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Biomedical subjects

K Stasiak

Publications and source records attributed to K Stasiak.

10 recordsLinked to original sources
PubMed2005

A RhoGAP protein as a main immune suppressive factor in the Leptopilina boulardi (Hymenoptera, Figitidae)-Drosophila melanogaster interaction.

To protect its eggs, the endoparasitoid wasp Leptopilina boulardi injects immune suppressive factors into Drosophila melanogaster host larvae. These factors are localized in the female long gland and reservoir. We analyzed the protein content of these tissues and found that it strongly differed between virulent and avirulent parasitoid strains. Four protein bands present in virulent long glands were eluted and their immune suppressive effect was assessed in vivo, allowing demonstrating a major effect of one of these proteins. The corresponding cDNA encodes a predicted 30 kDa subunit containing a Ras homologous GTPase Activating Protein (RhoGAP) domain, suggesting a possible involvement in the regulation of actin cytoskeleton changes. Using Western-blot experiments, we showed that this protein is abundant in virulent female long glands but is undetectable in virulent females deprived of long glands or in long glands from avirulent wasps. Its potential role in modifying the morphology and the adhesive properties of the host lamellocytes, involved in Drosophila cellular immune responses, is discussed.

Amino Acid Sequence↗
PubMed2005

Characteristics of pathogenic and mutualistic relationships of ascoviruses in field populations of parasitoid wasps.

Ascoviruses are disseminated among larvae in lepidopteran populations by parasitic wasps during oviposition. Ascovirus relationships with these wasps vary from pathogenic to mutualistic, and experimentally can be shown possibly to be commensal non-pathogenic virus having little or no effect. Most ascoviruses are pathogens that female wasps vector mechanically. Other ascoviruses have a more intimate relationship with their wasp vectors in that their genome is stably maintained in all wasp nuclei through several generations by vertical transmission. In this relationship, these viruses are mutualistic, enhancing the successful development of the wasp larvae by suppressing lepidopteran defence mechanisms. The DpAV4 ascovirus is a mutualist in certain Diadromus wasps but is pathogenic or not when vectored by other species of this genus. These various biologies suggest that ascovirus/wasp relationships depend on wasp regulatory factors that control virus replication. Thus, certain ascoviruses can potentially have either a pathogenic, mutualistic, or non-pathogenic relationship with a specific wasp vector, the type of relationship being dependent upon the species system in which the relationship evolved. Finally, because ascoviruses appear to be related to ichnoviruses (Polydnaviridae), the DpAV4/Diadromus system constitutes a possible interesting intermediate between the pathogenic ascoviruses and symbiotic viruses that evolved to be ichnoviruses.

Animals↗
PubMed1983

Abnormalities of cobalt-activated acylase from human sarcoma, carcinoma and the adjacent tissue.

Cobalt-activated acylase form-2 from human uterine myosarcoma, lung adenocarcinoma and the adjacent tissue was isolated, purified and characterized. It was found, that the enzyme from the malignant neoplasms differed both from the normal tissue and benign tumor acylase-2 in its Km value, temperature optimum and effect of some ions. Some abnormal properties (pH dependence, activation by cobalt and thermostability) were common for benign and malignant tumors. In lung tissue adjacent to adenocarcinoma, some deviations of acylase properties were observed, similar to that found in tumor, indicating that biochemical changes may be present also in tissues unaffected by the neoplastic growth by the histopathological criteria.

Adenocarcinoma↗
PubMed1978

Leiomyoma of the lung.

A case of asymptomatic pulmonary leiomyoma diagnosed by routine chest radiography and treated by lobectomy is reported. There is no particular clinical pattern that distinguishes this lesion, and diagnostic maneuvers to identify its nature are generally unrewarding except for biopsy. Resection is the recommended treatment.

Female↗