Effect of a volatile smoke component (acrolein) on human gingival fibroblasts: An in vitro study

Aim:

Tobacco and some of its volatile and non-volatile components have been found to affect many types of cells including human gingival fibroblasts. The aim of this present study was to estimate the effect of acrolein, a volatile fraction of cigarette smoke on the attachment, proliferation and ultra structure of human gingival fibroblasts in culture.

Materials and Methods:

Human gingival fibroblasts strains obtained from healthy subjects aged 20-30 years, were grown to confluency and utilized between 3^rd -6^th passages. The cell cultures seeded in 96 well microtitration plates at a density of 45,000 cells/well were incubated with acrolein at concentrations of 10^-4, 3×10^-5 and 10^-5 . Attachment ability was evaluated after three hours using Neubauer hemocytometer. For the proliferation assay cell cultures seeded at a density of 10,000 cells/well were incubated at concentrations of 10^-4, 3×10^-5, 10^-5, 3×10^-6, 10^-6 and cell count determined after 5 days using a hemocytometer. Cell morphology was examined under phase contrast microscope.

Results:

Acrolein produced a dose-dependent cytotoxic effect on human gingival fibroblasts with complete inhibition of attachment and proliferation at higher concentrations.

Conclusion:

This supports the hypothesis that cigarette smoke is a great risk factor in the development and progression of periodontal disease.

The efficacy of flapless implant surgery on soft-tissue profile comparing immediate loading implants to delayed loading implants: A comparative clinical study

Aims and Objectives

To assess the efficacy of flapless implant surgery on soft-tissue profile and to compare the clinical outcomes of flapless implant therapy on immediate loading (IL) implants to delayed loading (DL) implants.

Materials and Methods

The study sample consisted of 20 patients who were partially edentulous in the anterior maxillary region. They were divided into two groups. In group I (IL) 10 implants were placed and immediately provisionalized and restored with a metal ceramic crown on the 14th day. In group II (DL) 10 implants were placed and loaded after 4 months. Single-piece implants were used for the IL group and two-piece implants were used for the DL group. All soft tissue parameters i.e., modified plaque index (mPI), modified bleeding index (mBI), papillary index (PPI), marginal level of soft tissue (ML) and width of keratinized mucosa (WKM) were recorded at baseline, Day 60, Day 120 and Day 180.

Results:

The success rate in group I was found to be 80%, which was lower than the success rate in group II which was found to be 90%. On comparison, there is no statistically significant difference in success rate between the two study groups. There was no statistically significant difference between the groups over time in parameters like mPI, mBI, ML and WKM. The mean PPI score in group II showed a significant increase from when compared to group I.

Conclusion:

The results of this study indicated that flapless implant surgery using either immediately loading implants or DL implants, demonstrate enhancement of implant esthetics.

Effect of a controlled release device containing minocycline microspheres on the treatment of chronic periodontitis: A comparative study

INTRODUCTION

Adjunctive therapy with locally delivered antimicrobials has resulted in improved clinical outcomes. The aim of this study was to evaluate the efficacy and safety of locally administered minocycline microspheres (Arestin) in the treatment of chronic periodontitis.

MATERIALS AND METHODS

A total of 60 sites from 15 patients in the age group of 35-50 years, who had periodontal pockets measuring 5-8 mm and had been diagnosed with chronic periodontitis, were selected for the study. The selected groups were randomly assigned to either the control group (group A) or the treatment/test group (group B). Only scaling and root planing were done at the base line visit for the control sites followed by local application of Arestin (1 mg). Clinical parameters such as plaque index, gingival index, and gingival bleeding index were recorded at baseline, day 30, day 90, and day 180 in the selected sites of both the groups. Probing pocket depth also was recorded at baseline, day 90, and day 180 for both the groups.

RESULTS

A statistically significant reduction was observed in both groups. Group B showed better results than Group A and these differences were statistically significant.

CONCLUSION

The results of this study clearly indicate that treatment with scaling and root planing plus minocycline microspheres (Arestin) is more effective and safer than scaling and root planing alone in reducing the signs of chronic periodontitis.

Neonatal mortality among low birth weight infants during the initial months of the academic year

OBJECTIVE

Proper management of very low weight (<1500 g) infants requires specific expertise. During July and August, pediatric interns start new rotations and advance in responsibilities by postgraduate level. We test the hypothesis that low weight births in teaching hospitals exhibit increased neonatal mortality during the initial training months.

STUDY DESIGN

Population-based cohort of 5184 very low weight and 15 232 moderately low weight infants in California from 19 regional teaching hospitals with medical training programs. Logistic regression methods controlled for both individual covariates and temporal patterns in neonatal mortality.

RESULT

We found no difference in neonatal mortality between very low weight infants born in teaching hospitals during July and August and those born in other months (adjusted odds ratio (AOR): 0.98, 95% confidence interval (CI), 0.78 to 1.23). Investigation of moderately low birth weight infants also indicated no increased neonatal mortality.

CONCLUSION

Infants most likely to die in the neonatal period do not appear to be at elevated risk of neonatal mortality during July and August.

Subepithelial connective tissue grafts for the coverage of denuded root surfaces: a clinical report

AIMS AND OBJECTIVES

The aim of this study is to determine the effectiveness of subepithelial connective tissue grafts (SCTG) in the coverage of denuded roots.

MATERIALS AND METHODS

A total of 16 sites with > or =2 mm of recession height were included in the study for treatment with SCTG. The clinical parameters, such as recession height, recession width, width of keratinized gingiva, probing pocket depth, and clinical attachment level were measured at the baseline, third month, and at the end of the study [sixth month]. The defects were treated with a coronally positioned pedicle graft combined with connective tissue graft.

RESULTS

Out of 16 sites treated with SCTG, 11 sites showed complete (100%) root coverage; the mean root coverage obtained was 87.5%. There was a statistically significant reduction in recession height, recession width, and probing pocket depth. There was also a statistically significant increase in the width of keratinized gingiva and also a gain in clinical attachment level. The postoperative results were both clinically and statistically significant ( P 0.05).

CONCLUSION

From this study, it may be concluded that SCTG is a safe and effective method for the coverage of denuded roots.

Effect of three commercial mouth rinses on cultured human gingival fibroblast: an in vitro study

AIM

To examine the effect of three commercial mouth rinses (Hexidine 0.2%, Listerine Cool Mint, Betadine 1%) upon cultured human gingival fibroblast proliferation.

MATERIALS AND METHODS

Human gingival fibroblasts were cultured and incubated in Dulbecco's Minimum Eagle's Medium containing Chlorhexidine, Listerine, Povidone-Iodine at varying concentrations (1%, 2%, 5%, 10%, 20% and 100% of the given solution) at 37 degrees C for 1, 5 and 15 min. Control cells received an equal volume of Dulbecco's Minimum Eagle's Medium without adding mouth rinses, for similar duration of exposure at 37 degrees C. Following incubation the media were removed, cells were washed twice with medium, supplemented with 10% Fetal Bovine Serum, and fibroblasts in the test and control group were allowed to recover in the same media for 24 h.

RESULTS

In all the three groups, the proliferation inhibition was dependent on the concentration of solublized mouth rinses in the cell culture but independent of the duration of exposure to all three mouth rinses. The results showed that all three solutions were toxic to cultured human gingival fibroblasts, Chlorhexidine being the most cytotoxic. It was seen that at dilute concentrations (1% and 2% of given solutions) Listerine was more cytotoxic than Chlorhexidine and Povidone-Iodine.

CONCLUSION

These results suggest that Chlorhexidine, Listerine and Povidone-Iodine are capable of inducing a dose-dependent reduction in cellular proliferation of fibroblasts. The results presented are interesting, but to know the clinical significance, further studies are needed.

Early prediction of poor outcome in extremely low birth weight infants by classification tree analysis

OBJECTIVE

To predict death or neurodevelopmental impairment (NDI) in extremely low birth weight infants by classification trees with recursive partitioning and automatic selection of optimal cut points of variables.

STUDY DESIGN

Data from the Trial of Indomethacin Prophylaxis in Preterms were randomly divided into development (n=784) and validation sets (n=262). Three models were developed for the combined outcome of death (8 days to 18 months) or NDI (cerebral palsy, cognitive delay, deafness, or blindness at 18 months corrected age): antenatal: antenatal data; early neonatal: antenatal+first 3 days data; and first week: antenatal, first 3 days, and 4th to 8th days data. Decision trees were tested on the validation set.

RESULTS

Variables associated with death/NDI in each model were: Antenatal: Gestation<or=25.5 weeks and antenatal steroids<7 days. Early neonatal: Birth weight<or=787 g and fluid intake>01 mL/kg/d. First week: Birth weight<or=787 g: transfusion>3 mL/kg/d. Birth weight>787 g: cranial echodense intraparenchymal lesion and transfusion>1 mL/kg/d. Correct classification rates were 61% to 62% for all models.

CONCLUSIONS

The ability to predict long-term morbidity/death in extremely low birth weight infants does not improve significantly over the first week of life. Effects of different variables depend on age.

Hospital periodontal surgery

Phenytoin-induced gingival overgrowth is a recognized side effect in many cerebral palsy patients using diphenyl hydantoin for the control of seizures. Severe gingival overgrowth in these patients can affect normal masticatory function, lead to poor occlusal development, and compromise esthetics. This report addresses the complex nature of treating phenytoin-induced gingival overgrowth in a mentally retarded 20-year-old female patient. For this patient, full-mouth gingivectomy procedure was performed under general anesthesia in a single session. Post operative follow-up was uneventful. This article discusses major indications, contraindications, and protocols to be followed for periodontal surgical procedures done under general anesthesia.

Care of very low birth weight infants with respiratory distress syndrome: an evidence-based review

Since 1959, when it was reported that many preterm infants had surfactant deficiency, there has been a remarkable improvement in the prevention of respiratory distress syndrome (RDS) and in the care of infants who develop RDS. Antenatal corticosteroids and surfactant replacement have improved the care of very low birth weight infants.

Comparison of the prediction of extremely low birth weight neonatal mortality by regression analysis and by neural networks

AIMS

To compare the prediction of mortality in individual extremely low birth weight (ELBW) neonates by regression analysis and by artificial neural networks.

STUDY DESIGN

A database of 23 variables on 810 ELBW neonates admitted to a tertiary care center was divided into training, validation, and test sets. Logistic regression and neural network models were developed on the training set, validated, and outcome (mortality) predicted on the test set. Stepwise regression identified significant variables in the full set. Regression models and neural networks were then tested using data sets with only the identified significant variables, and then with variables excluded one at a time.

RESULTS

The area under the curve (AUC) of receiver operating characteristic (ROC) curves for neural networks and regression was similar (AUC 0.87+/-0.03; p=0.31). Birthweight or gestational age and the 5-min Apgar score contributed most to AUC.

CONCLUSIONS

Both neural networks and regression analysis predicted mortality with reasonable accuracy. For both models, analyzing selected variables was superior to full data set analysis. We speculate neural networks may not be superior to regression when no clear non-linear relationships exist.

Hypocapnia and hypercapnia in respiratory management of newborn infants

Recent experimental and clinical data demonstrate that both hypocapnia and hypercapnia during the neonatal period may result in beneficial or adverse consequences. Multiple retrospective studies report a strong association between PaCO2 levels less than 25 to 30 mm Hg and an increased incidence of cystic PVL and CP in preterm infants. Prolonged exposure to PaCO2 values less than 25 to 30 mm Hg is also associated with hearing loss in term and near-term infants. A low tidal volume strategy combined with permissive hypercapnia is potentially a strategy that could prevent lung injury. Clearly, more randomized, controlled trials are needed before this latter strategy or that of permissive hypercapnia can be recommended routinely for preterm, near-term, or term gestation infants with respiratory disorders.

Hemodynamic effects of levcromakalim in neonatal porcine pulmonary hypertension

Levcromakalim (LKM; a K(ATP) channel opener) reverses hypoxic pulmonary vasoconstriction in isolated pulmonary arteries and perfused lungs. This vasorelaxation is blocked by glibenclamide (GLB; a K(ATP) channel blocker). We evaluated the hemodynamic effect of LKM followed by GLB in a chronically instrumented neonatal porcine model of pulmonary hypertension, created by exposing piglets to hypoxia (n = 7) or heat-killed group B streptococci (GBS) (n = 6). Hypoxia increased pulmonary arterial pressure (PAP), which LKM decreased, and GLB subsequently increased in a dose-dependent manner. Systemic arterial pressure (SAP) did not change with hypoxia but was also decreased by LKM and increased by GLB. GBS also led to increased PAP, but LKM significantly reduced only SAP, which was then increased by GLB. We conclude LKM is capable of reversing hypoxic, but not GBS-induced, pulmonary hypertension but lacks specificity for the neonatal pulmonary vasculature.

Effect of cigarette smoke extract on neonatal porcine vascular smooth muscle cells

RATIONALE

Cigarette smoke exposure in the perinatal period increases the risk of various prenatal and postnatal complications, including sudden infant death syndrome (SIDS) and persistent pulmonary hypertension of the newborn (PPHN). We investigated the cellular effects of cigarette smoke extract (CSE) in the developing vasculature.

METHODS

Vascular smooth muscle cells (VSMC) were isolated from neonatal porcine carotid arteries, splenic arteries, and main and resistance pulmonary arteries. Effects of CSE on VSMC proliferation, viability, apoptosis, and media nitrates and nitrites were evaluated. The effects of known constituents of CSE (nicotine, benzopyrene, acrolein, acetaldehyde), aged CSE, CSE with added hemoglobin, devolatilized CSE, CSE with added dithiothreitol (DTT), and reduced glutathione (GSH) on cell proliferation and viability were assessed.

RESULTS

CSE caused a dose- and time-dependent decrease in neonatal VSMC numbers isolated from all four sites, mainly as a result of increased cell necrosis and not apoptosis. Nitrates and nitrites were below the threshold of detection. Nicotine and benzopyrene did not affect cell counts, while acrolein and acetaldehyde decreased cell counts in a dose-dependent manner. Addition of hemoglobin, devolatilization, and the addition of DTT or GSH slightly decreased CSE inhibition.

CONCLUSIONS

CSE causes necrosis of neonatal VSMC, and this toxicity is mediated mainly by volatile components such as acrolein and acetaldehyde, possibly in association with nitric oxide and carbon monoxide.

Chronic exposure to cigarette smoke extract impairs endothelium-dependent relaxation of chicken embryo pulmonary arteries

Maternal smoking may increase the risk for various adverse neonatal outcomes including persistent pulmonary hypertension of the newborn (PPHN). We investigated whether chronic prenatal cigarette smoke extract (CSE) exposure could produce abnormal vasoreactivity in pulmonary arteries. Daily injections of CSE (diluted in phosphate buffered saline) or vehicle were added to the air cells of fertilized eggs starting on day 5 of the 21-day incubation period of the chicken embryo. On day 19, pulmonary arteries were dissected out and their contractile properties were assessed using small vessel myography. Endothelium-dependent and endothelium-independent vasorelaxations were examined by using acetylcholine (ACh, 10(-8) to 10(-4) M) and sodium nitroprusside (SNP, 10(-8) to 10(-4) M), respectively. The drug concentration inducing 50% of the maximal relaxation was determined for each concentration-response curve and expressed as negative log molar (pD(2)). Exposure to CSE significantly decreased the sensitivity of pulmonary arteries to ACh (pD(2) control group: 7.29 +/- 0.24; pD(2) CSE-exposed group 6.24 +/- 0.12, p < 0.05). SNP elicited similar responses in vessels of both groups at all tested concentrations. In conclusion, chronic prenatal exposure to CSE impaired endothelium-dependent but not endothelium-independent vasodilation in chicken embryo pulmonary arteries. This observation suggests that cigarette smoke components may produce deleterious effects on fetal vascular endothelial vasorelaxant pathways, leading to the development of adverse outcomes such as PPHN.

Prediction of neurologic morbidity in extremely low birth weight infants

OBJECTIVE

(1) Identify major determinants of adverse neurodevelopmental outcome in extremely low birth weight (ELBW) infants. (2) Compare neural networks and regression analysis in the prediction of major handicaps and Bayley scores (MDI and PDI) in individual ELBW neonates followed to 18 months.

STUDY DESIGN

Retrospective cohort study of regional tertiary care NICU database. A database with 21 selected variables was divided into training (n = 144) and test sets (n = 74). The training set was used to train a neural network and develop regression equations to predict outcomes in the test set.

RESULTS

Determinants (descending order of contribution to variance): Major handicap: intraventricular hemorrhage (IVH) grade, necrotizing enterocolitis > or = stage II, black race, and no chorioamnionitis; low MDI: IVH grade, plurality, bronchopulmonary dysplasia (BPD), lower maternal grade, and no chorioamnionitis; low PDI: IVH grade, BPD, periventricular leukomalacia, lower maternal grade, and no chorioamnionitis. Regression techniques and neural networks were comparable and had relatively low sensitivity and correlation with adverse outcomes.

CONCLUSION

Much of the variance in ELBW neurologic outcome cannot be explained by either regression analysis or neural network approaches.