Dermal filler complications and management
Michael Parker, Charlie James in Fundamentals for Cosmetic Practice, 2022
Hyaluronidase is an enzyme which dissolves hyaluronic acid, the key constituent in most dermal fillers. It needs to be injected directly into the area suspected of being devoid of arterial blood supply. A standard dose required for lysis of dermal fillers is 200 units. Some practitioners advocate mixing it with lidocaine or normal saline to increase the volume of solution and subsequently create a larger effective volume. Once administered, the area should be massaged and observed for one hour. If there is no improvement this may be repeated for three to four cycles. It is worth noting that approximately one in 1,000 people have an allergy to hyaluronidase, and subsequently, a skin test should be performed by injecting four units into the skin and observing for five minutes. Should a wheal appear in the skin then an allergy to hyaluronidase should be suspected. Even if no wheal is apparent, please be mindful that a life-threatening anaphylaxis could still occur after hyaluronidase hypodermolysis.
Transport of Radiolabeled Enzymes
Lelio G. Colombetti in Biological Transport of Radiotracers, 2020
The binding of iodine depends upon the nature and number of amino acids in the molecule of the enzyme to be labeled. By using the technique of Hunter and Greenwood,20 Matthews21 was able to label several plasma proteins, and Cohen et al.22 labeled hyaluronidase and streptokinase. Meyniel and Veyre23 have carried out a study upon the choice of labeling agents, and Parsons et al.24 have labeled proteinases with 125I to demonstrate their binding to plasma proteins. Bolton and Hunter25 have perfected their iodination process by the addition of acylating agents, Aprotinin (the pancreatic trypsin inhibitor of Kunitz) has been labeled with 125I and 99mTc by Kutas et al.,26 and recently Baret et al.27,28 have labeled cupro-zinc and manganese superoxide dismutase (Mn S.O.D.) from human erythrocytes, human crude extracts, and blood mitochondrial fractions.
Emergencies associated with cosmetological procedures
Biju Vasudevan, Rajesh Verma in Dermatological Emergencies, 2019
Stop injecting if you observe blanching, as soft tissue ischemia presents as pain, mottling, and blanching at the site of injection immediately postinjection. Features that may appear later are formation of vesicles and bulla, bluish discoloration, and necrosis [16]. If you notice blanching, gauze soaked in warm saline should then be applied to facilitate vasodilation [17,18]. If the filler used is a HA-based one, hyaluronidase should be injected, and the whole area should be flooded with the product and massaged. The risk of allergic reaction to hyaluronidase (which may be of ovine or bovine or human recombinant sources) must be taken into consideration [19,20,21]. Special caution must be taken with those patients who have allergy to bee stings, as the hyaluronidase shares 30% sequence identity with bee venom. The availability of hyaluronidase in the clinic should be confirmed before starting treatment. Typically, a range of 8–16 units of hyaluronidase 0.5 mL of HA will dissolve the cosmetically imperfect swelling. For emergency situations when occlusion or ischemia is suspected, use more. As per the literature, it is an exceedingly rare situation where native HA had to be dissolved with hyaluronidase. Immediate application of nitroglycerin paste to facilitate vascular dilatation and blood flow to the area should be done. Additionally, anticoagulants such as aspirin and nonsteroidal anti-inflammatory agents, as well as vitamins that inhibit platelet aggregation, should be encouraged in any protocol to treat cutaneous tissue ischemia [22–25].
New cyclopentaquinoline hybrids with multifunctional capacities for the treatment of Alzheimer’s disease
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2018
Kamila Czarnecka, Małgorzata Girek, Karolina Maciejewska, Robert Skibiński, Jakub Jończyk, Marek Bajda, Jacek Kabziński, Przemysław Sołowiej, Ireneusz Majsterek, Paweł Szymański
Inflammation is a complex biological response to aggressive agents (pathogens, injury), involving local vascular system and immune system. The inflammation is regulated by anti-inflammatory mediators, including cytokines, chemokines, and by several cellular enzymes, such as hyaluronidase. Hyaluronidase is an enzyme responsible for hyaluronan depolymerisation and by this process; it weakens the integrity of tissues during the inflammation. The prolonged inflammatory process is commonly associated with the development of some chronic disease, such as AD or cancers. Mostly for the treatment of inflammatory diseases, the non-steroidal anti-inflammatory (NSAIDs) are in common use. Due to the many side effects, such as gastrointestinal, renal, and cardiovascular toxicity, their use should be limited43. Therefore, novel drugs with anti-inflammatory properties are being investigated.
Hyaluronan-based delivery of therapeutic oligonucleotides for treatment of human diseases
Published in Expert Opinion on Drug Delivery, 2019
HA is degraded by specific enzymes called hyaluronidases that hydrolyze 1,4-β-glycosidic linkages between disaccharide repeat units. In humans, there are 6 isoforms of hyaluronidase from which Hyal1 and Hyal2 exist in most tissues and body fluids, intracellularly and in serum [29]. However, it should be noted that hyaluronidase activity differs substantially in different types of tissues. The overall result of hyaluronidase activity is that 5 out of 15 g of HA is daily replaced in a 70-kg individual [30]. In injured tissues, HA can be degraded by free radicals. HA degradation produces multiple effects in tissues. For example, HMW HA displays anti-inflammatory and immune-suppressive properties, whereas low-molecular-weight (LMW) HA is a potent proinflammatory and angiogenic molecule [31]. The biodegradability is an important property of HA that can be used for the release of ON therapeutics controlled by enzymatic degradation. Moreover, enzymatic degradation of HA coating for a nanoparticulate vehicle should change the chemical composition on the surface of the nanoparticles, which can be used for dynamic interactions with cell surface receptors. It is also important to consider that the LMW HA fragments generated in the course of HA vehicles degradation can initiate inflammatory responses and angiogenesis.
Dexmedetomidine vs hyaluronidase addition to fluoroscopy-guided caudal analgesia with steroid in lumbosacral spine surgery. A comparative double blinded study
Published in Egyptian Journal of Anaesthesia, 2021
Sanaa F. Wasfy, Waleed H. Nofal, Mona A. Ammar
Hyaluronidase is effective as an adjuvant to local anesthesia in different regional blocks such as supraclavicular and peribulbar blocks. Hyaluronidase increases tissue permeability and facilitates other drug delivery to nerve roots [10]. Studies have confirmed the positive analgesic effect of epidural addition of hyaluronidase to steroids in the management of chronic pain due to central spinal stenosis, nerve root radiculopathy or failed back syndrome The presence of epidural septa or adhesions may eliminate the continuity of this space. Fibrosis might occur in the absence of previous back surgery due to aging, previous epidural catheter insertion or repeated aseptic inflammation after disc rupture [23–25]. However, the effect of adding hyaluronidase to epidural steroids on the early acute postoperative pain after spine surgery has not been investigated yet.
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