Cyclo(Gly-Gln) inhibits the cardiorespiratory depression produced by beta-endorphin and morphine.

Glycyl-L-glutamine (Gly-Gln; beta-endorphin 30-31) is an endogenous dipeptide that is synthesized through the post-translational processing of beta-endorphin. Previously, we showed that Gly-Gln inhibits the hypotension and respiratory depression produced by central beta-endorphin administration. In this study, we tested whether cyclo(Gly-Gln), a non-polar, cyclic Gly-Gln derivative, was similarly effective following intracerebro-ventricular (i.

Estrogen-regulated uterine vascularization modulates the guinea pig intrauterine environment.

The effects of experimentally-induced, uterine vascular restriction on uterine blood flow (UBF) and uterine blood volume (UBV) capacity, as well as the dependent intrauterine oxygen tension (IUpO2) measurements used as an indication of luminal nutrient availability, were examined using ovariectomized, estrogen (E)-treated guinea pigs. Following 3 days of E treatment, both UBF and UBV measurements were found to be elevated and associated with a causally-related increase in intraluminal uterine oxygen availability levels. Following the acute clamping of the uterine arteries, both UBF and UBV levels decreased dramatically and induced a rapid fall in associated intrauterine luminal oxygen tension measurements.

Lactation and salt loading similarly alter neuropeptide Y, but differentially alter somatostatin, in separate sets of rat neural lobe axons.

Neuropeptide Y (NPY) and somatostatin immunoreactivities are present in neural lobe axons of the rat pituitary. Both peptides are upregulated during lactation, because NPY gene expression increases in the hypothalamus and plasma concentrations of somatostatin are elevated. However, the effects of lactation on NPY and somatostatin in the neural lobe are unknown.

Determination of energy density threshold for laser ablation of bacteria. An in vitro study.

The Nd:YAG and CO2 lasers have been shown to be bactericidal at relative low energy densities. However, at energy densities exceeding 120 J/cm2 (CO2) and 200 J/cm2 (Nd:YAG), laser irradiation also causes irreparable root surface damage. The purpose of this study was to determine, in vitro, the energy density threshold at which microbial ablation could be achieved while inflicting the least amount of damage to the root surfaces of human teeth.

Treatment of root fracture by CO2 and Nd:YAG lasers: an in vitro study.

The purpose of this in vitro study was to use scanning electron microscopy and polarized light microscopy to evaluate the feasibility of using either the CO2 laser or an Nd:YAG laser in combination with air/water surface cooling to effect fusion of fractured tooth roots. The experimental unit consisted of 81 single-rooted teeth, each with an induced root fracture. Fifty-six teeth that had been reapproximated in dental stone and 25 teeth that had been reapproximated with C-clamps were assigned to untreated control groups or groups for treatment using CO2 and Nd:YAG lasers.

Mega-analysis of meta-analysis: an examination of meta-analysis with an emphasis on once-daily aminoglycoside comparative trials.

Meta-analysis is increasingly performed to try and answer clinical questions around which controversy exists. We performed meta-analyses using three different methods as examples to illustrate problems and points to consider when doing such work. The questions of interest were comparing frequency of nephrotoxicity and clinical effectiveness with once-daily aminoglycoside regimens versus multiple-daily dose aminoglycoside regimens.

Regulation of sympathetic presynaptic components in rat left ventricle during ligation of abdominal aorta.

To assess the effects of long-term pressure overload on sympathetic presynaptic components in the left ventricle, young adult male rats were subjected to surgical constriction of the suprarenal abdominal aorta. At 4 and 8 wk postsurgery, but not at 1 wk, left ventricular sympathetic activity, measured by the net fractional norepinephrine (NE) decrease after alpha-methyl-p-tyrosine methyl ester administration, was elevated in the aortic-banded rats. However, left ventricular NE was reduced only at 8 wk.

Awareness of physiological responding under stress and nonstress conditions in temporomandibular disorders.

To test the hypothesis that individuals with temporomandibular disorders (TMD) have deficits in proprioceptive awareness, 20 TMD patients were compared with 20 nonpain individuals matched to the TMD patients on age and gender. Left and right frontalis, masseter, and temporalis were monitored, as were forearm extensor, heart rate, and skin conductance while the participants viewed a nonstressful film segment. Following the film segment, participants provided self-reports of these physiological responses.

Types and activities of voltage-operated calcium channels change during development of rat pituitary neurointermediate lobe.

Cultures of pituitary neurointermediate lobe cells were established from rats aged 1, 12, and 42 days to identify the types and assess the activities of Ca2+ channels present in melanotropes, glial-like cells, and fibroblasts during development. Day 12 represents the time at which dopaminergic axons have become distributed throughout the lobe, glial cells begin to lose their radial orientation, and melanotropes robustly express the short isoform of the dopamine D2 receptor. Thus, we studied Ca2+ channels in relation to the event of innervation of melanotropes.

Analysis of Lactobacillus phages and bacteriocins in American dairy products and characterization of a phage isolated from yogurt.

Yogurt and acidophilus milk that contain Lactobacillus acidophilus could promote human health because L. acidophilus can inhibit enteric and food-borne microbial pathogens. To evaluate the stability of diary L.

Occlusal vertical dimension in prosthodontics.

Occlusal vertical dimension is important in all aspects of prosthodontics. Unfortunately, there is no scientific method of determining the correct occlusal vertical dimension. The amount of interocclusal rest space (IRS) is a rough guide since muscle tone, which determines the space, is variable.

Melanotrope dopamine D2 receptor isoform expression in the developing rat pituitary.

This study measured melanotrope mRNA and protein expression for the dopamine D2 receptor, and its long isoform, in relation to the appearance of dopamine in axons of the postnatal rat pituitary intermediate lobe. At postnatal day 2, prior to the onset of dopaminergic innervation, D2 receptor (D2T) mRNA was expressed heterogeneously in a subpopulation of melanotropes which also expressed the long isoform (DL). The D2L mRNA appeared to be predominant during early postnatal development, since the D2T probe, which did not discriminate between the isoforms, and the D2L probe hybridized generally to the same cells, as demonstrated in serial sections.

Quantitative analysis of the dentin adhesive interface by Auger spectroscopy.

The ultimate success of a dentin adhesive bond is dependent in large part on specific conditions at the interface between the tooth and the adhesive. Most current dentin adhesive systems use some sort of pre-treatment to demineralize the first few microns of the dentin surface, leaving a meshwork of collagen into which the adhesive resin can penetrate, infiltrate, and polymerize. The general hypothesis tested in this experiment was that the penetration and distribution of adhesive resin into the demineralized zone are a function of the conditioner used as a pre-treatment for the adhesive application.

High-performance liquid chromatographic determination of phenylephrine and its conjugates in human plasma using solid-phase extraction and electrochemical detection.

An HPLC method for the determination of phenylephrine and its conjugates in human plasma was developed and validated. The method for quantitation involved extraction of diluted plasma (subject to hydrolysis with beta-glucuronidase for 30 min with 500 units of enzyme per 0.1 ml of plasma at 37 degrees C for the conjugates) on solid-phase weak cation-exchange cartridges followed by elution of the analyte and the internal standard (ethylnorphenylephrine) with 5% triethylamine in methanol.

Regulation of phosphatidylinositide transduction system in the rat spinal cord during aging.

Age-related functional alterations in a variety of neurotransmitter systems result in modulation of interneuronal communications which has some relevance in neurological deficits observed in the aging process. The synergistic interactions between protein kinase and inositol 1,4,5-trisphosphate (insP3)/Ca2+ pathways underlie a variety of cellular responses to external stimuli. To determine whether age-dependent changes occur in the regulation of protein kinase C and inositol 1,4,5-trisphosphate/Ca2+ pathways, insP3 contents as a marker for the release of intracellular calcium, saturation binding analysis of Ins P3 receptor using [3H]inositol 1,4,5-trisphosphate, slot/northern blot analysis of Ins P3 receptor-encoding mRNA transcripts, and the activities of Ca2+/phospholipid-dependent protein kinase C isozymes were investigated in the rat spinal cord.

Developmental and regional changes in brain norepinephrine levels in diabetic C57BL/KsJ mice: effects of estradiol and progesterone.

Developmental and diabetes-associated changes in regional brain norepinephrine (NE) concentrations, and the influence of estradiol (E) and progesterone (P) on NE levels, were correlated with changes in blood glucose levels and body weight (obesity) in developing 4-16-week-old C57BL/KsJ (db/db) mice relative to corresponding age-matched control (+/?) parameters. Regional brain (i.e.

Clinical evaluation of restored maxillary incisors: veneers vs. PFM crowns.

This cross-sectional study compared the periodontal health and clinical acceptability of maxillary incisors restored with porcelain veneers vs. porcelain-fused-to-metal crowns. The authors evaluated 60 patients, a total of 120 restorations, in groups according to the age of the restorations (zero to 60 months).

Adaptation to macular scotomas in persons with low vision.

Persons with scotomas in their central 20 degrees of vision often do not notice these blind spots within their visual field and have visual performance difficulties far exceeding what would be expected from standard vision tests. Before persons with macular scotomas can be assisted to optimally use their remaining vision for a better quality of life, more must be known about how the visual system adapts to a macular scotoma. Important issues include spatial and temporal characteristics of perceptual completion and metamorphopsia, development of preferred retinal loci for fixation and visual search, and dynamics of the preferred retinal locus development in terms of the changes in the eye movement system.

Transient expression of S-100 by melanotropes of the rat pituitary intermediate lobe during development.

S-100, an acidic calcium-binding protein, is co-localized with vimentin in glial-like cells in the adult rat pituitary intermediate lobe. S-100 and melanotrope markers were not co-localized in the adult. During development, S-100 and vimentin were not co-localized but appeared in cells with different morphological characteristics.

Glial-like cells of the rat pituitary intermediate lobe change morphology and shift from vimentin to GFAP expression during development.

This study demonstrated morphological changes in glial-like cells of the rat pituitary intermediate lobe during early postnatal development, and a subsequent shift in protein expression from vimentin to GFAP. Vimentin immunoreactivity was detected in the lobe at embryo day 14 and was localized in radially-oriented, bipolar cells whose processes spanned the thickness of the intermediate lobe. At electron microscopical resolution, processes contained intermediate filaments, cell nuclei were indented while secretory vesicles characteristic of the endocrine cells were not found.

Increased urinary excretion of analogs of Krebs cycle metabolites and arabinose in two brothers with autistic features.

A marked increase in analogs of Krebs cycle metabolites was found in the urine of two brothers with autistic features. These metabolites included citramalic, tartaric (3-OH-malic), and 3-oxoglutaric acids and compounds tentatively identified as a citric acid analog and partially identified as a phenylcarboxylic acid by the fragmentation pattern of the trimethylsilyl (TMS) derivatives of the compounds and mass shifts of the same compounds derivatized with perdeuterated N,O-bis(trimethylsilyl)trifluoroacetamide. The molecular mass of the TMS derivative of the tentatively identified citric acid analog was 596 Da, based on a finding of a significant M - 15 ion at m/z 581.

Contributions of facial morphology, age, and gender to EMG activity under biting and resting conditions: a canonical correlation analysis.

Theoretical studies suggest that facial morphology may confer a mechanical advantage to particular individuals during force production, but not during rest. However, prior studies on the relationship between facial morphology and EMG suffer from various methodological limitations. We examined the hypothesis that facial morphology variables contribute significantly and meaningfully to the variance in masticatory muscle EMG when subjects produce specific levels of interocclusal force, but not when subjects are at rest.

Effect of aging on the kinetics of blood-brain barrier uptake of tryptophan in rats.

Purpose: The purpose of this investigation was to examine the effect of aging on the blood-brain barrier (BBB) transport of tryptophan.

Methods: A well established in-situ brain perfusion technique was used to examine brain uptake of 14C-tryptophan in 2-, 12- and 24-month old Sprague-Dawley rats; perfusate tryptophan concentrations ranged from 0.00175 to 2 mM.

Scanning transmission electron microscopy/energy-dispersive spectroscopy analysis of the dentin adhesive interface using a labeled 2-hydroxyethylmethacrylate analogue.

In an attempt to compare the morphology of the dentin adhesive interface and the wetting and penetration of the adhesive in relation to the dentin surface, we studied four dentin adhesive systems using scanning transmission electron microscopy (STEM) and energy-dispersive spectroscopy (EDS). 2-Hydroxyethylmethacrylate (HEMA), a monomer common to many commercial dentin adhesive systems, was altered to produce a thiolated analogue (HETMA). Sulfur, traceable by EDS and STEM, was substituted for the oxygen atom in the backbone of the HEMA molecule.