A joint physics and radiobiology DREAM team vision - Towards better response prediction models to advance radiotherapy.

Radiotherapy developed empirically through experience balancing tumour control and normal tissue toxicities. Early simple mathematical models formalized this practical knowledge and enabled effective cancer treatment to date. Remarkable advances in technology, computing, and experimental biology now create opportunities to incorporate this knowledge into enhanced computational models. The ESTRO DREAM (Dose Response, Experiment, Analysis, Modelling) workshop brought together experts across disciplines to pursue the vision of personalized radiotherapy for optimal outcomes through advanced modelling. The ultimate vision is leveraging quantitative models dynamically during therapy to ultimately achieve truly adaptive and biologically guided radiotherapy at the population as well as individual patient-based levels. This requires the generation of models that inform response-based adaptations, individually optimized delivery and enable biological monitoring to provide decision support to clinicians. The goal is expanding to models that can drive the realization of personalized therapy for optimal outcomes. This position paper provides their propositions that describe how innovations in biology, physics, mathematics, and data science including AI could inform models and improve predictions. It consolidates the DREAM team's consensus on scientific priorities and organizational requirements. Scientifically, it stresses the need for rigorous, multifaceted model development, comprehensive validation and clinical applicability and significance. Organizationally, it reinforces the prerequisites of interdisciplinary research and collaboration between physicians, medical physicists, radiobiologists, and computational scientists throughout model development. Solely by a shared understanding of clinical needs, biological mechanisms, and computational methods, more informed models can be created. Future research environment and support must facilitate this integrative method of operation across multiple disciplines.

Characteristics of heart failure with a preserved ejection fraction in black South African patients.

Background: Heart failure with a preserved ejection fraction (HFpEF) is common in the elderly (≥75 years) and associated with arterial stiffness. The mean age of HFpEF presentation is lower (40-55 years) in sub-Saharan Africa. No clinical study has been conducted on HFpEF in identifying and characterising this phenotype at a younger age, moreover in a South African black population where the risk of HFpEF is two times higher than in other ethnic groups. This study investigated the characteristics of HFpEF in a black South African population, the biochemical markers that predict HFpEF and cardiac structural changes in this HF phenotype. Methods: Sixty-six participants with HFpEF and 213 controls were enrolled. All participants gave informed consent and completed a standardised questionnaire. Echocardiographic, anthropometric, central haemodynamic measurements, pulse wave velocity (PWV) and biomarker analysis were done. Results: The mean age of HFpEF participants was 54.88 ± 13.51 years. Most of the participants (76 %) were between 20 and 64 years, while only 24 % were older. HFpEF participants were hypertensive, and more obese with increased incidence of alcohol consumption. PWV was increased in HFpEF (9.97 ± 2.78 m/s) when compared to participants without HFpEF (6.11 ± 2.18 m/s), p < 0.0001. There were no significant associations between central haemodynamic parameters, N-terminal pro B-type natriuretic peptide (NT-proBNP) (p = 0.9746), and galectin-3 (p = 0.2166). NT-proBNP, but not galectin-3, was associated with left ventricular hypertrophy (p = 0.0002) and left atrial diameter (p = 0.0005). Conclusion: HFpEF in South Africa is predominant in obese young to middle-age individuals with arterial stiffness and who consume alcohol regularly. NT-proBNP could be used to diagnose HFpEF, however, should be interpreted with caution in populations with a high prevalence of obesity.

Mouse organoids as an in vitro tool to study the in vivo intestinal response to cytotoxicants.

Cross-species comparison of drug responses at the organoid level could help to determine the human relevance of findings from animal studies. To this end, we first need to evaluate the in vitro to in vivo translatability of preclinical organoids. Here, we used 5-fluorouracil (5-FU) as an exemplar drug to test whether the in vivo gut response to this cytotoxicant was preserved in murine intestinal organoids. Mice treated with 5-FU at 20 or 50 mg/kg IV (low and high dose, respectively) displayed diarrhea at clinically relevant exposures. 5-FU also induced intestinal lesions, increased epithelial apoptosis, and decreased proliferation in a dose-dependent manner. To enable comparison between the in vitro and in vivo response, top nominal in vitro drug concentrations that caused significant cytotoxicity were chosen (dose range 1-1000 µM). The inferred intracellular concentration in organoids at 1000 µM was within the tissue exposure range related to intestinal toxicity in vivo. 5-FU at ≥ 100 µM decreased ATP levels and increased Caspase-3 activity in intestinal organoids. In keeping with the in vivo findings, 5-FU increased the percentage of Caspase-3-positive cells and reduced Ki67 staining. At the transcriptome level, there was an overlap in the activity of pathways related to 5-FU's mode of action, lipid and cholesterol metabolism and integrin signaling across in vivo gut and organoids. The predicted activity state of upstream regulators was generally well preserved between setups. Collectively, our results suggest that despite their inherent limitations, organoids represent an adequate tool to explore the intestinal response to cytotoxicants.

Large-scale production of 88Y and 88Zr/88Y generators: A proof of concept study for a 70 MeV H- cyclotron.

The large-scale production of 88Y with proton-induced reactions has been investigated from the perspective of new generation 70 MeV H- cyclotrons. Tandem target configurations are presented for both the direct production of 88Y as well as for producing 88Zr/88Y generators. Based on the relevant excitation functions, physical yields have been derived for 88Y production with Y2O3/SrCO3 tandem targets and 88Zr production with Zr/Y2O3 tandem targets. Yields are presented for optimized targets (i.e. optimum yield) as well as for balanced thermal loads on the individual targets. Liquid 88Zr/88Y generators have been produced using both natural Zr and Nb target materials, the former for dedicated productions and the latter as a byproduct by processing spent irradiated Nb capsules which normally would constitute radioactive waste. These stock solutions, which contain both the target material and 88Zr precursor, are retained virtually unchanged after processing except for the removal of 88Y on AG MP-50 macroporous cation-exchange resin. Methods are presented for the preparation of Nb stock solutions in hydrofluoric acid and Zr stock solutions in sulphuric acid. It is shown that multi-Ci productions of 88Y are feasible at a 70 MeV cyclotron facility, suitable for the needs of fracking applications. In addition, 88Zr/88Y generators can provide 88Y with very high specific activity, suitable for labelling of biomolecules. LA-UR-20-24305.

Different methods of cell quantification can lead to different results: a comparison of digital methods using a pilot study of dendritic cells in HIV-positive patients.

BACKGROUND: Although new digital pathology tools have improved the positive cell quantification, there is a heterogeneity of the quantification methods in the literature. The aim of this study was to evaluate and propose a novel dendritic cells quantification method in squamous cell carcinoma comparing it with a conventional quantification method. MATERIAL AND METHODS: Twenty-six squamous cell carcinomas HIV-positive cases affecting the oropharynx, lips and oral cavity were selected. Immunohistochemistry for CD1a, CD83, and CD207 was performed. The immunohistochemical stains were evaluated by automated examination using a positive pixel count algorithm. A conventional quantification method (unspecific area method; UA) and a novel method (specific area method; SA) were performed obtaining the corresponding density of positive dendritic cells for the intratumoral and peritumoral regions. The Mann-Whitney U test was used to verify the influence of the quantification methods on the positive cell counting according to the evaluated regions. Data were subjected to the ANOVA and Student's t-test to verify the influence of the tumour location, stage, histological grade, and amount of inflammation on the dendritic cells density counting. RESULTS: The cell quantification method affected the dendritic cells counting independently of the evaluated region (P-value <0.05). Significant differences between methods were also observed according to the tumour features evaluations. CONCLUSIONS: The positive cell quantification method influences the dendritic cells density results. Unlike the conventional method (UA method), the novel SA method avoids non-target areas included in the hotspots improving the reliability and reproducibility of the density cell quantification.

Extending the life of SnO268Ge/68Ga generators used in the radiolabelling of ion exchange resins.

The SnO268Ge/68Ga generator system is widely used in medical imaging to provide a regular supply of the radionuclide 68Ga (T½ = 68.3 min) for positron emission tomography (PET). These generators are also used to supply 68Ga for the fabrication of tracer particles for application in positron emission particle tracking (PEPT). The tracer particles are fabricated by radiolabelling ion exchange resins such as Purolite NRW100 with 68Ga; however, contaminants from the degradation of the SnO2 column over time interfere with the uptake of 68Ga. The major contaminants are Zn(II), Fe(III) and Sn(IV) with 68Ge (IV) being eluted from the column as it degrades. This paper describes an improved method to purify the 68Ga supply using an Amberchrom CG-71m absorption resin column integrated into a newly designed separation panel. This method reduces the amount of Zn(II) and Fe(III) in the 68Ga eluate and improves the radiolabelling performance by more than 10% when compared to the un-purified product. The method can extend the life-span of the generator by several months.

Hydrallantois in the mare--a report of five cases.

Hydrallantois in the mare is a very rare condition, and clinical reports help to gather information to elucidate its pathogenesis, treatment options and prognosis. Five different cases of hydrallantois in the mare are reported in this article, all with the involvement of placentitis. The five mares were presented because of acute distention of the abdomen, dyspnoea, stiff gait and a lack of appetite. After a gradual release of the excessive amount of allantoic fluid, an abortion was induced in all five mares. The foals were either born dead or euthanized. The mares recovered quickly. One mare conceived within the same season, one remained barren despite several cycles of natural breeding, and no data were available on the other three mares. In this series, the condition is reported for the first time in two Shetland ponies, both pregnant with foals sharing a close genetic background. In both cases, the condition led to hyperlipidemia. The condition as it occurs in nulliparous mares is also discussed. Finally, the possible involvement of placentitis in the pathogenesis is emphasized.

Prevalence and correlates of atypical patterns of drug use progression: findings from the South African Stress and Health Study.

OBJECTIVE: Atypical sequences of drug use progression are thought to have important implications for the development of substance dependence. The extent to which this assumption holds for South African populations is unknown. This paper attempts to address this gap by examining the prevalence and correlates of atypical patterns of drug progression among South Africans. METHOD: Data on substance use and other mental health disorders from a nationally representative sample of 4351 South Africans were analysed. Weighted cross tabulations were used to estimate prevalence and correlates of atypical patterns of drug use progression. RESULTS: Overall, 12.2% of the sample reported atypical patterns of drug use progression. The most common violation was the use of extra-medical drugs prior to alcohol and tobacco. Gender was significantly associated with atypical patterns of drug use with the risk pattern varying by the type of drug. None of the anxiety or mood disorders were associated with atypical patterns of use. Atypical patterns of drug use were not associated with increased risk for a lifetime substance use disorder. CONCLUSION: Atypical patterns of drug use initiation seem more prevalent in South Africa compared to other countries. The early use of extra-medical drugs is common, especially among young women. Drug availability and social environmental factors may influence patterns of drug use. The findings have important implications for prevention initiatives and future research.

Immunohistochemical profile of odontogenic epithelium in developing dog teeth (Canis familiaris).

Tumors of the jaw bones and oral soft tissue are relatively common lesions in dogs. The aim of this study was to find cell markers to differentiate odontogenic epithelium from nonodontogenic epithelium for future research on the pathogenesis and pathology of odontogenic neoplasms in dogs. Keratin 14 and 19 staining was observed in odontogenic and nonodontogenic epithelium, whereas amelogenin and p75 neurotrophin receptor immunoreactivity was observed in certain odontogenic epithelial cells at various stages of development but not in other epithelial cells. Calretinin staining was observed in the alveolar epithelial cells directly overlying the developing tooth germ in 28 of 39 sections (71.8%), as well as the dental laminae in 30 of 35 sections (85.7%) and Serres rests in 24 of 28 sections (85.7%). Focal positivity was detected in the respiratory mucosa, some hair follicles, and fusion epithelium of the palate, but no calretinin staining was observed in other oral epithelial cells; therefore, calretinin has potential to be utilized as a marker to differentiate odontogenic form nonodontogenic epithelium.

Tracheal carcinosarcoma (true malignant mixed tumour) in a Belgian Blue heifer.

This report describes a case of a carcinosarcoma or true malignant mixed tumour (salivary gland type) of the trachea in a Belgian Blue heifer. At post-mortem examination a nodular, well-circumscribed, firmly attached mass was found in the tracheal wall, severely compressing the tracheal lumen. Histologically the tumour was biphasic, with varying proportions of epithelial elements dispersed throughout a matrix showing varying degrees of myxo-chondroid and cartilaginous differentiation. The histological features of the tumour were consistent with a combination of an adenoid cystic carcinoma and a chondrosarcoma. Immunolabelling demonstrated smooth muscle actin in the cytoplasm of both the epithelial and mesenchymal components, thus fulfilling the diagnostic criteria for a mixed tumour. To our knowledge this is the first report of a mixed tumour of the trachea in a domestic animal.

On the longevity of Schistosoma curassoni.

It is demonstrated that Schistosoma curassoni, a parasite of sheep, cattle and goats in parts of West Africa, will live for at least 8 years 5 months in a sheep. The sheep was exposed to 500 cercariae of S. curassoni liberated from infected Bulinus wrighti. The sheep died of natural causes, and at post-mortem 28 pairs of adult S. curassoni were removed from the mesenteric and rectal veins. All female worms were gravid, and eggs were hatched from faeces to produce miracidia. The development of immune responses of the host had apparently little or no effect on the viability of the eggs. Histological studies of the liver, small and large intestines revealed mild pathological symptoms. The longevity of S. curassoni is the first record of longevity of schistosomes to be based on worm counts.

The suitability of paraffin-embedded material to predict metastatic potential of oral squamous cell carcinoma.

BACKGROUND: The presence of regional metastasis in oral squamous cell carcinoma (OSCC) is an important prognostic factor. This study was undertaken to identify histological features and biological markers from paraffin-embedded primary OSCC that may predict the presence of regional metastases. MATERIALS AND METHODS: Fifty-three en-bloc primary OSCC resections were divided into two groups, 26 with lymph node metastases and 27 without metastases. The pattern of infiltration, presence of vascular or perineural infiltration and tumour necrosis were evaluated while expression of p53, p21 and Rb were assessed in the two groups. DNA ploidy status was also determined with a flow cytometer. RESULTS: The presence of DNA aneuploidy was found to be the only statistically significant predictor of regional metastases. Seventy-seven per cent of the primary OSCC with lymph node metastases showed DNA aneurploidy. CONCLUSION: DNA flow cytometry obtained from archival material could be used as a parameter to predict regional metastases.

Fhit protein expression in oral epithelium: immunohistochemical evaluation of three antisera.

BACKGROUND: A number of studies have shown that the Fhit tumour suppressor protein is abundantly expressed in normal epithelial cells of human organs and that this expression is lost or reduced in the majority of cancers arising in these epithelial tissues. A variety of antiFhit sera have been used but a systematic comparison of the different antisera has not yet been reported. MATERIALS AND METHODS: We compared the Fhit expression pattern in the epithelium of fibrous epuli, oral lichen planus, oral epithelial dysplasia and oral squamous cell carcinomas (OSCC) using three different Fhit antisera. RESULTS: The antigstFhit sera from two sources gave very similar results for all types of oral lesions except for lichen planus and showed that about 60% of OSCCs have lost Fhit expression. CONCLUSION: Although different staining patterns were found for the three antisera, all three could be used for evaluation of Fhit expression in OSCC.

FHIT RNA and protein expression in oral squamous cell carcinomas.

BACKGROUND: To investigate the possible role of FHIT, a possible tumour suppressor gene, in oral carcinogenesis, we examined 17 oral squamous cell carcinomas (OSCCs) for genetic alterations. MATERIALS AND METHODS: Fresh tissue was obtained during surgery, snap-frozen in liquid nitrogen and stored at -70 degrees C. Nested PCR amplification to examine the integrity of FHIT mRNA was performed on the reverse transcribed complementary DNA obtained from the frozen normal and tumour tissue. Immunohistochemistry was done on formal in-fixed paraffin-embedded tissue protein from the same cases using a polyclonal antiserum against the full length Fhit. RESULTS: Twelve out 17 (71%) OSCCs showed reduced or absent Fhit protein and half of the cases with reduced Fhit protein exhibited aberrant RT-PCR products. CONCLUSION: Immunohistochemical detection of Fhit protein expression in OSCCs is the more sensitive method to determine the status of Fhit in these tumours, in agreement with previous studies of other tumour types.

Immunohistochemical evaluation of Fhit protein expression in oral squamous cell carcinomas.

The expression of Fhit (fragile histidine triad) protein in oral squamous cell carcinoma (OSCC) and adjacent oral epithelium was evaluated by immunohistochemistry on formalin-fixed paraffin-embedded blocks of 32 cases of OSCC. Rabbit polyclonal anti-GST-Fhit antiserum at 1:600 was used, after antigen enhancement in a microwave pressure cooker, in a saturated lead thiocyanate solution. This antiserum has been shown specifically to detect human Fhit by immunohistochemistry at dilutions up to 1:10,000. The Fhit protein expression was evaluated using both the intensity and extent of staining. Normal stratified squamous epithelium showed strong positivity, especially in the stratum spinosum and areas of keratinisation. Basal and parabasal cells were negative or expressed low levels of Fhit relative to the squamous epithelium. Mild and moderate epithelial dysplasia showed Fhit expression in the superficial layers, while Fhit expression was absent from severely dysplastic lesions. A reduction or loss of Fhit expression was found in 21 (66%) of the OSCC. The alterations in Fhit protein expression in OSCC, and not in normal tissues, are consistent with the proposal that Fhit inactivation plays a role in oral carcinogenesis.

Warthin's tumour is not an Epstein-Barr virus related disease.

BACKGROUND: The histogenesis of Warthin's tumour (WT) is controversial. A possible role for Epstein-Barr virus (EBV) has been suggested. MATERIALS AND METHODS: Twenty formaldehyde-fixed, paraffin-embedded blocks of WT from the parotid gland were examined for the presence of EBV. In situ hybridisation was performed using EBV encoded small nuclear RNAs (EBER1/2) probes labelled with fluorescein isothiocyanate. An EBV-positive P3HR-1 cell line processed to paraffin wax was used as a positive control and a brain section as negative control. RESULTS: EBER1/2 could not be found in the neoplastic epithelial cells in any of the tumours nor in the adjacent normal parotid tissues. Individual positive lymphocytes were present in 7 tumours. CONCLUSIONS: These results indicated that EBV is not involved in the pathogenesis of WT.

A comparison of norepinephrine- and ACTH-stimulated lipolysis in white and brown adipocytes of female rats.

1. Isolated white and brown adipocytes (WFA and BFA) from the rat were compared with respect to their lipolytic responsiveness towards norepinephrine (NE) and adrenocorticotrophic hormone (ACTH). 2. NE yielded a Km value of 702.7 +/- 30.6 nM for WFA and 142.5 +/- 7.2 nM for BFA. The maximum lipolytic response (Vm) was 145.7 +/- 1.2 nmol glycerol/micrograms DNA/90 min for WFA and 23.7 +/- 0.2 nmol glycerol/micrograms DNA/90 min for BFA. 3. ACTH yield Km values of 31.6 +/- 1.5 and 31.9 +/- 3.1 nM for WFA and BFA, respectively. Vm values of 141.9 +/- 1.0 and 34.2 +/- 0.5 nmol glycerol/micrograms DNA/90 min were observed for WFA and BFA, respectively.