What Are the Complications, Reconstruction Survival, and Functional Outcomes of Modular Prosthesis and Allograft-prosthesis Composite for Proximal Femur Reconstruction in Children With Primary Bone Tumors?

BACKGROUND: Proximal femur reconstruction after bone tumor resection in children is a demanding surgery for orthopaedic oncologists because of the small bone size and possible limb-length discrepancy at the end of skeletal growth owing to physis loss. The most commonly used reconstruction types used for the proximal femur are modular prostheses and allograft-prosthesis composites. To our knowledge, there are no previous studies comparing the outcomes after modular prosthesis and allograft-prosthesis composite reconstruction of the proximal femur in children with primary bone tumors. QUESTIONS/PURPOSES: (1) What was the cumulative incidence of reoperation for any reason after allograft-prosthesis composite and modular prosthesis reconstructions of the proximal femur in children with primary bone tumors? (2) What was the cumulative incidence of reconstruction removal or revision arthroplasty in those two treatment groups? (3) What complications occurred in those two treatment groups that were managed without further surgery or with surgery without reconstruction removal? METHODS: Between 2000 and 2021, 54 children with primary bone tumors underwent resection and reconstruction of the proximal femur at a single institution. During that time, allograft-prosthesis composite reconstruction was used in very young children, in whom we prioritize bone stock preservation for future surgeries, and children with good response to chemotherapy, while modular prosthesis reconstruction was used in older children and children with metastatic disease at presentation and poor response to chemotherapy. We excluded three children in whom limb salvage was not possible and 11 children who underwent either reconstruction with free vascularized fibular graft and massive bone allograft (n = 3), an expandable prosthesis (n = 3), a massive bone allograft reconstruction (n = 2), a rotationplasty (n = 1), standard (nonmodular) prosthesis (n = 1), or revision of preexisting reconstruction (n = 1). Further, we excluded two children who were not treated surgically, three children with no medical or imaging records, and three children with no follow-up. All the remaining 32 children with reconstruction of the proximal femur (12 children treated with modular prosthesis and 20 children treated with allograft-prosthesis composite reconstruction) were accounted for at a minimum follow-up time of 2 years. Children in the allograft-prosthesis group were younger at the time of diagnosis than those in the modular prosthesis group (median 8 years [range 1 to 16 years] versus 15 years [range 9 to 17 years]; p = 0.001]), and the follow-up in the allograft-prosthesis composite group was longer (median 5 years [range 1 to 23 years] versus 3 years [range 1 to 15 years]; p = 0.37). Reconstruction with hemiarthroplasty was performed in 19 of 20 children in the allograft-prosthesis composite group and in 9 of 12 children in the modular prosthesis group. A bipolar head was used in 16 of 19 children, and a femoral ceramic head without acetabular cup was used in 3 of 19 children in the allograft-prosthesis composite reconstruction group. All 9 children in the modular prosthesis group were reconstructed with a bipolar hemiarthroplasty. Reconstruction with total arthroplasty was performed in one child in the allograft-prosthesis composite group and in three children in the modular prosthesis group. For both groups, we calculated the cumulative incidence of reoperation for any reason and the cumulative incidence of reconstruction removal or revision arthroplasty; we also reported qualitative descriptions of serious complications treated nonoperatively in both groups. RESULTS: The cumulative incidence of any reoperation at 10 years did not differ between the groups with the numbers available (36% [95% confidence interval 15% to 58%] in the allograft-prosthesis composite group versus 28% [95% CI 5% to 58%] in the modular proximal femoral replacement group). The cumulative incidence of reconstruction removal or revision arthroplasty at 10 years likewise did not differ between the groups with the numbers available (10% [95% CI 2% to 28%] versus 12% [95% CI 0% to 45%], respectively). In the allograft-prosthesis composite group (20 children), hip instability (n = 3), nonunion (n = 2), fracture of the greater trochanter (n = 1), screw loosening (n = 1), limb-length discrepancy (n = 1), and coxalgia due to acetabular wear (n = 1) were treated surgically without reconstruction removal. Complications treated without surgery included resorption of the allograft at the trochanteric region (n = 4), fracture of the greater trochanter (n = 4), limb-length discrepancy (n = 6), and coxalgia due to acetabular wear (n = 2). In the modular prosthesis group (12 children), hip instability (n = 1), coxalgia due to acetabular wear (n = 1), and limb-length discrepancy (n = 1) were treated surgically without reconstruction removal. Complications treated without surgery included hip instability (n = 2), stress shielding (n = 6), infection (n = 1), sciatic nerve palsy (n = 1), and limb-length discrepancy (n = 3). CONCLUSION: Although the two groups of children were not directly comparable due to differences in age and clinical characteristics, both modular prosthesis and allograft-prosthesis composite reconstructions of the proximal femur after bone tumor resection appear to be reasonable options with similar revision-free survival and complications. Therefore, the type of reconstruction following proximal resection in children with bone sarcoma should be chosen taking into consideration factors such as patient age, bone size, implant availability, technical expertise, and the surgeon's preference. Although children treated with expandable prostheses were not included in this study, such prostheses may be useful in bridging the surgical defect while correcting residual limb-length discrepancies even though they face limitations such as small intramedullary diameter, short residual bone segments, as well as stress shielding, loosening, and breakage. LEVEL OF EVIDENCE: Level III, therapeutic study.

Similar complications, implant survival, and function following modular prosthesis and allograft-prosthesis composite reconstructions of the proximal femur for primary bone tumors: a systematic review and meta-analysis.

PURPOSE: There is a lack of consensus regarding the best type of reconstruction of the proximal femur following bone tumor resection. The objective of this study was to analyze the complication risks, implant survival, and functional outcomes following modular prosthesis (MP) and allograft-prosthesis composite (APC) reconstruction of the proximal femur after primary bone tumor resections. METHODS: We performed a search in the PubMed and Scopus libraries, obtaining 1 843 studies. We included studies reporting functional outcomes, complications, and implant survival of proximal femur reconstruction with MP or APC following primary bone tumor resection with a 2-year minimum follow-up. We excluded studies analyzing metastatic patients or studies with pooled data in which it was impossible to separate the data of patients with primary bone tumors from those with bone metastases. RESULTS: We analyzed 18 studies (483 patients) reporting on 234 (48%) patients with MP reconstruction and 249 (52%) patients with APC reconstruction. The risk of complications was similar in patients with MP reconstruction (29%; 95% CI [0.11; 0.47]) and APC reconstruction (36%; 95% CI [0.24; 0.47]) (p = 0.48). Implant survival following MP reconstruction ranged from 81 to 86% at 5 years, 75 to 86% at 10 years, and 82% at 15 years. Implant survival following APC reconstruction ranged from 86 to 100% at 5 years and 86% at 10 years, and 86% at 15 years. Functional outcomes following MP reconstruction and APC reconstruction ranged from 24.0 to 28.3 and from 21.9 to 27.8, respectively. CONCLUSION: Patients with primary bone tumor of the proximal femur who underwent MP or APC reconstruction seem to have similar complication risks, implant survival, and functional outcomes.

Pattern of response of unresectable and metastatic cutaneous squamous cell carcinoma to programmed death-1 inhibitors: A review of the literature.

Cutaneous squamous cell carcinoma (cSCC) is the second most frequent nonmelanoma skin cancer (NMSC). The majority of in situ cSCC [cSCC (Tis)] can be cured surgically, while local advanced and metastatic ones require other treatments, but there are no therapies approved by U.S. Food and Drug Administration (FDA). Available treatments for these stages included radiotherapy, chemotherapy as cisplatin, but responses to these treatments are usually of short duration. Programmed death-1 (PD-1) inhibitors (pembrolizumab, nivolumab, and cemiplimab) are an innovative immunologic treatment that now has been shown to be useful for the treatment of advanced cSCC. Nowadays, data about the response rate with the use of PD-1 inhibitors in cSCC are still few and, especially, the duration of the response after the start of treatment is short. Moreover, the number of cases is too small to express the beneficial effects of these treatments, although most data reported in the literature show quite good response rates. This review focused on some of the studies and associated results through an interesting research on search engines of all the cases about these systemic drugs, analyzing effects and side effects, and the research has been conducted considering published cases since March 2016 to October 2019.

Sequence-specific validation of LAMP amplicons in real-time optomagnetic detection of Dengue serotype 2 synthetic DNA.

We report on an optomagnetic technique optimised for real-time molecular detection of Dengue fever virus under ideal as well as non-ideal laboratory conditions using two different detection approaches. The first approach is based on the detection of the hydrodynamic volume of streptavidin coated magnetic nanoparticles attached to biotinylated LAMP amplicons. We demonstrate detection of sub-femtomolar Dengue DNA target concentrations in the ideal contamination-free lab environment within 20 min. The second detection approach is based on sequence-specific binding of functionalised magnetic nanoparticles to loops of LAMP amplicons. Melting studies reveal that true positive and spurious amplicons have different melting points and this allows us to discriminate between them. This is found to be in a good agreement with subsequent studies on real-time sequence-specific discrimination of LAMP amplicons. The specific binding causes clustering of magnetic nanoparticles via binding to multiple sites (loops) emerging in the elongation phase of LAMP. Formation of nanoclusters is monitored via the depletion of the optomagnetic signal due to free nanoparticles. After sequence-specific validation, we claim detection of down to 100 fM of Dengue target after 20 min of LAMP with a contamination background.

CHO cells knocked out for TSC2 display an improved productivity of antibodies under fed batch conditions.

The kinase mTOR operates in two cellular complexes, mTORC1 and mTORC2. mTORC1 adjusts metabolic activity according to external growth conditions and nutrients availability. When conditions are prosperous, mTOR facilitates protein and lipid biosyntheses and inhibits autophagy, while under metabolic constraints, however, its attenuation induces a catabolic program, energy preservation and autophagy. CHO is a key cell line for manufacturing of biologics owing to its remarkable ability to grow to high densities and maintain protein production and secretion for extended times. While high mTOR activity has been associated with high productivity in CHO cells, its inhibition by rapamycin has also been documented to augment productivity via promotion of viability. Here using CRISPR/Cas9 editing we engineered CHO cells to enforce high mTORC1 activity by knocking-out TSC2, a major mTOR inhibitory protein, or PTEN, a phosphatase that attenuates the PI3K/AKT/mTOR pathway. Only TSC2-deleted cells exhibited a constitutive activation of mTORC1 under fed batch conditions. Cells grew larger in size, synthesized more proteins and displayed an over twofold elevation in their specific productivity. While peak viable cell density was compromised, overall titers increased to an extent dependent upon the parental clone. Our data underscore manipulation of TSC as a strategy to improve performance of CHO cell in bioreactors. Biotechnol. Bioeng. 2016;113: 1942-1952. © 2016 Wiley Periodicals, Inc.

On-chip detection of rolling circle amplified DNA molecules from Bacillus globigii spores and Vibrio cholerae.

For the first time DNA coils formed by rolling circle amplification are quantified on-chip by Brownian relaxation measurements on magnetic nanobeads using a magnetoresistive sensor. No external magnetic fields are required besides the magnetic field arising from the current through the sensor, which makes the setup very compact. Limits of detection down to 500 Bacillus globigii spores and 2 pM of Vibrio cholerae are demonstrated, which are on the same order of magnitude or lower than those achieved previously using a commercial macro-scale AC susceptometer. The chip-based readout is an important step towards the realization of field tests based on rolling circle amplification molecular analyses.

Improved Titer in Late-Stage Mammalian Cell Culture Manufacturing by Re-Cloning.

Improving productivity to reduce the cost of biologics manufacturing and ensure that therapeutics can reach more patients remains a major challenge faced by the biopharmaceutical industry. Chinese hamster ovary (CHO) cell lines are commonly prepared for biomanufacturing by single cell cloning post-transfection and recovery, followed by lead clone screening, generation of a research cell bank (RCB), cell culture process development, and manufacturing of a master cell bank (MCB) to be used in early phase clinical manufacturing. In this study, it was found that an additional round of cloning and clone selection from an established monoclonal RCB or MCB (i.e., re-cloning) significantly improved titer for multiple late phase monoclonal antibody upstream processes. Quality attributes remained comparable between the processes using the parental clones and the re-clones. For two CHO cells expressing different antibodies, the re-clone performance was successfully scaled up at 500-L or at 2000-L bioreactor scales, demonstrating for the first time that the re-clone is suitable for late phase and commercial manufacturing processes for improvement of titer while maintaining comparable product quality to the early phase process.

Breast Cancer-Related Neoplastic Alopecia: A Case Report and Review of the Literature.

Neoplastic alopecia (NA) is defined as an organized hair loss in single or multiple areas of the scalp caused by a primary tumor that has metastasized to the skin of the scalp. Due to its localization and clinical appearance, NA should be placed in differential diagnosis with alopecia areata or other entities. To date, pathognomonic dermoscopic criteria of NA have not yet been described: the absence of classical criteria of other scalp diseases in addition to a major neovascularization with on-focus arborizing vessels and erosions or ulcerations may help the clinician to suspect a diagnosis of secondary alopecia. Dermatologists should pay more attention to these rare forms of secondarism because in exceptional cases, a simple alopecia of the scalp can hide a new, relapsing or metastatic neoplasia.

Overview on the treatment of Lyme disease in pregnancy.

Lyme disease is a tick-borne illness, which is typically caused by Borrelia Burgdoferi. Over time, a typical Borreliosis skin reaction takes shape, i.e. the formation of an annular erythema that tends to expand centrifugally with erythematous edges whose diameter can reach up to 20 cm. The symptoms of Lyme disease are not only cutaneous but there may be a systemic involvement. Obviously, this disease can also affect pregnant women and for this reason this review aims to summarize the main ways of treatment to avoid worsening of the clinical condition in the mother and an eventual, albeit rare, involvement of the fetus.

Current therapies for actinic keratosis.

Actinic keratosis (AK) is a very common skin disease caused by chronic sun damage, which in 75% of cases arises on chronically sun-exposed areas, such as face, scalp, neck, hands, and forearms. AKs must be considered an early squamous cell carcinoma (SCC) for their probable progression into invasive SCC. For this reason, all AK should be treated, and clinical follow-up is recommended. The aims of treatment are: (i) to clinically eradicate evident and subclinical lesions, (ii) to prevent their evolution into SCC, and (iii) to reduce the number of relapses. Among available treatments, it is possible to distinguish lesion-directed therapies and field-directed therapies. Lesion-directed treatments include: (i) cryotherapy; (ii) laser therapy; (iii) surgery; and (iv) curettage. Whereas, field-directed treatments are: (i) 5-fluorouracil (5-FU); (ii) diclofenac 3% gel; (iii) chemical peeling; (iv) imiquimod; and (v) photodynamic therapy (PDT). Prevention plays an important role in the treatment of AKs, and it is based on the continuous use of sunscreen and protective clothing. This review shows different types of available treatments and describes the characteristics and benefits of each medication, underlining the best choice.

Is There More Than One Road to Nevus-Associated Melanoma?

The association of melanoma with a preexisting nevus is still a debated subject. Histopathological data support an associated nevus in approximately 30% of all excised melanomas. The annual risk of an individual melanocytic nevus becoming malignant is extremely low and has been estimated to be approximately 0.0005% (or less than 1 in 200,000) before the age of 40 years, to 0.003% (1 in 33,000) in patients older than 60 years. Current understanding, based on the noticeable, small, truly congenital nevi and nevi acquired early in life, is that the first develops before puberty, presents with a dermoscopic globular pattern, and persists for the lifetime, becoming later a dermal nevus in the adult. In contrast, acquired melanocytic nevi develop mostly at puberty and usually undergo spontaneous involution after the fifth decade of life. The purpose of this review is to analyze the data of the literature and to propose, on the basis of epidemiological and clinical-dermoscopic characteristics, a new model of melanogenesis of nevus-associated melanoma.

Highly sensitive detection of DNA hypermethylation in melanoma cancer cells.

Aberrant hypermethylation of CpG islands in the promoter region of tumor suppressor genes is a promising biomarker for early cancer detection. This methylation status is reflected in the methylation pattern of ctDNA shed from the primary tumor; however, to realize the full clinical utility of ctDNA methylation detection via liquid biopsy for early cancer diagnosis, improvements in the sensitivity and multiplexability of existing technologies must be improved. Additionally, the assay must be cheap and easy to perform in a clinical setting. We report the integration of methylation specific PCR (MSP) to melt curve analysis on giant magnetoresistive (GMR) biosensors to greatly enhance the sensitivity of our DNA hybridization assay for methylation detection. Our GMR sensor is functionalized with synthetic DNA probes that target methylated or unmethylated CpG sites in the MSP amplicon, and measures the difference in melting temperature (Tm) between the two probes (ΔTm), giving an analytical limit of detection down to 0.1% methylated DNA in solution. Additionally, linear regression of ΔTm's for serial dilutions of methylated:unmethylated mixtures allows for quantification of methylation percentage, which could have diagnostic and prognostic utility. Lastly, we performed multiplexed MSP on two different genes, and show the ability of our GMR assay to resolve this mixture, despite their amplicons' overlapping Tm's in standard EvaGreen melt analysis. The multiplexing ability of our assay and its enhanced sensitivity, without necessitating deep sequencing, represent important steps toward realizing an assay for the detection of methylated ctDNA in plasma for early cancer detection in a clinical setting.

Integration of rolling circle amplification and optomagnetic detection on a polymer chip.

Rolling circle amplification (RCA) combined with padlock probe recognition of a DNA target is attractive for on-chip nucleic acid testing due to its high specificity and isothermal reaction conditions. However, the integration of RCA on an automated chip platform is challenging due to the different reagents needed for the reaction steps and the temperature sensitivity of the phi29 polymerase. Here, we describe the integration of an RCA assay on a single-use polymer chip platform where magnetic microbeads are used as solid support to transport the DNA target between three connected reaction chambers for (i) padlock probe annealing and ligation, (ii) RCA, and (iii) optomagnetic detection of RCA products. The three chambers were loaded with reagents by sequential filling combined with passive microfluidic structures. After loading, the on-chip assay steps were automated. For an assay in which all steps but the padlock probe annealing on the target were performed on-chip, we found a limit of detection (LOD) for a synthetic influenza target of 2 pM after 45 min of RCA, which is comparable to the corresponding laboratory assay. The entire assay, including padlock probe annealing, could be performed on-chip with an LOD of 20 pM after 45 min of RCA. This LOD can likely be reduced by further optimizing the microbead mixing. The results present important steps towards the integration and automation of RCA and potentially also other complex multi-step assays on a single-use polymer chip for molecular analysis.

Quantification of cDNA on GMR biosensor array towards point-of-care gene expression analysis.

Gene expression analysis at the point-of-care is important for rapid disease diagnosis, but traditional techniques are limited by multiplexing capabilities, bulky equipment, and cost. We present a gene expression analysis platform using a giant magnetoresistive (GMR) biosensor array, which allows multiplexed transcript detection and quantification through cost-effective magnetic detection. In this work, we have characterized the sensitivity, dynamic range, and quantification accuracy of Polymerase chain reaction (PCR)-amplified complementary DNA (cDNA) on the GMR for the reference gene GAPDH. A synthetic GAPDH single-stranded DNA (ssDNA) standard was used to calibrate the detection, and ssDNA dilutions were qPCR-amplified to obtain a standard curve. We demonstrate that the GMR platform provides a dynamic range of 4 orders of magnitude and a limit of detection of 1 pM and 0.1 pM respectively for 15 and 18-cycle amplified synthetic GAPDH PCR products. The quantitative results of GMR analysis of cell-line RNA were confirmed by qPCR.

Dermatoscopic features of Koebner phenomenon in lichen planus on light and dark skin.

The Koebner phenomenon is well described and well known in clinical practice. Sometimes it can take on a linear appearance, the diagnosis of which can be facilitated by the use of dermatoscopy. In this case, we present a comparison between a linear Koebner phenomenon on light and dark skin, reporting the salient dermatoscopic characteristics and relating them to histopathology.

Targetoid erythema surrounding multiple seborrheic keratoses induced by chemotherapy with gemcitabine.

The cutaneous adverse effects of gemcitabine include allergic skin rash frequently associated with pruritus, alopecia, sweating, dermatitis with boils, and ulcerations. We report the case of a patient that developed inflammation of seborrheic keratoses after gemcitabine treatment.

Improving the early diagnosis of early nodular melanoma: can we do better?

INTRODUCTION: Cutaneous melanoma is the sixth most common malignant cancer in the USA. Among different subtypes of melanoma, nodular melanoma (NM) accounts about 14% of all cases but is responsible for more than 40% of melanoma deaths. Early diagnosis is the best method to improve melanoma prognosis. Unfortunately, early diagnosis of NM is particularly challenging given that patients often lack identifiable risk factors such as many moles or freckles. Moreover, early NM may mimic a range of benign skin lesions that are not routinely excised or biopsied in every day practice. For this reason, specific clinical and skin imaging clues have been proposed to improve early detection of NM. Areas covered: The review discusses about the noninvasive tools to diagnose thin melanoma, particularly NM. Expert commentary: Currently, dermatologists present a wide opportunity of diagnostic tools. Current data suggest that the early diagnosis of NM is a major challenge as the majority of early NM are symmetric, roundish, and lack specific pattern. Another promising strategy is based on recent data suggesting that artificial intelligence based on deep convolutional neural networking is able to outperform average dermatologist. Further research is necessary to validate the performance of this method in the real world and in the clinical setting.

Two-dimensional salt and temperature DNA denaturation analysis using a magnetoresistive sensor.

We present a microfluidic system and its use to measure DNA denaturation curves by varying the temperature or salt (Na+) concentration. The readout is based on real-time measurements of DNA hybridization using magnetoresistive sensors and magnetic nanoparticles (MNPs) as labels. We report the first melting curves of DNA hybrids measured as a function of continuously decreasing salt concentration at fixed temperature and compare them to the corresponding curves obtained vs. temperature at fixed salt concentration. The magnetoresistive sensor platform provided reliable results under varying temperature as well as salt concentration. The salt concentration melting curves were found to be more reliable than temperature melting curves. We performed a two-dimensional mapping of the melting profiles of a target to probes targeting its wild type (WT) and mutant type (MT) variants in the temperature-salt concentration plane. This map clearly showed a region of optimum ability to differentiate between the two variants. We finally demonstrated single nucleotide polymorphysm (SNP) genotyping using both denaturation methods on both separate sensors but also using a differential measurement on a single sensor. The results demonstrate that concentration melting provides an attractive alternative to temperature melting in on-chip DNA denaturation experiments and further show that the magnetoresistive platform is attractive due to its low cross-sensitivity to temperature and liquid composition.

Comparative study of therapeutic antibody candidates derived from mini-pool and clonal cell lines.

The long journey of developing a drug from initial discovery target identification to regulatory approval often leaves many patients with missed window of opportunities. Both regulatory agencies and biopharmaceutical industry continue to develop creative approaches to shorten the time of new drug development in order to deliver life-saving medicine to patients. Generally, drug substance materials to support the toxicology and early phase clinical study can only be manufactured after creating the final Master Cell Bank (MCB) of the clonally derived cell line, which normally takes 1-2 years. With recent advances in cell line development, cell culture process and analytical technologies, generating more homogeneous bulk/mini-pool population with higher productivity and acceptable quality attributes has become a norm, thereby making it possible to shorten the timeline to initiate First in Human (FIH) trial by using bulk/mini-pool generated materials to support toxicology and FIH studies. In this study, two monoclonal antibodies of different subclasses (IgG1 and IgG4) were expressed from the mini-pool cells as well as clonally derived cell lines generated from the same mini-pool. Cell growth, productivity, and product quality were compared between the materials generated from the mini-pool and clonally derived cell line. The results demonstrate the similarity of the antibody products generated from mini-pool cells and clonally derived cell lines from the same mini-pool, and strongly support the concept and feasibility of using antibody materials produced from mini-pool cultures for toxicology and FIH studies. The strategy to potentially shorten the FIH timeline is discussed. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1456-1462, 2017.