All Publications

  • Prospective pilot study of the Three Good Things positive psychology intervention in short-term stay hospitalised patients. Postgraduate medical journal Zehner, N., Polding, L., Faraci Sindra, V., Shieh, L. 2022


    BACKGROUND: The 'Three Good Things' (3GT) positive psychology protocol developed at Duke University has been shown to decrease depressive symptoms and emotional exhaustion in healthcare providers. Whether hospitalised patients may also benefit from the 3GT protocol has not previously been explored.OBJECTIVES: To determine the impact and efficacy of the 3GT protocol with hospitalised patients experiencing serious/chronic illness.DESIGN: Patient-level randomised control trial.SETTING: Medical units of an academic, tertiary care medical centre.PATIENTS: 221 adults over the age of 18 years admitted to inpatient wards (intensive care units excluded) at Stanford Hospital between January 2017 and May 2018.INTERVENTIONS: Patients were randomised to the 3GT intervention arm or the control arm with no intervention.MEASUREMENTS AND MAIN RESULTS: There was no significant difference between the intervention and control groups in the primary outcomes of improved positivity scores, decreased negativity scores or increased positive-to-negative emotional ratios.CONCLUSIONS: A journal-based application of the 3GT protocol did not result in a statistically significant improvement in patient's emotional health.

    View details for DOI 10.1136/postgradmedj-2021-141010

    View details for PubMedID 35302042

  • Age-related Changes in Malaria Clinical Phenotypes During Infancy are Modified by Sickle Cell Trait. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America Zehner, N., Adrama, H., Kakuru, A., Andra, T., Kajubi, R., Conrad, M., Nankya, F., Clark, T. D., Kamya, M., Rodriguez-Barraquer, I., Dorsey, G., Jagannathan, P. 2021


    BACKGROUND: Young infants are protected against Plasmodium falciparum malaria. Mechanisms driving this protection remain unclear due to a poor understanding of malaria clinical phenotypes during infancy.METHODS: We enrolled a birth cohort of 678 infants in Busia, Uganda, an area of high malaria transmission. We followed infants through 12 months of age, and quantified protection against parasitemia and clinical disease.RESULTS: Symptomatic malaria incidence increased from 1.2 to 2.6 episodes per person year between 0-<6 months and 6-12 months of age, while the monthly probability of asymptomatic parasitemia given infection decreased from 32% to 21%. Sickle cell trait (HbAS) was protective against symptomatic malaria (incidence rate ratio (IRR) = 0.57 comparing HbAS vs. HbAA, 95% CI 0.44-0.74, p<0.001), but age modified this relationship (Pint=<0.001), with non-linear protection that waned between 0-9 months of age before increasing. Increasing age was associated with higher parasite densities at the time of infection, and, in infants with HbAS, a reduced ability to tolerate high parasite densities without fever.CONCLUSIONS: Age-dependent changes in HbAS protective efficacy in infancy were accompanied by differential loss of anti-parasite and anti-disease protection among HbAS and HbAA infants. This provides a framework for investigating mechanisms underlying infant protection against malaria.

    View details for DOI 10.1093/cid/ciab245

    View details for PubMedID 33738485

  • SEVERITY OF MALARIA IN A BIRTH COHORT OF INFANTS LIVING IN A HIGHLY ENDEMIC AREA OF UGANDA Zehner, N., Andra, T., Kajubi, R., Ssewanyana, I., Conrad, M., Nankya, F., Adrama, H., Clark, T. D., Kamya, M., Dorsey, G., Jagannathan, P. AMER SOC TROP MED & HYGIENE. 2019: 291–92
  • Two-Site Internally Cooperative Mechanism for Enzyme Kinetics in a Hydrogel Forming Recombinant Protein. Biomacromolecules Zehner, N. A., Dietrick, S. M., Tirrell, D. A., Kennedy, S. B. 2015; 16 (11): 3651-6


    A recombinant protein, ATCTA, consisting of three domains, α-helix (A), thrombin cleavage site (T), and water-soluble coil (C), forms hydrogels via the self-association of its flanking α-helices into tetrameric bundles, which act as cross-links for the hydrogel network. In the presence of thrombin, the hydrogel degrades due to the thrombin cleavage sites. To better understand the proteolysis reaction in ATCTA, we performed a series of kinetic experiments on the proteins ATC, CTA, CTATC, and ATCTA. The KM and kcat of ATC and CTA were determined to be 88 ± 5 μM and 6.4 ± 0.1 s(-1) and 91 ± 9 μM and 6.1 ± 0.1 s(-1), respectively. Using these kinetic parameters, a model based on a two-site internally cooperative mechanism was developed to describe the kinetics of proteins containing two cleavage sites. This model was then validated by comparing predicted results with kinetic data from the proteolysis of ATCTA.

    View details for DOI 10.1021/acs.biomac.5b01110

    View details for PubMedID 26402311