Use of antigen-detection immunoassays in assessment of trypanotolerance in N'Dama cattle

Evaluates possible contributions of the antigen-detection enzyme immunoassays (ELISA) for the diagnosis of Trypanosoma vivase, T.congolense, and T.Bucei infections in N'Dama cattle in Gabon, Central Africa. The assays are based on monoclonal antibodies which recoginse trypanosome antigens specific for each of the three species, and animals are termed "antigenaemic" when found positive by this technique but not found parasitaemic by the buffy coat technique. Suggests that the ELISA could offer a practical possibility for selection of trypanotolerant cattle based on infection criteria

Evaluation of a field test for trypanotolerance in young N'Dama cattle

Evaluates components of a short term test for trypanotolerance criteria in N'Dama post-weaners exposed to a medium natural trypanosome challenge in Gabon; compares the effectiveness of different measures of control of development of anaemia; and measures the post-test recovery of packed red cell volume (PCV) values following treatment with a trypanocidal drug

Aspects of trypanotolerance and their association with performance in N'Dama cattle

A study was conducted to assess the correlation between criteria of trypanotolerance and production. N'dama post weaner cattle with different weights and from different age groups were studied for weight gain, packed cell volume (PCV) and for the presence of trypanosomes. The analysis approach was to simultaneously estimate the phenotypic relationships between parasitaemia aspects, anaemia control aspects and daily liveweight change of the animals

Measurement of trypanotolerance criteria and their effect on reproductive performance of N'Dama cattle

Evaluates in detail how environmental and stress factorts affect trypanosome infection in N'Dama cows and their calves, the linkages with curative drug treatment given under the management regime prevailing, the linkages with anaemia control as measured by packed red cell volume (PCV), and the resultant influences on animal performance. Major findings were that over the period from calf birth to weaning, while calves and their dams grazing together had similar numbers of trypanosome infections detected, the Trypanosoma vivax : T. congolense rations were very different: 1:0.7 in calves and 1:2.8 in cows. This indicated that some ability to control the development of parasitaemia following T. vivax infection might be being acquired, from weaning onwards. Table 1 summarizes the data on trypanosome infection, curative drug treatment, PCV value and performance trait levels in the 458 pre-weaner calves, the 458 lactating cows and the 1028 cow-year reproduction records available over the 5-year period. These are the actual overall infection rates recorded, the levels of curative drug treatments required and the PCV values, calf growth and cow calving rates achieved

Aspects of trypanotolerance and associations with growth rate in post-weaner N'Dama cattle under high trypanosomiasis risk

A study conducted to find out the ability of N'Dama cattle to control parasitaemia and anaemia at a ranch in Gabon. Examines the effect of parasitaemia on daily liveweight change

Artificial intelligence-based pathology as a biomarker of sensitivity to atezolizumab–bevacizumab in patients with hepatocellular carcinoma: a multicentre retrospective study

Background Clinical benefits of atezolizumab plus bevacizumab (atezolizumab–bevacizumab) are observed only in a subset of patients with hepatocellular carcinoma and the development of biomarkers is needed to improve therapeutic strategies. The atezolizumab–bevacizumab response signature (ABRS), assessed by molecular biology profiling techniques, has been shown to be associated with progression-free survival after treatment initiation. The primary objective of our study was to develop an artificial intelligence (AI) model able to estimate ABRS expression directly from histological slides, and to evaluate if model predictions were associated with progression-free survival. Methods In this multicentre retrospective study, we developed a model (ABRS-prediction; ABRS-P), which was derived from the previously published clustering-constrained attention multiple instance learning (or CLAM) pipeline. We trained the model fit for regression analysis using a multicentre dataset from The Cancer Genome Atlas (patients treated by surgical resection, n=336). The ABRS-P model was externally validated on two independent series of samples from patients with hepatocellular carcinoma (a surgical resection series, n=225; and a biopsy series, n=157). The predictive value of the model was further tested in a series of biopsy samples from a multicentre cohort of patients with hepatocellular carcinoma treated with atezolizumab–bevacizumab (n=122). All samples in the study were from adults (aged ≥18 years). The validation sets were sampled between Jan 1, 2008, to Jan 1, 2023. For the multicentre validation set, the primary objective was to assess the association of high versus low ABRS-P values, defined relative to cross-validation median split thresholds in the first biopsy series, with progression-free survival after treatment initiation. Additionally, we performed spatial transcriptomics and matched prediction heatmaps with in situ expression profiles. Findings Of the 840 patients sampled, 641 (76%) were male and 199 (24%) were female. Across the development and validation datasets, hepatocellular carcinoma risk factors included alcohol intake, hepatitis B and C virus infections, and non-alcoholic steatohepatitis. Using cross-validation in the development series, the mean Pearson’s correlation between ABRS-P values and ABRS score (mean expression of ABRS genes) was 0·62 (SD 0·09; mean p<0·0001, SD<0·0001). The ABRS-P generalised well on the external validation series (surgical resection series, r=0·60 [95% CI 0·51–0·68], p<0·0001; biopsy series, r=0·53 [0·40–0·63], p<0·0001). In the 122 patients treated with atezolizumab–bevacizumab, those with ABRS-P-high tumours (n=74) showed significantly longer median progression-free survival than those with ABRS-P-low tumours (n=48) after treatment initiation (12 months [95% CI 7–not reached] vs 7 months [4–9]; p=0·014). Spatial transcriptomics showed significantly higher ABRS score, along with upregulation of various other immune effectors, in tumour areas with high ABRS-P values versus areas with low ABRS-P values. Interpretation Our study indicates that AI applied on hepatocellular carcinoma digital slides is able to serve as a biomarker for progression-free survival in patients treated with atezolizumab–bevacizumab. This approach could be used in the development of inexpensive and fast biomarkers for targeted therapies. The combination of AI heatmaps with spatial transcriptomics provides insight on the molecular features associated with predictions. This methodology could be applied to other cancers or diseases and improve understanding of the biological mechanisms that drive responses to treatments