The Use of Lasers in Enhancing the Bond Strength of Orthodontic Brackets.

Background: The use of lasers in orthodontics has garnered interest for its potential to enhance the bond strength between orthodontic brackets and tooth surfaces, a crucial factor for successful orthodontic treatment. This study aims to investigate the effect of laser irradiation on the bond strength of orthodontic brackets in a sample of 30 patients. Materials and Methods: Thirty patients undergoing orthodontic treatment were divided into two groups. In Group A, brackets were bonded using conventional methods, while in Group B, brackets were bonded after laser irradiation. A diode laser operating at 810 nm was used, with an energy setting of 2.5 W for 20 s. After bonding, a universal testing machine measured the bond strength in megapascals (MPa). The adhesive remnant index (ARI) was also recorded to determine the mode of bond failure. Statistical analyses were conducted to compare the results between the groups. Results: The mean bond strength in Group B (laser irradiation) was significantly higher (P < 0.05) than in Group A (conventional bonding). Group B exhibited a mean bond strength of 9.72 MPa, whereas Group A showed a mean bond strength of 7.41 MPa. The ARI scores indicated that Group B had more adhesive remaining on the tooth surface, suggesting a stronger bond. Conclusion: Laser irradiation prior to orthodontic bracket bonding resulted in significantly enhanced bond strength compared to conventional bonding methods. The increased bond strength and greater adhesive remnant on the tooth surface indicate that laser irradiation improves the adhesion between brackets and tooth enamel. Integrating lasers into orthodontic procedures has the potential to elevate treatment outcomes by ensuring durable bracket adhesion.

Antifungal and Antiproliferative Activity of Pistagremic Acid and Flavonoids Extracted from the Galls of Pistacia chinensis subsp. integerrima.

Pistacia chinensis subsp. integerrima (J.L. Stewart) Rech. f. is a plant known for its therapeutic applications in traditional medicine, which are related to its antimicrobial, anticancer, antioxidant, anti-inflammatory, analgesic, antidiarrheal, and muscle relaxant properties. The galls of P. chinensis are rich in triterpenes and flavonoids, and we here report the extraction of pistagremic acid (1), apigenin (2) and sakuranetin (3) from this source. The isolated compounds were tested against Aspergillus flavus, Candida albicans, Candida glabrata, Fusarium solani, Microsporum canis and Trichoderma longibrachiatum. The results highlighted the antimicrobial activity of flavonoids 2 and 3, suggesting that this class of molecules may be responsible for the effect related to the traditional use. On the other hand, when the compounds and the extract were tested for their antiproliferative activity on a panel of 4 human cancer cell lines, the triterpene pistagremic acid (1) showed a higher potential, thus demonstrating a different bioactivity profile. Structure-based docking and molecular dynamics simulations were used to help the interpretation of experimental results. Taken together, the here reported findings pave the way for the rationalization of the use of P. chinensis extracts, highlighting the contributions of the different components of galls to the observed bioactivity.

Intrauterine myelomeningocele repair: effect on short-term complications of prematurity.

OBJECTIVE: To determine whether short-term complications of prematurity are affected by intrauterine myelomeningocele repair. METHODS: Medical records of the first 100 infants undergoing intrauterine myelomeningocele repair (IUMR) at the Vanderbilt University Medical Center were reviewed. Infants born at <34 weeks' gestation were identified. Two controls were identified for each IUMR infant. Controls were matched for gestational age, sex, birth weight, antenatal steroids, and mode and month of delivery. Development of respiratory distress syndrome, intraventricular hemorrhage, and chronic lung disease and days on ventilator and length of hospital stay were recorded. The results are expressed as mean values and ranges. Comparison of data between groups was performed using the Mann-Whitney U test. Categorical data were compared using the chi-square test and Fisher's exact test. p

Gestational age at intrauterine myelomeningocele repair does not influence the risk of prematurity.

OBJECTIVE: To determine the effect of gestational age at the time of intrauterine myelomeningocele repair on the duration of pregnancy and the gestational age at the time of delivery. METHODS: This study is a retrospective chart review of the maternal and neonatal medical records of all infants undergoing intrauterine myelomeningocele repair at Vanderbilt University Medical Center. Birth weight, gestational age at the time of surgery and gestational age at the time of delivery were recorded. Infants were divided into 2 groups depending on gestational age at the time of surgery, either > or = 25 weeks' gestation (group 1) or < 25 weeks (group 2). Results were expressed as medians and interquartile ranges. Statistical analysis was done using the unpaired (2-sample) t test; p values < or = 0.05 were considered significant. RESULTS: Ninety-five infants were studied. Fifty-one infants were repaired after 25 weeks' gestation (group 1) at a median gestational age of 26.3 weeks (range 25.6-27.6). Their median gestational age at delivery was 34.4 weeks (range 32.6-35.3). Forty-four infants were repaired before 25 weeks' gestation (group 2). Surgery was done at a median gestational age of 23.6 weeks (range 22.4-24.5). The median gestational age at delivery was 34 weeks (range 31.6-35.3; p = 0.88). CONCLUSION: Early intrauterine myelomeningocele repair before 25 week's gestation does not decrease the gestational age at delivery when compared with repair after 25 weeks.

Changes in pulmonary artery pressure during the acute phase of respiratory distress syndrome treated with three different types of surfactant.

We studied the changes in acceleration time/right ventricular ejection time ratio (AT/RVET; indicative of changes in pulmonary artery pressure) calculated from Doppler ultrasound examinations performed before and 1, 6, and 12 h after the first and second doses of surfactant following the administration of each of three different surfactants during the acute phase of the respiratory distress syndrome. Maximum fractional inspired oxygen concentration (F(I,O2)) and peak inspiratory pressure (PIP) were recorded during each 4 h period from birth for the first 24 h and subsequently every 24 h until 72 h. Eighty-three infants were studied. Fifty patients weighing > 1 kg received Exosurf (n = 29) or ALEC (n = 21) and 33 weighing < or = 1 kg received Exosurf (n = 22) or Survanta (n = 11). The AT/RVET rose rapidly after administration of all three surfactants. There was no significant difference in the change in AT/RVET between those > 1 kg who received Exosurf and those who received ALEC (a synthetic surfactant). Similarly, there was no difference between those infants < or = 1 kg who received Exosurf and those who received Survanta. The F(I,O2) requirements, but not PIP, were lower in those infants who received Survanta at 12 and 20 h compared with those who received Exosurf. There was no significant difference in the F(I,O2) or PIP requirements between infants > 1 kg who received Exosurf compared with those who received ALEC. The rise in AT/RVET found in this study after administration of ALEC, Exosurf, or Survanta suggests that similar and rapid falls in pulmonary artery pressure occur after all three surfactant administrations, despite the difference in clinical response demonstrated between Exosurf and Survanta.

Pulmonary artery pressure: early predictor of chronic lung disease in preterm infants.

AIM: To determine if pulmonary artery pressure (PAP) in ventilated preterm infants is independently associated with the development of chronic lung disease (CLD) and whether early assessment has any prognostic value. METHODS: Two cohorts (development n = 55; and validation n = 28) of preterm infants were studied at 24 hours of age. PAP was assessed non-invasively using its inverse correlation with the corrected acceleration time to right ventricular ejection time ratio (AT:RVET(c)), calculated from the pulmonary artery Doppler waveform. Clinical and respiratory variables were also collected. Using logistic regression analysis to identify factors independently associated with CLD, a prognostic score was developed to predict CLD. The ability of the score to predict CLD was described using receiver operating characteristic (ROC) curves. RESULTS: Birthweight, inspired oxygen concentration, and AT:RVET(c) were independently predictive of CLD. The area under the ROC curve was 0.96 for the development and 0.89 for the validation cohort. Exclusion of AT:RVET(c) resulted in a reduction to 0.88 and 0.73, respectively. CONCLUSION: PAP is independently associated with CLD. An early assessment of PAP using AT:RVET(c) may permit the early prediction of CLD as part of a multifactorial scoring system.

Changes in pulmonary artery pressure in infants with respiratory distress syndrome following treatment with Exosurf.

The pulmonary artery pressure (PAP) changes were studied using Doppler echocardiography in preterm infants treated with an artificial surfactant (Exosurf) during the acute phase of respiratory distress syndrome (RDS). The ratio of pulmonary artery acceleration time to the right ventricular ejection time (AT:RVET), measured from the Doppler wave form, was determined in 38 infants before the first dose of Exosurf, at one and six hours after the first dose, immediately before the second dose of Exosurf, and at one, six, 12, 36, and 60 hours subsequently. The median AT:RVET ratio corrected for heart rate (AT:RVET(c)) increased significantly an hour after administration of the first dose of Exosurf from 0.330 (0.273-0.410) to 0.380 (0.303-0.445) and similarly an hour after the second dose from 0.426 (0.252-0.495) to 0.440 (0.373-0.500). These changes occurred against a steady increase in the median AT:RVET(c) over the first 72 hours. It is concluded that the reduction in PAP correlates well with clinical parameters of disease severity and raises questions regarding the mode of action of Exosurf.

Prevalence and seasonal fluctuations of intestinal parasitic infections in the Nablus area, West Bank of Jordan.

A total of 22,970 stool specimens collected from patients attending the Central Medical Laboratory in the city of Nablus in the period of 1981-1986 were examined for intestinal parasites. Of these 7412 (32.3%) were positive. Entamoeba histolytica (22.9%), Giardia lamblia (7.3%), and Ascaris lumbricoides (5.7%) were the most prevalent intestinal parasites found. Other intestinal parasites present included Hymenolepis nana, Trichomonas hominis, Trichuris trichiura, Taenia saginata, Enterobius vermicularis and Strongyloides stercoralis. Seasonal occurrence of intestinal parasites in the West Bank of Jordan was also studied in the period January 1981-August 1987. Lower prevalence rates of intestinal parasites generally occurred during winter and early spring. Peak incidence occurred during summer and early autumn. The reasons for these seasonal variations are discussed.