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1.  Identification of Ugandan HIV Type 1 Variants with Unique Patterns of Recombination in pol Involving Subtypes A and D 
Most HIV-1 infections in Uganda are caused by subtypes A and D. The prevalence of recombination and the sites of specific breakpoints between these subtypes have not been reported. HIV-1 pol sequences encoding protease (amino acids 1-99) and reverse transcriptase (amino acids 1-324) from 102 pregnant Ugandan women were analyzed by the Recombinant Identification Program, SimPlot, and examination of phylogenetically informative sites to identify sites of recombination between sequence segments belonging to different subtypes. Thirteen percent (13 of 102) of the pol sequences contained strong evidence of recombination between subtypes A and D. At least nine different patterns of recombination were observed. Five women infected with a recombinant virus transmitted the recombinant virus perinatally. In this population-based study, intersubtype recombinants were common. The large number of different types of pol recombinants identified suggests that recombination occurs readily in the pol region. Perinatal transmission of the recombinant viruses demonstrates their evolutionary stability.
PMCID: PMC2573392  PMID: 12015904
2.  ERalpha-status of disseminated tumour cells in bone marrow of primary breast cancer patients 
Isolated disseminated tumour cells (DTC) are regarded as surrogate markers for minimal residual disease in breast cancer. Characterisation of these cells could help understand the known limitations of adjuvant therapy. Of particular interest is their oestrogen-receptor (ER) status because endocrine adjuvant therapy remains a cornerstone of breast cancer treatment.
Bone marrow (BM) aspirates from 254 patients with primary breast cancer were included in this study. A double immunofluorescence staining procedure was established for the identification of cytokeratin (CK) positive/Erα-positive cells. ERα status of the primary tumour was assessed immunohistochemically using the same antibody against ERα.
In 107 of 254 (42%) breast cancer patients, CK-positive cells could be detected in the BM. More than one DTC in the BM was observed in 38 of the 107 patients. The number of detected cells ranged between 1 and 55 cells per 2 × 106 mononuclear cells. DTCs demonstrated ERα positivity in 12% of the patients. The ERα expression was heterogeneous in 10 of the 38 (26%) patients with more than one DTC. The concordance rate of ERα status between primary tumour and DTC was 28%. Only 12 of 88 patients with ERα-positive tumours also had ERα-positive DTCs.
Primary tumours and DTCs displayed a concordant ERα status in only 28% of cases. Most of the DTCs were ERα negative despite the presence of an ERα-positive primary tumour. These findings further underline the distinct nature of DTCs and may explain the failure rates seen in conventional endocrine adjuvant therapy.
PMCID: PMC2614509  PMID: 18793387
3.  Presence of apoptotic and nonapoptotic disseminated tumor cells reflects the response to neoadjuvant systemic therapy in breast cancer 
Breast Cancer Research  2006;8(5):R60.
Neoadjuvant systemic therapy (NST) is an established strategy to reduce tumor size in breast cancer patients prior to breast-conserving therapy. The effect of NST on tumor cell dissemination in these patients is not known. The aim of this study was to investigate the incidence of disseminated tumor cells (DTC), including apoptotic DTC, in breast cancer patients after NST, and to investigate the correlation of DTC status with therapy response.
Bone marrow aspiration was performed in 157 patients after NST. DTC were detected by immunocytochemistry using the A45–B/B3 anticytokeratin antibody. To detect apoptotic DTC the antibody M30 (Roche Diagnostics, Germany) was used, which detects a neo-epitope expressed only after caspase cleavage of cytokeratin 18 during early apoptosis.
The incidence of DTC in breast cancer patients was 53% after completion of NST. Tumor dissemination was observed more frequently in patients with no change/progressive disease (69%) than in patients with partial remission or complete remission of the primary tumor (46%) (P < 0.05). Ten out of 24 patients with complete remission, however, were still bone marrow positive. Apoptotic DTC were present in 36 of 157 (23%) breast cancer patients. Apoptotic cells only were detected in 14% of the patients with partial remission or complete remission, but were detected in just 5% of the patients with stable disease. Apoptotic DTC were detectable in none of the patients with tumor progression.
The pathological therapy response in breast cancer patients is reflected by the presence of apoptotic DTC. Patients with complete remission, however, may still have nonapoptotic DTC. These patients may also benefit from secondary adjuvant therapy.
PMCID: PMC1779490  PMID: 17062129
4.  Performance of Applied Biosystems ViroSeq HIV-1 Genotyping System for Sequence-Based Analysis of Non-Subtype B Human Immunodeficiency Virus Type 1 from Uganda 
Journal of Clinical Microbiology  2001;39(12):4323-4327.
The Applied Biosystems ViroSeq HIV-1 Genotyping System is a commercially available, integrated system for sequence-based analysis of drug resistance mutations in human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase (RT). We evaluated the performance of this system for analysis of non-subtype B HIV-1 by analyzing plasma samples from Ugandan women and infants. Plasma samples were obtained from 105 women and 25 infants enrolled in a Ugandan clinical trial. HIV-1 analysis was performed with the ViroSeq system according to the manufacturer's instructions, except that the volume of plasma used for analysis was less than the recommended 0.5 ml for some samples. Viral loads ranged from 2,313 to 2,336,400 copies/ml. PCR products suitable for sequencing were amplified from all samples tested. Complete sequences for protease (amino acids 1 to 99) and RT (amino acids 1 to 320) were obtained for 102 of 105 (97%) of the maternal samples tested and all 25 of the infant samples tested. Complete double-stranded sequences were obtained for 90 of 105 (86%) of the maternal samples tested and 22 of 25 (88%) of the infant samples tested. The sequences obtained with this system were used for HIV-1 subtyping. The subtypes identified were A, C, D, and A/D recombinant HIV-1. The performances of the seven sequencing primers were similar for the subtypes examined. The ViroSeq system performs well for analysis of Ugandan plasma samples with subtypes A, C, D, and A/D recombinant HIV-1. The availability of this genotyping system should facilitate studies of HIV-1 drug resistance in countries where these subtypes are prevalent.
PMCID: PMC88543  PMID: 11724839

Results 1-4 (4)