Absence of erythrocyte sequestration in a case of babesiosis in a splenectomized human patient

Background

The importance of vascular occlusion in the pathogenesis of human haemoprotozoal disease is unresolved.

Methods

Giemsa-stained tissue sections from a human case of Babesia microti infection in a splenectomized patient with chronic lymphocytic leukaemia and colon cancer were examined to ascertain the distribution of parasitized erythrocytes within the vascular lumen.

Results

No evidence of sequestration was observed.

Conclusion

This first report on the vascular location of B. microti in human tissue suggests that severe multi-organ failure due to babesiosis is independent of sequestration of parasitized erythrocytes. A similar pathogenesis may also cause multi-organ failure in other intraerythrocytic protozoal infections, including falciparum malaria.

A comparison of prognostic tumor markers obtained on image-guided breast biopsies and final surgical specimens

BACKGROUND

This study was initiated to determine whether tumor markers obtained on image-guided breast biopsy specimens provide accurate prognostic information for women with invasive breast cancer.

METHODS

Prognostic tumor markers on preoperative image-guided biopsy and final surgical specimens were compared in 44 patients with invasive breast cancer.

RESULTS

Progesterone receptor (PR) discordance was 18%. In 87% of PR discordant cases, the image-guided biopsy was positive and the final specimen was negative (P = 0.03). Tumor grade was discordant in 36% of patients Discordance for estrogen receptor (ER) = 2%; MIB-1 = 18%; Her2/neu = 9%; EGFR = 10%; p53 = 9%; and bcl-2 = 0%. The discordance for these markers was random and did not reach statistical significance.

CONCLUSION

Image-guided core needle biopsies provide reliable information for the majority of prognostic tumor makers. A positive progesterone receptor is significantly more likely to be determined by core biopsy rather than the final surgical specimen. Tumor grade should be based upon the final surgical specimen whenever possible.

Preclinical toxicology studies with azithromycin: genetic toxicology evaluation

Azithromycin was subjected to a series of three in vitro and one in vivo genetic toxicology assays for the detection of drug-associated gene or chromosomal effects. In the Ames Salmonella typhimurium tester strains TA1535, TA1537, TA98 and TA100, the presence of azithromycin was not associated with any increase in the number of his- revertants. Urine from mice dosed with up to 200 mg/kg of azithromycin also had no effect on the number of revertants in these same strains suggesting the absence of mutagenic excretory products following oral exposure. When tested up to the cytotoxic level of 240 micrograms/ml, azithromycin caused no increase in the mutant frequency at the thymidine kinase locus of L5178Y/TK cells. Both the mammalian and microbial gene mutation assays included the presence of rat-liver postmitochondrial (S9) fraction for the detection of mutagenic biotransformation products. Mitogen-stimulated human lymphocytes cultured in the presence of 2.5-7.5 micrograms/ml azithromycin for 24 h or 30.0-40.0 micrograms/ml azithromycin for 3 h in the presence of rat S9 had chromosomal aberration frequencies that were no different than negative control cells even though slight to moderate mitotic suppression was associated with these concentrations. In vivo assessment of this compound was completed in male and female mice with a single oral dose of 200 mg/kg followed by sacrifice at 6, 24 or 48 h later and metaphase analysis of bone marrow for chromosomal aberrations. No statistically significant elevations of chromosomally aberrant cells were found. We conclude that azithromycin does not cause gene mutations in microbial or mammalian cells, or chromosomal aberrations in cultured human lymphocytes or in mouse bone marrow in vivo.