Solution Structures of the Acyl Carrier Protein Domain from the Highly Reducing Type I Iterative Polyketide Synthase CalE8

Biosynthesis of the enediyne natural product calicheamicins γ1I in Micromonospora echinospora ssp. calichensis is initiated by the iterative polyketide synthase (PKS) CalE8. Recent studies showed that CalE8 produces highly conjugated polyenes as potential biosynthetic intermediates and thus belongs to a family of highly-reducing (HR) type I iterative PKSs. We have determined the NMR structure of the ACP domain (meACP) of CalE8, which represents the first structure of a HR type I iterative PKS ACP domain. Featured by a distinct hydrophobic patch and a glutamate-residue rich acidic patch, meACP adopts a twisted three-helix bundle structure rather than the canonical four-helix bundle structure. The so-called ‘recognition helix’ (α2) of meACP is less negatively charged than the typical type II ACPs. Although loop-2 exhibits greater conformational mobility than other regions of the protein with a missing short helix that can be observed in most ACPs, two bulky non-polar residues (Met992, Phe996) from loop-2 packed against the hydrophobic protein core seem to restrict large movement of the loop and impede the opening of the hydrophobic pocket for sequestering the acyl chains. NMR studies of the hydroxybutyryl- and octanoyl-meACP confirm that meACP is unable to sequester the hydrophobic chains in a well-defined central cavity. Instead, meACP seems to interact with the octanoyl tail through a distinct hydrophobic patch without involving large conformational change of loop-2. NMR titration study of the interaction between meACP and the cognate thioesterase partner CalE7 further suggests that their interaction is likely through the binding of CalE7 to the meACP-tethered polyene moiety rather than direct specific protein-protein interaction

Hypothermia for moderate or severe neonatal encephalopathy in low-income and middle-income countries (HELIX): a randomised controlled trial in India, Sri Lanka, and Bangladesh

Background: Although therapeutic hypothermia reduces death or disability after neonatal encephalopathy in high-income countries, its safety and efficacy in low-income and middle-income countries is unclear. We aimed to examine whether therapeutic hypothermia alongside optimal supportive intensive care reduces death or moderate or severe disability after neonatal encephalopathy in south Asia. Methods: We did a multicountry open-label, randomised controlled trial in seven tertiary neonatal intensive care units in India, Sri Lanka, and Bangladesh. We enrolled infants born at or after 36 weeks of gestation with moderate or severe neonatal encephalopathy and a need for continued resuscitation at 5 min of age or an Apgar score of less than 6 at 5 min of age (for babies born in a hospital), or both, or an absence of crying by 5 min of age (for babies born at home). Using a web-based randomisation system, we allocated infants into a group receiving whole body hypothermia (33·5°C) for 72 h using a servo-controlled cooling device, or to usual care (control group), within 6 h of birth. All recruiting sites had facilities for invasive ventilation, cardiovascular support, and access to 3 Tesla MRI scanners and spectroscopy. Masking of the intervention was not possible, but those involved in the magnetic resonance biomarker analysis and neurodevelopmental outcome assessments were masked to the allocation. The primary outcome was a combined endpoint of death or moderate or severe disability at 18–22 months, assessed by the Bayley Scales of Infant and Toddler Development (third edition) and a detailed neurological examination. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT02387385. Findings: We screened 2296 infants between Aug 15, 2015, and Feb 15, 2019, of whom 576 infants were eligible for inclusion. After exclusions, we recruited 408 eligible infants and we assigned 202 to the hypothermia group and 206 to the control group. Primary outcome data were available for 195 (97%) of the 202 infants in the hypothermia group and 199 (97%) of the 206 control group infants. 98 (50%) infants in the hypothermia group and 94 (47%) infants in the control group died or had a moderate or severe disability (risk ratio 1·06; 95% CI 0·87–1·30; p=0·55). 84 infants (42%) in the hypothermia group and 63 (31%; p=0·022) infants in the control group died, of whom 72 (36%) and 49 (24%; p=0·0087) died during neonatal hospitalisation. Five serious adverse events were reported: three in the hypothermia group (one hospital readmission relating to pneumonia, one septic arthritis, and one suspected venous thrombosis), and two in the control group (one related to desaturations during MRI and other because of endotracheal tube displacement during transport for MRI). No adverse events were considered causally related to the study intervention. Interpretation: Therapeutic hypothermia did not reduce the combined outcome of death or disability at 18 months after neonatal encephalopathy in low-income and middle-income countries, but significantly increased death alone. Therapeutic hypothermia should not be offered as treatment for neonatal encephalopathy in low-income and middle-income countries, even when tertiary neonatal intensive care facilities are available. Funding: National Institute for Health Research, Garfield Weston Foundation, and Bill & Melinda Gates Foundation. Translations: For the Hindi, Malayalam, Telugu, Kannada, Singhalese, Tamil, Marathi and Bangla translations of the abstract see Supplementary Materials section

Neoadjuvant chemotherapy among patients treated for nonmetastatic breast cancer in a population with a high HIV prevalence in Johannesburg, South Africa

Paul Ruff,1,2 Herbert Cubasch,2,3 Maureen Joffe,2,4 Evan Rosenbaum,5 Nivashni Murugan,2,3 Ming-Chih Tsai,2,3 Oluwatosin Ayeni,2 Katherine D Crew,5–7 Judith S Jacobson,6,7 Alfred I Neugut5–7 1Division of Medical Oncology, Department of Internal Medicine, University of the Witwatersrand, Faculty of Health Sciences, 2Noncommunicable Diseases Research Division, Wits Health Consortium, University of the Witwatersrand, Faculty of Health Sciences, 3Department of Surgery, Chris Hani Baragwanath Academic Hospital and University of the Witwatersrand, Faculty of Health Sciences, 4MRC Developmental Pathways of Health Research Unit, Department of Paediatrics, University of Witwatersrand, Faculty of Health Sciences, Johannesburg, South Africa; 5Department of Medicine, College of Physicians and Surgeons, Columbia University, 6Herbert Irving Comprehensive Cancer Center, Columbia University, 7Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA Background: Neoadjuvant (primary) chemotherapy (NACT) is the standard of care for locally advanced breast cancer. It also allows for the short-term assessment of chemotherapy response; a pathological complete responses correspond to improved long-term breast cancer outcomes. In sub-Saharan Africa, many patients are diagnosed with large nonresectable tumors. We examined NACT use in breast cancer patients who visited public hospitals in Johannesburg, South Africa. Methods: We assessed demographic characteristics, tumor stage and grade, hormone receptor status, and human immunodeficiency virus (HIV) status of female patients diagnosed with nonmetastatic invasive carcinoma of the breast at Chris Hani Baragwanath Academic Hospital between January 1, 2009, and December 31, 2011. The patients received neoadjuvant, adjuvant, or no chemotherapy. Trastuzumab was unavailable. We developed logistic regression models to analyze the factors associated with NACT receipt in these patients. Results: Of 554 women with nonmetastatic breast cancer, the median age at diagnosis was 52 years (range: 28–88 years). Only 5.8% of patients were diagnosed with stage I disease; 49.3% and 44.9% were diagnosed with stages II and III, respectively. Most patients had hormone-responsive tumors: luminal A, 38.1%; luminal B1 (human epidermal growth factor receptor 2 [HER2]-negative and high grade), 12.5%, and luminal B2 (HER2-positive any grade), 11.6%; 11.6% had a HER2-enriched tumor and 20.6% a triple-negative tumor. Eighty (14.4%) patients were HIV-positive. In total, 195 patients (35.2%) received NACT, 264 (47.7%) patients received adjuvant chemotherapy, and 95 patients (17.1%) received no chemotherapy, including 62 (11.2%) patients who received only hormonal therapy. Of patients receiving NACT, 125 (64.1%) were evaluable for clinical response. Eighty (64.0%) patients had a clinically significant response; 19 (15.2%) patients had a stable disease, and 26 (20.8%) patients had a progressive disease. Multivariate analysis showed age <40 years and disease stage to be independently associated with the receipt of NACT. Conclusion: Most women receiving NACT with available response data showed a clinical benefit. Stage III disease at diagnosis and age <40 years were predictors of neoadjuvant versus adjuvant chemotherapy treatment. Keywords: breast cancer, chemotherapy, neoadjuvant, South Africa, HIV, LMIC

The Drug Release Study of Ceftriaxone from Porous Hydroxyapatite Scaffolds

Hydroxyapatite (HAP) is an important biomedical material that is used for grafting osseous defects. It has an excellent bioactivity and biocompatibility properties. To isolate hydroxyapatite, pieces of cleaned cattle’s bone were heated at different temperature range from 400°C up to 1,200°C. A reasonable yield of 60.32% w/w HAP was obtained at temperature range from 1,000°C to 1,200°C. Fourier transform infrared spectra and the thermogravimetric measurement showed a clear removal of organic at 600°C as well as an excellent isolation of HAP from the bones which was achieved at 1,000–1,200°C. This was also confirmed from X-ray diffraction of bone sample heated at 1,200°C. The concentration ions were found to be sodium, potassium, lithium, zinc, copper, iron, calcium, magnesium, and phosphate present in bones within the acceptable limits for its role in the bioactivity property of HAP. Glucose powder was used as a porosifier. Glucose was novel and excellent as porogen where it was completely removed by heating, giving an efficient porosity in the used scaffolds. The results exhibited that the ceftriaxone drug release was increased with increasing the porosity. It was found that a faster, higher, and more regular drug release was obtained from the scaffold with a porosity of 10%