Supply of care by dental therapists and emergency dental consultations in Alaska native communities in the Yukon-Kuskokwim delta: a mixed methods evaluation.

OBJECTIVES: Examine the relationship between supply of care provided by dental therapists and emergency dental consultations in Alaska Native communities. METHODS: Explanatory sequential mixed-methods study using Alaska Medicaid and electronic health record (EHR) data from the Yukon-Kuskokwim Health Corporation (YKHC), and interview data from six Alaska Native communities. From the Medicaid data, we estimated community-level dental therapy treatment days and from the EHR data we identified emergency dental consultations. We calculated Spearman partial correlation coefficients and ran confounder-adjusted models for children and adults. Interview data collected from YKHC providers (N=16) and community members (N=125) were content analysed. The quantitative and qualitative data were integrated through connecting. Results were visualized with a joint display. RESULTS: There were significant negative correlations between dental therapy treatment days and emergency dental consultations for children (partial rank correlation = -0.48; p⟨0.001) and for adults (partial rank correlation = -0.18; p=0.03). Six pediatric themes emerged: child-focused health priorities; school-based dental programs; oral health education and preventive behaviors; dental care availability; healthier teeth; and satisfaction with care. There were four adult themes: satisfaction with care; adults as a lower priority; difficulties getting appointments; and limited scope of practice of dental therapy. CONCLUSIONS: Alaska Native children, and to a lesser extent adults, in communities served more intensively by dental therapists have benefitted. There are high levels of unmet dental need as evidenced by high emergency dental consultation rates. Future research should identify ways to address unmet dental needs, especially for adults.

Survey of infection control and antimicrobial stewardship practices in Australian residential aged-care facilities.

This study assessed infection prevention and antimicrobial stewardship (AMS) practices in Australian residential aged-care facilities (RACF). Two hundred and sixty-five surveys (15.6%) were completed with all states represented and the majority (177 (67.3%)) privately run. Only 30.6% RACF had infection control trained staff on site. Few facilities had AMS policies, only 14% had antimicrobial prescribing restrictions. Most facilities offered vaccination to residents (influenza vaccination rates >75% in 73% of facilities), but pneumococcal vaccination was poor.

HTLV x-gene product: requirement for the env methionine initiation codon.

The human T-cell leukemia viruses (HTLV) are replication-competent retroviruses whose genomes contain gag, pol, and env genes as well as a fourth gene, termed x, which is believed to be the transforming gene of HTLV. The product of the x gene is now shown to be encoded by a 2.1-kilobase messenger RNA derived by splicing of at least two introns. By means of S1 nuclease mapping of this RNA and nucleic acid sequence analysis of a complementary DNA clone, the complete primary structure of the x-gene product has been determined. It is encoded by sequences containing the env initiation codon and one nucleotide of the next codon spliced to the major open reading frame of the HTLV-I and HTLV-II x gene.

Human GM-CSF: molecular cloning of the complementary DNA and purification of the natural and recombinant proteins.

Clones of complementary DNA encoding the human lymphokine known as granulocyte-macrophage colony-stimulating factor (GM-CSF) were isolated by means of a mammalian cell (monkey COS cell) expression screening system. One of these clones was used to produce recombinant GM-CSF in mammalian cells. The recombinant hematopoietin was similar to the natural product that was purified to apparent homogeneity from medium conditioned by a human T-cell line. The human T-cell GM-CSF was found to be 60 percent homologous with the GM-CSF recently cloned from murine lung messenger RNA.

School-age children's safety attitudes, cognitions, knowledge, and injury experiences: how do these relate to their safety practices?

BACKGROUND: A variety of factors affect the safety and risk practices of school-age children, but rarely have multiple factors been considered simultaneously. OBJECTIVE: To examine children's safety attitudes and cognitions more thoroughly and assess how these factors, along with children's safety knowledge and injury experiences, relate to children's safety practices. METHODS: Over several classroom sessions, boys and girls in two age groups (7-9, 10-12 years) completed a psychometrically sound questionnaire that indexes their behaviors, attitudes, cognitions, knowledge, and injury experiences. RESULTS: Fewer safety practices were reported by older than younger children and boys than girls. Children's attitudes, cognitions, knowledge, and injury experiences each correlated with safety practices, but only safety attitudes and injury experiences predicted practices in a multivariate model. CONCLUSION: Exploring the relative influence of numerous factors on safety practices highlights the important role that attitudes play in predicting children's safety practices. Implications of these results for injury prevention programming are discussed.

Aromatic and basic residues within the EVH1 domain of VASP specify its interaction with proline-rich ligands.

Short contiguous peptides harboring proline-rich motifs are frequently involved in protein-protein interactions, such as associations with Src homology 3 (SH3) and WW domains. Although patches of aromatic residues present in either domain interact with polyprolines, their overall structures are distinct, suggesting that additional protein families exist that use stacked aromatic amino acids (AA domains) to bind polyproline motifs [1] [2] [3]. A polyproline motif (E/DFPPPPTD/E in the single-letter amino-acid code), present in the ActA protein of the intracellular bacterial pathogen Listeria monocytogenes, serves as a ligand for the Ena/VASP protein family --the vasodilator-stimulated phosphoprotein (VASP), the murine protein Mena, Drosophila Enabled (Ena) and the Ena/VASP-like protein Evl [4] [5] [6] [7]. These share a similar overall structure characterized by the two highly conserved Ena/VASP homology domains (EVH1 and EVH2) [5]. Here, using three independent assays, we have delineated the minimal EVH1 domain. Mutations of aromatic and basic residues within two conserved hydrophilic regions of the EVH1 domain abolished binding to ActA. Binding of an EVH1 mutant with reversed charges could partially be rescued by introducing complementary mutations within the ligand. Like SH3 domains, aromatic residues within the EVH1 domain interacted with polyprolines, whereas the ligand specificity of either domain was determined by reciprocally charged residues. The EVH1 domain is therefore a new addition to the AA domain superfamily, which includes SH3 and WW domains.

Detection of naphthenic acids in fish exposed to commercial naphthenic acids and oil sands process-affected water.

Naphthenic acids are a complex mixture of carboxylic acids that occur naturally in petroleum. During the extraction of bitumen from the oil sands in northeastern Alberta, Canada, naphthenic acids are released into the aqueous phase and these acids become the most toxic components in the process-affected water. Although previous studies have exposed fish to naphthenic acids or oil sands process-affected waters, there has been no analytical method to specifically detect naphthenic acids in fish. Here, we describe a qualitative method to specifically detect these acids. In 96-h static renewal tests, rainbow trout (Oncorhynchus mykiss) fingerlings were exposed to three different treatments: (1) fed pellets that contained commercial naphthenic acids (1.5mg g(-1) of food), (2) kept in tap water that contained commercial naphthenic acids (3mg l(-1)) and (3) kept in an oil sands process-affected water that contained 15mg naphthenic acids l(-1). Five-gram samples of fish were homogenized and extracted, then the mixture of free fatty acids and naphthenic acids was isolated from the extract using strong anion exchange chromatography. The mixture was derivatized and analyzed by gas chromatography-mass spectrometry. Reconstructed ion chromatograms (m/z=267) selectively detected naphthenic acids. These acids were present in each fish that was exposed to naphthenic acids, but absent in fish that were not exposed to naphthenic acids. The minimum detectable concentration was about 1microg naphthenic acids g(-1) of fish.

Overexpression of a transmembrane isoform of neural cell adhesion molecule alters the invasiveness of rat CNS-1 glioma.

CNS-1 is a highly invasive neural cell adhesion molecule (NCAM)-positive rat glioma that exhibits similarities in its pattern of infiltration to human gliomas. To investigate whether increasing NCAM expression alters invasive behavior, retroviruses encoding human NCAM 140 and a cytoplasmic truncation of NCAM 140 were used to transduce a population of CNS-1 glioma cells that had a relatively low endogenous level of NCAM. Compared to cells transduced with a control virus, cells overexpressing either intact or truncated human NCAM 140 showed decreased invasion of a reconstituted basal lamina. Changes in growth rate or in key matrix metalloproteinase activities could not account for this result. In a migration assay on type IV collagen, cells exhibited a substrate concentration-dependent increase in the rate of migration; however, overexpression of NCAM 140 or truncated NCAM 140 inhibited motility at higher substrate concentrations. Consistent with these findings was the decreased spread of NCAM 140 overexpressers in vivo following instillation of cells into the right frontal cortex of rat brain. NCAM 140 overexpressers showed considerably more restricted perivascular and periventricular spread than cells transduced with a control virus. However, NCAM-140-overexpressing tumor exhibited a less cohesive pattern of growth near the site of tumor instillation and more individual cell infiltration of brain parenchyma with more pronounced perineuronal satellitosis. The stability of recombinant NCAM expression was confirmed by recovering tumor cells from tumor-bearing animals and measuring NCAM levels by flow cytometry. These observations show that overexpression of NCAM 140 decreases the long-range spread of CNS-1 glioma along basal lamina pathways but enhances local infiltration of neuropil.

Novobiocin activates the mating response in yeast through the alpha-pheromone receptor, Ste2p.

In a previous publication we reported the isolation of several yeast mutants sensitive to the coumarin drug novobiocin. Here we characterise the wild-type gene (NBS5), obtained by rescuing a novobiocin-sensitive nbs5 strain to natural novobiocin resistance. We show that nbs5 is allelic to the previously characterised gene sst2, conferring super-sensitivity to the mating pheromones. Although nbs5/sst2 cells of both mating types are super-sensitive to the opposite mating pheromone, only cells of mating-type a are sensitive to novobiocin. We show that the entire effect of the drug is mediated through Ste2p, the alpha-pheromone receptor. Thus, novobiocin is a functional agonist of Ste2p, and may identify a potentially useful interaction between coumarin drugs and the family of G-protein-coupled receptors.

The first gene in the biosynthesis of the polyketide antibiotic TA of Myxococcus xanthus codes for a unique PKS module coupled to a peptide synthetase.

The polyketide antibiotic TA is synthesized by the Gram negative bacterium Myxococcus xanthus in a multi-step process in which a unique glycine-derived molecule is used as a starter unit and elongated through the condensation of 11 acetate molecules by polyketide synthases (PKSs). Analysis of a 7.2 kb DNA fragment, encoding the protein that carries out the first condensation step, revealed that the fragment constitutes a single open reading frame, referred to as Ta1, which lacks the 5' and 3' ends and displays two regions of similarity to other proteins. The first 1020 amino acid residues at the N terminus of the polypeptide are similar to sequences of the large family of enzymes encoding peptide synthetases. They are followed by a second region displaying a high degree of similarity to type I PKS genes. The genetic analysis of this open reading frame is compatible with the proposed chemical structure of TA. The data indicate that the genes encoding TA have a modular gene organization, typical of a type I PKS system. The unusual feature of Ta1 is that the first PKS module of TA resides on the same polypeptide as the peptide synthetase functional unit.

Effect of weight loss on mortality in overweight and obese nursing home residents during a 5-year follow-up.

BACKGROUND/OBJECTIVES: The objective of this study was to ascertain the effect of weight loss over the course of 1 year on 5-year mortality in old nursing home (NH) residents in different classes of body mass index (BMI). SUBJECTS/METHODS: A longitudinal study was conducted on 161 NH residents aged ⩾ 70 years at the Istituto di Riposo per Anziani, Padova, Italy. Data were collected using a comprehensive geriatric assessment at baseline and at a 1-year follow-up visit. Mortality was recorded over a 5-year follow-up. We divided our sample into four groups using as cutoffs a BMI of 25 and a weight gain or loss of 5% at 1 year (BMI ⩾ 25 and weight stable/gain, BMI ⩾ 25 and weight loss, BMI<25 and weight stable/gain and BMI <25 and weight loss). RESULTS: People with a BMI ⩾ 25 and weight loss suffered the worst decline in activities of daily living, whereas those with a BMI <25 and weight loss had the most significant decline in nutritional status, which coincided with the worst decline in the Multidimensional Prognostic Index among the groups whose weight changed. Compared with those with a BMI ⩾ 25 and weight stable/gain (reference group), those with a BMI <25 were at the highest risk of dying (in association with weight loss: hazard ratio HR=3.60, P=0.005; in association with weight stable/gain: HR=2.45, P=0.01), and the mortality risk was also increased in people with a BMI ⩾ 25 and weight loss (HR=1.74, P=0.03). CONCLUSIONS: In conclusion, weight loss increases the mortality risk in frail, disabled NH residents, even if they are overweight or obese.

Hypothalamic 24-hour rhythms in histamine, histidine, decarboxylase and histamine-N-methyltransferase.

Twenty-four hour rhythms of histamine (H), its biosynthetic enzyme, L-histidine decarboxylase (EC 4.1.1.22, HD) and its inactivation enzyme, histamine N-methyltransferase (EC 2.1.1.8, HMT) were assayed in the 63-day-old male rat hypothalamus using a modified single isotopeenzyme microassay. H was found to have a 24-h rhythm with a maximum concentration at 11:00 h (lights on 10:00-22:00 h) and a minimum at 23:00 h. In vitro HD and HMT activities were also found to have 24-h rhythms with peak activites in both occurring at 04:00 h. HMT also had a broad secondary peak throughout the day, whereas HD activity during the day was dominated by a mid-light trough at 16:00 h. These rhythms are considered significant for evaluation of the control and physiological role of histamine in the mammalian hypothalamus.

The effects of castration on histamine levels and 24-hour rhythm in the male rat hypothalamus.

Holtzman male rats were castrated or sham-operated at 22 days of age and raised in a 12 h light: 12 h dark illumination cycle. At age 63 days they were sacrificed by decapitation at six different times during the light:dark (L:D) cycle, and hypothalamic histamine (H) concentrations were measured using a modified single isotope-enzyme microassay. Hypothalamic H was significantly elevated in the castrated rats at all but two of the six times sampled during the L:D cycle, when compared with the sham-operated controls. Both surgical groups had similar 24-h rhythms of hypothalamic H concentrations, with the peak concentration occurring during the light phase followed by a rapid drop to the minimum 2-3 h later. However, the castrated rats appeared to attain both maximal and minimal concentrations somewhat earlier in the day. These results provide circumstantial evidence that hypothalamic H may have a role in the hypothalamo-hypophyseal-gonadal axis in the male rat.

Cloning and characterization of a Myxococcus xanthus cytochrome P-450 hydroxylase required for biosynthesis of the polyketide antibiotic TA.

The antibiotic TA, a complex macrocyclic polyketide of Myxococcus xanthus, is produced, like many other polyketides, through successive condensations of acetate by a type I polyketide synthase (PKS) mechanism. The chemical structure of this antibiotic and the mechanism by which it is synthesized indicate the need for several post-modification steps, such as a specific hydroxylation at C-20. Previous studies have shown that several genes, essential for TA biosynthesis, are clustered in a region of at least 36kb, which was subsequently cloned and analyzed. In this study, we report the analysis of a DNA fragment, containing a specific cytochrome P-450 hydroxylase, presumably responsible for the sole non-PKS hydroxylation at position C-20. Functional analysis of the cytochrome P-450 hydroxylase gene through specific gene disruption confirms that it is essential for the production of an active TA molecule.

Attenuation of experimental autoimmune encephalomyelitis by Compound 48/80 in Lewis rats.

The appearance of increased levels of histamine in the central nervous system (CNS) concomitant with the development of clinically significant acute experimental autoimmune encephalomyelitis (EAE) in male Lewis rats suggests that CNS-associated mast cells may mediate acute EAE in Lewis rats. We now report that, compared to controls, rats with acute EAE exhibit fewer detectable mast cells in their dura mater and velum interpositum. In addition, intracisternal, but not intraperitoneal administration of Compound 48/80 just prior to the appearance of clinical signs of acute or recurrent EAE in male and female rats, respectively, significantly attenuates the clinical severity of both forms of EAE. These results further support the hypothesis that CNS-associated, but not peripheral mast cells are mediators or modulators of acute and recurrent EAE in Lewis rats.

The identification and purification of a mammalian-like protein kinase C in the yeast Saccharomyces cerevisiae.

We have purified a yeast protein kinase that is phospholipid-dependent and activated by Diacylglycerol (DAG) in the presence of Ca2+ or by the tumour-promoting agent tetradecanoyl-phorbol acetate (TPA). The properties of this enzyme are similar to those of the mammalian protein kinase C (PKC). The enzyme was purified using chromatography on DEAE-cellulose followed by hydroxylapatite. The latter chromatography separated the activity to three distinguishable sub-species, analogous to the mammalian PKC isoenzymes. The fractions enriched in PKC activity contain proteins that specifically bind TPA, are specifically phosphorylated in the presence of DAG and recognized by anti-mammalian PKC antibodies.

Histamine-induced microvascular leakage in pial venules: differences between the SJL/J and BALB/c inbred strains of mice.

The actions of histamine on pial venule leaky site formation were measured intravitally in two inbred strains of mice (BALB/c and SJL/J). Pial venules were visualized using a cranial window microscopy technique, and microvascular leaky site formation was assessed visually using a fluorescein-dextran indicator. SJL/J mice were found to be sensitive to histamine-induced leakage, whereas the BALB/c strain was refractory. Exposure to pertussis toxin enhanced the sensitivity to histamine in the SJL/J strain, but little effect was observed for BALB/c mice. However, the employment of a polymerase chain reaction (PCR) technique for the detection of mRNA for histamine H1 receptor identified receptor-specific message in isolated cerebrovascular endothelium from both strains of mice. The lack of pial responsiveness in the BALB/c mice remains unexplained. Mast cells in the dura mater were found to be more numerous in SJL/J mice than in BALB/c mice. This observation supports previous observations of strain-specific differences in CNS inflammation. The results support the concept that genetically controlled differences in vascular sensitivity and localization of CNS-associated mast cells may play important roles in the generation of vasogenic edema and inflammation in CNS trauma and disease.

An unusual beta-ketoacyl:acyl carrier protein synthase and acyltransferase motifs in TaK, a putative protein required for biosynthesis of the antibiotic TA in Myxococcus xanthus.

The antibiotic TA of Myxococcus xanthus is produced by a type-I polyketide synthase mechanism. Previous studies have indicated that TA genes are clustered within a 36-kb region. The chemical structure of TA indicates the need for several post-modification steps, which are introduced to form the final bioactive molecule. These include three C-methylations, an O-methylation and a specific hydroxylation. In this study, we describe the genetic analysis of taK, encoding a specific polyketide beta-ketoacyl:acyl carrier protein synthase, which contains an unusual beta-ketoacyl synthase and acyltransferase motifs and is likely to be involved in antibiotic TA post-modification. Functional analysis of this beta-ketoacyl:acyl carrier protein synthase by specific gene disruption suggests that it is essential for the production of an active TA molecule.

A NusG-like transcription anti-terminator is involved in the biosynthesis of the polyketide antibiotic TA of Myxococcus xanthus.

The antibiotic TA of Myxococcus xanthus is synthesized through a type I polyketide synthase mechanism. Previous studies have indicated that several genes essential for TA production are clustered within a 40-kb region and are transcriptionally co-regulated. In this study, we report the genetic analysis of the first gene in the TA gene cluster, identified as a NusG-like transcription anti-terminator. Functional analysis of this NusG-like anti-terminator gene by specific gene disruption confirms that it is essential for TA production but not for normal growth and development.