. There was no relationship between these viral and B. henselae infections in cats.

[Usefulness of genotypic analysis for investigation of an epidemic of Shigella sonnei infections in Ooami-shirasato Town, Chiba Prefecture]

In March 1996, an epidemic of Shigella sonnei infection occurred in Ooamishira-sato Town, Chiba Prefecture. Colicine typing, antibiotic resistance patterns, plasmid profiles, pulsed-field gel electrophoresis (PFGE) and random amplified poly-morphic DNA (RAPD) were used for the investigation of the epidemic. Ninety-four isolates from patients exhibited three different colicine types and five different antibiotic resistance patterns. But the patterns of plasmid profile, PFGE and RAPD were uniform among the isolates with different colicine type and antibiotic resistance pattern. It is possible that these isolates belonged to a single bacterial clone and circulated through human to human.

[Disinfection of sandpit by steam and changes of bacterial flora after the disinfection]

The effect of steam on sandpit disinfection was investigated by supplying steam into sandpits covered with a sheet cover. To evaluate the effect, total number of viable bacteria, number of aerobic sporeforming bacteria, coliforms and fecal coliforms were measured four weeks before, just before, immediately after, two and four weeks after the disinfection. Disinfection of coliforms and fecal coliforms was accomplished when temperature of sand reached more than 60 degrees C. Total number of viable bacteria and number of aerobic sporeforming bacteria also reduced by disinfection with steam. However, after 2 and 4 weeks of disinfection, number of coliforms and fecal coliforms recovered to the same level before disinfection, and total viable count also restored its number. In addition, a significant increase in the number of aerobic sporeforming bacteria was noted both after 2 and 4 weeks of disinfection. These results indicate that the effect of steam disinfection in transient and can not be used for the routine method of disinfection in sandpit.

[Multicenter prospective study of retinopathy of prematurity--IV. Comparison with the data from University of Miami]

We investigated the records of 360 cases of retinopathy of prematurity (ROP) in 12 institutions in Japan (we treated the severe progressive "plus" disease by coagulation therapy), and compared them with data from University of Miami (Ophthalmology 94: 620-629, 1987), as representative of the natural course of ROP without coagulation therapy in those days. The timing of the first examination and the first positive diagnosis were later at University of Miami than in Japan. The time of maximal severity of the disease and occurrence of regression were also later the University of Miami than in Japan. In Japan, the first examination was performed at 29 weeks of postconceptional age or at 3 weeks after birth. At the University of Miami, the first examination was performed at 32 weeks of postconceptional age. If the severe progressive "plus" disease is to be properly treated by photo-coagulation or cryotherapy, it is essential to commence fundus examination earlier.

[Multicenter prospective study of retinopathy of prematurity--II. Optimum timing of the first examination]

We reviewed the records of 360 cases of retinopathy of prematurity (ROP) in 12 institutions in Japan, and investigated the optimum timing of the first examination. On the basis of the onset of ROP and the timing of the first treatment, the first ophthalmological examination should be performed 3 weeks after birth or 29 weeks of postconceptional age at the latest. Regarding the visibility of the fundus, there was little hazy media after 29 weeks of postconceptional age. Under the basic policy that the severe progressive "plus" disease should be properly treated, we concluded that the first ophthalmological examination should be performed 3 weeks after birth at the latest. When the gestational age at birth is less than 26 weeks, funduscopy at the post conceptional age of 29 weeks is advisable.

[Multicenter prospective study of retinopathy of prematurity--III. Timing of the coagulation therapy and the course of retinopathy of prematurity after coagulation]

We reviewed the records of 360 cases of retinopathy of prematurity (ROP) in 12 institutions in Japan, and investigated the timing of the coagulation therapy and the course of ROP after coagulation. The first coagulation therapy was performed at 9.6 weeks after birth and 35.9 weeks of postconceptional age on the average. The severity index in individual infants also showed that the disease became worse during the period from 32 to 36 weeks of postconceptional age. However, the fundus was clearly visible and there was no primary hazy media during this period. On the basis of the results of the timing of the first treatment, the visibility of the fundus, and the severity index in individual infants, we concluded that an ophthalmological examination with special care should be performed during the period from 32 to 36 weeks of postconceptional age.

High prevalence of thermostable direct hemolysin (TDH)-like toxin in Vibrio mimicus strains isolated from diarrhoeal patients

A total of 17 isolates of Vibrio mimicus from patients, 29 from environment and 2 from food was examined for toxigenicity. Sixteen (94%) clinical isolates and one (50%) from food produced TDH-like toxin, whereas none of the environmental isolates did so. The food from which V. mimicus with TDH-like toxin production was isolated, was one which had caused food poisoning. Only one environmental strain produced CT-like toxin, whilst ST-like toxin was not detected from any strains tested.

[Isolation of vero toxin-producing Escherichia coli (enterohemorrhagic E. coli) O111:H- from 2 cases diagnosed as appendicitis]

Vero toxin-producing E. coli O111:H- was isolated from 2 cases of patients with severe abdominal pain and bloody diarrhea and were diagnosed as appendicitis. E. coli from both cases produced both VT1 and VT2.

Bone marrow peroxidases of spontaneously hypertensive rats

The activity of peroxidases and the level of myeloperoxidase in the bone marrow of spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHR-SP) were determined in comparison with normotensive Wistar Kyoto rats (WKY). In the cetyltrimethylammonium bromide extract of bone marrow, the peroxidase activities using guaiacol or Kl as the electron donor of male and female WKY were different from those of SHR and SHR-SP. The peroxidase activity was also separately determined as myeloperoxidase and eosinophil peroxidase by the use of ion-exchange high pressure liquid chromatography. In males, SHR and SHR-SP contained a low activity of eosinophil peroxidase compared with WKY. Bone marrows of female SHR and SHR-SP contained a lower activity of myeloperoxidase, while SHR and SHR-SP possessed a higher activity of eosinophil peroxidase compared with WKY. No change of the level of myeloperoxidase in the bone marrow was observed among male animals. A significant decrease in the level of myeloperoxidase was observed in female SHR and SHR-SP. Therefore, these results indicate that the change in the activity of the peroxidases in the bone marrow is accompanied by the spontaneously hypertensive state.

Bone marrow peroxidase in mice: determination of the level and the catalytic activity

The level of myeloperoxidase and the peroxidase activity in the bone marrow were determined in the various strains of mice. The levels of myeloperoxidase, which was determined by a immunostaining coupled with sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE), were ranged from 3 to 5 micrograms per mg protein in the bone marrow of various strains of mice. No strain difference of the enzyme activity toward guaiacol was observed among mice. On the other hand, the activity toward KI of C3H/He mice was lower than C57BL/6, Balb/c and ddY mice.

Development of early lesions of microangiopathy in chronically diabetic monkeys

A chronic diabetic state was produced in Macaca fuscatus , and these diabetic monkeys were kept without insulin treatment for up to 25 mo. The metabolic derangements were characterized by hyperglycemia, insulinopenia, hyperglucagonemia, ketonemia, and hyperlipidemia. Significant thickening of the capillary basement membrane of the gastrocnemius muscle was observed in the chronically diabetic monkeys, and became obvious in the course of diabetic state; 732 +/- 35 A in controls, 750 +/- 58 A in diabetic monkeys with duration of 4 mo, and 1165 +/- 112 A in those with duration of more than 11 mo. In addition to duration of the diabetic state, severity of hyperglycemia is also thought to play an important role in the capillary basement membrane thickening judging from the fact that diabetic monkeys with constant hyperglycemia showed a greater membrane thickening. Ultrastructural alterations, such as significant thickening of glomerular basement membrane and increase of mesangial matrix, were observed in kidney as well. These results indicate that diabetic microangiopathy has been produced by metabolic derangements characterized by chronic hyperglycemia, insulinopenia, and hyperlipidemia.