Effect of Feronia limonia on mosquito larvae

Bioassay guided fractionation of the acetone extract of Feronia limonia dried leaves afforded a potent mosquito larvicide, identified as n-hexadecanoic acid and found to be effective against fourth instar larvae of Culex quinquefasciatus, Anopheles stephensi and Aedes aegypti, with LC50 of 129.24, 79.58 and 57.23 ppm, respectively.

Folding and characterization of the amino-terminal domain of human tissue inhibitor of metalloproteinases-1 (TIMP-1) expressed at high yield in E. coli

Methods are described for producing an active amino-terminal domain of tissue inhibitor of metalloproteinases-1 (N-TIMP-1) from inactive protein expressed as inclusion bodies in E. coli. Yields exceed 20 mg per litre of bacterial culture. Activity measurements, CD spectroscopy and NMR spectroscopy of the 15N-labeled protein show that it is fully active, homogeneous in conformation and suitable for high-resolution structural analysis. The affinity of N-TIMP-1 for matrix metalloproteinases 1, 2 and 3 is 6-8-fold less than that of the recombinant full-length protein, indicating that deletion of the C-terminal domain reduces the free energy of interaction by < 10%.

Increased backbone mobility in beta-barrel enhances entropy gain driving binding of N-TIMP-1 to MMP-3

The high-affinity inhibition of stromelysin 1 (MMP-3) by tissue inhibitor of metalloproteinases 1 (TIMP-1) helps control tissue remodeling and tumor development. The interaction of N-TIMP-1 with the catalytic domain of MMP-3 has been investigated by titration calorimetry and 15N NMR. Their unfavorable enthalpy of binding of +6.5 kcal mol(-1) is unusual among protein-protein associations, deviates from structure-based prediction, and is compensated by a net entropy increase providing at least 18 kcal mol(-1) of favorable free energy of binding at a 1M reference state. The small heat capacity of binding agrees well with the heat capacity predicted from 65% of the surface buried on binding being polar, and suggests that the hydrophobic effect can account for only part of the entropy of binding. Using NMR, binding-induced changes in the backbone of N-TIMP-1 were checked as one possible source of conformational entropy changes. MMP binding slightly increases rigidity in some contact sites in TIMP-1 but increases mobility remotely in the otherwise rigid beta-barrel core of N-TIMP-1, increasing 15N relaxation evidence of pico- to nanosecond and micro- to millisecond fluctuations of beta-strands A-F. Residual dipolar couplings suggest dynamic deviations from X-ray coordinates of the complex. These suggest that the beta-barrel has small backbone conformational fluctuations, while segments of strands betaB, betaE and betaF might experience fluctuations only in their backbone environment. This is a distinctive example of affinity between two well-structured proteins being enhanced by increased conformational entropy in the reservoir of a folding core.

Effect of Bi-functional Hierarchical Flower-like CoS Nanostructure on its Interfacial Charge Transport Kinetics, Magnetic and Electrochemical Behaviors for Supercapacitor and DSSC Applications

Metal sulfides are of great interest for future electrode materials in supercapacitor and solar cell applications owing to their superior electrochemical activity and excellent electrical conductivity. With this scope, a binary transition metal sulfide (CoS) is prepared via one-step hydrothermal synthesis. Hexagonal phase of CoS with space group of P6₃/mmc(194) is confirmed by XRD analysis. Additional cubic Co₃S₄ phase in the prepared sample originates the mixed valence state of Co (Co²⁺ and Co³⁺) is affirmed from XPS analysis. Morphological features are visualized using HRSEM images that shows nanoflower shaped star-anise structure. Employing the prepared CoS as active electrode material, interfacial charge transport kinetics is examined by EIS-Nyquist plot. The supercapacitive performances are tested in two and three-electrode system which exhibited respective specific capacitances of 57 F/g and 348 F/g for 1 A/g. Further, the fabricated asymmetric CoS//AC supercapacitor device delivers an appreciable energy density of 15.58 Wh/kg and power density of 700.12 W/kg with excellent cyclic stability of 97.9% and Coulombic efficiency of 95% over 2000 charge-discharge cycles. In addition, dye-sensitized solar cells are fabricated with CoS counter electrode and the obtained power conversion efficiency of 5.7% is comparable with standard platinum based counter electrode (6.45%). Curie-Weiss plot confirms the transition of paramagnetic nature into ferrimagnetic behavior at 85 K and Pauli-paramagnetic nature at 20 K respectively. Temperature dependent resistivity plot affirms the metallic nature of CoS sample till 20 K and transition to semiconducting nature occurs at <20 K owing to Peierl’s transition effect.

Curcumin ameliorates streptozotocin-induced liver damage through modulation of endoplasmic reticulum stress-mediated apoptosis in diabetic rats

We investigated the effect of curcumin on liver injury in diabetic rats induced by streptozotocin (STZ) through modulation of endoplasmic reticulum stress (ERS) and unfolded protein response (UPR). Experimental diabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg), and curcumin was given at 100 mg/kg by gavage for 56 days. We observed that curcumin improved the morphological and histopathological changes, significantly decreased hepatic ERS marker protein: glucose-regulated protein 78, and improved liver function in diabetic rats. Moreover, treatment with curcumin markedly decreased the sub-arm of the UPR signaling protein such as phospho-double-stranded RNA-dependent protein kinase-like ER kinase, CCAAT/enhancer-binding protein homologous protein, tumor necrosis factor receptor-associated factor 2, and inositol-requiring enzyme1α; and inhibited tumor necrosis factor α, interleukin 1β, phospho-p38 mitogen-activated protein kinase, and apoptosis signal-regulating kinase 1 in liver tissues of diabetic rats. Apoptotic and anti-apoptotic signaling proteins, such as cleaved caspase-3 and B-cell lymphoma 2, were significantly increased and decreased, respectively in diabetic rats; curcumin treatment prevented all of these alterations. In summary, our results indicate that curcumin has the potential to protect the diabetic liver by modulating hepatic ERS-mediated apoptosis, and provides a novel therapeutic strategy for the diabetic liver damage.

Conformational trapping in a membrane environment: a regulatory mechanism for protein activity?

Functional regulation of proteins is central to living organisms. Here it is shown that a nonfunctional conformational state of a polypeptide can be kinetically trapped in a lipid bilayer environment. This state is a metastable structure that is stable for weeks just above the phase transition temperature of the lipid. When the samples are incubated for several days at 68 degrees C, 50% of the trapped conformation converts to the minimum-energy functional state. This result suggests the possibility that another mechanism for functional regulation of protein activity may be available for membrane proteins: that cells may insert proteins into membranes in inactive states pending the biological demand for protein function.

Three-photon microscopy shows that somatic release can be a quantitatively significant component of serotonergic neurotransmission in the mammalian brain

Recent experiments on monoaminergic neurons have shown that neurotransmission can originate from somatic release. However, little is known about the quantity of monoamine available to be released through this extrasynaptic pathway or about the intracellular dynamics that mediate such release. Using three-photon microscopy, we directly imaged serotonin autofluorescence and investigated the total serotonin content, release competence, and release kinetics of somatic serotonergic vesicles in the dorsal raphe neurons of the rat. We found that the somata of primary cultured neurons contain a large number of serotonin-filled vesicles arranged in a perinuclear fashion. A similar distribution is also observed in fresh tissue slice preparations obtained from the rat dorsal raphe. We estimate that the soma of a cultured neuron on an average contains about 9 fmoles of serotonin in about 450 vesicles (or vesicle clusters) of < or =370 nm average diameter. A substantial fraction (>30%) of this serotonin is released with a time scale of several minutes by K(+)-induced depolarization or by para-chloroamphetamine treatment. The amount of releasable serotonin stored in the somatic vesicles is comparable to the total serotonin content of all the synaptic vesicles in a raphe neuron, indicating that somatic release can potentially play a major role in serotonergic neurotransmission in the mammalian brain.

The monensin-mediated transport of Na+ and K+ through phospholipid bilayers studied by 23Na- and 39K-NMR

Addition of monesin to preparations of large unilamellar vesicles made from egg yolk phosphatidylcholine (EPC) in sodium or potassium chloride solution and from dioleoylphosphatidylcholine (DOPC) in sodium chloride solutions gives rise to dynamic 23Na- and 39K-NMR spectra. The dynamic spectra arise from the monensin-mediated transport of the metal ions through the membrane. The kinetics of the transport are followed as a function of monensin and metal ion concentrations and are compatible with a model in which one monensin molecule transports one metal ion. Rate constants for the association and dissociation of the monensin-metal complex in the membrane/water interface are extracted and the stability constants for complex formation are evaluated. The rate constants in DOPC are similar to those in EPC, confirming that diffusion is not rate-limiting in the transport process and that dissociation of the complex is the rate-limiting step. Although potassium on its own is transported more rapidly, sodium forms the more stable complex and is therefore transported preferentially in competition with potassium.

TIMP-1 contact sites and perturbations of stromelysin 1 mapped by NMR and a paramagnetic surface probe

Surfaces of the 173 residue catalytic domain of human matrix metalloproteinase 3 (MMP-3(DeltaC)) affected by binding of the N-terminal, 126 residue inhibitory domain of human TIMP-1 (N-TIMP-1) have been investigated using an amide-directed, NMR-based approach. The interface was mapped by a novel method that compares amide proton line broadening by paramagnetic Gd-EDTA in the presence and absence of the binding partner. The results are consistent with the X-ray model of the complex of MMP-3(DeltaC) with TIMP-1 (Gomis-Rüth et al. (1997) Nature 389, 77-81). Residues Tyr155, Asn162, Val163, Leu164, His166, Ala167, Ala169, and Phe210 of MMP-3(DeltaC) are protected from broadening by the Gd-EDTA probe by binding to N-TIMP-1. N-TIMP-1-induced exposure of backbone amides of Asp238, Asn240, Gly241, and Ser244 of helix C of MMP-3(DeltaC) to Gd-EDTA confirms that the displacement of the N-terminus of MMP-3(DeltaC) occurs not only in the crystal but also in solution. These results validate comparative paramagnetic surface probing as a means of mapping protein-protein interfaces. Novel N-TIMP-1-dependent changes in hydrogen bonding near the active site of MMP-3(DeltaC) are reported. N-TIMP-1 binding causes the amide of Tyr223 of MMP-3(DeltaC) bound by N-TIMP-1 to exchange with water rapidly, implying a lack of the hydrogen bond observed in the crystal structure. The backbone amide proton of Asn162 becomes protected from rapid exchange upon forming a complex with N-TIMP-1 and could form a hydrogen bond to N-TIMP-1. N-TIMP-1 binding dramatically increases the rate of amide hydrogen exchange of Asp177 of the fifth beta strand of MMP-3(DeltaC), disrupting its otherwise stable hydrogen bond.

Surface charge effects upon membrane transport processes: the effects of surface charge on the monensin-mediated transport of lithium ions through phospholipid bilayers studied by 7Li-NMR spectroscopy

Addition of monensin to preparations of large unilamellar vesicles prepared from egg-yolk phosphatidylcholine (egg PC) or egg PC containing 5% phosphatidylserine (PS-) or cetylpyridinium (CP+) ions in lithium chloride solution allows the transport of Li+ ions to be monitored by an NMR magnetisation transfer technique. The kinetics of the transport are followed as a function of the metal ion and monensin concentrations and are compatible with a model in which one monensin molecule transports one Li+ ion. The data allow the extraction of the rate constants for the association and dissociation of the monensin-Li+ complex in the water/membrane interfaces and the evaluation of the stability constants for complex formation in the interfaces. Placing positive charge (CP+) on the membrane surface reduces the formation rate by a factor of about three but hardly alters the dissociation rate. Placing negative charge (PS-) on the membrane surface hardly alters the formation rate but speeds the dissociation rate by about a factor of three. Data from relaxation times of 7Li+ inside the vesicles and from the total enclosed volumes as the vesicles are formed, point to appreciable Li+ surface interactions that increase as the charge on the surface is made more negative. The size of the vesicles formed by the dialytic detergent removal technique increases with the surface charge. The results support a view that enzyme-phospholipid or substrate-phospholipid interactions could play an important role in determining the efficacity of action of membrane bound enzymes. The relevance of the results in the role of Li+ in the control of manic depression is also discussed.

Changes in matrix composition during the growth and regression of human hemangiomas

BACKGROUND

Hemangiomas offer an uncommon opportunity to study rapid vessel growth and spontaneous regression of a vascular human tumor. In contrast, venous malformations are another type of vascular tumor that grows slowly without spontaneous involution. Extracellular matrix (ECM) molecules modulate the responsiveness of endothelial cells to mitogenic stimuli such as basic fibroblast growth factor (bFGF), a well-recognized stimulant of angiogenesis. In this study we hypothesized that in hemangiomas, sites of angiogenesis may have a different ECM composition than sites of vascular regression.

MATERIALS AND METHODS

Using immunohistochemistry, we analyzed proliferating hemangiomas, regressing hemangiomas, venous malformations, and normal skin for the basement membrane ECM molecules collagen IV and laminin and plasma-borne ECM molecules fibronectin and vitronectin. We used metabolic labeling to determine whether primary human dermal microvascular endothelial cells regulated FGFR-1 or FGFR-2 when grown on these different matrices.

RESULTS

We found that proliferating hemangiomas showed extensive deposition of vitronectin in the subendothelial space. In contrast, regressing hemangiomas or venous malformations did not show vitronectin deposition. Venous malformations, which are composed of ectatic lakes of venous channels, also lacked laminin in their basement membranes. We also found that cultured microvascular endothelial cells grown on vitronectin increased synthesis of FGFR-1 and FGFR-2 protein.

CONCLUSIONS

Changes in the ECM environment occur in conjunction with the angiogenic state of a vascular human tumor. Furthermore, changes in the ECM environment alone can directly regulate synthesis of angiogenic growth factor receptors.

NMR structure of tissue inhibitor of metalloproteinases-1 implicates localized induced fit in recognition of matrix metalloproteinases

A high quality solution structure of the matrix metalloproteinase inhibitory N-terminal domain of recombinant human tissue inhibitor of metalloproteinases-1 (N-TIMP-1) has been determined. For the rigidly packed residues, the average RMSD to the mean structure is 0. 57 A for the backbone atoms and 1.00 A for all heavy atoms. Comparison of the solution structure of free N-TIMP-1 with the crystal structure of TIMP-1 bound to the catalytic domain of MMP-3 ( Gomis-R]uth et al., 1997 ) shows that the structural core of the beta barrel flanked by helices is nearly unchanged by the association with MMP-3, evident from a backbone RMSD of 1.15 A. However, clear differences in the conformation of the MMP-binding ridge of free and MMP-bound TIMP-1 suggest induced fit throughout the ridge. The MMP-dependent conformational changes in the ridge include a dramatic bending of AB loop residues Glu28 through Leu34, moderate hinge bending of the CD-loop about residues Ala65 and Cys70, and modest bending of the Cys1 through Pro6 segment. A large number of interresidue Nuclear Overhauser enhancements (NOEs) augmented by stereospecific assignments, torsion restraints, and dipolar couplings (an average of 18 non-trivial restraints per residue) engender confidence in these structural inferences. A tight cluster of three lysine residues and one arginine residue atop beta-strands A and B, and identical among TIMP sequences, form the heart of a highly conserved electropositive patch that may interact with anionic components of the extracellular matrix.

Pretreatment loss to follow-up of tuberculosis patients in Chennai, India: a cohort study with implications for health systems strengthening

Background

Pretreatment loss to follow-up (PTLFU) is a barrier to tuberculosis (TB) control in India’s Revised National TB Control Programme (RNTCP). PTLFU studies have not been conducted in India’s mega-cities, where patient mobility may complicate linkage to care.

Methods

We collected data from patient registries for May 2015 from 22 RNTCP designated microscopy centers (DMCs) in Chennai and audited addresses and phone numbers for patients evaluated for suspected TB to understand how missing contact information may contribute to PTLFU. From November 2015 to June 2016, we audited one month of records from each of these 22 DMCs and tracked newly diagnosed smear-positive patients using RNTCP records, phone calls, and home visits. We defined PTLFU cases as including: (1) patients who did not start TB therapy within 14 days and (2) patients who started TB therapy but were lost to follow-up or died before official RNTCP registration. We used multivariate logistic regression to identify factors associated with PTLFU.

Results

In the audit of May 2015 DMC registries, out of 3696 patients evaluated for TB, 1273 (34.4%) had addresses and phone numbers that were illegible or missing. Out of 344 smear-positive patients tracked from November 2015 to June 2016, 40 (11.6%) did not start TB therapy within 14 days and 36 (10.5%) started therapy but were lost to follow-up or died before official RNTCP registration, for an overall PTLFU rate of 22.1% (95%CI: 17.8%—26.4%). Of all PTLFU patients, 55 (72.4%) were lost to follow-up and 21 (27.6%) died before starting treatment or before RNTCP registration. In the regression analysis, age > 50 years (OR 2.9, 95%CI 1.4—6.5), history of prior TB (OR 3.9, 95%CI 2.2—7.1), evaluation at a high patient volume DMC (OR 3.2, 95% CI 1.7—6.3), and absence of legible patient contact information (OR 4.5, 95%CI 1.3—15.1) were significantly associated with PTLFU.

Conclusions

In an Indian mega-city, we found a high PTLFU rate, especially in patients with a prior TB history, who are at greater risk for having drug-resistance. Enhancing quality of care and health system transparency is critical for improving linkage of newly diagnosed patients to TB care in urban India.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3039-3) contains supplementary material, which is available to authorized users.

Survival motor neuron protein reduction deregulates autophagy in spinal cord motoneurons in vitro

Spinal muscular atrophy (SMA) is a genetic disorder characterized by degeneration of spinal cord motoneurons (MNs), resulting in muscular atrophy and weakness. SMA is caused by mutations in the Survival Motor Neuron 1 (SMN1) gene and decreased SMN protein. SMN is ubiquitously expressed and has a general role in the assembly of small nuclear ribonucleoproteins and pre-mRNA splicing requirements. SMN reduction causes neurite degeneration and cell death without classical apoptotic features, but the direct events leading to SMN degeneration in SMA are still unknown. Autophagy is a conserved lysosomal protein degradation pathway whose precise roles in neurodegenerative diseases remain largely unknown. In particular, it is unclear whether autophagosome accumulation is protective or destructive, but the accumulation of autophagosomes in the neuritic beadings observed in several neurite degeneration models suggests a close relationship between the autophagic process and neurite collapse. In the present work, we describe an increase in the levels of the autophagy markers including autophagosomes, Beclin1 and light chain (LC)3-II proteins in cultured mouse spinal cord MNs from two SMA cellular models, suggesting an upregulation of the autophagy process in Smn (murine survival motor neuron protein)-reduced MNs. Overexpression of Bcl-x_L counteracts LC3-II increase, contributing to the hypothesis that the protective role of Bcl-x_L observed in some SMA models may be mediated by its role in autophagy inhibition. Our in vitro experimental data indicate an upregulation in the autophagy process and autophagosome accumulation in the pathogenesis of SMA, thus providing a valuable clue in understanding the mechanisms of axonal degeneration and a possible therapeutic target in the treatment of SMA.

Role of alpha(v) integrins and angiogenesis during wound repair

Angiogenesis, the formation of new blood vessels from pre-existing blood vessels, is thought to be critical for wound repair. Yet few studies have critically examined dermal wound repair in a system in which angiogenesis was impaired. Since alpha(v)-containing integrins are critical for angiogenesis, we administered either an alpha(v) integrin blocking antibody or cyclic Arg-Gly-Asp peptide into a murine excisional wound model to restrict wound angiogenesis. Although both methods markedly decreased wound angiogenesis, decreased angiogenesis had no significant effect on wound epithelization, contraction, or ultimate wound closure. These results suggest that if other cellular components of wound healing are intact, moderate impairment of angiogenesis alone does not necessarily retard normal wound healing.

Sonochemical synthesis, structural, magnetic and grain size dependent electrical properties of NdVO4 nanoparticles

NdVO4 nanoparticles are successfully synthesized by efficient sonochemical method using two different structural directing agents like CTAB and P123. The phase formation and functional group analysis are carried out using X-ray diffraction (XRD) and fourier transform infra red (FT-IR) spectra, respectively. Using Scherrer equation the calculated grain sizes are 27 nm, 24 nm and 20 nm corresponding to NdVO4 synthesized by without surfactant, with CTAB and P123, respectively. The TEM images revealed that the shape of NdVO4 particles is rice-like and rod shaped particles while using CTAB and P123 as surfactants. The growth mechanism of NdVO4 nanoparticles is elucidated with the aid of TEM analysis. From electrical analysis, the conductivity of NdVO4 nanoparticles synthesized without surfactant showed a higher conductivity of 5.5703 × 10(-6) S cm(-1). The conductivity of the material depends on grain size and increased with increase in grain size due to the grain size effect. The magnetic measurements indicated the paramagnetic behavior of NdVO4 nanoparticles.

Understanding pretreatment loss to follow-up of tuberculosis patients: an explanatory qualitative study in Chennai, India

Introduction

Pretreatment loss to follow-up (PTLFU)-dropout of patients after diagnosis but before treatment registration-is a major gap in tuberculosis (TB) care in India and globally. Patient and healthcare worker (HCW) perspectives are critical for developing interventions to reduce PTLFU.

Methods

We tracked smear-positive TB patients diagnosed via sputum microscopy from 22 diagnostic centres in Chennai, one of India's largest cities. Patients who did not start therapy within 14 days, or who died or were lost to follow-up before official treatment registration, were classified as PTLFU cases. We conducted qualitative interviews with trackable patients, or family members of patients who had died. We conducted focus group discussions (FGDs) with HCWs involved in TB care. Interview and FGD transcripts were coded and analysed with Dedoose software to identify key themes. We created categories into which themes clustered and identified relationships among thematic categories to develop an explanatory model for PTLFU.

Results

We conducted six FGDs comprising 53 HCWs and 33 individual patient or family member interviews. Themes clustered into five categories. Examining relationships among categories revealed two pathways leading to PTLFU as part of an explanatory model. In the first pathway, administrative and organisational health system barriers-including the complexity of navigating the system, healthcare worker absenteeism and infrastructure failures-resulted in patients feeling frustration or resignation, leading to disengagement from care. In turn, HCWs faced work constraints that contributed to many of these health system barriers for patients. In the second pathway, negative HCW attitudes and behaviours contributed to patients distrusting the health system, resulting in refusal of care.

Conclusion

Health system barriers contribute to PTLFU directly and by amplifying patient-related challenges to engaging in care. Interventions should focus on removing administrative hurdles patients face in the health system, improving quality of the HCW-patient interaction and alleviating constraints preventing HCWs from providing patient-centred care.

Tissue inhibitor of metalloproteinases-1 undergoes microsecond to millisecond motions at sites of matrix metalloproteinase-induced fit

The N-terminal, matrix metalloproteinase (MMP)-inhibitory fragment of recombinant, human tissue inhibitor of metalloproteinases (TIMP-1) exhibits varied backbone dynamics and rigidity. Most striking is the presence of chemical exchange in the MMP-binding ridge reported to undergo conformational change upon MMP binding. Conformational exchange fluctuations in microseconds to milliseconds map to the sites of MMP-induced fit at residues Val29 through Leu34 of the AB loop and to the Ala65 and Cys70 "hinges" of the CD loop of TIMP-1. Slow chemical exchange is also present at the type I turn of the EF loop at the base of the MMP-binding ridge. These functional slow motions and other fast internal motions are evident from backbone (15)N spin relaxation at 500 and 750 MHz, whether interpreted by the model-free formalism with axial diffusion anisotropy or by the reduced spectral density approach. The conformational exchange is confirmed by its deviation from the trend between R(2) and the cross-correlation rate eta. The magnetic field-dependence indicates that the chemical exchange broadening in the AB and CD loops is fast on the time-scale of chemical shift differences. The conformational exchange rates for most of these exchanging residues, which can closely approach MMP, appear to be a few thousand to several thousand per second. The slow dynamics of the TIMP-1 AB loop contrast the picosecond to nanosecond dynamics reported in the longer TIMP-2 AB loop.

The Evidence for External Beam Radiotherapy in High-Risk Neuroblastoma of Childhood: A Systematic Review

AIMS

External beam radiotherapy is widely used in various ways in the management of neuroblastoma. Despite extensive clinical experience, the precise role of radiotherapy in neuroblastoma remains unclear. The purpose of this systematic review was to survey the published literature to identify, without bias, the evidence for the clinical effectiveness of external beam radiotherapy as part of the initial multimodality treatment of high-risk neuroblastoma. We considered four areas: treatment of the tumour bed and residual primary tumour, identification of any dose-response relationship, treatment of metastatic sites, identification of any technical advances that may be beneficial. We also aimed to define uncertainties, which may be clarified in future clinical trials.

MATERIALS AND METHODS

Bibliographic databases were searched for neuroblastoma and radiotherapy. Reviewers assessed 1283 papers for inclusion by title and abstract, with consensus achieved through discussion. Data extraction on 57 included papers was carried out by one reviewer and checked by another. Studies were assessed for their level of evidence and risk of bias, and a descriptive analysis of data was carried out.

RESULTS

Fifteen papers provided some evidence that radiotherapy to the tumour bed and residual tumour may possibly be of value. However, there is a significant risk of bias and no evidence that all subgroups will benefit. There is some suggestion from six papers that dose may be important, but no hard evidence. It remains unclear whether irradiation of metastatic sites is helpful. Technical advances may be of value in radiotherapy of high-risk neuroblastoma.

CONCLUSIONS

There are data that show that radiotherapy is of some efficacy in the management of high-risk neuroblastoma, but there is no level one evidence that shows that it is being used in the best possible way. Prospective randomised trials are necessary to provide more evidence to guide development of optimal radiotherapy treatment schedules.