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Practical Neurology Feb 2020The skull base is the major bony and soft tissue interface for the intracranial and extracranial compartments. Its anatomy is complex, containing multiple traversing... (Review)
Review
The skull base is the major bony and soft tissue interface for the intracranial and extracranial compartments. Its anatomy is complex, containing multiple traversing foramina that act as conduits for various neurovascular structures. The optimum imaging modality depends on the specific diagnostic question and area of interest; both CT and MR have complementary roles. This article focuses on the applied compartmental anatomy of the skull base and specific imaging protocols, and discusses the range of pathologies that neurologists will encounter.
Topics: Humans; Intracranial Hypertension; Magnetic Resonance Imaging; Skull Base; Skull Base Neoplasms; Tinnitus; Tomography, X-Ray Computed
PubMed: 31649103
DOI: 10.1136/practneurol-2019-002383 -
Yi Chuan = Hereditas Sep 2019Base editing is a newly developed precise genome editing technique based on the CRISPR/Cas system. According to different base modification enzymes, the current base... (Review)
Review
Base editing is a newly developed precise genome editing technique based on the CRISPR/Cas system. According to different base modification enzymes, the current base editing systems can be divided into cytosine base editors (CBE) and adenine base editors (ABE). They use cytosine deaminases or artificially evolved adenine deaminases to perform single-base editing, and achieve C to T (G to A) or A to G (T to C) substitutions, respectively. Due to high efficiency, independence of DNA double-strand breaks, and no need for donor DNA, base editing systems have been successfully applied in diverse species including animals, plants and other organisms since the first report in 2016. Therefore, base editing systems will have a high prospect of providing important support for gene therapy and crop genetic improvement in the future. In this review, we describe the development and current applications of base editing systems for basic research and biotechnology, highlight the challenges, and discuss the directions for future research in this important field. The information presented may facilitate interested researchers to grasp the principles of base editing, to use relevant base editing tools in their own studies, or to innovate new versions of base editing in the future.
Topics: Adenine; Aminohydrolases; Animals; Biotechnology; CRISPR-Cas Systems; Cytosine; Cytosine Deaminase; DNA Breaks, Double-Stranded; Gene Editing; Plants
PubMed: 31549678
DOI: 10.16288/j.yczz.19-205 -
Neuroimaging Clinics of North America Feb 2022For pathologic conditions affecting the skull base and cerebellopontine angle, imaging techniques have advanced to assess for residual disease, disease progression, and... (Review)
Review
For pathologic conditions affecting the skull base and cerebellopontine angle, imaging techniques have advanced to assess for residual disease, disease progression, and postoperative complications. Knowledge regarding various surgical approaches of skull base tumor resection, expected postoperative appearance, and common postsurgical complications guides radiologic interpretation. Complexity of skull base anatomy, small size of the relevant structures, lack of familiarity with surgical techniques, and postsurgical changes confound radiologic evaluation. This article discusses the imaging techniques, surgical approaches, expected postoperative changes, and complications after surgery of the skull base, with emphasis on the cerebellopontine angle, anterior cranial fossa, and central skull base regions.
Topics: Cerebellopontine Angle; Humans; Magnetic Resonance Imaging; Postoperative Complications; Skull Base; Skull Base Neoplasms; Treatment Outcome
PubMed: 34809836
DOI: 10.1016/j.nic.2021.08.005 -
Journal of Nephrology 2006Mixed acid-base disturbances, defined as the simultaneous presence of two or more acid-base disorders, are commonly observed in hospitalized patients, especially those... (Review)
Review
Mixed acid-base disturbances, defined as the simultaneous presence of two or more acid-base disorders, are commonly observed in hospitalized patients, especially those in critical care units. Certain clinical settings are commonly associated with mixed acid-base disorders, including cardiorespiratory arrest, sepsis, drug intoxications, diabetes mellitus, and organ failure (especially renal, hepatic, and pulmonary failure). As a general rule, the symptoms and signs of the underlying disease that gives rise to the observed mixed acid-base disorder dominate the clinical picture. The basic principles underlying the diagnosis of mixed acid-base disorders are identical to those required for the identification of simple acid-base disturbances. The management of mixed acid-base disturbances is aimed at restoring the altered acid-base status by reversing all the elemental components present, thus it encompasses the therapy of each simple acid-base disorder.
Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Diagnosis, Differential; Humans; Severity of Illness Index
PubMed: 16736447
DOI: No ID Found -
Der Anaesthesist Feb 2022In 1981 the Canadian Peter Stewart presented a new concept for the interpretation of the acid-base balance. Rehm et al. published the first German language article on... (Review)
Review
In 1981 the Canadian Peter Stewart presented a new concept for the interpretation of the acid-base balance. Rehm et al. published the first German language article on this topic. In 2007 the works of Deetjen and Lichtwarck-Aschoff as well as Funk presented both the physiological and clinical foundations of the Stewart concept as well as algorithms to interpret the acid-base status more precisely. Furthermore, since 2004 many other publications on the Stewart concept have been published, which have sometimes been controversially discussed and has not yet found its way into the everyday interpretation of blood gas analysis. This gap is intended to be filled by this work. It introduces a simple, practical algorithm and provides an approach to understanding the acid-base balance and the Stewart concept, which assumes that the plasma ions determine the pH value and the base excess (BE) in the plasma.
Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Algorithms; Blood Coagulation Tests; Blood Gas Analysis; Canada; Humans; Hydrogen-Ion Concentration
PubMed: 34269868
DOI: 10.1007/s00101-021-01008-4 -
Der Radiologe Dec 2019Knowledge of skull base anatomy is essential for recognizing the pathological conditions affecting the skull base structures (including cranial nerves and cerebral... (Review)
Review
CLINICAL ISSUE
Knowledge of skull base anatomy is essential for recognizing the pathological conditions affecting the skull base structures (including cranial nerves and cerebral vasculature), for correct interpretation of their presentation on imaging studies, and finally for proper planning of surgical skull base approaches.
PURPOSE OF THE ARTICLE
The main goal of the following work is to present a brief recapitulation of the regular skull base anatomy (with a focus on the bony structures) and based on this, to provide an overview of the most commonly used neurosurgical skull base approaches (illustrated using radiological case presentations).
DIAGNOSTIC WORK-UP
Already at the step of the preoperative workup, the suitable radiological technique and proper choice of technical parameters for image acquisition lays the foundation for a successful surgical procedure and for the reliable assessment of operative results.
CONCLUSION
Each radiologist should be familiar with basic principles of neurosurgical approaches and operative techniques used in skull base surgery and with their appearance in postoperative images.
Topics: Cranial Nerves; Humans; Magnetic Resonance Imaging; Neurosurgical Procedures; Skull Base; Skull Base Neoplasms
PubMed: 31628501
DOI: 10.1007/s00117-019-00601-4 -
Advances in Oto-rhino-laryngology 2020Benign tumors of the anterior cranial base may originate from intracranial, cranial, or extracranial sites. Intracranial tumors such as meningiomas may secondarily... (Review)
Review
Benign tumors of the anterior cranial base may originate from intracranial, cranial, or extracranial sites. Intracranial tumors such as meningiomas may secondarily involve the cranial base and extend into the sinuses or nasal cavity. Bony tumors arising from the cranium include benign fibro-osseous lesions such as osteoma, fibrous dysplasia, and ossifying fibroma. The most common extracranial tumors that may extend to the skull base include angiofibroma and inverted papilloma. Symptoms are nonspecific and diagnosis is often delayed. In most cases, a diagnosis can be established based on the clinical presentation and radiographic features. Some small asymptomatic tumors may be observed for growth (meningioma, osteoma), whereas others should be treated due to continued destructive growth (angiofibromas) or potential for malignancy (inverted papilloma). Surgery remains the predominant treatment modality for benign tumors of the anterior cranial base. The major advance in recent decades has been the adoption of endoscopic techniques. Advances in endoscopic transnasal surgery have dramatically altered the surgical landscape, enabling the removal of tumors of the anterior cranial base with minimal morbidity. Due to decreased morbidity in comparison to transfacial or transcranial approaches, endoscopic transnasal surgery has lowered the threshold for surgery for benign tumors and can be applied to adult as well as pediatric populations. Anatomical limits include the anterior cranial base from the frontal sinus to the sella and optic canals and laterally to the mid-plane of the orbital roofs. Large dural defects can be reliably reconstructed using local (nasoseptal) and regional (extracranial pericranial) vascularized flaps.
Topics: Humans; Magnetic Resonance Imaging; Natural Orifice Endoscopic Surgery; Neoplasm Staging; Plastic Surgery Procedures; Skull Base; Skull Base Neoplasms; Tomography, X-Ray Computed
PubMed: 32731223
DOI: 10.1159/000457930 -
Advances in Chronic Kidney Disease Sep 2017Acid-base disorders are in patients with chronic kidney disease, with chronic metabolic acidosis receiving the most attention clinically in terms of diagnosis and... (Review)
Review
Acid-base disorders are in patients with chronic kidney disease, with chronic metabolic acidosis receiving the most attention clinically in terms of diagnosis and treatment. A number of observational studies have reported on the prevalence of acid-base disorders in this patient population and their relationship with outcomes, mostly focusing on chronic metabolic acidosis. The majority have used serum bicarbonate alone to define acid-base status due to the lack of widely available data on other acid-base disorders. This review discusses the time course of acid-base alterations in CKD patients, their prevalence, and associations with CKD progression and mortality.
Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Bicarbonates; Disease Progression; Humans; Prevalence; Renal Dialysis; Renal Insufficiency, Chronic; Risk Factors
PubMed: 29031354
DOI: 10.1053/j.ackd.2017.08.003 -
The Veterinary Clinics of North... Mar 2017Hydrogen concentration is a critical determinant of many physiologic functions and is tightly regulated. Any alteration in acid-base equilibrium sets into motion a... (Review)
Review
Hydrogen concentration is a critical determinant of many physiologic functions and is tightly regulated. Any alteration in acid-base equilibrium sets into motion a compensatory response by either the lungs or the kidneys. The compensatory response attempts to return the ratio between Pco and [HCO] to normal and thereby minimize the pH change. A primary increase or decrease in one component is associated with a predictable compensatory change in the same direction in the other component, and the expected compensation can be estimated clinically in dogs and cats.
Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Animals; Cat Diseases; Cats; Dog Diseases; Dogs
PubMed: 28012785
DOI: 10.1016/j.cvsm.2016.11.003 -
Folia Neuropathologica 2022Tumour-to-meningioma metastasis (TTMM) is an uncommon phenomenon, however repeatedly found in the literature. Meningiomas occur to be the most frequent target of... (Review)
Review
Tumour-to-meningioma metastasis (TTMM) is an uncommon phenomenon, however repeatedly found in the literature. Meningiomas occur to be the most frequent target of metastatic expansion of systemic cancers. Meningiomas often vary in symptoms and treatment, and this largely depends on the tumour location. Due to their variable locations, they can be classified as convexity meningiomas, which includes falcine and parasagittal tumours, and cranial base, which includes tumours located in the olfactory groove, sphenoid wing, petrous bone and other cranial base locations. The aim of this study was to analyse all data regarding metastases to cranial base meningiomas. We performed a literature search to locate all cases of metastases to cranial base meningiomas in PubMed and Medline databases using the following key words: metastasis to meningioma, meningioma metastasis, and cranial base meningioma. We collected patient and cancer parameters, exact meningioma location and clinical presentations including characteristics which may suggest TTMM. We found 100 articles describing 111 patients of metastasis to cranial base meningioma. Among these articles, 55 cases (49.55%) included metastases to non-skull base meningiomas. In 24 cases (21.62%), the location of meningioma was not precisely described or other data were unavailable, in particular histopathological examination. The most common location of TTMM was sphenoid wing, which was found in 9 patients. The other locations included cerebellopontine angle in 5 patients, and tuberculum sellae in 3 cases. 81.25% cases of TTMM were reported in women, and the most common cancer origins were the breast (28.3%), lung (18.7%), kidney (9.38%) and prostate (9.38%). In two cases the metastatic origin was unclear, and in 15.6% of cases the patients were in remission for more than 1 year. In 78.1% of cases patients presented focal deficits, followed by increased intracranial pressure, and seizures. In almost one-third of cases, TTMM first appeared from a previously unknown cancer. Rapid clinical presentation of cranial nerve palsies may suggest the dual nature of intracranial pathology. The metastasis to cranial base meningioma should be suspected in patients with oncological background, regardless of meningioma parameters or cancer status.
Topics: Male; Humans; Female; Meningeal Neoplasms; Meningioma; Skull Base Neoplasms; Skull Base; Treatment Outcome
PubMed: 36734379
DOI: 10.5114/fn.2022.123500