五种新化合物对亚洲玉米螟幼虫生长发育和消化生理的影响(英文)

研究了五个新化合物对亚洲玉米螟 (Ostriniafurnacalis)五龄幼虫的拒食活性以及对其生长发育和中肠蛋白酶活性的影响 ,并与川楝素的作用效果进行了比较。结果表明 ,川楝素以及C19、C2 3 、C2 4、C2 6、C2 8在 5 0 0mg kg浓度下拒食活性分别为 5 1 16 %、5 7 6 1%、4 2 8%、5 1 0 8%、36 73%、5 1 6 7% ,其中C19、C2 4、C2 8拒食活性与川楝素相当。在 2 0mg kg浓度 ,生长发育实验表明C19、C2 6、C2 8具有较好的抑制幼虫生长作用 ,其中C2 8的作用与川楝素相当 ;药剂对中肠蛋白酶的影响结果表明 ,川楝素和C2 8对弱碱性类胰蛋白酶、类胰凝乳蛋白酶表现为激活作用 ,C19、C2 4、C2 6对两种蛋白酶在 2 4h激活 ,4 8h抑制。对相关作用机理进行了探讨。     

克罗烷二萜的昆虫拒食活性及构效关系研究

以饲料柱称重法测定25个克罗烷二萜新化合物对亚洲玉米螟Ostrinia furnacalis(Guenee)5龄幼虫的拒食活性,并进行构效关系分析。结果表明：立体效应对拒食活性意义 重大;C₉边链、C₁₈位的酯基对活性具有一定影响;C_{4处的螺环氧结构看来并非活性所必需。且在25μg/mL时选择法测定中,活性最高的化合物拒食率为57.9%,而500/μg/mL时非选择法测定中拒食率为43.2%。}     

THE RELATIONSHIP BETWEEN INSECT GROWTH REGULATORS WITH JUVENILE HORMONE ACTIVITY AND INSECT FEEDING BEHAVIOURAL RESPONSE

Abstract  Five insect growth regulators (IGRs) with juvenile hormone (JH) activity including fenoxy-carb, methoprene, NC-170, NC-184 and NC-196 were selected to study on the relationship between IGRs and feeding behaviour of the fourth instar larvae of Calospilos suspecta (Warren) and the fifth instar larvae of Ostrinia furnacalis Guenee, by topical and dietary applications as well as "diet column" methods. The results indicated that the antifeeding indices of methoprene, fenoxycarb, NC-170, NC-184, NC-196 and toosendanin against the fifth instar larvae of Ostrinia furnacalis in no-choice test were -37. 7, 14. 6, -12. 3, 10. 9, 14. 7 and 62. 2% respectively. Methoprene could stimulate the two species of insects to feed, whereas fenoxycarb had some antifeeding activity, and the effects of all the tested chemicals were different. Therefore, disturbances of IGRs with JH activity on insect feeding behavioural response may be one of the mechanisms of action not to be ignored. Moreover, by comparing "diet column" method with "faeces weight" method, it was suggested that the two methods might be applied in bioassay of antifeeding behaviour.     

THE BIOLOGICAL ACT'IVITIES OF YELLOW AZALEA,RHODODENDRON MOLLE G. DON AGAINST THE VEGETABLE LEAFMINER,LIRIOMYZA SATIVAE (DIPTERA: AGROMYZIDAE) *

Abstract The results of laboratory and greenhouse bioassays indicated that Rhodojaponin‐ III (Abbr. R‐ 1) and extracts of flowers from Rhododendron molle G. Don possessed signficant feeding inhibition and insectcidal properties against the larvae and adults of Liromyzia sativae. Treated with 500 mg/L R‐ III 1 000 mg/L molosul‐tap, and 10 000 mg/L methanol(MeOH) ethyl acetate (EtOAc), CH₂Cl₂, methanol‐water (MeOH‐H₂O) extracts the rates of feeding inhibition were 77. 34 % 74.30 % 82.15 % 77.50 % 67. 33 % 62.85 % against the 2nd instar larvae, and were 67.66% 55.21 % 49.72% 54.26% 46.81 % 38.53% against the 3rd instar larvae, respectively;LC₅₀ values against the 2nd instar larvae were 208.65, 166.05, 2.74 ± 10³,766.72, 5.95 ± 10³, 1.85 ± 10³mg/L, and against 3rd larvae were 300.62, 256.00, 4.33 ±10³, 1.03 ± 10³,9.79 ± 10³, and 2.62± 10³mg/L, respectively. Against the adults, LC₅₀ values of R‐III EtOAc extract and molosultap were 159.07.723.87 and 134.55mgL respectively after treatment for 24 h.     

CHANGES OF FATTY ACIDS IN LARVAE OF THE WHEAT BLOSSOM MIDGE,SITODIPLOSIS MOSELLANA (GEHIN) (DIPTERA: CECIDOMYIIDAE)*

Abstract The changes of fatty acids in larvae of the wheat blossom midge, Sitodiplosis mosellana (Gehin) at different periods were examined by gas choromatography. There were 10–16 kinds of fatty acids, of which the predominant ingredients were palmitic (C_16:0), oleic (C_18:1) and linoleic (C_18:2) acids which were more than 95% in total fatty acids, stearic acid (C_18:0) about 2%‐3.5% and any of the others was less than 1%. The fatty acid compositions increased from mid‐May, when larvae of the wheat blossom midge left the wheat‐ears and fallen on the ground, to April of next year before pupating and emerging. No arachidic acid (C_20.0) was discovered in over‐summering, over‐wintering as well as inactive over‐wintered larvae. The content of saturated fatty acids in over‐summering, overwintering as well as inactive over‐wintered larvae were less than those of in active over‐wintered larvae and wheat‐ear larvae. Therefore, changes of the arachidic acid and the proportions of saturated fatty acids/unsaturated fatty acids could be used as one of the biochemical criteria to determine the active state and the degree of diapause in larvae of the wheat blossom midge.     

A Comparison of Growth Inhibition of Tetrahymena furgasoni by C19 and C21 Steroids

The growth inhibition of Tetrahymena furgasoni (once known as “T. pyriformis W”) by C₁₉ and C₂₁ steroids of similar structure was measured by determining cell population at 24 h and 48 h following addition of the steroid. A cis-fusion of the A/B rings junction, unsaturation at C-1,2, or C-4,5 and carbonyl substitution all enhanced inhibition, whereas the presence of two hydroxyl groups decreased inhibition. The results indicated that the transformation of C₁₉ and C₂₁ steroids by this protozoon may be part of a detoxication mechanism.     

EFFECTS OF CYASTERONE ON GROWTH AND DEVELOPMENT OF DIAMONDBACK MOTH,PLUTELLA XYLOSTELLA (L.)*

Abstract Cyasterone is the main phytoecdysteroid component from cultured plants of Ajuga nipponensis, and common in other Ajuga species. Results showed that when treated with 50 mg/L cyasterone, the egg hatching of diamondback moth was retarded. The total percentage of eggs hatched in treatment was 94.7%, significantly less than that in control, which was 100%. Low toxicity and good antifeeding activity to the 3rd instar larvae were exhibited, which are dependent upon concentration. The growth and development of diamondback moth were affected by cyasterone. It was found that, at concentrations higher than 50 mg/L cyasterone, the larval growth and egg production were inhibited; while promoted at lower concentrations. This dual role of cyasterone might be attributed to its hormonal activity and antifeeding activity, which resulted in poor nutrition. The pupation and eclosion were hindered by treatment of larvae. This insect species was more susceptible to cyasterone than 20‐hydroxyecdysone.     

EFFECTS OF LOWERING TEMPERATURE DURING CULTURE ON THE PRODUCTION OF POLYUNSATURATED FATTY ACIDS IN THE MARINE DIATOM PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE)1

The composition of fatty acids and contents of eicosapentaenoic acid (EPA) and polyunsaturated fatty acids (PUFAs) of the economically important marine diatom, Phaeodactylum tricornutum (Bohlin), were investigated to see whether reducing the culture temperature enhances the production of EPA and PUFAs. The contents of EPA and PUFAs of P. tricornutum were found to be higher at lower temperature when cultured at 10, 15, 20, or 25°C. When the cells grown at 25°C were shifted to 20, 15, or 10°C, the contents per dry mass of PUFAs and EPA increased to the maximal values in 48, 24, and 12 h, respectively. The highest yields of PUFAs and EPA per unit dry mass (per unit volume of culture) were 4.9% and 2.6% (12.4 and 6.6 mg·L^?1), respectively, when temperature was shifted from 25 to 10°C for 12 h, both being raised by 120% compared with the control. The representative fatty acids in the total fatty acids, when temperature was lowered from 25 to 10°C, decreased proportionally by about 30% in C_16:0 and 20% in C_16:1(n?7) but increased about 85% in EPA. It was concluded that lowering culture temperature of P. tricornutum could significantly raise the yields of EPA and PUFAs.     

Contact and residual toxicities of 30 plant extracts to Colorado potato beetle larvae

Abstract

Contact and residual toxicities of 30 plant extracts were investigated on third instar larvae of Colorado potato beetle, Leptinotarsa decemlineata. The plant samples were collected during the spring and summer of 2002 and were dried and ground. The plant samples were treated with methanol and the residue was eluted with distilled water containing 10% acetone, resulting in plant extracts. In contact bioassays, the beetle larvae were treated with 40% (w/w) plant extract using a Potter Spray Tower. The insects were incubated at 28±2°C under a 16 h: 8 h photo regime and the mortality was recorded at 24 h intervals for 7 days. The plant extracts exhibited varying toxicity to the larvae ranging from 0 – 91% after 24 h incubation and Artemisia vulgaris, Hedera helix, Humulus lupulus, Lolium temulentum, Rubia tinctoria, Salvia officinalis, Sambucus nigra, Urtica dioica, Verbascum songaricum, and Xanthium strumarium extracts resulted in significantly higher mortality than the control. Generally, prolonged incubation time did not result in an increase in mortality. After 48 h of incubation, 10 plant extracts yielded a significant mortality and H. lupulus extract, the most toxic extract among those tested, caused 99% mortality which is similar the mortality caused by the chemical standard, imidacloprid. In residual assays, potato leaflets were treated with 20% (w/w) plant-extract concentrations using a Potter Spray Tower. Third instar larvae were added to a glass jar to which treated leaflets were transferred before incubation at the temperature and photo regime described above. Mortality was recorded at 24 h intervals for 7 days. Five plant extracts, H. lupulus, L. temulentum, Reseda lutea and Solanum nigrum, induced significantly higher mortalities compared with controls. Chenopodium album extract was the most toxic, killing 34.9% of exposed larvae, followed by L. temulentum, H. lupulus and S. nigrum after 72 h incubation. The results exhibited that certain plant extracts were toxic to the beetle larvae and may have potential for controlling this destructive pest under field conditions.     

Evaluation of larvicidal potential of certain insect pathogenic fungi extracts against Anopheles stephensi and Culex quinquefasciatus

Fungal metabolites are attracting attention as potential microbial insecticides, and they are anticipated to overcome the problems of pesticide resistance and environmental pollution that are associated with the indiscriminate use of conventional synthetic insecticides. The relative bioefficacies of selected fungal pathogens, Aspergillus flavus, A. niger, A. parasiticus, Fusarium sporotrichoides and Penicillium verrucosum were observed against Anopheles stephensi and Culex quinquefasciatus larvae. A. flavus demonstrated the greatest bioefficacy with 50% lethal concentration (LC₅₀) values of 9.54 and 10.98 ppm against Anopheles stephensi and Culex quinquefasciatus larvae, respectively, after 24‐h exposure. The bioefficacy of A. flavus increased in both species with an exposure time of 48 h, with LC₅₀ values of 7.26 and 8.55 ppm, respectively.     

An enzyme from Myrothecium verrucaria that degrades insect cuticles for biocontrol of Aedes aegypti mosquito

Summary Myrothecium verrucaria produced a high activity of extracellular insect cuticle degrading enzymes, chitinases, proteinases and lipases. Both first (I) instar and fourth (IV) instar larvae of a mosquito, Aedes aegypti, a vector of yellow fever and dengue, were susceptible to crude culture filtrate (100% mortality within 48 h at 170 mg/l) . The supplementation of purified M. verrucaria endo-chitinase with commercial lipase decreased the lethal time (LT₅₀) from 48 h to 24 h for I instar and 120 h to 96 h for IV instar. Our results of the larvicidal activity indicate that the cuticle degrading enzyme complex of M. verrucaria has a good potential for the control of mosquitoes.     

Photosynthetic Pathways and Life Form Types for Native Plant Species from Hulunbeier Rangelands,Inner Mongolia,North China

Photosynthetic pathway Types (C₃, C₄, and CAM) and life forms of native species from Hulunbeier rangelands, north China were studied. Of the total 258 species, 216 species in 132 genera and 42 families had C₃ photosynthetic pathway, including dominant herbs, e.g. Stipa baicalensis Roshev. and Leymus chinensis (Trin.) Tzvel., Filifolium sibiricum Kitam. and Arudinella hirta (Thunb.) Koidz. 38 species in 28 genera and 10 families were found with C₄ photosynthesis, and 4 species in 2 genera and 1 family had CAM photosynthetic pathway. The occurrence of C₄ species was common in Gramineae and Chenopodiaceae, and the two families were leading ones within C₄ plants. More than 52 % of the total 258 species were in H form, 21 % in Th form, 19 % in G form; the other life form Types, e.g. Ch, M, N, and HH, formed less than 3 %. 68 % of C₄ species were in Th form and 24 % in H form, indicating that these Types were the dominant life forms for C₄ species in the rangeland region. The occurrence of C₄ species was closely related with plant habitats, disturbed lands had the highest C₄ abundance (55 % of the total C₄ species), followed by grasslands and sandy soil, and forests had the lowest C₄ abundance (8 %). Hence the occurrence of C₄ species could be efficient indicator for rangeland dynamics in Hulunbeier rangelands.     

具保幼激素活性昆虫生长调节剂与昆虫摄食行为反应的关系(英文)

本文以烯虫酯、双氧威、ＮＣ－１７０、ＮＣ－１８４和ＮＣ－１９６等具保幼激素活性的昆虫生长调节剂（ＩＧＲｓ）为药剂,以丝绵木金星尺蠖 Ｃａｌｏｓｐｉｌｏｓ ｓｕｓｐｅｃｔａ４龄幼虫和亚洲玉米螟 Ｏｓｔｒｉｎｉａ　ｆｕｒｎａｃａｌｉｓ５龄幼虫为试材,采用点滴法和混药饲喂法,结合非选择性饲料柱称重法,研究了ＩＧＲｓ与昆虫摄食行为之间的关系。结果表明,烯虫酯、双氧威、ＮＣ－１７０、ＮＣ－１８４、ＮＣ－１９６和川楝素对亚洲玉米螟５龄幼虫的非选择性拒食率依次为－３７．７、１４．６、－１２．３、１０．９、１４．７和６２．２％,烯虫酯刺激两种试虫取食,而双氧威则有一定的拒食作用,不同药剂表现出的影响不尽一致。因此,外源具保幼激素活性的活性物质对昆虫摄食行为反应的干扰破坏,可能是ＩＧＲs作用机理中不可忽视的重要方面之一。对饲料柱称重法和虫粪称重法进行了比较,证实两种方法结果相近,趋势一致,均可用于昆虫摄食行为的生测。     

Chemotaxonomic Implications of the n‐Alkane Composition and the Nonacosan‐10‐ol Content in Picea omorika,Pinus heldreichii,and Pinus peuce

The n‐alkane composition and the nonacosan‐10‐ol content in the needle cuticular waxes of Serbian spruce (Picea omorika), Bosnian pine (Pinus heldreichii), and Macedonian pine (Pinus peuce) were compared. The amount of nonacosan‐10‐ol in the needle waxes of P. omorika was higher than those in P. heldreichii and P. peuce. The range of n‐alkanes was also wider in P. omorika (C₁₈–C₃₅) than in P. heldreichii and P. peuce (C₁₈–C₃₃). The dominant n‐alkanes were C₂₉ in the needle waxes of P. omorika, C₂₃, C₂₇, and C₂₅ in those of P. heldreichii, and C₂₉, C₂₅, C₂₇, and C₂₃ in those of P. peuce. The waxes of P. omorika contained higher amounts of n‐alkanes C₂₉, C₃₁, and C₃₃, while those of P. heldreichii and P. peuce had higher contents of n‐alkanes C₂₁, C₂₂, C₂₃, C₂₄, and C₂₆. The principal component analysis of the contents of nine n‐alkanes showed a clear separation of the Serbian spruce populations from those of the two investigated pine species, which partially overlapped. The separation of the species was due to high contents of the n‐alkanes C₂₉ and C₃₁ (P. omorika), C₁₉, C₂₀, C₂₁, C₂₂, C₂₃, and C₂₄ (P. heldreichii), and C₂₈ (P. peuce). Cluster analysis also showed a clear separation between the P. omorika populations on one side and the P. heldreichii and P. peuce populations on the other side. The n‐alkane and terpene compositions are discussed in the light of their usefulness in chemotaxonomy as well as with regard to the biogeography and phylogeny of these rare and endemic conifers.     

Insecticidal activity of garlic juice in two dipteran pests

Abstract

• 1 Botanical products excluding pyrethroids constitute a small, but growing portion of the U.K. pesticides market. With increasing legislative pressure upon chemical pesticides such as organophosphates, interest in this sector is increasing steadily.
• 2 Garlic Allium sativum L. juices and extracts form the basis of several commercially available pest control products, but the performance of these products is variable, possibly due to lack of quality control upon batches of materials in the manufacturing process.
• 3 Some garlic products designed for use in the food industry are subjected to rigorous batch‐control to ensure organoleptic consistency. We studied the insecticidal efficacy of a commercially produced food grade garlic juice using two target dipteran pests, Delia radicum (L.) and Musca domestica L.
• 4 Exposure of the two species to different concentrations of garlic juice revealed variability in insecticidal effect across life stages. LC₅₀ values recorded for D. radicum were: eggs (7‐day exposure) 0.8%; larvae (24‐h exposure) 26.4%; larvae (48‐h exposure) 6.8%; and adults (24‐h exposure) 0.4%. LC₅₀ values recorded for M. domestica were: eggs (7‐day exposure) 1.6%; larvae (24‐h exposure) 10.1%; larvae (24‐h exposure) 4.5%; and adults (24‐h exposure) 2.2%.
• 5 Mortality rates caused by the garlic juice were comparable with those obtained with the organophosphate pesticide Birlane^®, indicating parity of effect at various concentrations depending on life stage.
• 6 We conclude that this product may provide an effective, naturally‐derived insecticide for use in agricultural systems against dipteran pests.

     

STEROLS OF 14 SPECIES OF MARINE DIATOMS (BACILLARIOPHYTA)1

The sterol compositions of 14 species of marine diatoms were determined by gas chromatography and gas chromatography-mass spectrometry. A variety of sterol profiles were found. The sterols 24-methylcholesta-5,22E-dien-3β-ol, cholest-5-en-3β-ol, and 24-methylcholesta-5,24(28)-dien-3β-ol, previously described as the most common sterols found in diatoms, were major sterols in only a few of the species. In light of this and other recent data, it is clear that these three sterols are not typical constituents of many diatom species. Most of the centric species examined had 24-methylcholesta-5,24(28)-dien-3β-ol and 24-methylcholest-5-en-3β-ol as two of their major sterols. The exception was Rhizosolenia setigera, which possessed cholesta-5,24-dien-3β-ol as its single major sterol. In contrast to the centric species, the pennate diatoms examined did not have any particular sterols common to most species. Minor levels ofΔ⁷-sterols, rarely found in large amounts in diatoms, were found in four species. C₂₉sterols were found in many species; seven contained 24-ethylcholest-5-en-3β-ol and three contained 24-ethylcholesta-5,22E-dien-3β-ol, reinforcing previous suggestions that C₂₉ sterols are not restricted to higher plants and macroalgae. 24-Ethylcholesta-5,22E-dien-3β-ol may prove to be useful for taxonomy of the genus Amphora and the order Thalassiophysales. A major sterol of Fragilaria pinnata was the uncommon algal sterol 23,24-dimethylcholesta-5,22E-dien-3β-ol. Cholesta-5,24-dien-3β-ol was the only sterol found in the culture of Nitzschia closterium. This differed from previous reports of 24-methylcholesta-5,22E-dien-3β-ol as the single major sterol in N. closterium. Two C₂₈ sterols possessing an unusual side chain were found in Thalassi-onema nitzschioides, a C_28:2 sterol (16%) and a C_28:1 sterol in lower abundance (2.5%), which may be 23-methylcholesta-5,22E-dien-3β-ol and 23-methyl-5α-cholest-22E-en-3β-ol, respectively. The species Cylindrotheca fusiformis, T. nitzschioides, and Skeletonema sp. may be useful as direct sources of cholesterol in mariculture feeds due to their moderate to high content of this sterol.     

SEASONAL CHANGES IN THE PROXIMATE AND FATTY ACID COMPOSITION OF SOME NATURALLY GROWN FRESHWATER CHLOROPHYTES1

The protein content of the filamentous Cladophora glomerata (L.) Kz., Ulothrix zonata (Web, & Mohr) Kz. and Spirogyra sp., collected from natural populations for 1 year, averaged 8.0–12.4% of the total dry weight; whereas, the corresponding levels of lipid, cellulose and ash were 11.9–16.1%, 10.0–17.8% and 14.6–24.0%, respectively. Mean values for carbohydrates, estimated by difference, ranged from 32.8 to 56.0%. The colonial Scenedesmus dimorphus (Turp.) Kz. and the unicellular Cosmarium laeve Rab., on the other hand, contained more protein, lipid and carbohydrate (estimated by difference) averaging 13–15.0%, 22.5–25.9% and 415–46.8%, respectively, and less cellulose (7.5–9.8%) and ash (8.2–9.8%). A consistent pattern of seasonal variation in the proximate composition was not normally evident for any species, reflecting the influence of several environmental parameters on the algae. Cladophora contained the greatest amount of phospholipid averaging; 10% by weight of total lipid with the smallest quantity (5%) in Scenedesmus. The predominant phospholipid fatty acid in all species was C_18:1 followed by C_18:2, C_18:3 and C_16:1 in Cladophora, Ulothrix and Spirogyra, and C_16:1, C_18:2 and C_16:0 in Scenedesmus and Cosmarium. Oleic (C_18:1) and hexadecanoic (C_16:1) acids were predominant in the neutral lipids of all the algae, followed by C_16:0, C_18:2 and C_18:3. The concentration of the different fatty acids of each Species varied considerably during the year with the proportion of C_16:0 and C_16:1, usually rising and that of C_18:1 failing during the colder months.     

Presence of activated lymphocytes in the urine of patients with superficial bladder cancer after intravesical immunotherapy with bacillus Calmette-Guérin

Summary To study the mode of action of intravesical bacillus Calmette-Guérin (BCG) immunotherapy in the prevention and cure of superficial bladder cancer, flow-cytofluorometric analysis of the cellular immunological reaction in the urine of patients was performed. Fresh urinederived leucocytes were obtained from eight patients before (t ₀) and 24 h (t ₂₄) and 48 h (t ₄₈) after repeated intravesical BCG instillations (at least 5 instillations). For two patients urine-derived leucocytes were investigated at the first BCG instillation. The number of leucocytes in the urine was markedly increased 24 h after repeated BCG instillations, indicating a local cellular immunological reaction induced by BCG. The mean number of cells per milliliter of urine at that time was 2.9×10⁶±3.6×10⁶ (n = 8). These leucocytes consisted mainly of granulocytes (75±11%,n = 8). In addition monocytes/macrophages (4±2%,n = 8) and T lymphocytes were present (1±1%,n = 5). The relative increase of monocytes/macrophages in the urine after BCG application tended to be higher compared to the other leucocyte subtypes. As T lymphocytes may play an important role in the BCG-mediated antitumour activity, subsets of lymphocytes were further characterized att ₀,t ₂₄, andt ₄₈ after repeated BCG instillations. The lymphocyte population consisted mainly of T cells (86% CD3⁺,t ₀). Most of the T cells were CD4⁺ (helper/inducer) and were significantly decreased at 48 h (62±9% att ₀ vs 49±6% att ₄₈). Lymphocytes partly expressed HLA-DR antigens (44%,t ₀). The percentage of lymphocytes with interleukin-2 (IL-2) receptors (CD25⁺) was significantly increased at 24 h and 48 h, compared to pre-instillation values (19±11% and 10±4% vs 3±3% respectively). Natural killer cells (CD 16⁺ and/or CD56⁺) and B cells (CD 19⁺) were less numerous (10% and 19% att ₀ respectively). After the first BCG instillation the increase in the number of leucocytes in urine seemed to be less compared to the numbers after repeated BCG instillations. Lymphocytes could not be detected in the urine collected before or after the first BCG instillation. In conclusion, we demonstrated the presence of considerable numbers of leucocytes in the urine 24 h after repeated BCG instillations, i.e. shortly after immunological activation. The antigen expression of the lymphocytes suggested that they may represent the lymphocytes in the bladder wall. Expression of HLA-DR and IL-2 receptors on lymphocytes indicated activation of T cells by the intravesical BCG treatment. These leucocytes may be useful for functional studies, which are essential to elucidate the actual effector mechanism(s) in the mode of action of BCG against superficial bladder cancer in man.