Corrigendum: An Alternative Perfusion Approach for the Intensification of Virus-Like Particle Production in HEK293 Cultures

[This corrects the article DOI: 10.3389/fbioe.2020.00617.].

A Qualitative Assessment of Bone Mineral Density in Individuals With Hemifacial Microsomia: A Cone-Beam Computed Tomography Study

OBJECTIVE

The purpose of this study is to utilize cone-beam computed tomography (CBCT) to compare the bone mineral density (BMD) on the affected versus nonaffected side, among individuals with hemifacial microsomia (HFM).

METHODS

This retrospective study included 9 patients with HFM. Pretreatment CBCT volumes were imported into Invivo5 software, which was used to measure BMD through Hounsfield units (HU) in 3 regions of the mandible; inferior to the lower lateral incisors, inferior to the first molar and at the ramus inferior to the sigmoid notch. Each region was measured at the buccal cortical bone, lingual cortical bone, and cancellous bone. The densities on the right and left sides were compared by Wilcoxon signed-rank test.

RESULTS

Overall, the BMD on the affected side tended to show slightly lower values when compared with the nonaffected side. Differences ranged from 14 HU at the lingual cortical plate of the first molar region to 234 HU at the buccal cortical plate of the ramus region. Differences were only statistically significant at the ramus region for the buccal (P = .002) and lingual (P < .001) cortical plates and at the lower incisor region at the buccal cortical plate (P = .016) and cancellous bone (P = .044). The differences, however, did not seem to be clinically significant.

CONCLUSIONS

The current study shows that the quality of bone on the affected side may be slightly reduced but did not seem to be clinically significant. This should be accounted for during surgical and orthodontic planning for patients with HFM.

An Alternative Perfusion Approach for the Intensification of Virus-Like Particle Production in HEK293 Cultures

Virus-like particles (VLPs) have gained interest over the last years as recombinant vaccine formats, as they generate a strong immune response and present storage and distribution advantages compared to conventional vaccines. Therefore, VLPs are being regarded as potential vaccine candidates for several diseases. One requirement for their further clinical testing is the development of scalable processes and production platforms for cell-based viral particles. In this work, the extended gene expression (EGE) method, which consists in consecutive media replacements combined with cell retransfections, was successfully optimized and transferred to a bioreactor operating in perfusion. A process optimization using design of experiments (DoE) was carried out to obtain optimal values for the time of retransfection, the cell specific perfusion rate (CSPR) and transfected DNA concentration, improving 86.7% the previously reported EGE protocol in HEK293. Moreover, it was successfully implemented at 1.5L bioreactor using an ATF as cell retention system achieving concentrations of 6.8·10¹⁰ VLP/mL. VLP interaction with the ATF hollow fibers was studied via confocal microscopy, field emission scanning electron microscopy, and nanoparticle tracking analysis to design a bioprocess capable of separating unassembled Gag monomers and concentrate VLPs in one step.

Using an expanded scalp flap without fascial flap harvest or skin grafting for total auricular reconstruction in hemifacial microsomia with low hairline

BACKGROUND

Total auricular reconstruction for hemifacial microsomia patients with extremely low hairline is a tough challenge in plastic surgery. In this work, a brand new technique using a singer expanded scalp flap without skin graft and combined with intense pulse light treatments (IPLT) for ear reconstruction is described in this special population.

METHODS

From January 2015 to April 2019, 41 hemifacial macrosomia (HFM) patients with 70-100% low hairline were enrolled in our study. Operative treatment was performed in 3 stages: 1. Expander insertion and inflation; 2. Expander removal, costal cartilage framework fabrication and auricular reconstruction; 3. Tragus reconstruction and reconstructed auricle refinement. Several IPLTs were performed every 45 days until local area become hairless during the whole course. The first IPLT could be executed either before all the operations or during the expansion period. The flap was treated with M22 system using a filter of 695-1200 nm. Follow up ranged from 10 months to 4 years.

RESULTS

During follow-up, 90.2% patients were surveyed as satisfied with the outcome, especially in the aspects of minimal scars, natural matched color and clear contour of the reconstructed ear. No serious complications happened. Patients starting the IPLT during the expansion period required less treatment times of depilation (p < 0.05).

CONCLUSION

Auricular reconstruction using a single expanded scalp flap combined with intense pulse light depilation is a safe, effective and less invasive technique for hemifacial microsomia with extremely low hairline, and providing highly satisfying results. Initialing the IPLD during the expansion period is recommended.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Effects of high fat medium conditions on cellular gene expression profile: a network analysis approach

AIM

This study aimed to evaluate high fat medium (HFM) effect on the gene expression profile of human Sk-hep1 cells and to determine critical differential proteins.

BACKGROUND

There is a correlation between high fat diet (HFD), obesity, and non-alcoholic fatty liver disease. Despite wide range of investigations, understanding molecular mechanism of HFD effect on onset and progression of NAFLD warrants further examination. In this study, network analysis is applied to obtain a clear perspective about HFD effects and NAFLD.

METHODS

Gene expression profiles of human Sk-hep1 cells treated with HFM versus controls were extracted from GEO. Data were analyzed by GEO2R where the significant and characterized DEGs were included in the PPI network. The top 10 nodes of query DEGs based on four centrality parameters were selected to determine central nodes. The common hub nodes with at least other one central group were identified as central nodes. Action map was provided for the introduced central nodes.

RESULTS

Heterogeneous nuclear ribonucleoprotein family including A1, A2/B1, D, R, and D-like, and five proteins (PRPF40A, SRSF1, PCF11, LSM8, and HSP90AA1) were introduced as differential proteins.

CONCLUSION

mRNA processing and several biological terms including hypoxia and oxidative stress, apoptosis, regulation of cell morphology and cytoskeletal organization, and differentiation of micro tubes were introduced as dysregulated terms under HFM condition.

The proton-coupled folate transporter (PCFT-SLC46A1) and the syndrome of systemic and cerebral folate deficiency of infancy: Hereditary folate malabsorption

The proton-coupled folate transporter (PCFT-SLC46A1) is the mechanism by which folates are absorbed across the brush-border membrane of the small intestine. The transporter is also expressed in the choroid plexus and is required for transport of folates into the cerebrospinal fluid. Loss of PCFT function, as occurs in the autosomal recessive disorder "hereditary folate malabsorption" (HFM), results in a syndrome characterized by severe systemic and cerebral folate deficiency. Folate-receptor alpha (FRα) is expressed in the choroid plexus, and loss of function of this protein, as also occurs in an autosomal recessive disorder, results solely in "cerebral folate deficiency" (CFD), the designation for this disorder. This paper reviews the current understanding of the functional and structural properties and regulation of PCFT, an electrogenic proton symporter, and contrasts PCFT properties with those of the reduced folate carrier (RFC), an organic anion antiporter, that is the major route of folate transport to systemic tissues. The clinical characteristics of HFM and its treatment, based upon the thirty-seven known cases with the clinical syndrome, of which thirty have been verified by genotype, are presented. The ways in which PCFT and FRα might interact at the level of the choroid plexus such that each is required for folate transport from blood to cerebrospinal fluid are considered along with the different clinical presentations of HFM and CFD.

Stress in Parents of a Child with Hemifacial Microsomia: The Role of Child Characteristics and Parental Coping Strategies

OBJECTIVE

Examine stress levels of parents of children with hemifacial microsomia (HFM) and the relationship of parental stress to child characteristics and cognitive coping strategies.

DESIGN

Prospective cross-sectional study.

PARTICIPANTS AND SETTING

Parents with a child (age 3-19 years) with HFM (N = 31) were recruited through the Department of Orthodontics and the Craniofacial Center, Sophia-Erasmus Medical Center, Rotterdam, The Netherlands. Intervention and Outcome Measures: The adapted and shortened Dutch version of the parental stress index (NOSI-K) was used to measure parental stress, and the cognitive emotion-regulation questionnaire was used to measure cognitive coping strategies. Pearson correlations and a multiple regression analysis were performed.

RESULTS

The hierarchical multiple regression analysis showed associations between increased parental stress and learning difficulties and use of acceptance as a coping strategy. This suggests that problems other than the characteristic visual appearance of the child's face in HFM have a greater influence on parental stress.

CONCLUSIONS

Learning difficulties of the child with HFM and parental acceptance affect stress in parents with a child with HFM the most and are important in the search for a targeted tailoring of intervention for parents with high levels of parental stress.

Role of the tryptophan residues in proton-coupled folate transporter (PCFT-SLC46A1) function

The proton-coupled folate transporter (PCFT) mediates folate absorption across the brush-border membrane of the proximal small intestine and is required for folate transport across the choroid plexus into the cerebrospinal fluid. In this study, the functional role and accessibility of the seven PCFT Trp residues were assessed by the substituted-cysteine accessibility method. Six Trp residues at a lipid-aqueous interface tolerated Cys substitution in terms of protein stability and function. W85C, W202C, and W213C were accessible to N-biotinyl aminoethylmethanethiosulfonate; W48C and W299C were accessible only after treatment with dithiotreitol (DTT), consistent with modification of these residues by an endogenous thiol-reacting molecule and their extracellular location. Neither W107C nor W333C was accessible (even after DTT) consistent with their cytoplasmic orientation. Biotinylation was blocked by pemetrexed only for the W48C (after DTT), W85C, W202C residues. Function was impaired only for the W299C PCFT mutant located in the 4th external loop between the 7th and 8th transmembrane helices. Despite its aqueous location, function could only be fully preserved with Phe and, to a lesser extent, Ala substitutions. There was a 6.5-fold decrease in the pemetrexed influx Vmax and a 3.5- and 6-fold decrease in the influx Kt and Ki, respectively, for the W299S PCFT. The data indicate that the hydrophobicity of the W299 residue is important for function suggesting that during the transport cycle this residue interacts with the lipid membrane thereby impacting on the oscillation of the carrier and, indirectly, on the folate binding pocket.

A novel deletion mutation in the proton-coupled folate transporter (PCFT; SLC46A1) in a Nicaraguan child with hereditary folate malabsorption

Hereditary folate malabsorption (OMIM 229050) is a rare autosomal recessive disorder caused by loss-of-function mutations in the proton-coupled folate transporter gene (pcft/SLC46A1) resulting in impaired folate transport across the intestine and into the central nervous system. We report a novel, homozygous, deletion mutation in a child of Nicaraguan descent in exon 2 (c.558-588 del, ss778190447) at amino acid position I188 resulting in a frameshift with a premature stop.