Assessment of aldehyde dehydrogenase in viable cells

Cytosolic aldehyde dehydrogenase (ALDH), an enzyme responsible for oxidizing intracellular aldehydes, has an important role in ethanol, vitamin A, and cyclophosphamide metabolism. High expression of this enzyme in primitive stem cells from multiple tissues, including bone marrow and intestine, appears to be an important mechanism by which these cells are resistant to cyclophosphamide. However, although hematopoietic stem cells (HSC) express high levels of cytosolic ALDH, isolating viable HSC by their ALDH expression has not been possible because ALDH is an intracellular protein. We found that a fluorescent aldehyde, dansyl aminoacetaldehyde (DAAA), could be used in flow cytometry experiments to isolate viable mouse and human cells based on their ALDH content. The level of dansyl fluorescence exhibited by cells after incubation with DAAA paralleled cytosolic ALDH levels determined by Western blotting and the sensitivity of the cells to cyclophosphamide. Moreover, DAAA appeared to be a more sensitive means of assessing cytosolic ALDH levels than Western blotting. Bone marrow progenitors treated with DAAA proliferated normally. Furthermore, marrow cells expressing high levels of dansyl fluorescence after incubation with DAAA were enriched for hematopoietic progenitors. The ability to isolate viable cells that express high levels of cytosolic ALDH could be an important component of methodology for identifying and purifying HSC and for studying cyclophosphamide-resistant tumor cell populations.     

Synergistic effect of aqueous extract of Telfaria occidentalis on the biological activities of artesunate in Plasmodium berghei infected mice

Background

Resistance to most antimalarial drugs has encouraged the use of herbal preparations along with prescribed orthodox drugs.

Objective

To investigate effect of co-administration of aqueous extract of T. occidentalis leaves; commonly used as antimalarial and haematinic agent in Nigeria and artesunate using P. berghei animal model.

Methods

In vivo curative antiplasmodial effect of T. occidentalis (200mg/kg) alone and combination with artesunate (2mg/kg) were evaluated using albino mice infected with 10⁶ parasitized erythrocytes of P. berghei intraperitoneally. The haematological parameters: haemoglobin level, red blood cells and white blood cells and packed cell volume were monitored using standard methods.

Results

Aqueous extract of T. occidentalis, artesunate and the combination gave 72.17±4.07%, 70.43± 4.27% and 85.43±3.65% reduction in parasitaemia after 48hours respectively. A significant enhancement of the PCV was obtained with the coadministration of artesunate and aqueous extract (p< 0.01). Similar trends were also observed with heamatological parameters at 72hours of administration.

Conclusion

This study revealed a synergistic effect of the co-administration on parasite clearance rate of P. berghei infection in mice, with a significant enhancement of haematological parameters within 48 hours of administration. This indicates a rapid rate of recovery from plasmodial infections with the co-administration.     

Effect of body mass index on the outcomes of patients with upper and lower urinary tract cancers treated by radical surgery: Results from a Canadian multicenter collaboration

ObjectiveTo evaluate the effect of body mass index (BMI) on the outcomes of patients with urinary tract carcinoma treated with radical surgery.Materials and methodsData were collected from 10 Canadian centers on patients who underwent radical cystectomy (RC) (1998–2008) or radical nephroureterectomy (RNU) (1990–2010). Various parameters among subsets of patients (BMI<25, 25≤BMI<30, and BMI≥30 kg/m²) were analyzed. Kaplan-Meier and multivariate analyses were performed to assess the effect of BMI on overall survival, disease-specific survival, and recurrence-free survival (RFS).ResultsAmong the 847 RC and 664 RNU patients, there was no difference in histology, stage, grade, and margin status among the 3 patient subsets undergoing either surgery. However, RC patients with lower BMIs (<25 kg/m²) were significantly older (P = 0.004), had more nodal metastasis (P = 0.03), and trended toward higher stage (P = 0.052). RNU patients with lower BMIs (<25 kg/m²) were significantly older (P = 0.0004) and fewer received adjuvant chemotherapy (P = 0.04) compared with those with BMI≥30 kg/m²; however, there was no difference in tumor location (P = 0.20), stage (P = 0.48), and management of distal ureter among the groups (P = 0.30). On multivariate analysis, BMI was not prognostic for overall survival, disease-specific survival, and RFS in the RC group. However, BMI≥30 kg/m² was associated with more bladder cancer recurrences and worse RFS in the RNU group (HR = 1.588; 95% CI: 1.148–2.196; P = 0.0052).ConclusionsIncreased BMI did not influence survival among RC patients. BMI≥30 kg/m² is associated with worse bladder cancer recurrences among RNU patients; whether this is related to difficulty in obtaining adequate bladder cuff in patients with obesity requires further evaluation.     

Osteosarcoma: use of MR imaging and MR spectroscopy in clinical decision making

Magnetic resonance (MR) imaging was performed on 14 patients with histologically proved osteosarcoma (mean age, 14.4 years). There was excellent correlation of intramedullary tumor extent as determined with MR imaging and pathologic examination (r = 99%). This was facilitated by the presence of a chemical shift artifact at the tumor-marrow interface on the T1-weighted images. The correlation between CT and pathologic findings was not as good (r = 84%). In a single patient, however, a 10-cm length of sclerotic bone was incorrectly interpreted as being tumor. If this case is excluded, the correlation between CT and pathologic findings improves significantly (r = 96%). T2-weighted images were optimal in demonstrating soft-tissue bulk and breach of the epiphysis or cortex. Vascular involvement was also readily defined. The T2 value of the tumor soft-tissue component decreased in patients who were deemed to have responded well to therapy. Two patients with very high T2 values after chemotherapy developed wide-spread metastatic disease and died. Phosphorus-31 MR spectroscopy of five patients with osteosarcoma showed elevated levels of phosphomonoesters (PMEs), inorganic phosphate (Pi), and phosphodiesters (PDEs). PME and PDE peak areas decreased in three patients after chemotherapy, while Pi peak areas increased.