Interdental Cleaning and Oral Health Status in an Adult Cohort, 2015 to 2018.

Interdental cleaning is routinely recommended, despite limited evidence supporting efficacy to prevent advanced oral disease endpoints, such as caries and periodontal disease. We aimed to examine associations between interdental cleaning and oral health in a large, generalizable prospective cohort of adults in the United States. Data were drawn from wave 3 (2015 to 2016, n = 26,086 included in analysis) and wave 4 (2016 to 2018, n = 22,585) of the adult component (age ≥18 y) of the nationally representative Population Assessment of Tobacco and Health Study. Survey-weighted multivariable regression models estimated the associations between wave 3 weekly interdental cleaning frequency and 6 measures of self-reported oral health-overall rating, tooth extractions, gum bleeding, loose teeth, bone loss around teeth, and gum disease-cross-sectionally and prospectively, with adjustment for established periodontal disease risk factors. As compared with no interdental cleaning, interdental cleaning ≥7 times/wk was prospectively associated with greater odds of excellent self-rated oral health (adjusted odds ratio, 1.37; 95% CI, 1.17 to 1.62), lower odds of bleeding gums (adjusted odds ratio, 0.62; 95% CI, 0.54 to 0.70), but not statistically significantly lower odds of other oral health conditions in the following 12 mo. Older age, lower socioeconomic status, diabetes, and cigarette smoking were consistently associated with worse oral health across all outcome measures. Findings were largely robust to alternative model and variable specifications. Interdental cleaning is associated with better perceived oral health and less self-reported gingivitis. Prevention of more advanced disease states was not demonstrated. These findings should be interpreted cautiously given the self-reported nature of the measures and relatively short follow-up period.

Experimental evidence on promotion of electric and improved biomass cookstoves.

Improved cookstoves (ICS) can deliver "triple wins" by improving household health, local environments, and global climate. Yet their potential is in doubt because of low and slow diffusion, likely because of constraints imposed by differences in culture, geography, institutions, and missing markets. We offer insights about this challenge based on a multiyear, multiphase study with nearly 1,000 households in the Indian Himalayas. In phase I, we combined desk reviews, simulations, and focus groups to diagnose barriers to ICS adoption. In phase II, we implemented a set of pilots to simulate a mature market and designed an intervention that upgraded the supply chain (combining marketing and home delivery), provided rebates and financing to lower income and liquidity constraints, and allowed households a choice among ICS. In phase III, we used findings from these pilots to implement a field experiment to rigorously test whether this combination of upgraded supply and demand promotion stimulates adoption. The experiment showed that, compared with zero purchase in control villages, over half of intervention households bought an ICS, although demand was highly price-sensitive. Demand was at least twice as high for electric stoves relative to biomass ICS. Even among households that received a negligible price discount, the upgraded supply chain alone induced a 28 percentage-point increase in ICS ownership. Although the bundled intervention is resource-intensive, the full costs are lower than the social benefits of ICS promotion. Our findings suggest that market analysis, robust supply chains, and price discounts are critical for ICS diffusion.

Comparative Antiviral Efficacy of Generic Sofosbuvir versus Brand Name Sofosbuvir with Ribavirin for the Treatment of Hepatitis C.

BACKGROUND: Chronic hepatitis C infection is a major cause for liver failure and liver cancer and can be treated with highly effective all oral directly acting antiviral (DAA) drugs. Generic versions of these DAAs are available in India. METHOD: This was an open-label, single-center, prospective, nonrandomized observational study for the comparative safety and efficacy of generic versus brand name sofosbuvir with ribavirin therapy for chronic hepatitis C infection (all genotypes). Between December 2014 and December 2015, 66 patients received either generic sofosbuvir (400mg) or brand name SOLVALDI (400mg) with weight based ribavirin for 24 weeks in a single multispecialty hospital in Mumbai. Monitoring viral loads and safety labs was performed as per national guidelines. RESULTS: Sustained virologic response was 72.4% versus 75.7% (p=0.78) among patients treated with generics and SOVALDI, respectively. At 4 weeks on-treatment, approximately 90% of patients from both groups had undetectable or below the lower limit of quantification. Change in hemoglobin was comparable in both groups (p=0.26). CONCLUSION: Generic versions of sofosbuvir reported in this study are safe and efficacious to treat hepatitis C. However, bioequivalency studies of all generic DAAs need to be performed before wider use of such drugs for the treatment of hepatitis C.

Impaired bioavailability of rifampicin in presence of isoniazid from fixed dose combination (FDC) formulation.

The present study describes comparative bioavailability of rifampicin (RIF) after administration of a single component RIF (450 mg) capsule and rifampicin-isoniazid (RIF-INH) (450+300 mg) fixed dose combination (FDC) capsule formulations. Six healthy male volunteers participated in a single dose, two treatment, two period, cross-over study. A sensitive, specific and accurate HPTLC method was developed, validated and employed for estimation of RIF and its major active metabolite, 25-Desacetylrifampicin (25-DAR) levels, in urine. Using the urinary excretion data various pharmacokinetic parameters: AUC(0-24), AUC(0-infinity), cumulative amount excreted in 24 h, peak excretion rate, etc. for both RIF and 25-DAR were calculated and compared statistically (ANOVA, 90% confidence interval for ratio). Significant decrease in the bioavailability ( approximately 32% as RIF and approximately 28% as 25-DAR) of RIF from FDC capsules was observed. The present bioavailability study confirms our serious doubts about the stability of RIF in presence of INH in acidic environment of stomach, which probably is the main factor responsible for the reduced bioavailability of RIF from RIF-INH combination formulations. This study underlines the fact that there is an urgent need to reconsider the formulation of the FDC product in order to minimize or avoid the decomposition of RIF in gastrointestinal tract.

Influence of postdatism and meconium on fetal erythropoietin.

OBJECTIVE: To determine whether fetal erythropoietin (Epo) concentrations are increased in pregnancies extending beyond 41 weeks' gestation and whether this is influenced by the presence of meconium-stained amniotic fluid. METHODS: Epo concentrations were measured in 116 fetal umbilical cord blood samples from otherwise uncomplicated pregnancies between 37 to 43 weeks' gestation during the period of October 1996 to October 1997. An enzyme-linked immunosorbent assay kit was used to measure Epo. Maternal demographics and birth outcomes including Apgar score, cord blood pH, and base deficit were obtained. Fetuses born between 41 and 43 weeks' gestation (post-term) were compared with matched controls born between 37 and 40 weeks' gestation (term). In addition, both post-term and term fetuses with meconium-stained amniotic fluid were compared with matched controls without meconium. RESULTS: Post-term fetuses without meconium had significantly higher Epo levels compared with term fetuses (mean +/- SEM: 50.6 +/- 6.5 versus 29.5 +/- 3.3 mIU/ml, p = 0.002). When matched for gestational age, fetuses with meconium-stained amniotic fluid had significantly greater Epo concentrations compared with controls without meconium (post-term, 80.7 versus 50.6 mIU/ml; term, 61.4 versus 29.5 mIU/ml; p < 0.05). However, no significant difference in Epo levels was found between post-term fetuses with meconium and term fetuses with meconium (80.7 +/- 15.7 mIU/ml versus 61.4 +/- 12.8 mIU/ml, respectively). Mean cord blood pH and base deficit values for all groups were within normal clinical range. CONCLUSION: Cord blood Epo concentrations were significantly increased in pregnancies extending beyond 41 weeks. Irrespective of gestational age, meconium-stained amniotic fluid was associated with a significant rise in Epo. High Epo levels in these pregnancies imply subacute or chronic fetal hypoxia. Close clinical monitoring of post-term fetuses and those with meconium-stained amniotic fluid is warranted.

Erythropoietin in obstetrics.

Our objective was to discuss the role of erythropoietin in fetal erythropoiesis and to review its clinical uses in perinatal medicine. All relevant articles compiled through a MEDLINE search (years 1986-1997) were reviewed. Erythropoietin is essential for fetal erythropoiesis and is produced in response to hypoxia and anemia. Cord blood erythropoietin is purely fetal and reflects tissue oxygenation. It has been found to be increased in many complicated pregnancies with underlying fetal hypoxia. Erythropoietin could be used as a marker of fetal hypoxia because its concentration rises rapidly by increased production in response to hypoxia. Its measurement might enable more accurate timing of hypoxic injury. In addition, erythropoietin levels have been well correlated with perinatal brain damage and may facilitate treatment of high risk neonates. Erythropoietin has also been used successfully in anemia of prematurity, decreasing the transfusion requirement. However, studies are still needed to determine the optimal doses of erythropoietin and iron supplementations required for maximizing the red blood cell response. Erythropoietin has been examined as potential maternal therapy in various disorders during pregnancy. These include end-stage renal disease, severe antepartum iron deficiency anemia, and postpartum anemia. Erythropoietin has been found to be effective and well tolerated in these conditions. An additional promising use lies in the optimization of maternal red blood cell mass to allow autologous blood donation. This may be critical in cases where a large amount of bleeding might be anticipated, as with placenta previa. This would also minimize the donor transfusion-related hazards. Erythropoietin with its wide clinical applications could improve maternal and neonatal outcome.

Interleukin-10 induces E-selectin on small and large blood vessel endothelial cells.

In vitro, expression of E-selectin is largely restricted to endothelial cells activated by inflammatory cytokines. Under activated conditions, cytokines such as interleukin (IL) 10, released by keratinocytes in large quantities, may also increase the expression of E-selectin on the dermal microvasculature. The aim of the present study was to investigate the expression of E-selectin on cultured human dermal microvascular endothelial cells (HDMEC) isolated from neonatal foreskins when exposed to IL-10. Expression of E-selectin was determined by immunofluorescence microscopy, FACS analysis, an HL-60 cell-binding assay, and quantitative polymerase chain reaction (PCR) analysis. For comparison with large blood vessel cells, the expression of E-selectin on human umbilical vein endothelial cells (HUVEC) was also determined in parallel by FACS and reverse transcriptase-PCR analysis under identical conditions. These studies demonstrate that IL-10 induces the expression of E-selectin on both HDMEC and HUVEC and that the level of expression of HDMEC is comparable with that induced by IL-1 beta and tumor necrosis factor-alpha. When HL-60 cells are incubated with HDMEC pretreated with IL-10, a consistent increase in adherence of HL-60 to endothelial cells is observed. This adherence was found to be mediated by L-selectin. PCR analysis and the quantification of E-selectin cDNA by a novel, highly sensitive and specific PCR-immunoassay demonstrate the induction of E-selectin mRNA at the transcriptional level. The induction of the expression of E-selectin by IL-10 on HDMEC may provide additional insights into the pathogenic mechanism of neutrophil accumulation at the site of inflammation in inflammatory skin diseases.

Antigen presentation by human dermal microvascular endothelial cells. Immunoregulatory effect of IFN-gamma and IL-10.

Human dermal microvascular endothelial cells (HDMEC) play a central role in many aspects of the inflammatory and immune reactions in skin. HDMEC display a phenotypic diversity ranging from cells with an epithelioid morphology to those that show both morphologic and biochemical characteristics of macrophages. Here it is shown that HDMEC possess the capability to both process and present Ags. T lymphocyte clones specific for peptide p94-104, which are derived from the protein of group I allergen of Dermatophagoides pteronyssinus, a major house dust mite allergen, and restricted by HLADR11, proliferated specifically to stimulation with the group I allergen of D. pteronyssinus and with peptide p94-104 presented by HDMEC. Preincubation for 48 h with IFN-gamma enhanced the expression of class II MHC Ags on HDMEC, which in turn increased the capacity of HDMEC to present Ag. When HDMEC were primed with Ag in the presence of IL-10, a 75% inhibition of Ag-specific T cell proliferation was observed. IL-10 also inhibited T cell proliferation induced by IFN-gamma-stimulated HDMEC. These findings demonstrate that HDMEC possess the ability to process and present Ag to CD4+ T cells and that these reactions are stimulated by IFN-gamma and inhibited by IL-10. The reduced Ag-presenting capacity of HDMEC mediated by IL-10 is not associated with a down-regulation of class II MHC expression. No significant reduction of HLA-DR expression was detected either at the protein or gene level when HDMEC were incubated with IFN-gamma and IL-10 as compared with incubation with IFN-gamma alone. The profound down-regulatory effect of IL-10 on Ag presentation may provide a new pharmacologic approach to control inflammatory responses in skin.

Retinoids upregulate phagocytosis by human dermal microvascular endothelial cells.

Animals fed a diet deficient in vitamin A show severe physiological changes that often result in death. At the cellular level, retinoids have been shown to induce differentiation of cells derived from a wide spectrum of tissues, including the vasculature. To understand further the mechanisms for these events, we studied the effects of 13-cis-retinoic acid, all-trans-retinoic acid, all-trans-retinol, and all-trans-retinol acetate on human dermal microvascular endothelial cells (HDMEC). Concentrations of retinoids in the physiological range from 0 to 1 microM were used in our experiments. These concentrations were nontoxic to HDMEC. Here we report that in addition to the known effect of retinoids on keratinocytes and sebacytes, retinoids induced morphological and functional changes in HDMEC that gave these cells macrophage like characteristics. 13-Cis-retinoic acid and all-trans-RA induced HDMEC to phagocytize and to increase the production of hydrogen peroxide and superoxide anion. These two retinoids also changed the morphology of endothelial cells from typical small compact cuboidal epithelioid cells to cells with larger cytoplasm and indistinct cell membranes. The retinoid-stimulated HDMEC deposited increased amounts of extracellular matrix. All-trans-retinol and all-trans-retinol acetate did not significantly affect HDMEC in all parameters tested. The induction of these properties provides a new model with which to study how retinoids regulate gene expression using a normal, nontransformed cell line.

In vivo studies of unlabeled and radioiodinated rhodamine-123.

Radioiodinated rhodamine-123 (Rh123), potential tumor imaging agent, was injected in mice bearing experimentally-induced tumors to investigate its tissue distribution. Some accumulation of radioactivity was found in tumors; most of it cleared rapidly from the blood after injection. Also, the radioiodinated Rh123 had metabolized to water-soluble species which was excreted in urine and feces. Unlabeled Rh123, on the other hand, accumulated only marginally in the tumors. However, it was found to accumulate significantly in the heart; as much as seventy times the level in blood at 4 h post-injection. Accumulation of unlabeled Rh123 increased steadily even at 24 h post-injection; whereas, it cleared rapidly from the blood via the kidney. This finding of selective accumulation of Rh123 in heart could be exploited in synthesizing 11C- and 18F-labeled Rh123 for use in PET studies of the myocardium.

Synthesis of nitrogen-13 labeled alkylamines via amination of organoboranes.

Organoboranes react with nitrogen-13 labeled ammonia to produce alkylamines in moderate yield. When 13N labeled ammonia was bubbled into a tetrahydrofuran solution containing 0.5M tridecylborane, 1-[13N]aminodecane was formed in 25-30 min from the end of bombardment (EOB) in 40-60% overall yield. 1-[13N]aminooctane and 1-[13N]aminohexane were also synthesized from appropriate organoboranes in similar yield.

Carbon-11 labeled dialkylketones: synthesis of 9-[11C]heptadecan-9-one.

9-[11C]heptadecan-9-one was synthesized from di-n-octylthexylborane via cyanidation with K11CN. The rearrangement of the organoborane intermediate followed by alkaline oxidation produced the title compound in 55-60 min from the end of bombardment (EOB) in 50-70% overall yield. The reaction sequence is applicable for the synthesis of various dialkyl ketones.

Use of 11C as a tracer for studying the synthesis of [11C]urea from [11C]cyanide.

The use of reversed-phase liquid chromatography and radiochemical detection with carbon-11 (t1/2 = 20.4 min) as a tracer allowed the study of the preparation of [11C]urea from [11C]cyanide at no-carrier-added concentrations. [11C]cyanate was readily prepared by permanganate oxidation of [11C]cyanide at 75 degrees C. The conversion of NH4O11CN (approximately 0.03 mM) to [11C]urea in the presence of excess ammonium ions (0.28 M) was found to best fit pseudo first order reaction kinetics with a rate constant of 0.065 +/- 0.008 min-1 at 75 degrees C. Heating at higher temperatures (180-200 degrees C) revealed that the conversion of NH4O11CN to [11C]urea occurred in high yield in less than 3 min. The hydrolysis of [11C]cyanate to [11C]carbonate, a possible side reaction, was found to proceed at a rate of 0.010 +/- 0.001 min-1 at 113 degrees C.

Syntheses with isotopically labelled carbon. Methyl iodide, formaldehyde and cyanide.

Many of the uniquely labelled synthetic precursors currently employed in the design of sophisticated radiolabelled compounds have their origins in the field of hot atom chemistry. Particularly, the development during the past few years of automated, on-line synthetic procedures which combine the nuclear reaction, hot atom and classical chemistry, and rapid purification methods has allowed the incorporation of useful radionuclides into suitable compounds of chemical and biochemical interest. The application of isotopically labelled methyl iodide, formaldehyde, and cyanide anion as synthetic intermediates in research involving human physiology and nuclear medicine, as well as their contributions to other scientific methodology, is reviewed.