Steinernema pwaniensis n. sp., a new entomopathogenic nematode (Nematoda: Steinernematidae) from Tanzania.

A new species of entomopathogenic nematode, Steinernema pwaniensis n. sp., belonging to the glaseri group, is described from Tanzania. The infective juveniles of S. pwaniensis n. sp. are characterized by a body length of 978 µm (808-1131), distance from anterior end to excretory pore of 86 µm (80-95) and a tail length of 87 µm (75-95). The ratios a, c and E% of S. pwaniensis n. sp. are substantially lower than those of all other African 'glaseri' group members. The first-generation males of S. pwaniensis n. sp. can be distinguished by a large spicule length of 92 µm (80-97) and by the absence of the caudal mucron, while second-generation males possess a short spine-like mucron. First-generation females have a peg-like tail tip bearing three spine-like projections. Second-generation females can be recognized by a slightly protruding vulva and well-developed post-anal swelling. The new species is further characterized by sequences of the internal transcribed spacer (ITS) and partial 28S regions of the ribosomal DNA. Phylogenetic analyses show that S. pwaniensis n. sp. forms a strongly supported monophyletic clade with two other East African species, S. ethiopiense and S. karii.

The significance of the tail projections in female entomopathogenic nematodes within the family Steinernematidae.

Several taxonomic studies of the entomopathogenic nematode family Steinernematidae have reported on the minute tail projections on the tail tips of females of the first generation; however, the occurrence and morphology of these traits in other steinernematid species and their taxonomic significance are still unclear. In the present study, the tail projections in females of seven steinernematid species belonging to four phylogenetic clades were examined. The projections are present in all of the tested species and their number and shape is consistent within species but significantly differs among species. It thus seems that these structures may have taxonomic significance at the species level. Based on these results, we suggest that every description of a new species in the family Steinernematidae should contain a precise morphology of the female tail, focused on these projections, using both light and scanning electron microscopy.

[Osteoplastic decompressive craniotomy--indication and surgical technique]. / Osteoplastická dekompresivní kraniotomie--indikace a operacní technika.

Decompressive craniotomy is usually carried out using decompressive craniectomy (osteoclastic decompressive craniotomy) when the bone flap is removed. In situations when the level of expansion does not call for decomopressive craniectomy, we do not remove the bone flap and we perform osteoplastic decompressive craniotomy. The indication is based on assessment and cross correlation of the following parameters: intracranial pressure,midline shift and the number of pathologies on CT, actual influence of antiedematous therapy, expected cerebral oedema progression and especially according to the size of the dural defect after duratomy. In the course of osteoplastic decompressive craniotomy, decompression is secured by the elevation of the unfixed bone flap during cerebral tissue expansion. After the oedema regression, the elevated bone flap spontaneously drops to its original position and is reattached. The danger of bone plate depression is eliminated with the use of a bevel bone cut using a Gigli saw. Osteoplastic decompressive craniotomy is an effective method of treating brain oedema when the degree of expansion does not require decompressive craniectomy.

[Tactical and technical notes for decompression craniotomy--a review]. / Poznámky k operacní taktice a technice dekompresivní kraniotomie--prehledný referát.

The authors present the tactics and technique of the decompression craniotomy (DC). DC is one of the principal neurosurgical procedures in the treatment of intracranial hypertension. Early indication and perfect technical completion of the procedure are the prerequisites for achieving the anticipated decompressive effect. While indications of DC are frequently discussed in the scientific literature, the procedure's tactics and techinque is usually overlooked. The report mentions the DC development and significance from its historical perspective. Decompression craniotomy should be performed as a preventive procedure to prevent secondary brain damage. Four types of craniotomy are used in order to perform decompression: subtemporal, circular, bifrontal and hemispheral. The hemispheral DC best fulfills the essential requirement regarding the brain stem direct compression release. The technical aspect of the hemispheral decompression procedure is described further in the report. The authors discuss some technical aspects, which, provided they are followed, should prevent the surgical method from failure. Incorrect technical performance, especially insufficient extent of the decompression, along with its late indication, is the principal factor discrediting the idea of decompression craniotomy.

Steinernema weiseri n. sp. (Rhabditida, Steinernematidae), a new entomopathogenic nematode from Europe.

Steinernema weiseri n. sp. is described from a roadside with apple trees near Ceské Budejovice, Czech Republic. The species is also widely distributed in Germany and Slovakia, from where it had previously been reported as Steinernema spec. F. The British Steinernema sp. D1 is considered conspecific with S. weiseri n. sp. Males of the new species are mainly characterised by light brown, slightly curved spicules with a long manubrium and the presence of a short tail mucron in the second generation. Third-stage infective juveniles are characterised by a 'medium size' body and tail length, short hyaline tail portion (mostly around 1/3 of tail length), the excretory pore situated in the mid-pharynx region, lip region slightly offset, angular and flattened, and the lateral field having nine equally developed lines separated by eight distinct ridges. S. weiseri n. sp. is most similar to S. feltiae, with which it did not hybridise. RFLP analysis of the ITS region of the rDNA repeat shows S. weiseri n. sp. to be distinct from 50 other Steinernema species and isolates. The new species was found in a wide range of habitats and is readily maintained on Galleria mellonella larvae.

Comparison of the Galleria baiting technique and a direct extraction method for recovering Steinernema (Nematoda: Rhabditida) infective-stage juveniles from soil.

Forty soil samples from forests and other biotopes in Germany and the Czech Republic were studied for the presence of entomopathogenic nematodes using the Galleria bait method at the same time as a sieving-decanting method for direct extraction of infective-stage juveniles. Five Steinernema species were recovered from the samples from Germany and four species from the samples from Czechia. All five species were recovered with both methods, but the baiting technique was generally less effective and mixtures of species were frequently undetected. The direct extraction method provided quantitative estimates of infective-stage juvenile density but no information on their infectivity or on morphological characters of adults, and nematode cultures could not be established.

Factors influencing the infectivity of a Canadian isolate of Steinernema kraussei (Nematoda: Steinernematidae) at low temperature.

The effectiveness of Canadian isolate 76 of Steinernema kraussei, at 10 degrees C, in penetrating Galleria mellonella larvae (percentage parasitism and number of IJs developed to adult nematodes) was measured at different host densities (differing number of larvae and size of experimental arena) and for different durations of exposure. The greater the size of the inoculum of infective juvenile nematodes per unit area and the longer the duration of exposure, the greater the number of larvae that were killed and the larger the number of mature nematodes in the larval host. The infection rate (alpha) and the adjusted infection rate (beta) were determined using the modified Anderson model. This model successfully described the behavior of the S. kraussei-G. mellonella interaction.

[Arteriovenous malformations associated with aneurysms of the vein of Galen]. / Arteriovenózní malformace s aneurysmatem vena magna Galeni.

The aneurysms of the vein of Galen may be defined as a midline arteriovenous fistula with aneurysmal dilatation of the median venous sac. From the literature and author's experiences a survey of embryology, pathophysiology as well as contemporary state of diagnosis and therapy of vein of Galen malformation is presented.

Survey of heterorhabditidae and steinernematidae (rhabditida, nematoda) in Western Canada.

A survey was done in the summer months along the Alaska Highway, in other parts of British Columbia, in northern Alberta, and in the Yukon Territory for steinernematid and heterorhabditid nematodes occurring in the top 10 cm of soil. Steinernema feltiae and Steinernema spp. were found at 18 and Heterorhabditis megidis at 7 sites of 125 sampled. Most nematodes were found where visible insect infestation occurred and where human influence on the habitat was substantial (e.g., agricultural, forested and bush-hedgerow habitats); none was found in grassland or virgin forests. Heterorhabditis megidis occurred in only the southern, warmer, drier region of British Columbia. In the laboratory some steinernematid isolates and H. megidis killed Galleria mellonella larvae at 13 and 22 C, whereas some isolates of Steinernema killed the larvae at only 13 C. Steinernema spp. from three high altitude sites with low, average July temperatures (13-14 C) are cold-active in that they produced infective juveniles at 13 C and killed G. mellonella at 6 C.

[Post-traumatic astrocytoma]. / Posttraumatisches Astrozytom.

A 25 year old woman developed a mixed pilocytic and fibrillary astrocytoma in scar tissue 20 years after the brain contusion. The case fulfilled the criteria of traumatic etiology of this brain tumor.