Overview of pyridine nucleotides review series

Pyridine nucleotides are abundant soluble coenzymes and they undergo reversible oxidation and reduction in several biological electron-transfer reactions. They are comprised of two mononucleotides, adenosine monophosphate and nicotinamide mononucleotide, and are present as oxidized and reduced nicotinamide adenine dinucleotides in their unphosphorylated (NAD(+) and NADH) and phosphorylated (NADP(+) and NADPH) forms. In the past, pyridine nucleotides were considered to be primarily electron-shuttling agents involved in supporting the activity of enzymes that catalyze oxidation-reduction reactions. However, it has recently been demonstrated that pyridine nucleotides and the balance between the oxidized and reduced forms play a wide variety of pivotal roles in cellular functions as important interfaces, beyond their coenzymatic activity. These include maintenance of redox status, cell survival and death, ion channel regulation, and cell signaling under normal and pathological conditions. Furthermore, targeting pyridine nucleotides could potentially provide therapeutically useful avenues for treating cardiovascular diseases. This review series will highlight the functional significance of pyridine nucleotides and underscore their physiological role in cardiovascular function and their clinical relevance to cardiovascular medicine.     

Treatment of skeletal class II division 1 malocclusion with mandibular deficiency using myofunctional appliances in growing individuals

Class II division 1 malocclusion is the most common malocclusion seen in day-to-day practice. The majority of the patients with class II division 1 malocclusions have the presence of underlying skeletal discrepancy between maxilla and mandible. The treatment of skeletal class II division 1 depends upon the age of the patient, growth potential, severity of malocclusion, and compliance of patient with treatment. Myofunctional appliance can be successfully used to treat growing patients with class II division 1 malocclusion having retrusive mandible. This article presents a discussion on treatment of class II division 1 due to mandibular deficiency with growth modification approach using myofunctional appliances and a series of three case reports of treatment of skeletal class II division 1 malocclusion using myofunctional appliance followed by fixed mechanotherapy.     

Maxilloturbinal Aids in Nasophonation in Horseshoe Bats (Chiroptera: Rhinolophidae)

Horseshoe bats (Family Rhinolophidae) show an impressive array of morphological traits associated with use of high duty cycle echolocation calls that they emit via their nostrils (nasophonation). Delicate maxilloturbinal bones inside the nasal fossa of horseshoe bats have a unique elongated strand-like shape unknown in other mammals. Maxilloturbinal strands also vary considerably in length and cross-sectional shape. In other mammals, maxilloturbinals help direct respired air and prevent respiratory heat and water loss. We investigated whether strand-shaped maxilloturbinals in horseshoe bats perform a similar function to those of other mammals, or whether they were shaped for a role in nasophonation. Using histology, we studied the mucosa of the nasal fossa in Rhinolophus lepidus, which we compared with Hipposideros lankadiva (Hipposideridae) and Megaderma lyra (Megadermatidae). Using micro-CT scans of 30 horseshoe bat species, we quantified maxilloturbinal surface area and skull shape within a phylogenetic context. Histological results showed horseshoe bat maxilloturbinals are covered in a thin, poorly vascularized, sparsely ciliated mucosa poorly suited for preventing respiratory heat and water loss. Maxilloturbinal surface area was correlated with basicranial width, but exceptionally long and dorsoventrally flat maxilloturbinals did not show enhanced surface area for heat and moisture exchange. Skull shape variation appears to be driven by structures linked to nasophonation, including maxilloturbinals. Resting echolocation call frequency better predicted skull shape than did skull size, and was specifically correlated with dimensions of the rostral inflations, palate, and maxilloturbinals. These traits appear to form a morphological complex, indicating a nasophonatory role for the strand-shaped rhinolophid maxilloturbinals. Anat Rec, 2018. © 2018 American Association for Anatomy.