[The structure of low-abundance and crowded infrapopulations of the tapeworm Hymenolepis diminuta inbred line--WMS IL1]. / Struktura infrapopulacji maloliczebnych i zageszczonych tasiemca Hymenolepis diminuta linii wsobnej--wms IL1.

An average of 4.9 tapeworms were discovered on day 7 of a low-abundance H. diminuta infection of rats of race WAG alb. After 11 months, the mean was only relatively slightly lower at 3.6. These means represent 97.1 and 71.4% of the 5 cysticercoids supplied. In turn, 7 days and 11 months after rats were supplied with 110 cysticercoids, the respective percent-ages were 85.1 and 56.0. All 7- and 12-day tapeworms from the low-abundance and crowded infrapopulations were characterized by the presence of a terminal proglottid of lingulate shape, in which the excretory canals joined. In contrast, older (48-day and 11-month-old) worms showed typical apolysis of gravid proglottids. There were no reports of the destrobilation of tapeworms, and the relatively large number of tapeworms persisting 11 months into the infection is particularly noteworthy. The results point to the lack of any rapid rejection of tapeworms of the kind characterized in many other studies on H. diminuta.

[The biological and anatomical-morphological properties of Hymenolepis diminuta tapeworms of WMS il1 and the WMS "strain"]. / Biologiczne i anatomo-morfologiczne wlasciwosci tasiemców Hymenolepis diminuta WMS il1 i WMS "strain".

Crowded infrapopulations of H. diminuta obtained from the WMS il1 inbred line resembled those of the potentially non-inbred WMS strain in not showing either the abrupt reductions in the numbers of worms or the destrobilation described by other autors. Denser populations of both types of tapeworm have a greather abundance of 4 - testis proglottids of the 1p3a type (having 1 testis on the poral side and three on the aporal), and fewer of type 0p3a. Changes in the positioning of genital ducts and pores show a marked positive correlation with the abundance of type 2pla proglottids. Strobilae of H. diminuta WMS il1 contain a relatively greather number of type 0p3a proglottids and fewer of type 1p3a, than those of the WMS "strain"; something which is probably linked with the respective selection of the maternal tapeworms.

Tapeworms morphological changeability in the chain of Hymenolepis diminuta WMS "strain" generations.

The investigations covered 54 subsequent generations of Hymenolepis diminuta WMS "strain" obtained through the administration of 6 cysticercoids of tapeworm to Wistar strain rats and WAG alb. rats. The number of tapeworms at 2.5 months after the infection of rats ranged from 3 to 6, on the average 5.2. Taking into consideration the most important type 1p2a (one testis on the poral side and two testes on the aporal side), 0p3a, 1p3a and 2p1a proglottids a significant differences was found in the distribution of the numerousity of type 1p3a proglottids (P < 0.05). This indicates a possibility of an unguided change of the number of proglottids of this type in a period covering 54 subsequent H. diminuta generations bred in laboratory conditions.

[The effect of crowding tapeworms Hymenolepis diminuta based on proglottids in the period of intensified variability]. / Wplyw stloczenia tasiemców Hymenolepis diminuta na budowe proglotydow w okresie ich wzmozonej zmiennosci.

Tapeworms obtained 13 months after the administration to rats of cysticercoids Hymenolepis diminuta - WMS il1 measured in 3-6-specimen populations an average of 677.9 mm in length while in 23-26-specimen populations an average of 356.9 mm in length. Strobilas of an exclusively unilateral (right-sided) position of genital pores (PGP) appeared in 76.3%-79.8% of tapeworms of the investigated groups. In such tapeworms belonging to 23-26-specimen populations the frequency of occurrence of typical proglottids containing 1 testis on the poral side and 2 testes on the aporal side (1p2a) and type 0p3a proglottids averaging 86.5% and 6.8%, respectively, declines in comparison to the average frequency of occurrence of proglottids of this type in 3-6-specimen populations amounting to 87.8% and 8.8%, respectively. The frequency of occurrence of four-testes (1p3a) proglottids averaged 5.5% in tapeworms from the 23-26-specimen populations and was 4.0% higher than the 1.5% average in tapeworms from the 3-6-specimen populations, in spite of the fact that in a population with a higher number of specimens proglottids are smaller and, therefore, have less room for an additional number of these organs. In tapeworms with variable PGP type 2p1a proglottids constituted the most frequent deviation in each of investigated group of different infection intensity. Their average frequency of occurrence rose from 0.4%-0.5% in tapeworms with unilateral PGP to an average of 5.5%-5.9% in tapeworms with variable PGP. Close positive correlation was found in tapeworms with variable PGP between the frequency of occurrence of such changes and the frequency occurrence of type 2p1a proglottids in every of investigated group (P < 0.01, r = from +0.887, to +0.918).

[Hereditary character of feature variability in Hymenolepis diminuta bred from oncospheres of defined origin]. / Dziedziczny charakter zmiennosci cech u Hymenolepis diminuta wyhodowanych z onkosfer okreslonego pochodzenia.

Three groups of tapeworms obtained 2.5 month after the administration to rats of a dose of 6 cysticercoids proceeding from oncospheres of the 24th generation of Hymenolepis diminuta were compared. Group I came from the oncospheres of only one proglottid of H. diminuta WMS "strain" tapeworm. Group II proceeded from 6 proglottids obtained each from another tapeworm of this "strain". Group III came from 6 proglottids, each from another tapeworm of H. diminuta WMS inbred line 1 (il1). The average number of type 0p3a proglottids in group I and II was similar and amounted to 4.0% and 4.7%, respectively, while in group III it was significantly higher than in the first two groups and reached an average of 8.4% (P < 0.01). There are also other significant differences between the two breeding lines-H. diminuta WMS "strain" and WMS il1 with respect to the number of typical 1p2a proglottids, type 1p3a proglottids, the second after 0p3a most common deviation from the typical 1p2a as well as all deviations taken together. This points to the influence of different breeding condition: non-inbred in case of H. diminuta WMS "strain" and inbred in case of H. diminuta WMS il1 on the investigated features.

[Comparison of the variability of tapeworms obtained as a result of infecting rats with Hymenolepis diminuta larvae of different ages]. / Porównanie zmiennosci tasiemców uzyskanych w wyniku zarazenia szczurów larwami Hymenolepis diminuta w róznym wieku.

In Hymenolepis diminuta WMS "strain" tapeworms which were obtained 2.5 months after the administration to rats of 2-month old larvae--cysticercoids++, isolated from Tribolium destructor, only one-sided position of genital pores (PGP) developed. The extended 7-month duration of the invasion of H. diminuta larvae stimulates the development of variable PGP already in 14.1% of 2.5-month tapeworms. In tapeworms with exclusively one-sided PGP in the first of the two groups mentioned, the number of type 1p2a proglottids (1 testis on the poral side and 2 testes on the aporal side) as well as type 0p3a, 1p3a and 2p1a amounted to 88.2%, 5.5%, 4.2% and 0.5%, respectively and similarly in the second group--88.3%, 5.6%, 4.5% and 0.6%, respectively. In tapeworms with variable PGP the mean number of the types of proglottids mentioned was different from (86.0%, 4.1%, 3.8% and 4.1%, respectively) the same figure in tapeworms with one-sided PGP. Particularly high correlation was found to occur between the number of PGP variations and type 2p1a proglottids (r = +0.928, P < 0.01).

Intensified morphological variability during patency in Hymenolepis diminuta originating from inbred tapeworm--WMS IL1.

Variable position of genital ducts and pores (PGP) was found in 23.3% of five months old tapeworms obtained as a result of administering to rats a dose of 6 cysticercoids proceeding from the third generation of inbred Hymenolepis diminuta--WMS il1. In tapeworms coming from generations no 18 and 32 PGP changes were reported only in 7.5 month, with only 5.9% of strobilas in the 32 generation group being characterized by this feature. These results indicate a time shift with respect to the appearance of PGP changes in tapeworms proceeding from latter inbred generations to a further period of tapeworm invasion in rats. The number of PGP changes is positively correlated with the number of type 2p1a proglottids (two testes on the poral and one on the aporal side). The average number of type Op3a proglottids increases with the number of generations. In 5-month old tapeworms of unilateral PGP coming from generation no 3, 18 and 32 it amounts to 5.9%, 6.6% and 8.1%, respectively.

[Stimulation of morphological changes in tapeworms from inbred Hymenolepis diminuta--WMS IL1]. / Stymulacja zmian morfologicznych u tasiemców pochodzacych z odleglych od wyjsciowego pokolen hodowli wsobnej hymenolepis diminuta-WMS il1.

The investigations focused on tapeworms obtained as a result of the administration to individual rats a dose of 6 cysticercoids coming from the 39th and 40th generation of one-specimen inbred Hymenolepis diminuta-WMS il1. In 7.5-month old tapeworms the position of genital pores (PGP) was exclusively right-hand side with the genital ducts typical of this feature. Type Op3a proglottids were the most common deviation from the typical number and topography of testes-1p2a (one testis between the ovary and the genital pore marking the poral side and two testes on the aporal side)-in such tapeworms. Their mean incidence amounted to 8.9%, exceeding by at least 2.9% the mean quantitative value of this feature in tapeworms proceeding from non-inbred H. diminuta "strains" which have been subjected to similar studies. 19.5-month old tapeworms, exactly a year older than the previous ones, all had variable PGP. The number of PGP changes was here correlated positively with the number of type 2p1a proglottids and negatively with the number of type 1p2a and 0p3a proglottids.