Biomedical subjects

A Raji

Publications and source records attributed to A Raji.

22 records · Page 2Linked to original sources

PubMed1992

Adhesion to and invasion of cultured human cells by Bartonella bacilliformis.

Bartonella bacilliformis was tested for its ability to adhere to and invade tissue culture cell monolayers. The parasite was able to efficiently bind and penetrate human dermal fibroblasts, human laryngeal epithelium, and human umbilical vein endothelial cells. Exposure of the organism to immune serum prepared against a crude Bartonella extract containing cell wall and membranous material resulted in decreased ability of the parasite to invade host cells. There was also an overall reduction in the invasiveness of bartonellae and total host cell association when human laryngeal epithelial cells and human umbilical vein endothelial cells were preexposed to cytochalasin D, indicating an active involvement of host cells in the uptake of bartonellae. Transmission electron microscopy revealed the presence of bartonellae inside and outside intracellular vacuoles. These data suggest that a surface-associated factor is involved in the invasion process and that internalization of the parasite by host cells involves a microfilament-dependent process similar to phagocytosis.

Adhesins, Bacterial↗

PubMed1992

[Isolated retrovesical and retroperitoneal hydatid cysts. 5 case reports].

In the light of five cases of isolated retrovesical and retroperitoneal hydatid cysts, the characteristics of these rare locations are reviewed and the hypotheses of pathogenesis are discussed. An abdominal or abdomino-pelvic mass is the most frequent sign. Ultrasonography and computed tomography are valuable in the diagnosis of these lesions. Partial cysto-pericystectomy via an extraperitoneal approach is the treatment of choice for these hydatid cysts.

Adolescent↗

PubMed1985

Genetic analysis of mutations that compensate for loss of Escherichia coli DNA topoisomerase I.

A transposon Tn10 insertion in topA, the structural gene of Escherichia coli DNA topoisomerase I, behaves as an excluded marker in genetic crosses with many strains of E. coli. However, derivative strains that accept this mutant topA allele are readily selected. We show that many of these topA mutant strains contain additional mutations that compensate for the loss of DNA topoisomerase I. Genetic methods for mapping and manipulating such compensatory mutations are described. These methods include a plate-mating test for the ability of strains to accept a topA::Tn10 allele and a powerful indirect selection for transferring compensatory mutations from male strains into non-compensatory female strains. One collection of spontaneous compensatory mutants is analyzed in detail and is shown to include compensatory mutations at three distinct loci: gyrA and gyrB, the genes that encode the subunits of DNA gyrase, and a previously unidentified locus near tolC. Mutations at this third locus, referred to as toc (topoisomerase one compensatory) mutations, do not behave as point mutations in transductional crosses and do not result in lowered DNA gyrase activity. These results show that wild-type strains of E. coli require DNA topoisomerase I, and at least one class of compensatory mutations can relieve this requirement by a mechanism other than reduction of DNA gyrase activity.

Alleles↗

PubMed1979

A new pattern of needle for microsurgical repair of nerves.

This paper describes the design for a microsurgical stainless steel atraumatic needle for primary suture of small peripheral nerves in which the epineurium is friable. The needle (manufactured by Dixey Instruments, U.K.) is curved with a spearshaped point and a small cutting edge on the concave surface. The rest of the body of the needle is round. We have found with histological evidence that there is an improvement in accuracy of suture placement on previously used needles in experimental and clinical microsurgery of peripheral nerves.

Microsurgery↗