-
Cancers Dec 2022Considering quality of life (QOL) is critical when discussing treatment options for patients undergoing endoscopic endonasal skull base surgery (EESBS) for cancers at... (Review)
Review
Considering quality of life (QOL) is critical when discussing treatment options for patients undergoing endoscopic endonasal skull base surgery (EESBS) for cancers at the base of the skull. Several questionnaires have been developed and validated in the last 20 years to explore QOL in this patient population, including the Anterior Skull Base Questionnaire, Skull Base Inventory, EESBS Questionnaire, and the Sino-Nasal Outcome Test for Neurosurgery. The Sino-Nasal Outcomes Test-22 and Anterior Skull Base Nasal Inventory-12 are other tools that have been used to measure sinonasal QOL in anterior cranial base surgery. In addition to pathology-related perturbations in QOL endoscopic surgical options (transsellar approaches, anterior cranial base surgery, and various reconstructive techniques) all have unique morbidities and QOL implications that should be considered. Finally, we look ahead to new and emerging techniques and tools aimed to help preserve and improve QOL for patients with anterior cranial base malignancies.
PubMed: 36612191
DOI: 10.3390/cancers15010195 -
Biology Methods & Protocols Jan 2017DNA base modifications and mutations are observed in all genomes throughout the kingdoms of life. Proteins involved in their establishment and removal were shown to use...
DNA base modifications and mutations are observed in all genomes throughout the kingdoms of life. Proteins involved in their establishment and removal were shown to use a base flipping mechanism to access their substrates. To better understand how proteins flip DNA bases to modify or remove them, we optimized and developed a pipeline of methods to step-by-step detect the process starting with protein-DNA interaction, base flipping itself and the ensuing DNA base modification or excision. As methylcytosine is the best-studied DNA modification, here we focus on the process of writing, modifying and reading this DNA base. Using multicolor electrophoretic mobility shift assays, we show that the methylcytosine modifier Tet1 exhibits little DNA sequence specificity with only a slight preference for methylated CpG containing DNA. A combination of chloroacetaldehyde treatment and high-resolution melting temperature analysis allowed us to detect base flipping induced by the methylcytosine modifier Tet1 as well as the methylcytosine writer M.HpaII. Finally, we show that high-resolution melting temperature analysis can be used to detect the activity of glycosylases, methyltransferases and dioxigenases on DNA substrates. Taken together, this DNA base flipping analytical pipeline (BaFAP) provide a complete toolbox for the fast and sensitive analysis of proteins that bind, flip and modify or excise DNA bases.
PubMed: 32161792
DOI: 10.1093/biomethods/bpx010 -
Journal of Neurological Surgery. Part... Feb 2018Skull base lesions in children and adolescents are rare, and comprise only 5.6% of all skull base surgery. Anterior skull base lesions dominate, averaging slightly... (Review)
Review
Skull base lesions in children and adolescents are rare, and comprise only 5.6% of all skull base surgery. Anterior skull base lesions dominate, averaging slightly more than 50% of the cases. Until recently, surgery of the anterior skull base was dominated by open procedures and endoscopic skull base surgery was reserved for benign pathologies. Endoscopic skull base surgery is gradually gaining popularity. In spite of that, open skull base surgery is still considered the "gold standard" for the treatment of anterior skull base lesions, and it is the preferred approach in selected cases. This article reviews current concepts and open approaches to the anterior skull base in children in the era of endoscopic surgery. Comprehensive literature review. Extensive intracranial-intradural invasion, extensive orbital invasion, encasement of the optic nerve or the internal carotid artery, lateral supraorbital dural involvement and involvement of the anterior table of the frontal sinus or lateral portion of the frontal sinus precludes endoscopic surgery, and mandates open skull base surgery. The open approaches which are used most frequently for surgical resection of anterior skull base tumors are the transfacial/transmaxillary, subcranial, and subfrontal approaches. Reconstruction of anterior skull base defects is discussed in a separate article in this supplement. Although endoscopic skull base surgery in children is gaining popularity in developed countries, in many cases open surgery is still required. In addition, in developing countries, which accounts for more than 80% of the world's population, limited access to expensive equipment precludes the use of endoscopic surgery. Several open surgical approaches are still employed to resect anterior skull base lesions in the pediatric population. With this large armamentarium of surgical approaches, tailoring the most suitable approach to a specific lesion in regard to its nature, location, and extent is of utmost importance.
PubMed: 29404240
DOI: 10.1055/s-0037-1621739 -
Oxidative Medicine and Cellular... 2022Radioanatomy provides surgeons with different choices to prevent the failure of reconstruction caused by improper flap selection and the occurrence of CSF leakage or...
OBJECTIVE
Radioanatomy provides surgeons with different choices to prevent the failure of reconstruction caused by improper flap selection and the occurrence of CSF leakage or other severe complications. To establish a radioanatomical model, this study radioanatomically investigated the use of the Hadad-Bassagasteguy nasoseptal flap (HBF) in skull base reconstruction performed via the transethmoidal, transsphenoidal, and transclival approaches to provide preoperative guidance for the selection of approaches for skull base reconstruction and preparation of the HBF.
METHODS
The computed tomography images of 40 Chinese adults were selected for the radioanatomical measurement of data related to the HBF and skull base reconstruction via the transethmoidal, transsphenoidal, and transclival approaches. The results were analyzed using radioanatomy combined with SPSS-based analysis.
RESULTS
In the 40 patients, the area of the HBF exceeded that of skull base defects reconstructed via the transethmoidal approach by 10.21 ± 1.97 cm, and the anterior margin width, posterior margin width, upper margin length, and lower margin lengths of the HBF all exceeded the corresponding values of skull base defects requiring reconstruction by at least 8.4 mm. The area of the HBF exceeded that of reconstructed skull base defects by an average of 10.72 ± 2.04 cm. The area of the HBF exceeded that of skull base defects reconstructed via the transclival approach by 9.01 ± 2.87 cm. The difference between the anterior margin width of the HBF and the middle width of skull base defects reconstructed via the transclival approach did not exceed 6 mm in only one case (5.4 mm).
CONCLUSION
In Chinese adults, the HBF can cover skull base defects reconstructed via the transethmoidal, transsphenoidal, and transclival approaches, permitting its use in skull base reconstruction performed via all three approaches. Radioanatomy can be used for preoperative guidance to plan surgery via the transethmoidal, transsphenoidal, and transclival approaches.
Topics: Adult; China; Endoscopy; Humans; Plastic Surgery Procedures; Skull Base; Surgical Flaps
PubMed: 35391934
DOI: 10.1155/2022/9940239 -
ChemistryOpen May 2024Base-filling, i. e., post-synthetic furnishing of an oligonucleotide scaffold with base moieties or their analogues, is an interesting alternative to the conventional...
Base-filling, i. e., post-synthetic furnishing of an oligonucleotide scaffold with base moieties or their analogues, is an interesting alternative to the conventional approach of sequential coupling of building blocks (modified or otherwise). Reversible attachment of the base moieties is particularly attractive as it allows the use of dynamic combinatorial chemistry and usually leads to higher fidelity. This concept article summarizes the various backbones and coupling reactions used for base-filling over the past fifteen years, discusses the impact of base stacking and pairing on efficiency and fidelity and highlights potential and realized applications.
PubMed: 38709096
DOI: 10.1002/open.202400088 -
Current Otorhinolaryngology Reports 2020Present an overview of perioperative considerations specific to endoscopic skull base surgery necessary to maximize successful outcomes. (Review)
Review
PURPOSE OF THE REVIEW
Present an overview of perioperative considerations specific to endoscopic skull base surgery necessary to maximize successful outcomes.
RECENT FINDINGS
The majority of perioperative considerations for endoscopic skull base surgery lack strong supporting evidence and frequently have varied use or implementation amongst institutions. A notable exception comes from a recent randomized controlled trial demonstrating the benefit of lumbar drainage in high-risk cerebrospinal fluid leaks.
SUMMARY
Skull base surgeons must consider a multitude of perioperative factors. While many components of perioperative management are extrapolated from related fields such as endoscopic sinus surgery or open cranial base surgery, additional high-quality studies are needed to delineate best practices specific to endoscopic skull base surgery.
PubMed: 32421026
DOI: 10.1007/s40136-020-00278-7 -
World Neurosurgery Oct 2021Skull base leiomyomas (LMs) and angioleiomyomas (ALMs) are rare, and the understanding of this disease is limited. We present a systematic literature review of skull...
BACKGROUND
Skull base leiomyomas (LMs) and angioleiomyomas (ALMs) are rare, and the understanding of this disease is limited. We present a systematic literature review of skull base LM and ALM and report a case of internal auditory canal (IAC) ALM.
METHODS
A systematic review was conducted following the PRISMA guidelines. PubMed and Embase were systematically queried for skull base LM and ALM, and Rayyan QCRI was used for the review. After applying exclusion criteria, individual articles were evaluated for quality control, data collection, and analysis. The presentation, management, and outcome of a 37-year-old man with a right-sided IAC ALM are described.
RESULTS
Of 68 unique entries, 27 studies were included. Thirty-four cases of skull base LM (n = 6) or ALM (n = 28) were identified. Average age at presentation was 45.1 ± 14.5 years, and 52.9% of patients were male. Tumor diameter was 2.75 ± 1.6 cm, with headaches being the most reported symptom. Commonly reported locations were the cavernous sinus and the external auditory canal. Only 3 cases of IAC ALM met the criteria for this review. All tumors were treated with surgery, and gross total resection was achieved in 27 patients. Radiation was given in 3 cases with subtotal resection.
CONCLUSIONS
Skull base LM and ALM are rare. Given the need for pathology, surgery has been the standard treatment for symptomatic skull base LM and ALM. It is important to understand the available data about this disease and consider it in the differential of skull base lesions.
Topics: Adolescent; Adult; Aged; Angiomyoma; Child; Child, Preschool; Ear Canal; Female; Humans; Leiomyoma; Male; Middle Aged; Neurosurgical Procedures; Skull Base; Skull Base Neoplasms; Young Adult
PubMed: 34182177
DOI: 10.1016/j.wneu.2021.06.096 -
Chembiochem : a European Journal of... Feb 2009THE FOREIGN LESION: The mechanistic questions for DNA base damage detection by repair proteins are discussed in this Minireview. Repair proteins could either probe and... (Review)
Review
THE FOREIGN LESION: The mechanistic questions for DNA base damage detection by repair proteins are discussed in this Minireview. Repair proteins could either probe and locate a weakened base pair that results from base damage, or passively capture an extrahelical base lesion in the first step of damage searching on double-stranded DNA. How some repair proteins, such as AGT (see figure), locate base lesions in DNA is still not fully understood.To remove a few damaged bases efficiently from the context of the entire genome, the DNA base repair proteins rely on remarkably specific detection mechanisms to locate base lesions. This efficient molecular recognition event inside cells has been extensively studied with various structural and biochemical tools. These studies suggest that DNA base damage can be located by repair proteins by using two mechanisms: a repair protein can probe and detect a weakened base pair that results from mutagenic or cytotoxic base damage; alternatively, a protein can passively capture and stabilize an extrahelical base lesion. Our chemical and structural studies on the direct DNA repair proteins hAGT, C-Ada and ABH2 suggest that these proteins search for weakened base pairs in their first step of damage searching. We have also discovered a very unique base-flipping mechanism used by the DNA repair protein AlkB. This protein distorts DNA and favors single stranded DNA (ssDNA) substrates over double-stranded (dsDNA) ones. Potentially, it locates base lesions in dsDNA by imposing a constraint that targets less rigid regions of the duplex DNA. The exact mechanism of how AlkB and related proteins search for damage in ssDNA and dsDNA still awaits further studies.
Topics: Alkylation; Base Pairing; Base Sequence; DNA; DNA Damage; DNA Repair; DNA Repair Enzymes; Disulfides; Humans; Macromolecular Substances; Models, Molecular; Molecular Sequence Data; Molecular Structure; Nucleic Acid Conformation; Nucleotides; Protein Conformation
PubMed: 19145606
DOI: 10.1002/cbic.200800580 -
Journal of Orthodontic Science 2022Cranial base parameters exhibit wide variations. This study evaluated cranial base morphological characteristics of class II and class I malocclusions to identify risk...
OBJECTIVE
Cranial base parameters exhibit wide variations. This study evaluated cranial base morphological characteristics of class II and class I malocclusions to identify risk factors for class II skeletal malocclusions.
METHODS
In this cross-sectional study, we recruited 30 class I adults and 30 class II adults and collected their lateral cephalograms. The cranial base length was calculated by measuring the base of the skull by determining the length of sella-to-nasion, basion to pterygomaxillary fissure, and pterygomaxillary fissure to point A. The cranial base angle was measured by the angle formed by the basion, sella, and nasion, and the base of the angle, which connects the basion and nasion, was measured.
RESULTS
The independent t-test for combined values showed no significant differences in one angular and five linear measures between groups. However, one angular measurement was positively correlated when men and women in class I and class II groups were analyzed separately.
CONCLUSION
Male patients with class II patterns exhibited larger cranial base angles than did those with class I patterns. Our study suggested that cranial base features have a minimal role in the development of class II malocclusions.
PubMed: 36188206
DOI: 10.4103/jos.jos_8_22 -
Journal of Oral Biology and... 2022The present study aimed to evaluate and compare the flexural strength and impact strength of heat-cured acrylic/Polymethyl methacrylate (PMMA) denture base resin and 3D...
OBJECTIVE
The present study aimed to evaluate and compare the flexural strength and impact strength of heat-cured acrylic/Polymethyl methacrylate (PMMA) denture base resin and 3D printed denture base resin.
METHODS
60 rectangular specimens were fabricated from conventional heat-cured acrylic and 3D-printed denture base resins. 15 specimens each of heat-cured acrylic and 3D printed denture base resin were tested for flexural strength and impact strength. The flexural strength was assessed using three point bend test while impact strength was assessed by Izod impact test.
RESULTS
The mean flexural strength of heat-cured acrylic resin was 92.01 ± 12.14 MPa and 3D printed denture base resin was 69.78 ± 7.54 MPa. The mean impact strength of heat-cured acrylic resin was 1.67 ± 0.79 kJ/m and 3D printed denture base resin was 1.15 ± 0.40 kJ/m.The differences in mean impact and flexural strength between heat-cured acrylic and 3D printed denture base resins were statistically significant.
CONCLUSION
Heat-cured acrylic denture base resin (DPI heat-cure) had greater flexural and impact strength than 3D printed denture base resin (Next Dent denture 3D+).
PubMed: 34745858
DOI: 10.1016/j.jobcr.2021.09.018