Inhibition of experimental caries by plaque prevention

abstract – The purpose of this study was to test the hypothesis that a frequent intake of sucrose does not produce caries if the teeth are regularly treated with an antibacterial agent. Twenty-four students with clean teeth and normal gingivae were assigned to one of the following three groups: (1) eight individuals ceased all active oral hygiene measures and rinsed 9 times daily with 50% sucrose, (2) eight students refrained from all active oral hygiene procedures, rinsed 9 times daily with sucrose and twice daily with 10 ml 0.2% chlorhexidine gluconate, (3) the third group consisted of two subgroups each comprising 4 students. One subgroup ceased all oral hygiene procedures and rinsed twice daily with 0.2% chlorhexidine gluconate. The other was instructed to practice meticulous tooth brushing twice daily. The experiment lasted for 22 days. The group who rinsed with sucrose showed heavy plaque accumulation, those who rinsed with sucrose + chlorhexidine showed a drastic reduction in the formation of plaque. In the subgroup rinsing with chlorhexidine only and in that performing good oral hygiene, plaque was non-existent. The gingival state essentially paralleled the plaque formation. The sucrose group showed a definite increase in Caries Index. No significant changes occurred in the group rinsing with sucrose + chlorhexidine, with chlorhexidine only, or in the group performing good oral hygiene. It is concluded that prevention of plaque formation inhibits the development of gingivitis and dental caries, even with frequent rinses of sucrose.     

Fusion of dispatching centres into one entity: effects on performance

Background: Dispatching centres were fused into one of the 112 entity, which caused concerns regarding whether the medical calls could be processed effectively also in the new centre. We evaluated the effects of the reform on key performance criteria in medical calls. Methods: This observational study in the Helsinki Dispatching Centre consisted of two periods: Period I 2 years before the reform and Period II 2 years after. The main outcome measures were answering and call processing times, accuracy of risk assessment and appropriate use of ambulances. Results: In Period I (n=574,276), 92.2% of all incoming phone calls were answered within 10 s and in Period II (n=758,022) 82.8% (P<0.0001). Time to dispatch a first responding fire unit increased from 98 to 113 s (P<0.0001) and an advanced life support unit in category A calls increased from 73 to 84 s (P<0.0001). In Period I 47.7%, 34.8% and 17.5% of phone calls were completed in <3, 3–5 and >5 min and in Period II 29.8%, 36.1% and 34.1% (P<0.0001). The number of three studied non‐transportation call types and unnecessary lights‐and‐siren responses increased significantly (P<0.0001 and 0.0001, respectively). Neither the accuracy of risk assessment in the three studied call types nor the rate of telephone‐guided cardiopulmonary resuscitation changed. Conclusions: The reform increased the total number of ambulance dispatches, prolonged answering and call processing times and had a negative effect on the appropriate use of ambulances. The accuracy of risk assessment was not affected. Evidence‐based data should be the basis for the future as dispatching centre processes are shown to be vulnerable during organisational reforms.     

简易4步让全身肌肤柔滑过冬

冬天干冷的气候会令全身肌肤可能因此越来越干燥、粗糙，失去水分和光泽。选择有良好滋润功效的沐浴露和身体乳液，让你在寒冷冬天也能拥有一身光滑细腻的肌肤。[编者按]     

Cost‐effectiveness of CT thorax and bronchoscopy in haemoptysis with normal CXR for exclusion of lung cancer

As fibre‐optic bronchoscopy and CT thorax become more widely used, patients with haemoptysis who had normal CXR and sputum results are more commonly offered both CT and bronchoscopy to exclude lung cancer. Doctors who are under possible litigation pressure arising from missed diagnoses of lung cancer are often exhaustive in their investigations, even when the haemoptysis has been transient. The present study aims to investigate the number of cancer patients who can be detected with the two investigations, and compare recent similar study results with archive results. We found that despite the use of more efficient investigation tools, the yield is paradoxically much lower and, hence, less cost‐effective than that of previous studies. The likely reason is that doctors tend to over‐investigate, even for short‐term, minimal blood‐streaked sputum, which is common among simple bronchitis. In order to be more cost‐effective, these investigations should be used more selectively and for high risk patients such as those with prolonged haemoptysis and those who are heavy smokers.     

Obstetric outcome of teenage pregnancies

A retrospective cohort study was performed in a tertiary centre to determine if teenage nulliparas (aged alpha19 years, study group) had higher incidences of instrumental and Caesarean deliveries compared with nulliparas aged 20-34 years (control group) selected from the first women in the birth registry who delivered after each study case and satisfying the criteria for controls. The hospital records of the study and control cases were retrieved for review. Comparison was made in the maternal demographics, major antenatal complications, outcome of labour, mode of delivery, and perinatal outcome. In the study group, maternal height was similar but the body mass index was lower. Although the mean birthweight was lower and the incidences of preterm labour and small-for-gestational-age infants higher, there were also increased incidences of large-for-gestational-age and macrosomic infants. While there was no difference in the types of labour, there were fewer Caesarean and instrumental deliveries, a finding that persisted even after excluding the preterm deliveries. Lastly, teenage mothers aged <17 years had similar outcomes to those aged 17-19 years. These results indicated that teenage mothers had better obstetric outcomes, despite the higher incidence of preterm labour, and that young adolescents (<17 years) performed as well as their older peers.      

Endothelium-dependent relaxation and effects of prostacyclin,endothelin and platelet-activating factor in human hand veins and arteries

An altered release of endothelium-derived vasoactive factors has been implicated in several vasospastic conditions. Since the functional role of the endothelium in the hand vasculature is largely unknown, we examined the effects of ‘endothelial removal’ on vascular reactivity, and the effects of some ‘endothelium-associated’ substances in isolated human hand veins and arteries. Acetylcholine induced a large relaxation (E_max= 97±1 %) in precontracted hand arteries. The relaxation was abolished by endothelial removal. In hand veins, acetylcholine induced a small relaxation (E_max= 13 ± 4%), which was unaffected by endothelial removal. An endothelium-dependent relaxation was, however, obtained with high concentrations ( 10^-6 mol 1^-1) of the Ca²⁺ ionophore A23187. Contractile responses to noradrenaline, serotonin and prostaglandin F_2x did not differ between vein segments with and without endothelium. Endothelin was a potent constrictor of both veins and arteries. The potency and maximum response did not differ between the two types of vessel. Indomethacin pretreatment of veins did not influence the endothelin-induced contractions, suggesting that cyclo-oxygenase products are not involved in the response. In endothelin-contracted veins and arteries, the prostacyclin analogue iloprost elicited relaxation of similar potency and amplitude. The maximum relaxation in veins was, however, 3 times larger than that produced by prostacyclin itself. Platelet-activating factor was devoid of contractile and relaxant effects in both veins and arteries. The present study indicates differences between human hand veins and arteries regarding endothelial-dependent relaxation, and suggests that the modulatory role of endothelium-derived relaxing factor(s) is small in hand veins. The contractile and relaxant effects of endothelin and iloprost, however, did not differ between veins and arteries.     

The Genetics of Birth Timing: Insights into a Fundamental Component of Human Development

The timing of birth necessitates the coupling of fetal maturation with the onset of parturition, and occurs at characteristic, but divergent gestations between mammals. Preterm birth in humans is an important but poorly understood outcome of pregnancy that uncouples fetal maturation and birth timing. The etiology of preterm birth is complex, involving environmental and genetic factors whose underlying molecular and cellular pathogenic mechanisms remain poorly understood. Animal models, although limited by differences with human physiology, have been crucial in exploring the role of various genetic pathways in mammalian birth timing. Studies in humans of both familial aggregation and racial disparities in preterm birth have contributed to the understanding that preterm birth is heritable. A significant portion of this heritability is due to polygenic causes with few true Mendelian disorders contributing to preterm birth. Thus far, studies of the human genetics of preterm birth using a candidate gene approach have met with limited success. Emerging research efforts using unbiased methods may yield promising results if concerns about study design can be adequately addressed. The findings from this frontier of research may have direct implications for the allocation of public health and clinical resources as well as spur the development of more effective therapeutics.