Maintenance of optogenetic channel rhodopsin (ChR2) function in aging mice: Implications for pharmacological studies of inhibitory synaptic transmission, quantal content, and calcium homeostasis.

Disruption of synaptic function is believed to represent a common pathway contributing to cognitive decline during aging. Optogenetics is a prodigious tool for studying relationships between function and synaptic circuitry but models utilizing viral vectors present limitations. Careful characterization of the functionality of channel rhodopsin in transgenic models is crucial for determining whether they can be used across aging.

Late-Onset, Short-Term Intermittent Fasting Reverses Age-Related Changes in Calcium Buffering and Inhibitory Synaptic Transmission in Mouse Basal Forebrain Neurons.

Aging is often associated with cognitive decline and recurrent cellular and molecular impairments. While life-long caloric restriction (CR) may delay age-related cognitive deterioration as well as the onset of neurologic disease, recent studies suggest that late-onset, short-term intermittent fasting (IF), may show comparable beneficial effects as those of life-long CR to improve brain health. We used a new optogenetic aging model to study the effects of late-onset (>18 months), short-term (four to six weeks) IF on age-related changes in GABAergic synaptic transmission, intracellular calcium (Ca) buffering, and cognitive status.

Amitriptyline Decreases GABAergic Transmission in Basal Forebrain Neurons Using an Optogenetic Model of Aging.

The antidepressant drug amitriptyline is used in the treatment of clinical depression and a variety of neurological conditions such as anxiety, neuropathic pain disorders and migraine. Antidepressants are associated with both therapeutic and untoward effects, and their use in the elderly has tripled since the mid-1990s. Because of this widespread use, we are interested in testing the acute effects of amitriptyline on synaptic transmission at therapeutic concentrations well below those that block voltage-gated calcium channels.

Properties of New Glass-Ionomer Restorative Systems Marketed for Stress-Bearing Areas.

Objectives: The purpose of this study was to evaluate the properties (fracture toughness, surface hardness) of newer conventional glass-ionomer restorative materials that are marketed for posterior stress-bearing areas compared with more traditional glass-ionomer restorative materials marketed for non-load-bearing areas and composite-resin restorative materials.

Methods And Materials: Notched-beam fracture toughness specimens were created in a mold with each tested material (Equia Forte, GC America, with and without a surface coating of Equia Forte Coat; Ketac Universal, 3M/ESPE; ChemFil Rock, Dentsply; Fuji IX GP Extra, GC; Ionostar Molar, VOCO; Filtek Z250, 3M/ESPE; Filtek Supreme Ultra, 3M/ESPE) and fractured using a universal testing machine after 24 hours of storage. Hardness values were determined on the surface of the fracture toughness specimens using a hardness tester.

Flexural strength of denture base acrylic resins processed by conventional and CAD-CAM methods.

Statement Of Problem: High flexural strength is one of the desirable properties for denture base resins, yet only few studies have evaluated the physical properties of newer denture bases such as computer-aided design and computer aided manufacturing (CAD-CAM) milled products.

Purpose: The purpose of this in vitro study was to compare the flexural strength of 3 different types of denture base resins: compression molded, injection molded, and CAD-CAM milled.

Material And Methods: Three groups (n=10) of acrylic denture base resins were tested: injection molded, compression molded, and CAD-CAM milled resin.

Effects of ethanol and varenicline on female Sprague-Dawley rats in a third trimester model of fetal alcohol syndrome.

Perinatal ethanol exposure disrupts a variety of developmental processes in neurons important for establishing a healthy brain. These ethanol-induced impairments known as fetal alcohol spectrum disorder (FASD) are not fully understood, and currently, there is no effective treatment. Further, growing evidence suggests that adult females are more susceptible to ethanol, with the effects of perinatal ethanol exposure also being sexually divergent.

Fracture Resistance of Ceramic Crowns Supported with Indirect Chair-side Composite Cores.

Aims And Objectives: To evaluate the influence of indirect chair-side polymerization of resin composite cores on the fracture resistance of overlaying IPS e.max Press crowns.

Materials And Methods: Root canals of 60 extracted premolars were prepared to receive #2 fiber posts after the crowns were sectioned 2 mm above the cervical line.

Characterization of age-related changes in synaptic transmission onto F344 rat basal forebrain cholinergic neurons using a reduced synaptic preparation.

Basal forebrain (BF) cholinergic neurons participate in a number of cognitive processes that become impaired during aging. We previously found that age-related enhancement of Ca(2+) buffering in rat cholinergic BF neurons was associated with impaired performance in the water maze spatial learning task (Murchison D, McDermott AN, Lasarge CL, Peebles KA, Bizon JL, and Griffith WH. J Neurophysiol 102: 2194-2207, 2009).

CT-measured bone attenuation in patients with chronic obstructive pulmonary disease: relation to clinical features and outcomes.

Osteoporosis is highly prevalent in chronic obstructive pulmonary disease (COPD) patients and has been related to several clinical features. However, most studies have been in relatively small COPD cohorts. Therefore, the objectives of this study were to compare bone attenuation measured on low-dose chest computed tomography (CT) between COPD subjects and smoker and nonsmoker controls, and to relate bone attenuation to clinical parameters, inflammatory biomarkers, and outcomes in a large, well-characterized COPD cohort.

Enhanced calcium buffering in F344 rat cholinergic basal forebrain neurons is associated with age-related cognitive impairment.

Alterations in neuronal Ca(2+) homeostasis are important determinants of age-related cognitive impairment. We examined the Ca(2+) influx, buffering, and electrophysiology of basal forebrain neurons in adult, middle-aged, and aged male F344 behaviorally assessed rats. Middle-aged and aged rats were characterized as cognitively impaired or unimpaired by water maze performance relative to young cohorts.

Learning styles of orthodontic residents.

Significant challenges face many orthodontic residency programs, particularly a shortage of full-time experienced faculty members. Due to this shortage, it is critical that program directors design comprehensive curricula that incorporate the most effective and efficient teaching methods. It is theorized that teaching effectiveness and efficiency are optimized when the course design and content closely match students' learning preferences.

Calcium buffering systems and calcium signaling in aged rat basal forebrain neurons.

Disturbances of neuronal Ca2+ homeostasis are considered to be important determinants of age-related cognitive impairment. Cholinergic neurons of the basal forebrain (BF) are principal targets of decline associated with aging and dementia. During the last several years, we have attempted to link these concepts in a rat model of 'normal' aging.

Functional compensation by other voltage-gated Ca2+ channels in mouse basal forebrain neurons with Ca(V)2.1 mutations.

Tottering (tg/tg) and leaner (tg(la)/tg(la)) mutant mice exhibit distinct mutations in the gene encoding the voltage-activated Ca(2+) channel alpha(1A) subunit (CACNA1A), the pore-forming subunit of the Ca(V)2.1 (P/Q type) Ca(2+) channels. These mice exhibit absence seizures and deficiencies in motor control and other functions.

Oral surgical handpiece use time parameters.

Purpose: To evaluate the clinical usage time parameters of handpieces used in oral surgical procedures.

Method And Materials: One hundred randomly selected clinical oral surgery exodontia procedures were timed to record lengths of continuous segments of both handpiece use and non-usage. Providers with experience ranging from general dentists to board certified oral surgeons were timed during surgical exodontia treatment involving 1 to 4 teeth of various complexities.

Low voltage-activated calcium and fast tetrodotoxin-resistant sodium currents define subtypes of cholinergic and noncholinergic neurons in rat basal forebrain.

Neurons of the basal forebrain (BF) possess unique combinations of voltage-gated membrane currents. Here, we describe subtypes of rat basal forebrain neurons based on patch-clamp analysis of low-voltage activated (LVA) calcium and tetrodotoxin-resistant (TTX-R) sodium currents combined with single-cell RT-PCR analysis. Neurons were identified by mRNA expression of choline acetyltransferase (ChAT+, cholinergic) and glutamate decarboxylase (GAD67, GABAergic).

Reduced mitochondrial buffering of voltage-gated calcium influx in aged rat basal forebrain neurons.

Alterations of neuronal Ca(2+) homeostatic mechanisms could be responsible for many of the cognitive deficits associated with aging in mammals. Mitochondrial participation in Ca(2+) signaling is now recognized as a prominent feature in neuronal physiology. We combined voltage-clamp electrophysiology with Ca(2+)-sensitive ratiometric microfluorimetry and laser scanning confocal microscopy to investigate the participation in Ca(2+) buffering of in situ mitochondria in acutely dissociated basal forebrain neurons from young and aged F344 rats.

Homeostatic compensation maintains Ca2+ signaling functions in Purkinje neurons in the leaner mutant mouse.

Several human neurological disorders have been associated with mutations in the gene coding for the alpha1 subunit of the P/Q type voltage-gated calcium channel (alpha1A/Ca(v)2.1). Mutations in this gene also occur in a number of neurologically affected mouse strains, including leaner (tg(la)/tg(la)).

Aluminum oxide air abrasion particles: a bacteriologic and SEM study.

Objective: The objective is to determine if aerobic and anaerobic sampling yields viable biologic contaminants in the aluminum oxide air abrasion powder as delivered by the manufacturer and to determine mean particle size for comparison with the published size from manufacturers and the range of sizes in the powders.

Method And Materials: Samples from 15 unopened aluminum oxide powder containers from 9 different manufacturers were plated on aerobic and anaerobic culture media. The cultures were incubated at 35 degrees C and observed at 24-hour intervals.

The effect of resin composite pins on the retention of class IV restorations.

Standardized Class IV cavity preparations were made in 48 human incisors. They were then divided into three groups of 16 teeth each. Group 1 was prepared with no internal retentive features.

Fracture strength of amalgam crowns with repaired endodontic access.

Endodontic therapy is accessed occlusally in posterior teeth, many of which have large, pre-existing amalgam restorations. These teeth are also commonly restored with an occlusal amalgam to repair the access opening. This study determined the fracture resistance of complex amalgam restorations that have repaired endodontic access compared with original, unrepaired, complex amalgams on endodontically-treated teeth.

Surface roughness of various packable composites.

Packable composite restorations have become a popular alternative to dental amalgam restorations in posterior teeth. A drawback inherent to composites is their difficulty in polishing, which often results in a dull or rough surface. This study compared the surface roughness of a resin-based hybrid composite material and five packable resin-based composites polished with either aluminum oxide disks or a rubber polishing system.

Higher-concentration carbamide peroxide effects on surface roughness of composites.

Background: Ten percent carbamide peroxide has been used extensively within the dental profession for the purpose of bleaching teeth. Although this method has been successful, the use of higher-concentration carbamide peroxides (20-35%) for home bleaching has increased substantially in the past few years. The purpose of this study was to evaluate changes in surface roughness of a hybrid and a microfilled composite after exposure to bleaching agents containing higher concentrations of carbamide peroxide.

Diagnostic utility of thermal printed panographs compared with corresponding computer monitor images.

Digital panoramic radiographs may be viewed with computer monitors or archived as thermal or laser prints. To compare the available diagnostic information from thermal print images to that of corresponding computer monitor images, four calibrated evaluators performed a qualitative analysis of 13 specified anatomic features in 60 pairs of digital panoramic images presented in random order on a computer monitor and as thermal printed images. Each anatomic site was rated both for subjective diagnostic quality and diagnostic utility using a nominal scale.

Single-cell RT-PCR detects shifts in mRNA expression profiles of basal forebrain neurons during aging.

The medial septum and nucleus of the diagonal band (MS/nDB) contain cholinergic and GABAergic neuronal populations that have been identified based on immunohistochemical staining and/or electrophysiological properties. We explored the molecular diversity of MS/nDB neurons using single-cell reverse transcription-polymerase chain reaction (scRT-PCR) to assess gene expression profiles during aging in individual neurons acutely isolated from young (2-4 months) and aged (26-27 months) F344 rats. Neuronal gene expression profiles were characterized by detection of mRNAs for choline acetyltransferase (ChAT, cholinergic) and glutamate decarboxylase (GAD67, GABAergic), as well as mRNAs for calcium binding proteins (CaBPs) calbindin-D28k, calretinin and parvalbumin.

Comparison of moist and dry heat penetration through orofacial tissues.

Application of superficial moist heat has been shown to have a beneficial effect on Temporomandibular Disorder (TMD) symptoms and is often recommended for patients with this disorder. A review of the literature shows that few studies have compared the effects of moist to dry heat. Throughout this study, moist and dry heat were applied through a commercial heating pad alternately for 20 minute intervals.