bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructural Localization of Calmodulin in Rat Incisor Ameloblasts and Odontoblasts During the Early Stages of Development
Authors: Goldberg M. , Escaig F. , Feinberg J. , Weinman S.
Published: January 2017

W visualized calmodulin distribution in rat incisor pre-secretory and secretory ameloblasts on ultrathin sections, using Lowicryl K4M embedding, antibody to calmodulin prepared from rabbit antiserum, and colloidal gold. The distribution of gold particles was compared with that observed in post-mitotic and secretory odontoblasts, and we also evaluated the effects of aldehyde fixation and fixation by rapid-freezing freeze-substitution.

Evaluation of gold particles showed enhanced immuno-staining during cell development. More particles were found in the cell bodies of secretory cells than in their processes. There was no difference between tissue fixed with aldehyde and that fixed by cryoprocessing.

Gold particles were present mainly in the rough endoplasmic reticulum and to a lesser extent in the nucleus, cytoplasm, and a few vesicles. Although the odontoblast processes displayed gold particles, the latter were never observed in pre-dentin or dentin. However, no such selective intracellular localization was observed in the ameloblasts, where gold particles were present not only in Tomes' processes but also in the interrod forming enamel, and to a lesser degree inside the forming rods. In the underlying enamel at later stages of mineralization, only background labeling was detected. The extracellular location of an intracellular calcium-binding protein suggests either the non-specific binding of antiserum with some enamel proteins or the release of small fragments of the secretory ameloblasts into the forming enamel.
Octacalcium Phosphate as a Precursor in Biomineral Formation
Authors: Brown W.E. , Eidelman N. , Tomazic B.
Published: January 2017

What are biominerals and how are they formed? It is usually assumed: (i) that the prototype for most apatitic biominerals is hydroxyapatite (OHAp), Ca5(PO4) 3OH; and (ii) that the OHAp structure has been modified by the presence of impurity ions and vacancy defects in specific OHAp lattice sites. The usual answer, at least implicitly, to the second question is that the apatitic mineral is formed directly by the precipitation of ions from the surrounding solution. Our answers are: (i) that apatitic biominerals are formed through a precursor mechanism in which octacalcium phosphate (OCP), Ca8H 2(PO4)6·5H2O, precipitates first and then hydrolyzes ireversibly in situ to a transition product intermediate to OCP and OHAp; and (ii) that this product, "octacalcium phosphate hydrolyzate" (OCPH), may contain (a) OHAp-like and OCP-like domains in varying amounts, (b) vacancy defects and impurity ions in lattice sites in these domains, and (c) various kinds of one-, two-, and three-dimensional defects which are not present in either the OHAp or the OCP lattice, these defects being formed during the in situ hydrolysis step.

A calcification model of this type was first proposed in 1957, but full acceptance was delayed because most of the evidence was circumstantial and in vitro in nature. The situation has changed radically because of three unrelated studies that are in vivo in nature but lead to the same conclusion:

I. 32P-pyrolysis studies of rat enamel: The results clearly demonstrated that an acidic calcium phosphate precursor was involved.

II. Precipitation of calcium phosphates in serum. Ultrafiltered serum was equilibrated with brushite. Subsequent changes in the ionic concentrations revealed that OCP was formed at first and then hydrolyzed to a more basic form, OCPH, but never reached the solubility of OHAp.

III. Physicochemical properties of cardiovascular biominerals: We recently characterized biominerals in cardiovascular deposits in an encompassing variety of ways. As an overall conclusion, OCPH was the prototype most compatible with the data [including indices of refraction, solubility, P2O74- formation on pyrolysis, thermogravimetric analysis (TGA) measurements, presence of water, and incorporation of CO32-, Na+, and Mg2+].

This calcification model has important consequences relative to all kinds of calcification and decalcification processes, including those of enamel.
Major Antigens of Human Oral Spirochetes Associated with Periodontal Disease
Authors: Umemoto T. , Zambon J.J. , Genco R.J. , Namikawa I.
Published: January 2017

Human oral spirochetes are prominent inhabitants of subgingival plaque in patients with periodontal disease. Measurements of serum antibody titers to these micro-organisms have been used to illuminate the role of human oral spirochetes in periodontal disease. In the present study, rabbit antisera to four oral spirochetes (including Treponema denticola ATCC33520 and three clinical isolates) were examined for reactivity to cell lysates. Western blotting demonstrated that the major treponemal antigens reactive with the rabbit antisera to T. denticola ATCC33520 and to strains 42, 48, and 57 possessed 53-kDa, 53-kDa, 56-kDa, and 56-kDa molecular weights, respectively. Human sera from patients with acute necrotizing ulcerative gingivitis (ANUG) and localized juvenile periodontitis (LJP) were also reactive with these antigens, particularly the 53-kDa antigen of T. denticola ATCC33520. A membrane-rich preparation was obtained from the cell lysate of T. denticola ATCC33520 by column chromatography and centrifugation, and applied to an SDS-polyacrylamide gel. The 53-kDa major peptide band was found. The membrane vesicles in an axial filament-membrane-containing fraction were agglutinated in the presence of the rabbit antiserum to T. denticola ATCC33520. Western blot analysis indicated that the 53-kDa antigen reacted strongly with the rabbit antiserum to T. denticola ATCC33520. These findings suggest that polypeptide antigens, such as the 53-kDa antigen from human oral spirochetes, play an important role in production of humoral antibodies associated with periodontal disease.
Identification of Periodontopathic Bacteria Based Upon their Peptidase Activities
Authors: Suido H. , Eguchi T. , Tanaka T. , Nakamura M.
Published: January 2017

Black-pigmented Bacteroides (BPB) and spirochetes are associated with some forms of periodontal diseases. The enzymes produced by these bacteria may participate in the destruction of gingival and periodontal tissues. Certain proteases and peptidases are unique to Bacteroides gingivalis and Treponema denticola. Our purpose was to study the peptidases of periodontopathogens and to evaluate the use of unique peptidases for detection and identification of these bacteria.

Bacteria used were BPB, Treponema, Fusobacterium, Capnocytophaga, Actinobacillus (Haemophilus), and Eikenella species. Twenty-five substrates, including mono-, di-, and tri-peptides of β-naphthylamide (β-NA) were employed for examination of peptidase activity. Clinically isolated BPB were obtained from 16 adult periodontitis patients. One hundred and ninety-three BPB strains were identified by conventional identification methods, and the peptidase activity was determined with N-Carbobenzoxy-glycyl-glycyl-L-arginine-β-naphthylamide (N-CBz-Gly-Gly-Arg-β-NA) used as a substrate.

Among tested periodontopathic bacteria, only B. gingivalis and T. denticola could strongly hydrolyze some substrates such as N-CBz-Gly-Gly-Arg-β-NA and N-Benzoyl-L-valyl-glycyl-L-arginine-4-methoxy-(3-naphthylamide (Bz-Val-Gly-Arg-β-NA). In subgingival plaque samples, all patients showed BPB, and eight out of 16 patients possessed B. gingivalis by culture. One hundred and ten strains out of 193 BPB isolated were identified as B. gingivalis. Ninety-nine percent of these B. gingivalis strains identified showed N-CBz-Gly-Gly-Arg-β-NAhydrolyzing activity on a newly developed colorimetric plate assay. However, none of the other strains showed this activity in cultures of subgingival plaque which did not allow growth of spirochetes.

Enzymes, such as N-CBz-Gly-Gly-Arg-peptidase and Bz-Val-Gly-Arg-peptidase, specific for B. gingivalis and T. denticola seem to be useful for rapid detection and identification of these bacteria.
Diagnosis of Periodontal Diseases: Reaction Paper
Authors: Novak M.J.
Published: January 2017

With the recent description of 12 different forms and sub-forms of periodontitis by the World Workshop in Clinical Periodontics (1989), increased emphasis has been placed on diagnosis. Dr. Ranney's review addressed the specificity and sensitivity of current diagnostic tests with respect to their ability to differentiate between health and disease and between the individual disease states. Although considerable microbiologic and immunologic data have been accumulated in the past decade, very little of this information has proved to be sufficiently sensitive to be of use in differential diagnosis. Clinical measurements provide us with an insensitive, retrospective analysis of what has already occurred but allow us to diagnose disease based on its natural history. Measures of attachment levels, by use of conventional probes, are only sufficiently sensitive indicators of periodontitis when as much as 20-30% of attachment has already been lost. Current technological improvements in probing measurements and radiographic assessment may increase sensitivity in this area. Future improvements in diagnostic techniques will occur with the advent of sensitive biochemical analyses of gingival crevicular fluid. These assays will provide a more objective analysis of inflammation and, in time, will provide sufficient sensitivity to allow for differentiation between and among the various forms of periodontal disease. Future directions in diagnosis will focus on the identification of disease-susceptible individuals and the prediction of future periodontal breakdown.
Intake and Metabolism of Fluoride
Authors: Whitford G.M.
Published: January 2017

The purpose of this paper is to discuss the major factors that determine the body burden of inorganic fluoride. Fluoride intake 25 or more years ago was determined mainly by measurement of the concentration of the ion in the drinking water supply. This is not necessarily true today because of ingestion from fluoride-containing dental products, the "halo effect", the consumption of bottled water, and the use of water purification systems in the home. Therefore, the concentration of fluoride in drinking water may not be a reliable indicator of previous intake. Under most conditions, fluoride is rapidly and extensively absorbed from the gastrointestinal tract. The rate of gastric absorption is inversely related to the pH of the gastric contents. Overall absorption is reduced by calcium and certain other cations and by elevated plasma fluoride levels. Fluoride removal from plasma occurs by calcified tissue uptake and urinary excretion. About 99% of the body burden of fluoride is associated with calcified tissues, and most of it is not exchangeable. In general, the clearance of fluoride from plasma by the skeleton is inversely related to the stage of skeletal development. Skeletal uptake, however, can be positive or negative, depending on the level of fluoride intake, hormonal status, and other factors. Dentin fluoride concentrations tend to increase throughout life and appear to be similar to those in bone. Research to determine whether dentin is a reliable biomarker for the body burden of fluoride is recommended. The renal clearance of fluoride is high compared with other halogens. It is directly related to urinary pH. Factors that acidify the urine increase the retention of fluoride and vice versa. The renal clearance of fluoride decreases and tissue levels increase when the glomerular filtration rate is depressed on a chronic basis.
Determinants of Childbirth Assistance in the Remote Islands of the Indian Sundarbans
Authors: Barman Debjani , Vadrevu Lalitha , Vyas Divya
Published: January 2017

Background:

India contributes to almost 70 percent of the maternal mortality in South East Asia. Improving access to skilled attendance at birth is crucial for addressing the issue of maternal deaths in the Indian context while majority of women deliver her child at home. Several issues of inaccessibility due to cost, distance, and lack of services still persist. The present research article, thus, discusses the determinants of child delivery care practices in a rural region like the Sundarbans in West Bengal, India.

Methods:

A household survey was conducted in the Patharpratima block of the Indian Sundarbans. A total of 1200 households were sampled using a two stage cluster sampling from 30 villages. Mothers were interviewed regarding child delivery practice of their youngest child along with other socio-demographic variables. Data analysis involves a multinomial logistic regression using STATA IC 10.

Results:

Child Delivery was assisted by formal providers in 48 percent of the cases, by informal providers in 30 percent cases and friends or relatives in 22 percent cases. Geographical location of the household, caste and religion, mother’s education and birth order were statistically significant predictors.

Conclusion:

Sundarbans as geographically isolated rural regions of the country face serious issue of inaccessibility. Following it high preference for home delivery and henceforth higher dependence on unskilled personnel for delivery in the region calls for specific plans to address the inaccessibility issue.
Cell Surface Carbohydrates Are Markers of Differentiation in Human Oral Epithelium
Authors: Dabelsteen Erik , Mandel Ulla , Clausen Henrik
Published: January 2017

Carbohydrates of the epithelial cell membrane are involved in cell-cell and cell-substrate interaction, and changes are seen in relationship to cell differentiation and neoplastic transformation. The terminal part of carbohydrate structures carried on oral epithelial cells often expresses antigens of the ABO and Lewis blood group systems. The expression of these antigens are in oral mucosa genetically regulated by the A, B, H, Lewis, and secretor genes with subsequent correspondence between the blood group antigens expressed on erythrocytes and on oral epithelial cells. Variation in expression of carbohydrates is also seen in relationship to terminal differentiation in that blood group antigens and their immediate precursor structures are sequentially expressed on cells during their pathway through the epithelium. Various organs and tissues differ in their expression of cell surface carbohydrates. In oral mucosa, a close relationship is seen between the type of tissue differentiation and expression of blood group antigen; keratinized, nonkeratinized, and junctional epithelium all show different patterns of carbohydrate expression.
Biophysical Approaches to Salivary Mucin Structure, Conformation and Dynamics
Authors: Gerken Thomas A.
Published: January 2017

Our understanding of the origins of the physical and biochemical properties of mucous glycoproteins is incomplete and not with out controversy. Recent molecular biological and biophysical studies revealing the architecture and solution structure and dynamics of a series of salivary mucins, invaluable toward resolving many of these questions, are discussed. Mucins are very large, structurally heterogeneous, and highly expanded molecules with the carbohydrate playing a key role in maintaining the extended mucin conformation.
Diagnosis and Management of Salivary Dysfunction
Authors: Valdez Ingrid H. , Fox Philip C.
Published: January 2017

Salivary gland dysfunction may occur as a result of common medications, cancer therapy, or Sjogren's syndrome. Affected patients may develop significant oral, dental, and upper gastrointestinal sequelae. This article reviews the basic elements in diagnosis of salivary dysfunction, including initial evaluation and specialized diagnostic procedures. Patient management depends primarily on the severity of salivary dysfunction. More severe permanent forms of dysfunction, such as radiation-induced and Sjogren's syndrome, require long-term care, with preventive measures to maintain the dentition and therapeutic attempts to increase oral fluids.
Sialochemistry: A Diagnostic Tool?
Authors: Aguirre A. , Testa-Weintraub L.A. , Banderas J.A. , Haraszthy G.G. , Reddy M.S. , Levine M.J.
Published: January 2017

Saliva has proven to be a discriminating element in forensic arenas, an effective indicator of acute diseases of salivary glands, and a promising probe for drug monitoring. With the advent of sensitive immunochemical assays, the compositional profile of human salivary secretions has been expanded considerably. Thus, the establishment of a range of "normal values" for a variety of "intrinsic" and "extrinsic" salivary components represented the initial step to use saliva as a diagnostic tool of oral health status. Unfortunately, numerous cross-sectional studies have shown a wide individual variation in the salivary composition of healthy populations, thus precluding its use as a diagnostic chair-side test for the screening of the most common chronic oral diseases (e.g., caries and periodontal disease). A possible explanation may arise from the wide functional versatility of salivary molecules. For instance, it has been recognized recently that in addition to its digestive properties, salivary amylase may modulate bacterial colonization, whereas histatins are not only antifungal but also bactericidal. Thus, low levels of already known antimicrobial salivary molecules (e.g., secretory IgA, lactoferrin, and lysozyme) could be compensated with higher concentrations of other molecules with antimicrobial activity, such as amylase and histatins. Consequently, for caries and periodontal diseases, longitudinal sialochemical studies may yield more insight than cross-sectional studies.
Effect of Whole Saliva Components on Enamel Demineralization In Vitro
Authors: Featherstone J.D.B. , Behrman J.M. , Bell J.E.
Published: January 2017

The aim of the present study was to use an in vitro enamel demineralization model (1) to confirm that whole saliva pretreatment conferred acid resistance to dental enamel and (2) to determine whether this phenomenon was attributable to specific salivary proteins, minerals, lipids, or some combination of these. Crowns of human teeth, each with one exposed window, were prepared in groups of ten. They were each pretreated by immersion individually in 4 ml of either (1) clarified whole saliva for 18, 72, or 168 h, (2) dialyzed saliva (3500 MWCO membrane), (3) the "flow-through" fraction from a DEAE separation of whole saliva (neutral and basic proteins), (4) the "eluted" fraction of a DEAE separation of whole saliva (anionic proteins), or (5) a combination of salivary lipids and the DEAE "flow-through" fraction of whole saliva (neutral and basic proteins). Control groups were group 6 with no pretreatment, group 7 pretreated for 168 h in a borate buffer (5 mmol/1), and group 8 pretreated in a mineral solution containing calcium (0.7 mmol/1) and phosphate (2.6 mmol/1). The crowns were then demineralized for 7 d in vitro (0.1 mol/1 acetate, 1 mmol/l Ca and phosphate, pH 5.0) to produce artificial caries-like lesions. Lesions were assessed by cross-sectional microhardness profiles, and mineral loss (AZ, μm x vol% mineral) calculated. Mineral loss (AZ) values decreased linearly with the square root of time of pretreatment by whole saliva, confirming a time-dependent protective effect of salivary pellicle against demineralization of enamel. Pretreatments (168 h) by whole saliva (group 1), dialyzed saliva (group 2), and lipid/'flow through" proteins (group 5) gave equivalent protection (approximately 55%). However, no protection was provided by DEAE-separated protein fractions (no lipid present) or by the mineral alone. The protection of surface enamel against demineralization appears to be given by a combination of specifically adsorbed salivary lipids and proteins.
Identification and Localization of G Proteins in Exocrine Glands
Authors: Watson Eileen L. , Di Julio Dennis , Oda Dolphine , Izutsu Kenneth T. , Oliver Constance
Published: January 2017

GTP-binding proteins were identified in rat parotid acinar plasma-enriched membranes (PM) by immunoblot analysis and localized immunohistochemically in the parotid gland as well as in other exocrine glands by using affinity-purified antisera specific for alpha subunits of the G proteins. Isolated rat parotid acinar PM immunoreacted strongly to antisera directed against Gsa, Giα1/α2, Gia3, and Goa; the signal for Goa, however, was weak with crude Go antisera. Immunohistochemical studies to identify and localize Go in rat parotid tissue revealed that antisera to Goα immunoreacted with ductal cells. In addition, strong immunoreactivity to Goa antisera was noted in ductal cells of other salivary glands including rat submandibular, mouse parotid, and mouse submandibular glands. Light labeling of rat parotid and submandibular gland acinar cells was also noted. In contrast, in the rat and mouse pancreas, Go antisera immunoreacted primarily with islet cells. Ductal cells were negative, but there was light labeling of rat pancreatic acinar cells. The apparent ductal specificity of Goa staining was further verified by demonstrating that Goa antisera immunoreacted strongly with HSG-PA cells, a human transformed salivary ductal cell line. The results demonstrate that rat parotid acinar plasma membranes express a number of G proteins including Go and that Go appears to be selectively expressed in the ductal cells of rat parotid gland and other salivary glands. The selective enrichment of Go in ductal cells suggests that this G protein may play an important role in ductal cell physiology.
Anti-Infectivity Activity of Human Salivary Secretions toward Human Immunodeficiency Virus
Authors: Robinovitch Murray R. , Iversen Jeanne M. , Resnick Lionel
Published: January 2017

The purpose of this investigation was to adapt an MT-2 cell syncytium-forming assay for measuring anti-infectivity activity of salivary secretions toward HIV and to determine the distribution of this activity in a population of healthy adult subjects. Whole saliva samples were collected from 27 volunteers, who reported that they did not belong to any group at high risk for HIV infection, and tested for anti-infectivity activity using the syncytium-forming assay. Nine of these subjects were subsequently retested on one or more occasions to assess the variability in appearance of this activity. Parotid and extraparotid salivas of six subjects were also tested. Samples were frozen immediately after collection and submitted in blinded fashion for quantitation of their anti-HIV activity using a syncytia-forming MT-2 cell assay or the p24 antigen ELISA. Nine out of the 27 subjects showed detectable anti-HIV infectivity activity. One parotid sample and one extraparotid sample out of four from subjects with positive whole salivas were positive and none of the parotid or extraparotid samples from two subjects with negative whole salivas were positive. The inhibitory activity ranged from 0.5 to 1 log 10 TCID50 /ml and could not be correlated with total protein content in saliva or any specific electrophoretic component. Filtration of the saliva through an Amicon 10 filter before incubation with the virus abolished the activity. Similar studies using two other biological fluids, urine and cerebrospinal fluid, revealed no anti-HIV infectivity activity. These findings confirm the presence in saliva of inhibitory activity directed toward HIV.
Aggregation of Human Immunodeficiency Virus Type 1 by Human Salivary Secretions
Authors: Bergey Earl J. , Cho Moon-Il , Hammarskjöld Marie-Louise , Rekosh David , Levine Michael J. , Blumberg Benjamin M. , Epstein Leon G.
Published: January 2017

Human immunodeficiency virus (HIV-1) is generally transmitted by parenteral contact with infected body secretions. Although extensive epidemiological data and familial studies have failed to provide any conclusive data that saliva may act as a vehicle for transmission of AIDS, both professional and public anxieties remain. The present study, as well as others, suggests that salivary secretions may act as inhibitors of HTV-1 replication in vitro. In our study, the inhibitory activity was determined to be associated mainly with secretions obtained from the human submandibular-sublingual glands. Human submandibular-sublingual (HSMSL) and parotid (HPS) salivas were collected and tested for their ability to modulate the replication of HIV-1, using a plaque assay on HeLa/CD4+ cell monolayers. Initial results examining freshly collected salivary samples from ten individuals confirmed the results previously obtained by Fox et al. (1988, 1989). An average plaque reduction of~66% was obtained with HSMSL, in contrast to 34% reduction obtained with HPS. Titration of the inhibitory activity in HSMSL showed detectable levels at a 1:500 dilution. Comparison of inhibitory activity of dialyzed and lyophilized saliva to fresh saliva indicated little difference between the two samples when filtration occurred after the addition of HIV-1. However, the effect of filtration was significantly diminished in the lyophilized samples. Electron microscopic examination of the saliva-HIV incubates revealed the aggregation/entrapment of virus particles by salivary components. These results suggest that human salivary secretions (with HSMSL > HPS) may have a role in modulating the infectivity of HIV-1.
Genetics of Salivary Protein Polymorphisms
Authors: Azen Edwin A.
Published: January 2017

Human salivary PRPs are determined by six closely linked genes on chromosome 12pl3.2. The many PRPs show complex electrophoretic patterns that differ between individuals and reflect numerous genetic polymorphisms. Frequent length and null polymorphisms are common among PRPs. Common themes emerge as a background for these PRP polymorphisms. First, posttranslational proteolysis occurs with double-banded patterns among acidic PRPs and the generation of numerous basic PRPs derived from precursor proteins. Specific mutations may interfere with proteolysis, preventing generation of double-banded acidic PRPs (as with the Pa protein) or of small basic PRPs from precursor proteins (as with Pm proteins). Second, single cysteine substitutions in PRPs (Pa from PRH1 and Gl 8 from PRB3) may lead to disulfide bonded homodimers as well as heterodimers with salivary peroxidase. Third, frequent homologous and unequal crossing-over within the PRP gene cluster leads to frequent protein size-variants (intragenic events as with the GI protein variants) and the generation of the PRB2 /1 fusion gene (intergenic event) with deletion of the PRB1 coding region and absence of multiple PRB 1 coded proteins (Ps, Pm, Pe) in PRB2/1 homozygotes. Fourth, null mutations may also be produced (as with PsO and Gl 0) by single nucleotide changes.
Induction of Type 2 Salivary Cystatin in Immunological and Chemical Kidney Injury
Authors: Cohen R.E. , Bedi G.S. , Neiders M.E. , Noble B.
Published: January 2017

We have previously reported that isoproterenol induces type 2 salivary cystatin in both submandibular glands and kidney tubule cells of rats but not in any other organs examined. In the present study, we investigated whether this salivary protein is induced in other conditions that show kidney tubule injury. Immunocytochemistry, using a monospecific antiserum to this cystatin, revealed specific staining within the proximal tubule epithelium of the cortex as well as in the inner and outer stripe of the medulla of immunologically and chemically injured rats. Cystatin could not be detected in kidneys from healthy rats by means of immunocytochemistry. Weak staining was found in 3/3 kidneys of rats treated with turpentine and in 5/5 animals treated with potassium dichromate. In rats treated with puromycin, cystatin could not be demonstrated in 5/5 animals having proteinuria of less than 100 mg/24 h; however, moderate staining was observed in 4/5 puromycin-treated rats having proteinuria greater than 100 mg/24 h. In Heymann nephritis, cystatin was present in 7/31 kidneys with proteinuria lasting 6 to 15 weeks and in none (0/ 7) with proteinuria of shorter duration. Strong staining was also observed in 10/10 kidneys from rats with moderate-to-severe chronic serum sickness. This study shows that elaboration of type 2 cystatin in rats is not limited to salivary glands and, with our previous study, suggests that induction of this cysteine proteinase inhibitor may represent a local response to generalized tissue injury in both submandibular and renal tissues. These findings further demonstrate that induction of cystatin in salivary glands is not unique to these glands and suggest that induction of this cysteine proteinase inhibitor may represent a local response to tissue injury caused by diverse mechanisms.
Composition and Cariogenic Potential of Dental Plaque Fluid
Authors: Margolis H.C. , Moreno E.C.
Published: January 2017

Our understanding of the chemical events that take place at the tooth-plaque interface has improved greatly through studies of the chemical composition and properties of dental plaque fluid. In the absence of fermentable carbohydrate, plaque fluid has been found to be supersaturated with respect to tooth mineral and other calcium phosphate phases, thus exhibiting the potential to support calculus formation and the remineralization of incipient carious lesions. Following the exposure to fermentable carbohydrate, the degree of saturation of plaque fluid decreases rapidly, primarily due to lactic acid production and the lowering of plaque fluid pH. The extent of these chemical changes has been shown to be associated with differences in caries history. Such studies have been facilitated by the recent development of microanalytical techniques. Unfortunately, little is known about the relationship between the observed chemical changes in plaque fluid and the microbial composition of plaque. Limited information is also available on the association of immune factors in plaque fluid with dental disease.
The Role of Proteoglycans in Hard and Soft Tissue Repair
Authors: Bertolami Charles N. , Messadi Diana V.
Published: January 2017

Healing of soft and hard tissues results from a progression of events initiated by injury and directed toward reestablishing normal structure and function. The ubiquity of proteoglycans in mammalian tissues virtually guarantees their involvement in tissue restitution. The dramatic advances in cellular and molecular biology in recent years have added significantly to understanding the specific roles played by proteoglycans in wound repair processes.
Failure of Cetirizine and Fexofenadine to Prevent Motion Sickness
Authors: Cheung Bob S , Heskin Raquel , Hofer Kevin D
Published: January 2017

OBJECTIVE:

To determine the effectiveness of 2 second-generation antihistamines in modulating motion sickness induced by Coriolis vestibular cross-coupling stimulation.

METHODS:

This prospective, randomized, double-blind, crossover, placebo-controlled study was conducted in 18 healthy adults. Subjects were exposed to Coriolis vestibular cross-coupling in the laboratory using the Staircase Profile Test for baseline susceptibility and when under the influence of cetizirine, fexofenadine, and placebo. Subjective evaluation of sickness symptoms was based on the Graybiel diagnostic criteria of acute motion sickness, Golding's scale, and the Coriolis Sickness Susceptibility Index.

RESULTS:

Repeated measures ANOVA and Friedman nonparametric ANOVA of rank tests revealed that there were significant differences in symptom assessments based on Graybiel's diagnostic criteria (p ≤ 0.001), subjective symptoms of motion sickness (p ≤ 0.001), and state-anxiety (p ≤ 0.001) before and after motion exposure. However, there are no significant differences between the baseline susceptibility to motion sickness and treatment with placebo, cetirizine, or fexofenadine.

CONCLUSIONS:

The failure of the second-generation antihistamines cetirizine and fexofenadine to prevent motion sickness suggests that the therapeutic actions of this class of antihistamines against motion sickness may be mediated through central versus peripheral receptors. The sedative effect of other antihistamines, such as hydroxyzine, may play a more significant role in alleviating motion sickness than previously thought.
Possible Intramuscular Midazolam-Associated Cardiorespiratory Arrest and Death
Authors: Taylor Jerry W. , Simon Kenneth B.
Published: January 2017

Midazolam hydrochloride is commonly used for dental or endoscopic procedures. Although generally considered safe when given intramuscularly, intravenous administration is known to cause respiratory and cardiovascular depression. This report describes the first published case of cardiorespiratory arrest and death associated with intramuscular administration of midazolam. Information regarding midazolam use is reviewed to provide recommendations for safe administration.
Acute Verapamil Toxicity in a Patient with Chronic Toxicity: Possible Interaction with Ceftriaxone and Clindamycin
Authors: Kishore Kamal , Raina Abhinav , Misra Vijay , Jonas Ernesto
Published: January 2017

OBJECTIVE:

To report a case of acute toxicity in a patient with chronic verapamil toxicity, possibly precipitated by intravenous administration of the highly protein-bound drugs ceftriaxone and clindamycin.

DATA SOURCES:

Case reports, review articles, and relevant laboratory and clinical studies identified by MEDLINE (1984-forward), and relevant cross references from those articles.

DATA EXTRACTION:

Data were abstracted from pertinent sources by one author and reviewed by the remaining authors.

CASE SUMMARY:

A 59-year-old man who had been receiving sustained-release verapamil 240 mg ql2h for more than two years for hypertension, and phenytoin 300 mg/d for many years for prophylaxis against seizures, was noted to be in junctional rhythm when he presented to the emergency room with bilateral pneumonia. Administration of intravenous ceftriaxone 1 g and clindamycin 900 mg precipitated symptoms of acute verapamil toxicity in this patient. The toxicity led to complete heart block requiring cardiopulmonary resuscitation and insertion of a temporary pacemaker. He spontaneously reverted to normal sinus rhythm after 16 hours. Subsequent cardiac evaluation, including echocardiogram, 48-hour dynamic electrocardiographic recording (Holter), and exercise stress test were normal. The patient has remained in sinus rhythm for more than one year after this episode.

CONCLUSIONS:

We believe that junctional rhythm on admission was a result of chronic verapamil toxicity. This may have been because of increased bioavailability of the drug or increased sensitivity of the receptors. Administration of ceftriaxone, clindamycin, or both agents might have precipitated acute verapamil toxicity by displacing verapamil from its protein-binding sites. Extreme caution is necessary when a highly protein-bound drug is given to a patient already receiving verapamil.
Henry Mayer Lecture 2009 from Dallas to SBS: The Popular, the Global and the Diverse on Television
Authors: Ang Ien
Published: January 2017

In her 2009 Henry Mayer Lecture, presented in Brisbane in March, Ien Ang reflects on her own work on global and popular television cultures, spanning almost 25 years. In particular, she traces the intellectual continuity from her first, classic book, Watching Dallas, published in 1985, to her last book, The SBS Story, published in 2008, from the point of view of her own experience as a migrant.
Newspaper Blogs: The Genuine Article or Poor Counterfeits?
Authors: Garden Mary
Published: January 2017

Blogging began as a grassroots alternative phenomenon, and it was some years before the mainstream media took notice, let alone responded by introducing their own blogs. However, the blogs of Australian journalists (especially those of News Ltd) have been criticised as being ineffective, although such criticism is based on anecdotal evidence rather than substantive data. This article presents the findings of a pilot study that examined the popularity, interactivity and hyperlinks of twelve political blogs across mainstream and alternative media sites. The greatest challenge of blogging has been to one of traditional journalism's weakest points: its lack of personal contact with readers. The results of this study indicate that there are Australian journalists who have taken up the challenge, with their blogs outshining their alternative counterparts, especially in terms of reader engagement. This represents an exciting new trend, where blogging, rather than being a threat, may reinvigorate mainstream media and help democratise news processes.
Connecting, Informing and Empowering Our Communities: Remote Indigenous Radio in the Northern Peninsula Area
Authors: Watson Ian
Published: January 2017

This study provides an insight into the role and functions of a remote Indigenous radio station that broadcasts to five communities in the Northern Peninsula Area (NPA) of Cape York, Queensland. It evaluates the activities of NPA Radio in the context of previous research that investigates how community-based media forms empower and inform specific sectors of society. Using field research, the study reveals five key themes relating to the role of NPA Radio in the communities of Seisia, New Mapoon, Bamaga, Umagico and Injinoo. These can briefly be described as providing information and community news; maintaining and sharing culture; connecting the communities of the NPA; connecting individuals and key services; and fostering a sense of belonging and ownership.
‘An Image of Hope in a Week of Despair’: Representations of Sam the Koala in the Australian Mainstream News Media
Authors: Due Clemence , Thompson Kirrilly , Every Danielle
Published: January 2017

Natural disasters are events with far-reaching humanitarian implications that frequently receive international attention through the use of an image that comes to represent the disaster in question. The most successful images often comprise ‘identifiable’ and therefore human victims. What is more unusual is for a single animal image to become representative of an entire disaster. This was the case with the 2009 Victorian bushfires in Australia, when the image of a firefighter offering a koala a drink gained international fame. Given that this image of ‘Sam’ the koala does not conform to traditional disaster imagery, we undertook a thematic analysis of mainstream news media representations of Sam in order to identify how she was represented by the media. In this article, we discuss these themes in relation to the ‘identifiable victim’, together with the implications of Sam's success in terms of disaster-relief campaigns.
Moral economy of flexible production: Fabricating precarity between the conveyor belt and the household
Authors: Kofti Dimitra
Published: January 2017

In this article I discuss some of the theoretical implications of adopting moral economy as an approach to analysing new forms of flexible production and work. Despite a growing interest in the anthropology of precarity and work, the linkages between political and moral economies have been relatively neglected. By discussing E.P. Thompson’s approach to moral economy as well as ways moral economy has been discussed in anthropology, the article argues it is a timely and encompassing approach for the study of flexible work and precarity, as well as compliance and resistance to inequality. A nexus of diverse moral frameworks of value converge at the production site and back home, contributing to the reproduction of precarity and capital under flexible forms of accumulation. The article suggests that moral economy may offer an encompassing approach to studying individual ideas and practices and their relation with collective moral frameworks and confinements and to exploring change and change potential. It draws from an ethnography based on long-term fieldwork in a privatized factory in Bulgaria, in the context of radical economic transformations and privatization projects. It scrutinizes solidarities, tensions and inequalities developed around the conveyor belt, with a particular focus on gender and employment status inequalities and their intertwinement with managerial and household practices.
Effect of Heme Oxygenase-1 Overexpression in Two Models of Lung Inflammation
Authors: Zampetaki A. , Minamino T. , Mitsialis S.A. , Kourembanas S.
Published: January 2017

An increasing number of studies implicate heme oxygenase-1 (HO-1) in the regulation of inflammation. Although the mechanisms involved in this cytoprotection are largely unknown, HO-1 and its enzymatic products, carbon monoxide and bilirubin, downregulate the inflammatory response by either attenuating the expression of adhesion molecules and thus inhibiting leukocyte recruitment or by repressing the induction of cytokines and chemokines. In the present study we used genetically engineered mice that express high levels of a human cDNA HO-1 transgene in lung epithelium to assess the effect of HO-1 on lung inflammation. Two separate models of inflammation were studied: hypoxic exposure and lipopolysaccharide (LPS) challenge. We found that both mRNA and protein levels of specific cytokines and chemokines were significantly elevated in response to hypoxia in the lungs of wild-type mice after 2 and 5 days of exposure but significantly suppressed in the hypoxic lungs of transgenic mice, suggesting that inhibition of these cytokines was caused by overexpression of HO-1. However, LPS treatment resulted in a very pronounced increase in mRNA levels of several cytokines in both wild-type and transgenic mice. Despite the high mRNA levels, significantly lower cytokine protein levels were detected in the bronchoalveolar lavage of HO-1 overexpressing mice compared with wild type, indicating that HO-1 leads to repression of cytokines in the airway. These results demonstrate that HO-1 activity operates through distinct molecular mechanisms to confer cytoprotection in the hypoxic and the LPS models of inflammation.
Mitochondrial Production of Oxygen Radical Species and the Role of Coenzyme Q as an Antioxidant
Authors: Genova Maria Luisa , Pich Milena Merlo , Biondi Annalisa , Bernacchia Andrea , Falasca Anna , Bovina Carla , Formiggini Gabriella , Castelli Giovanna Parenti , Lenaz Giorgio
Published: January 2017

The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS), which is considered as the pathogenic agent of many diseases and of aging. We have investigated the role of complex I in superoxide radical production and found by the combined use of specific inhibitors of complex I that the one-electron donor to oxygen in the complex is a redox center located prior to the sites where three different types of Coenzyme Q (CoQ) competitors bind, to be identified with an Fe–S cluster, most probably N2, or possibly an ubisemiquinone intermediate insensitive to all the above inhibitors. Short-chain Coenzyme Q analogs enhance superoxide formation, presumably by mediating electron transfer from N2 to oxygen. The clinically used CoQ analog, idebenone, is particularly effective, raising doubts on its safety as a drug. Cells counteract oxidative stress by antioxidants. CoQ is the only lipophilic antioxidant to be biosynthesized. Exogenous CoQ, however, protects cells from oxidative stress by conversion into its reduced antioxidant form by cellular reductases. The plasma membrane oxidoreductase and DT-diaphorase are two such systems, likewise, they are overexpressed under oxidative stress conditions.
Inverse Relationship Between Serum Bilirubin and Atherosclerosis in Men: A Meta-Analysis of Published Studies
Authors: Novotný Ladislav , Vítek Libor
Published: January 2017

Bilirubin, a major intravascular product of heme catabolism, is a potent antioxidant compound. Numerous studies have been published showing the relationship between serum bilirubin levels and atherosclerosis. In the present investigation all the epidemiological studies available on the effect of serum bilirubin levels and atherosclerotic disease were analyzed. Studies on the epidemiology of atherosclerotic diseases in relation to serum bilirubin levels were searched in the MEDLINE database. Selected studies were subdivided according to serum bilirubin levels and severity of atherosclerotic disease. Because of the limited number of females involved in the studies, only males were included into meta-analysis. Associations for ordered categorical variables (bilirubin and natural history of graded atherosclerosis) were assessed to find correlation and linear trend between analyzed variables. A stratified analysis was conducted to compare risks of clinical outcomes. Eleven relevant studies were used for analysis. A close negative relationship was found between serum bilirubin levels and severity of atherosclerosis (Spearman rank coefficient r = −0.31, P < 0.0001). The linear trend was confirmed in analysis of proportions with x2 values for both disease conditions to be very significant ( P < 0.0001). Unambiguous inverse relationship between serum bilirubin levels and atherosclerosis was demonstrated in this preliminary meta-analytic study. These results indicate the importance of hem oxygenase-related products in the prevention of oxidative stress-mediated diseases.
Antiapoptotic Action of Carbon Monoxide on Cultured Vascular Smooth Muscle Cells
Authors: Liu Xiao-Ming , Chapman Gary B. , Peyton Kelly J. , Schafer Andrew I. , Durante William
Published: January 2017

Vascular smooth muscle cells (SMCs) generate carbon monoxide (CO) from the degradation of heme by the enzyme heme oxygenase. Because recent studies indicate that CO influences the properties of vascular SMCs, we examined whether this diatomic gas regulates apoptosis in vascular SMCs. Treatment of cultured rat aortic SMCs with a cytokine cocktail consisting of interleukin-1β (5 ng/ml), tumor necrosis factor-α (20 ng/ml), and interferon-γ (200 U/ml) for 48 hr stimulated apoptosis, as demonstrated by DNA laddering, caspase-3 activation, and annexin V staining. However, the exogenous addition of CO (200 ppm) completely blocked cytokine-mediated apoptosis. The antiapoptotic action of CO was partially reversed by the soluble guanylate cyclase inhibitor, H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (10 μM). In contrast, the p38 mitogen-activated protein kinase inhibitor, SB203580 (10 μM), had no effect on SMC apoptosis. These findings indicate that CO is a potent inhibitor of vascular SMC apoptosis and that it blocks apoptosis, in part, by activating the cGMP signaling pathway. The ability of CO to inhibit vascular SMC apoptosis may play a critical role in attenuating lesion formation at sites of arterial damage.
Aggressive Lipid Management for Cardiovascular Prevention: Evidence from Clinical Trials
Authors: Friday Karen E.
Published: January 2017

Epidemiologic evidence shows that elevated serum cholesterol, specifically low-density lipoprotein cholesterol (LDL-C), increases the risk of coronary heart disease (CHD). Moreover, large-scale intervention trials demonstrate that treatment with HMG-CoA reductase inhibitors (statins), the most effective drug class for lowering LDL-C, significantly reduces the risk of CHD events. Unfortunately, only a moderate percentage of hypercholesterolemic patients are achieving LDL-C targets specified by the National Cholesterol Education Program (NCEP), in part because clinicians are not effectively titrating medications as needed to achieve LDL-C goals. Recent evidence suggests that more aggressive LDL-C lowering may provide greater clinical benefit, even in individuals with moderately elevated serum cholesterol levels. Furthermore, recent studies suggest that statins have cardioprotective effects in many high-risk individuals, including those with baseline LDL-C <100 mg/dl. High-density lipoprotein cholesterol (HDL-C) was recognized by the NCEP-Adult Treatment Panel II (ATP II) as a negative risk factor for CHD. The NCEP-ATP III guidelines have also reaffirmed the importance of HDL-C by increasing the low HDL-C designation from <35 to <40 mg/dl as a major risk factor for CHD. Similarly, triglyceride control will play a larger role in dyslipidemia management. As more clinicians effectively treat adverse lipid and lipoprotein cardiovascular risk factors, patients will likely benefit from reductions in cardiovascular events.