Tensile bond strength of sealants following Er:YAG laser etching compared to acid etching in permanent teeth

The aim of this in vitro study was to assess the effect of Er:YAG laser surface treatment on the tensile bond strength of a sealant in permanent teeth. A total of 30 sound third molars were selected and embedded in cold-cure acrylic resin. The enamel surfaces were flattened by a grinding. The teeth were randomly divided into three groups and pretreated as follows: (1) 37% phosphoric acid; (2) Er:YAG laser (1.5 ml/min water spray, 100 mJ energy output, 10 Hz frequency, focal distance 17 mm); (3) Er:YAG laser + 37% phosphoric acid. The treated surfaces were isolated by double adhesive Sellotape and after insertion of a split Teflon matrix at an isolated site, sealant was applied. The specimens were thermocycled and stored at 37°C in distilled water for 72 h, then subjected to a tensile bond strength test (50 kgf at 0.5 mm/min). The mean tensile bond strengths (±SD, in megapascals) were: 18.51±5.68 in group 1, 8.06±2.69 in group 2, and 17.33±5.04 in group 3. Data were submitted to analysis of variance and the Tukey test. No significant difference were found between groups 1 (37% phosphoric acid) and group 3 (Er:YAG laser + 37% phosphoric acid) but treatment with the Er:YAG laser alone (group 2) resulted in significantly lower tensile bond strength than seen in the other groups. In this setting, the Er:YAG laser prepared the enamel surface for sealing but did not eliminate the need for acid etching before sealant application.     

The Impact of Job-Demand-Control-Support on Leptin and Ghrelin as Biomarkers of Stress in Emergency Healthcare Workers

Despite the available literature on the consequences of night shiftwork on stress and food intake, its impact on leptin and ghrelin has never been studied. We previously demonstrated that leptin and ghrelin were biomarkers related to stress, and acute stress-induced a decrease in leptin levels and an increase in ghrelin levels. We performed a prospective observational study to assess the influence of night work, nutrition, and stress on the levels of ghrelin and leptin among emergency healthcare workers (HCWs). We took salivary samples at the beginning of a day shift and/or at the end of a night shift. We also monitored stress using the job demand-control-support model of Karasek. We recorded 24-h food intake during the day shift and the consecutive night shift and during night work and the day before. We included 161 emergency HCWs. Emergency HCWs had a tendency for decreased levels of leptin following the night shift compared to before the dayshift (p = 0.067). Furthermore, the main factors explaining the decrease in leptin levels were an increase in job-demand (coefficient −54.1, 95 CI −99.0 to −0.92) and a decrease in job control (−24.9, −49.5 to −0.29). Despite no significant changes in ghrelin levels between shifts, social support was the main factor explaining the increase in ghrelin (6.12, 0.74 to 11.5). Food intake (kcal) also had a negative impact on leptin levels, in addition to age. Ghrelin levels also decreased with body mass index, while age had the opposite effect. In conclusion, we confirmed that ghrelin and leptin as biomarkers of stress were directly linked to the job demand-control-support model of Karasek, when the main cofounders were considered.     

Effects of pancreastatin (24-49) on growth of normal pancreas and pancreatic cancer

In the present study, the effects of pancreastatin on growth are evaluated in two human pancreatic cancer cell lines, in vivo and in vitro, and on athymic nude mouse pancreas. SW-1990 and MIA PaCa-2 pancreatic cancer cell lines were grown in serum-supplemented and serum-free medium in the presence of pancreastatin (10(-11)-10(-6) M), or cholecystokinin (CCK) (10(-11)-10(-8) M) or combinations thereof. Growth was evaluated by [3H]thymidine incorporation and cell counts. Pancreastatin significantly inhibited DNA synthesis in both cell lines, and cell counts in SW-1990 on days 3 and 5 but not 7. CCK-stimulated cell growth was inhibited in both cell lines and mouse pancreas by pancreastatin. Pancreastatin had no effect in the presence of fetal bovine serum. In the in vivo experiments, pancreastatin (15 micrograms/kg) did not affect growth of SW-1990 xenografts to nude mice, but inhibited CCK-stimulated growth transiently. Pancreastatin (100 micrograms/kg) transiently decreased volumes of MIA PaCa-2 xenografts to nude mice and significantly decreased weight, protein, and DNA of mouse pancreas. Fasting glucose levels of mice treated with pancreastatin 100 micrograms/kg for 35 days were significantly lower than controls. Our results demonstrate that pancreastatin not only inhibits CCK-stimulated pancreatic growth but also has inhibitory effects by itself.     

Psychiatric problems among Iranian immigrants in Canada.

The number of Iranian immigrants in Canada has been increasing since 1979. This study is the result of a review of 111 charts of Iranian patients who were referred for psychiatric treatment between 1985 and 1988. Ninety-eight percent of them arrived in Canada after the Iranian revolution, which started in 1979, and the Iran-Iraq war of 1980. Ten percent were experiencing trauma as a result of their involvement with the revolutionary government or the war. The symptoms were in accordance with the DSM-III-R criteria for post-traumatic stress disorder. Sixty percent met the criteria for adjustment disorder with depressed or anxious mood. Six percent had been subjected to physical and psychological torture and confinement. This is the first study that looks at the prevalence of psychiatric illness among Iranians and illustrates the effect of migration and displacement in the integrity of the psychic life of this population.     

Pharmacokinetic and bioavailability of diltiazem sustained-release: influence of food and time of administration

Summary— Diltiazem is a calcium channel blocking agent known to be effective in the treatment of angina pectoris, hypertension and supraventricular arrhythmias. To improve the conditions of diltiazem administration in the treatment of hypertensive patients, a sustained-release formulation (Mono-Tildiem® LP 300 mg) allowing a single daily oral administration has been developed. The aim of the present study was to first evaluate the influence of food intake and second to evaluate those of the time of administration on the pharmacokinetic parameters and the bioavailability of this sustained-release formulation. The influence of these factors was investigated over two different open, randomized, cross-over studies in 12 healthy volunteers. Although a significant decrease in Tmax and an increase in Cmax occurred when diltiazem sustained-release was administered with food intake, AUC_0–48, and therefore the fraction absorbed, were not modified either by concurrent food intake or by different times of administration. The minor modifications of pharmacokinetic parameters of diltiazem sustained release observed were unlikely to induce any clinical consequence.