Machine Learning-Driven Multiscale Modeling: Bridging the Scales with a Next-Generation Simulation Infrastructure.

Interdependence across time and length scales is common in biology, where atomic interactions can impact larger-scale phenomenon. Such dependence is especially true for a well-known cancer signaling pathway, where the membrane-bound RAS protein binds an effector protein called RAF. To capture the driving forces that bring RAS and RAF (represented as two domains, RBD and CRD) together on the plasma membrane, simulations with the ability to calculate atomic detail while having long time and large length- scales are needed. The Multiscale Machine-Learned Modeling Infrastructure (MuMMI) is able to resolve RAS/RAF protein-membrane interactions that identify specific lipid-protein fingerprints that enhance protein orientations viable for effector binding. MuMMI is a fully automated, ensemble-based multiscale approach connecting three resolution scales: (1) the coarsest scale is a continuum model able to simulate milliseconds of time for a 1 µm2 membrane, (2) the middle scale is a coarse-grained (CG) Martini bead model to explore protein-lipid interactions, and (3) the finest scale is an all-atom (AA) model capturing specific interactions between lipids and proteins. MuMMI dynamically couples adjacent scales in a pairwise manner using machine learning (ML). The dynamic coupling allows for better sampling of the refined scale from the adjacent coarse scale (forward) and on-the-fly feedback to improve the fidelity of the coarser scale from the adjacent refined scale (backward). MuMMI operates efficiently at any scale, from a few compute nodes to the largest supercomputers in the world, and is generalizable to simulate different systems. As computing resources continue to increase and multiscale methods continue to advance, fully automated multiscale simulations (like MuMMI) will be commonly used to address complex science questions.

Endothelial cell dysfunction: Implications for the pathogenesis of peripheral artery disease.

Peripheral artery disease (PAD) is caused by occluded or narrowed arteries that reduce blood flow to the lower limbs. The treatment focuses on lifestyle changes, management of modifiable risk factors and vascular surgery. In this review we focus on how Endothelial Cell (EC) dysfunction contributes to PAD pathophysiology and describe the largely untapped potential of correcting endothelial dysfunction. Moreover, we describe current treatments and clinical trials which improve EC dysfunction and offer insights into where future research efforts could be made. Endothelial dysfunction could represent a target for PAD therapy.

Functional and Structural Brain Connectivity in Children With Bilateral Cerebral Palsy Compared to Age-Related Controls and in Response to Intensive Rapid-Reciprocal Leg Training.

Background: Compared to unilateral cerebral palsy (CP), less is known about brain reorganization and plasticity in bilateral CP especially in relation or response to motor training. The few trials that reported brain imaging results alongside functional outcomes include a handful of studies in unilateral CP, and one pilot trial of three children with bilateral CP. This study is the first locomotor training randomized controlled trial (RCT) in bilateral CP to our knowledge reporting brain imaging outcomes. Methods: Objective was to compare MRI brain volumes, resting state connectivity and white matter integrity using DTI in children with bilateral CP with PVL and preterm birth history (<34 weeks), to age-related controls, and from an RCT of intensive 12 week rapid-reciprocal locomotor training using an elliptical or motor-assisted cycle. We hypothesized that connectivity in CP compared to controls would be greater across sensorimotor-related brain regions and that functional (resting state) and structural (fractional anisotropy) connectivity would improve post intervention. We further anticipated that baseline and post-intervention imaging and functional measures would correlate. Results: Images were acquired with a 3T MRI scanner for 16/27 children with CP in the trial, and 18 controls. No conclusive evidence of training-induced neuroplastic effects were seen. However, analysis of shared variance revealed that greater increases in precentral gyrus connectivity with the thalamus and pons may be associated with larger improvements in the trained device speed. Exploratory analyses also revealed interesting potential relationships between brain integrity and multiple functional outcomes in CP, with functional connectivity between the motor cortex and midbrain showing the strongest potential relationship with mobility. Decreased posterior white matter, corpus callosum and thalamic volumes, and FA in the posterior thalamic radiation were the most prominent group differences with corticospinal tract differences notably not found. Conclusions: Results reinforce the involvement of sensory-related brain areas in bilateral CP. Given the wide individual variability in imaging results and clinical responses to training, a greater focus on neural and other mechanisms related to better or worse outcomes is recommended to enhance rehabilitation results on a patient vs. group level.

Optimal vocabulary selection approaches for privacy-preserving deep NLP model training for information extraction and cancer epidemiology.

BACKGROUND: With the use of artificial intelligence and machine learning techniques for biomedical informatics, security and privacy concerns over the data and subject identities have also become an important issue and essential research topic. Without intentional safeguards, machine learning models may find patterns and features to improve task performance that are associated with private personal information. OBJECTIVE: The privacy vulnerability of deep learning models for information extraction from medical textural contents needs to be quantified since the models are exposed to private health information and personally identifiable information. The objective of the study is to quantify the privacy vulnerability of the deep learning models for natural language processing and explore a proper way of securing patients' information to mitigate confidentiality breaches. METHODS: The target model is the multitask convolutional neural network for information extraction from cancer pathology reports, where the data for training the model are from multiple state population-based cancer registries. This study proposes the following schemes to collect vocabularies from the cancer pathology reports; (a) words appearing in multiple registries, and (b) words that have higher mutual information. We performed membership inference attacks on the models in high-performance computing environments. RESULTS: The comparison outcomes suggest that the proposed vocabulary selection methods resulted in lower privacy vulnerability while maintaining the same level of clinical task performance.

Uptake and safety of community-based "screen-and-treat" with thermal ablation preventive therapy for cervical cancer prevention in rural Lilongwe, Malawi.

Malawi has the highest invasive cervical cancer (ICC) mortality rate worldwide, and ICC is the leading cause of cancer death among women. In 2004, Malawi adopted visual inspection with acetic acid (VIA) and ablative treatment with cryotherapy. However, screening coverage has remained low (<30%) and few women (<50%) who require ablative treatment receive it. Additional barriers include long distances to health facilities and challenges with maintaining gas supplies. Thermal ablation is a safe and effective alternative to cryotherapy. We assessed the safety and uptake of community-based ICC screening with VIA and same-day treatment using a handheld thermocoagulator (HTU) in rural Malawi. We held educational talks alongside community leaders and conducted VIA screening in nonclinic community settings to nonpregnant women aged 25 to 49 years without history of hysterectomy or genital cancer/precancer. Eligible women received same-day thermal ablation and HIV testing/counseling. We collected cervical biopsies before treatment and followed up women at Weeks 6 and 12, with repeat biopsy at Week 12. Between July and August 2017, 408 (88%) of 463 eligible women underwent VIA. Overall, 7% (n = 30) of women had a positive VIA, of whom 93% (n = 28) underwent same-day thermal ablation. Among the 30 VIA-positive women, 5 had cervical intraepithelial neoplasia (CIN) 1, 4 had CIN 2/3 and 21 had benign histologic findings. Abnormal vaginal discharge (60%) and light vaginal bleeding (52%) were the most reported adverse events. There was high uptake of the community-based ICC screening in the study population and treatment was safe in this setting. Similar strategies that minimize false-positive results are urgently needed in Malawi.

Regulation of vascular tone and blood pressure by singlet molecular oxygen in inflammation.

PURPOSE OF REVIEW: The principle aim of this review is to prompt vascular researchers interested in vascular inflammation and oxidative stress to consider singlet molecular oxygen (1O2) as a potentially relevant contributor. A secondary goal is to propose novel treatment strategies to address haemodynamic complications associated with septic shock. RECENT FINDINGS: Increased inflammation and oxidative stress are hallmarks of a range of vascular diseases. We recently showed that in systemic inflammation and oxidative stress associated with models of inflammation including sepsis, the tryptophan catabolizing enzyme indoleamine 2,3-dioxygenase-1 (Ido1) contributes to hypotension and decreased blood pressure through production of singlet molecular oxygen (1O2). Once formed, 1O2 converts tryptophan bound to Ido1 to a vasoactive hydroperoxide which decreases arterial tone and blood pressure via oxidation of a specific cysteine residue of protein kinase G1α. SUMMARY: These works show, for the first time, that 1O2 contributes to arterial redox signalling and that Ido1 contributes to the regulation of blood pressure through production of a novel tryptophan-derived hydroperoxide, thus presenting a new signalling pathway as novel target in the treatment of blood pressure disorders such as sepsis.

Feasibility of upfront mobile money transfers for transportation reimbursement to promote retention among patients receiving lymphoma treatment in Malawi.

BACKGROUND: Cancer outcomes in sub-Saharan Africa (SSA) remain suboptimal, in part due to poor patient retention. Many patients travel long distances to receive care, and transportation costs are often prohibitively expensive. These are well-known and established causes of delayed treatment and care abandonment in Malawi and across SSA. METHODS: We sent visit reminder texts and offered upfront money to cover transportation costs through a mobile money transfer (MMT) platform to lymphoma patients enrolled in a prospective cohort in Malawi. The primary aim was to test the feasibility of upfront MMTs. RESULTS: We sent 1034 visit reminder texts to 189 participating patients. Of these texts, 614 (59%) were successfully delivered, with 536 (52%) responses. 320/536 (60%) MMTs were sent to interested patients and 312/320 (98%) came to their appointment on time. Of 189 total patients, 120 (63%) were reached via text and 84 (44%) received MMTs a median of three times (IQR 2-5). Median age of reachable patients was 41 (IQR 30-50), 75 (63%) were male, 62 (52%) were HIV+ and 79 (66%) resided outside of Lilongwe. CONCLUSION: MMTs were a feasible way to cover upfront transportation costs for patients reachable via text, however many of our patients were unreachable. Future studies exploring barriers to care, particularly among unreachable patients, may help improve the efficacy of MMT initiatives and guide retention strategies throughout SSA.

Uncovering a membrane-distal conformation of KRAS available to recruit RAF to the plasma membrane.

The small GTPase KRAS is localized at the plasma membrane where it functions as a molecular switch, coupling extracellular growth factor stimulation to intracellular signaling networks. In this process, KRAS recruits effectors, such as RAF kinase, to the plasma membrane where they are activated by a series of complex molecular steps. Defining the membrane-bound state of KRAS is fundamental to understanding the activation of RAF kinase and in evaluating novel therapeutic opportunities for the inhibition of oncogenic KRAS-mediated signaling. We combined multiple biophysical measurements and computational methodologies to generate a consensus model for authentically processed, membrane-anchored KRAS. In contrast to the two membrane-proximal conformations previously reported, we identify a third significantly populated state using a combination of neutron reflectivity, fast photochemical oxidation of proteins (FPOP), and NMR. In this highly populated state, which we refer to as "membrane-distal" and estimate to comprise ∼90% of the ensemble, the G-domain does not directly contact the membrane but is tethered via its C-terminal hypervariable region and carboxymethylated farnesyl moiety, as shown by FPOP. Subsequent interaction of the RAF1 RAS binding domain with KRAS does not significantly change G-domain configurations on the membrane but affects their relative populations. Overall, our results are consistent with a directional fly-casting mechanism for KRAS, in which the membrane-distal state of the G-domain can effectively recruit RAF kinase from the cytoplasm for activation at the membrane.

Use of indwelling pleural/peritoneal catheter in the management of malignant ascites: a retrospective study of 48 patients.

BACKGROUND: Patients suffering from malignant ascites usually require repeated large volume paracentesis (LVP) for symptomatic relief. This often requires hospital admission and has inherent risks. AIMS: To report the first Australian experience of placing tunnelled indwelling peritoneal catheters (IPeC) for management of recurrent malignant ascites. METHODS: A retrospective study was conducted of tunnelled IPeC use in patients with symptomatic malignant ascites in four hospitals in Western Australia (from 2010 to 2018). Procedure data, success rate and safety profile were collected from a database. RESULTS: Forty-eight patients (median age 65 years; female 56%) underwent 51 peritoneal catheter insertion procedures that were performed mostly by pleural specialists. The majority of patients (96%) had prior LVP (median two drainages, interquartile range (IQR) 1-4) before IPeC insertion. The IPeC was inserted successfully under ultrasound guidance in all patients. The median length of hospital stay for IPeC insertion and initial ascites drainage was 2 days (IQR 2-3 days) and most patients (96%) did not require further paracentesis after IPeC placement. The majority (96%) of patients experienced relief from ascites symptoms after catheter insertion. Most IPeC-related adverse events were self-limiting, including pain (in 25% cases), transient hypotension after initial fluid drainage (10%), peritoneal fluid leakage (10%), bacterial peritonitis (8%), fluid loculation (2%) and catheter dislodgement (2%). Six (12%) patients had IPeC removed. All patients with bacterial peritonitis responded to antibiotics and one required catheter removal. CONCLUSIONS: Use of tunnelled IPeC improves symptoms and can minimise further invasive drainage procedures in patients with symptomatic malignant ascites. Placement of IPeC was associated with a low rate of adverse events, most of which could be managed conservatively.

A nucleotide-dependent oligomerization of the Escherichia coli replication initiator DnaA requires residue His136 for remodeling of the chromosomal origin.

Escherichia coli replication initiator protein DnaA binds ATP with high affinity but the amount of ATP required to initiate replication greatly exceeds the amount required for binding. Previously, we showed that ATP-DnaA, not ADP-DnaA, undergoes a conformational change at the higher nucleotide concentration, which allows DnaA oligomerization at the replication origin but the association state remains unclear. Here, we used Small Angle X-ray Scattering (SAXS) to investigate oligomerization of DnaA in solution. Whereas ADP-DnaA was predominantly monomeric, AMP-PNP-DnaA (a non-hydrolysable ATP-analog bound-DnaA) was oligomeric, primarily dimeric. Functional studies using DnaA mutants revealed that DnaA(H136Q) is defective in initiating replication in vivo. The mutant retains high-affinity ATP binding, but was defective in producing replication-competent initiation complexes. Docking of ATP on a structure of E. coli DnaA, modeled upon the crystallographic structure of Aquifex aeolicus DnaA, predicts a hydrogen bond between ATP and imidazole ring of His136, which is disrupted when Gln is present at position 136. SAXS performed on AMP-PNP-DnaA (H136Q) indicates that the protein has lost its ability to form oligomers. These results show the importance of high ATP in DnaA oligomerization and its dependence on the His136 residue.

Biochemical and structural analyses reveal that the tumor suppressor neurofibromin (NF1) forms a high-affinity dimer.

Neurofibromin is a tumor suppressor encoded by the NF1 gene, which is mutated in Rasopathy disease neurofibromatosis type I. Defects in NF1 lead to aberrant signaling through the RAS-mitogen-activated protein kinase pathway due to disruption of the neurofibromin GTPase-activating function on RAS family small GTPases. Very little is known about the function of most of the neurofibromin protein; to date, biochemical and structural data exist only for its GAP domain and a region containing a Sec-PH motif. To better understand the role of this large protein, here we carried out a series of biochemical and biophysical experiments, including size-exclusion chromatography-multiangle light scattering (SEC-MALS), small-angle X-ray and neutron scattering, and analytical ultracentrifugation, indicating that full-length neurofibromin forms a high-affinity dimer. We observed that neurofibromin dimerization also occurs in human cells and likely has biological and clinical implications. Analysis of purified full-length and truncated neurofibromin variants by negative-stain EM revealed the overall architecture of the dimer and predicted the potential interactions that contribute to the dimer interface. We could reconstitute structures resembling high-affinity full-length dimers by mixing N- and C-terminal protein domains in vitro The reconstituted neurofibromin was capable of GTPase activation in vitro, and co-expression of the two domains in human cells effectively recapitulated the activity of full-length neurofibromin. Taken together, these results suggest how neurofibromin dimers might form and be stabilized within the cell.

Peptide-Induced Lipid Flip-Flop in Asymmetric Liposomes Measured by Small Angle Neutron Scattering.

Despite the prevalence of lipid transbilayer asymmetry in natural plasma membranes, most biomimetic model membranes studied are symmetric. Recent advances have helped to overcome the difficulties in preparing asymmetric liposomes in vitro, allowing for the examination of a larger set of relevant biophysical questions. Here, we investigate the stability of asymmetric bilayers by measuring lipid flip-flop with time-resolved small-angle neutron scattering (SANS). Asymmetric large unilamellar vesicles with inner bilayer leaflets containing predominantly 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and outer leaflets composed mainly of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) displayed slow spontaneous flip-flop at 37 ◦C (half-time, t1/2 = 140 h). However, inclusion of peptides, namely, gramicidin, alamethicin, melittin, or pHLIP (i.e., pH-low insertion peptide), accelerated lipid flip-flop. For three of these peptides (i.e., pHLIP, alamethicin, and melittin), each of which was added externally to preformed asymmetric vesicles, we observed a completely scrambled bilayer in less than 2 h. Gramicidin, on the other hand, was preincorporated during the formation of the asymmetric liposomes and showed a time resolvable 8-fold increase in the rate of lipid asymmetry loss. These results point to a membrane surface-related (e.g., adsorption/insertion) event as the primary driver of lipid scrambling in the asymmetric model membranes of this study. We discuss the implications of membrane peptide binding, conformation, and insertion on lipid asymmetry.

C9orf72 Poly(PR) Dipeptide Repeats Disturb Biomolecular Phase Separation and Disrupt Nucleolar Function.

Repeat expansion in the C9orf72 gene is the most common cause of the neurodegenerative disorder amyotrophic lateral sclerosis (C9-ALS) and is linked to the unconventional translation of five dipeptide-repeat polypeptides (DPRs). The two enriched in arginine, poly(GR) and poly(PR), infiltrate liquid-like nucleoli, co-localize with the nucleolar protein nucleophosmin (NPM1), and alter the phase separation behavior of NPM1 in vitro. Here, we show that poly(PR) DPRs bind tightly to a long acidic tract within the intrinsically disordered region of NPM1, altering its phase separation with nucleolar partners to the extreme of forming large, soluble complexes that cause droplet dissolution in vitro. In cells, poly(PR) DPRs disperse NPM1 from nucleoli and entrap rRNA in static condensates in a DPR-length-dependent manner. We propose that R-rich DPR toxicity involves disrupting the role of phase separation by NPM1 in organizing ribosomal proteins and RNAs within the nucleolus.

Singlet molecular oxygen regulates vascular tone and blood pressure in inflammation.

Singlet molecular oxygen (1O2) has well-established roles in photosynthetic plants, bacteria and fungi1-3, but not in mammals. Chemically generated 1O2 oxidizes the amino acid tryptophan to precursors of a key metabolite called N-formylkynurenine4, whereas enzymatic oxidation of tryptophan to N-formylkynurenine is catalysed by a family of dioxygenases, including indoleamine 2,3-dioxygenase 15. Under inflammatory conditions, this haem-containing enzyme is expressed in arterial endothelial cells, where it contributes to the regulation of blood pressure6. However, whether indoleamine 2,3-dioxygenase 1 forms 1O2 and whether this contributes to blood pressure control have remained unknown. Here we show that arterial indoleamine 2,3-dioxygenase 1 regulates blood pressure via formation of 1O2. We observed that in the presence of hydrogen peroxide, the enzyme generates 1O2 and that this is associated with the stereoselective oxidation of L-tryptophan to a tricyclic hydroperoxide via a previously unrecognized oxidative activation of the dioxygenase activity. The tryptophan-derived hydroperoxide acts in vivo as a signalling molecule, inducing arterial relaxation and decreasing blood pressure; this activity is dependent on Cys42 of protein kinase G1α. Our findings demonstrate a pathophysiological role for 1O2 in mammals through formation of an amino acid-derived hydroperoxide that regulates vascular tone and blood pressure under inflammatory conditions.

Bloodstream infections in oncology patients at Red Cross War Memorial Children's Hospital, Cape Town, from 2012 to 2014.

OBJECTIVES: This study was performed to investigate the epidemiology of bloodstream infection (BSI) in oncology patients at Red Cross War Memorial Children's Hospital (RCWMCH), Cape Town, with focus placed on the most common causes, complications, and antimicrobial susceptibilities in BSI. METHODS: A retrospective cross-sectional study was conducted in the Haematology-Oncology Unit of RCWMCH. All positive blood cultures from RCWMCH oncology patients obtained in 2012 to 2014 were retrieved to identify cases of BSI. RESULTS: Three hundred and forty-three positive cultures were identified, for 150 BSI episodes among 89 patients; 49.1% of the culture isolates were Gram-positive bacteria, 41.6% were Gram-negative bacteria, and 9.3% were fungal. Coagulase-negative Staphylococcus and viridans group Streptococcus were the most common Gram-positive isolates. Escherichia coli and Klebsiella species were the most common Gram-negative isolates. The majority of BSI episodes occurred in patients with haematological malignancies (74%), in the presence of severe neutropenia (76.4%), and were associated with chemotherapy (88%). Complications occurred in 14% of BSI. Fungal infections had the highest prevalence of complications (21.4%). Three children died during BSI, giving a case-fatality rate of 2%. CONCLUSIONS: BSI in these patients was caused mainly by Gram-positive bacteria and was associated with a low case-fatality rate. These results are consistent with worldwide experience of BSI in paediatric oncology.

Aggressive versus symptom-guided drainage of malignant pleural effusion via indwelling pleural catheters (AMPLE-2): an open-label randomised trial.

BACKGROUND: Indwelling pleural catheters are an established management option for malignant pleural effusion and have advantages over talc slurry pleurodesis. The optimal regimen of drainage after indwelling pleural catheter insertion is debated and ranges from aggressive (daily) drainage to drainage only when symptomatic. METHODS: AMPLE-2 was an open-label randomised trial involving 11 centres in Australia, New Zealand, Hong Kong, and Malaysia. Patients with symptomatic malignant pleural effusions were randomly assigned (1:1) to the aggressive (daily) or symptom-guided drainage groups for 60 days and minimised by cancer type (mesothelioma vs others), performance status (Eastern Cooperative Oncology Group [ECOG] score 0-1 vs ≥2), presence of trapped lung, and prior pleurodesis. Patients were followed up for 6 months. The primary outcome was mean daily breathlessness score, measured by use of a 100 mm visual analogue scale during the first 60 days. Secondary outcomes included rates of spontaneous pleurodesis and self-reported quality-of-life measures. Results were analysed by an intention-to-treat approach. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12615000963527. FINDINGS: Between July 20, 2015, and Jan 26, 2017, 87 patients were recruited and randomly assigned to the aggressive (n=43) or symptom-guided (n=44) drainage groups. The mean daily breathlessness scores did not differ significantly between the aggressive and symptom-guided drainage groups (geometric means 13·1 mm [95% CI 9·8-17·4] vs 17·3 mm [13·0-22·0]; ratio of geometric means 1·32 [95% CI 0·88-1·97]; p=0·18). More patients in the aggressive group developed spontaneous pleurodesis than in the symptom-guided group in the first 60 days (16 [37·2%] of 43 vs five [11·4%] of 44, p=0·0049) and at 6 months (19 [44·2%] vs seven [15·9%], p=0·004; hazard ratio 3·287 [95% CI 1·396-7·740]; p=0·0065). Patient-reported quality-of-life measures, assessed with EuroQoL-5 Dimensions-5 Levels (EQ-5D-5L), were better in the aggressive group than in the symptom-guided group (estimated means 0·713 [95% CI 0·647-0·779] vs 0·601 [0·536-0·667]). The estimated difference in means was 0·112 (95% CI 0·0198-0·204; p=0·0174). Pain scores, total days spent in hospital, and mortality did not differ significantly between groups. Serious adverse events occurred in 11 (25·6%) of 43 patients in the aggressive drainage group and in 12 (27·3%) of 44 patients in the symptom-guided drainage group, including 11 episodes of pleural infection in nine patients (five in the aggressive group and six in the symptom-guided drainage group). INTERPRETATION: We found no differences between the aggressive (daily) and the symptom-guided drainage regimens for indwelling pleural catheters in providing breathlessness control. These data indicate that daily indwelling pleural catheter drainage is more effective in promoting spontaneous pleurodesis and might improve quality of life. FUNDING: Cancer Council of Western Australia and the Sir Charles Gairdner Research Advisory Group.

Translation, psychometric validation, and baseline results of the Patient-Reported Outcomes Measurement Information System (PROMIS) pediatric measures to assess health-related quality of life of patients with pediatric lymphoma in Malawi.

INTRODUCTION: Internationally validated tools to measure patient-reported health-related quality of life (HRQoL) are available, but efforts to translate and culturally validate such tools in sub-Saharan Africa (SSA) are scarce, particularly among children. METHODS: The Patient-Reported Outcomes Measurement Information System 25-item pediatric short form (PROMIS-25) assesses six HRQoL domains-mobility, anxiety, depression, fatigue, peer relationships, and pain interference-by asking four questions per domain. There is a single-item pain intensity item. The PROMIS-25 was translated into Chichewa and validated for use in Malawi using mixed qualitative and quantitative methods. The validity and reliability of the PROMIS-25 was assessed. RESULTS: Fifty-four pediatric patients with lymphoma completed the PROMIS-25. Structural validity was supported by interitem correlations and principal component analysis. Reliability of each scale was satisfactory (range alpha = 0.71-0.93). Known group validity testing showed that anemic children had worse fatigue (P = 0.016) and children with poor performance status had worse mobility (P < 0.001) and pain interference (P = 0.005). Compared to children with cancer in the United States, children from Malawi reported lower levels of mobility, higher anxiety, higher depressive symptoms, higher fatigue, better satisfaction with peer relationships, and higher pain interference. CONCLUSION: Translation and cultural validation of the PROMIS-25 into Chichewa for Malawi was successful. Baseline HRQoL for patients with pediatric lymphoma in Malawi is poor for all domains except peer relationships. This emphasizes an urgent need to address HRQoL among children undergoing cancer treatment in SSA using self-reported instruments validated within the local context.

Utilization of fine needle aspiration cytology at Kamuzu central hospital.

BACKGROUND: Fine needle aspiration cytology (FNAC) has been widely accepted to be a safe, accurate, prompt and inexpensive procedure for diagnosis of both neoplastic and infectious diseases in adult and pediatric populations. Despite its value for diagnosis, FNAC is underutilized in resource limited countries. We reviewed the utilization of FNAC after it was introduced at Kamuzu Central Hospital (KCH). METHODS: A retrospective review of all FNAC performed at KCH laboratory during the period of January 2012 to July 2014 was conducted using an electronic database from KCH laboratory. We evaluated factors associated with a diagnostic sample using multivariate logistic regression model. RESULTS: 750 FNAC were reviewed from 722 patients: 56.9% were adults >15 years and 54% were female. The number of FNAC increased annually from 56 (2012) to 379 (2013) to 315 (up to July 2014). Of 750 FNAC, 56.4% were performed by non-pathologists. The most common sites were lymph nodes (38.1%), abdomen (25.8%), breast (16.3%), and head & neck (15.7%). Most of the samples (77.6%) were diagnostic. FNAC was more likely to be diagnostic if performed by pathologists versus non-pathologists (OR 1.78, 95% CI 1.20-2.64), in 2013 compared to 2012 (OR 1.95, 95% CI 1.05-3.56), or performed on a deep lesion versus a subcutaneous lesion (OR 1.71, 95% CI 1.15-2.5), or if samples were taken from the head and neck (OR 2.4, 95% CI: 1.39-4.39), and abdomen (OR 2.66, 95%CI1.59-4.42) compared to those from the lymph nodes. The odds of a diagnostic test did not differ significantly according to gender, HIV status, or age groups. CONCLUSION: Most FNACs successfully diagnosed the presence or absence of disease, with substantial improvements over time. However, training for non-pathologists may facilitate more diagnostic results.

Risk factors and reasons for treatment abandonment among children with lymphoma in Malawi.

PURPOSE: Lymphoma is the commonest pediatric cancer in sub-Saharan Africa (SSA). Frequent treatment abandonment contributes to suboptimal outcomes. We examined risk factors and reasons for treatment abandonment for this population in Malawi. METHODS: We conducted a mixed methods study among children < 18 years old with newly diagnosed lymphoma, prospectively enrolled during 2013-2016. All children received standardized diagnosis and treatment, and were followed for up to 2 years. Treatment abandonment was defined as failure to attend prescribed chemotherapy within 4 weeks, or post-treatment visit within 3 months. Child, guardian, and household characteristics associated with treatment abandonment were assessed. Semi-structured interviews were conducted with primary caregivers of children experiencing treatment abandonment. RESULTS: Of 121 children with newly diagnosed lymphoma, 72 (60%) had complete information regarding child, guardian, and household characteristics. Of these, 56 (78%) had Burkitt's and 16 (22%) Hodgkin's lymphoma. Forty-nine (68%) were male, median age was 10.6 years (interquartile range [IQR] 7.9-13.0), and 26 (36%) experienced treatment abandonment. Lack of guardian education and travel time ≥ 4 h to clinic were independently associated with treatment abandonment, with adjusted hazard ratio (aHR) 3.8 [95% confidence interval (CI) 1.5-8.9, p = 0.005] and aHR 2.9 (95% CI 1.2-6.9, p = 0.019), respectively. Commonest reasons for treatment abandonment endorsed by 15 guardians were community influence, suboptimal clinic environment, logistical challenges, transport costs, treatment toxicities, loss of hope, alternative healers, and beliefs about cure. CONCLUSIONS: These findings highlight families at risk for treatment abandonment, underlying reasons, and opportunities to improve retention in care for pediatric cancer patients in SSA.