Dr. Murai Éva szerk.: Parasitologia Hungarica 13. (Budapest, 1980)

Amylase: British Drug House (BDH) amylase, derived from bovine pancreas. Diastase: BDH. Examinations for adsorption of mammalian amylase were carried out on intact larvae incubated in a fivefold volume of maintenance medium relative to their body weight, under the foUowing scheme of experiment: I. Determination of oC-amylase activity in the maintenance medium of the L. intestinalis larvae 1. Controls: KRT, pH 7.2, containing 400 IU/ml penicillin and 0.25 mg/ml streptomycin, incubated under the same conditions as the test materials. 2. Specimens incubated in KRT (with antibiotics) for 60 min, and in fresh KRT for another 60 min. at 38°C. 3. Specimens incubated in 2.5% starch-containing KRT for 15, 60, 120 and 180 min. at 38°C. II. Effect of live stages on pancreatic OC-amylase activity. 1. Amylase control: 10 jjg/ml cC-amylase in KRT, incubated under the same conditions as the test material. 2. Larva control: L. intestinalis larvae incubated in KRT for 30 min. at 38°C. 3. Larvae incubated in 10 ug/ml oC-amylase containing KRT for 30 min. at 38 C. 4. Larvae preincubated in similar manner, but were washed after preincubation for 20 min. at 5°C. 5. Larvae incubated in 10 ug/ml ot-amylase containing KRT for 30 min. at 38 C, and washed after incubation in three changes of KRT at 38°C, for 60 min. on each occasion. 6. Stages incubated in 1% starch containing KRT for 30 min. at 38 C. 7. Larvae incubated in 1% starch +1 mg/ml OC-amylase containing KRT for 30 min. at 38°C. 8. Stages preincubated in lOjjg/ml diastase or amylase containing KRT for 30 min. at 38°C, washed in KRT for 10 minutes at 38°C, and incubated in 1% starch containing KRT for 60 min. at 38°C. 9. Stages preincubated in lOjig/ml diastase or amylase containing KRT for 30 min. at 5°C, washed in KRT for 10 min. at 38°C, and incubated in 1% starch containing KRT for 60 min. at 88°C. 10. Stages after single washing preincubated in 10 mg/ml diastase containing KRT for 15 min. Further treatment corresponds with the 8-9 groups. Extracts were prepared by homogenation of washed stages in five volumes of distilled water, and subsequent centrifugation of the homogenate at 19 000 g for 60 min. at +5°C. The supernatant was used for further study. The oC-amylase activity was measured by the dinitrosalycilic acid test (UJIHARA et al. , 1965), or by the iodine test (TAYLOR and THOMAS, 1968). Unit activity was defined for the first method as the quantity of amylase causing increase of the extinction measured at 546 mm by 1-000 OD units, for the second method as the quantity causing decrease of extinction at 690 by 1.000 OD units. All determinations were carried out in duplicate or triplicate. To determine hydrolysis in the KRT+10 mg/ml starch incubation systems, we modified the method of UJIHARA et al. as follows: 1 ml medium and 1 ml 3. 5 dinitrosalycilic acid reagent were mixed and boiled for 5 min. , diluted in 10 ml distilled water, and examined for extinction at 546 nm. The variation coefficients of the dinitrosalycilic acid and iodine tests were assessed as 5 and 11%, respectively, from 20 replica measurements with each. The brush-border of the tegument was detached as proposed by OAKS, KNOWLES and CAIN (1977). Ultrasonic treatment was performed with a MSE generator at 1. 5 A for 2x3 min. The differences between the mean values obtained in the experimental and control series were analysed for significance with Student's t-test.