Third molar agenesis in Down syndrome

The frequency, gender, and maxillary/mandibular occurrences of third molar agenesis have been studied in a Danish population of Down syndrome individuals (39 F and 31 M). The study was based on radiological examination and compared with 2 control groups of normal Caucasian populations. We found that the occurrence of third molar agenesis in Down syndrome individuals was around 4 times greater than in a normal population and higher than in corresponding previous studies. The agenesis occurred more often in the maxilla than in the mandible, and the frequency was not significantly higher in females than in males. The present study stresses the importance of focusing on the dental germs in the phenotypic discussion, as different genes are involved in tooth formation. The absence of teeth can contribute to an understanding of the interaction between genotype and phenotype.     

Utilization of dental health services among middle-aged people in Sweden and Denmark

In 1999, questionnaires were sent to random samples of 1001 Swedish citizens aged 55-79 years and 1175 Danish citizens aged 45-69 years. Various questions were asked concerning dental conditions, dental visit frequency per year, and money spent annually on dental care, etc. The objectives were to assess differences in the utilization of dental services and to compare out-of-pocket costs for dental care in Sweden and Denmark with control for age, gender, dental conditions and income. More than 80% of the subjects reported that a dentist had examined them less than 1 year previously. However, 77% of the Danes reported dental visits twice a year or more compared to 28% of the Swedes. Although the Danes reported a more frequent use of dental services, they had poorer dental conditions compared to the Swedes. Even though the Swedes used dental services less often than the Danes did, more subjects reported high 12-month out-of-pocket costs. In the present study, separate models were constructed for the two countries because there could be different mechanisms at play, as indicated by the results. The different insurance systems along with different degrees of commercialization in the two countries might be the most decisive factors in this context.     

Retention of basic life support skills 6 months after training with an automated voice advisory manikin system without instructor involvement

AIM: To evaluate the retention of skills 6 months after training in ventilation and chest compressions (CPR) on a manikin with computer based on-line voice advisory feedback and the possible effects of initial overtraining. METHODS: Thirty five volunteers had 20 min provisional CPR training on a manikin with computer based voice advisory feedback but without an instructor. The appropriate feedback was taken from a pre-recorded list depending on performance measured by the manikin--computer system versus set limits for ventilation and compression variables. One group in addition was randomised to receive 10 similar 3 min training sessions during 1 week in the following month (overtrained group). All ventilation and compression variables were measured without feedback before and after the initial training session, with feedback immediately thereafter, and both without and with feedback 6 months after the initial training session. RESULTS: The initial training improved all variables. Compressions with correct depth increased from a mean of 33 to 77%, and correct inflations from a mean of 9 to 58%. After 6 months, the results for the controls were not significantly different from pre-training, except for a higher of correct inflations (18%), while the overtrained group had better retention of skills including the correct compression depth (mean 61%) and inflations (mean 42%). When verbal feedback was added both the compressions and ventilations immediately improved both when tested immediately and 6 months after the initial training session. CONCLUSIONS: The computer-based voice advisory manikin (VAM) feedback system can improve immediate performance of basic life support (BLS) skills, with better long-term retention with overtraining.     

Sex hormone metabolism in prostate cancer cells during transition to an androgen-independent state

The progression of prostate cancer during androgen deprivation therapy is a serious clinical problem. Little is known, however, about the mechanisms behind the transition of the disease to an androgen-independent stage. In the present report, we provide evidence of substantial changes in both estrogen and androgen metabolism during the transition of cultured prostate cancer LNCaP (lymph node carcinoma of the prostate) cells. The results of enzyme activity measurements performed using HPLC suggest that, related to the transition, there exists a remarkable decrease in the oxidative 17 beta-hydroxysteroid dehydrogenase (17HSD) activity, whereas the reductive 17HSD activity seems to increase. Relative quantitative RT-PCR revealed that the decrease in oxidative activity largely coincided with the remarkable decrease in the expression of the HSD17B2 gene. Furthermore, the present data suggest that the observed increasing activity of 17HSD type 7 could lead to the increased intracellular production of 17 beta-estradiol during disease progression. This was supported by the cDNA microarray screening results, which showed a considerable overexpression of several estrogen up-regulated genes in the LNCaP cell line variant that represents progressive prostate cancer. Because 17HSDs critically contribute to the control of bioavailability of active sex steroid hormones locally in the prostate, the observed variation in intraprostatic 17HSD activity might be predicted to be crucially involved in the regulation of growth and function of the organ.     

Systemic inflammatory responses in African tick-bite fever

Information regarding the inflammatory response in African tick-bite fever (ATBF), an emerging spotted-fever-group rickettsiosis, in international travelers to sub-Saharan Africa, is scarce. Plasma/serum levels of von Willebrand factor (vWF), soluble (s) E-selectin, tumor necrosis factor-alpha, interleukin (IL)-6, interferon-gamma, IL-10, IL-13, IL-8, RANTES, macrophage inflammatory protein-1alpha, and C-reactive protein were studied, at both first presentation and follow-up, in 15 patients with travel-associated ATBF and in 14 healthy travelers who served as control subjects. Our main and novel findings are the following: (1) patients with ATBF had increased levels of vWF and sE-selectin, with a subsequent decrease at follow-up; (2) with the exception of IFN-gamma, levels of cytokines and chemokines were also increased in these patients at the first presentation; and (3) IL-10 and IL-13 tended to increase during follow-up, whereas most of the inflammatory cytokines decreased. The induction of these mediators and the balance between them may be critical both for the regulation of inflammation and for protective immunity in ATBF.     

Disturbed glutathione metabolism and decreased antioxidant levels in human immunodeficiency virus-infected patients during highly active antiretroviral therapy--potential immunomodulatory effects of antioxidants

Oxidative stress has been implicated in the pathogenesis of human immunodeficiency virus (HIV) infection. We examined the effect of highly active antiretroviral therapy (HAART) on plasma levels of several antioxidants and intracellular glutathione-redox status in CD4+ T cells, in 20 HIV-infected patients. HAART was accompanied by both an improvement of glutathione-redox status and an increase in levels of antioxidant vitamins, without full normalization. Glutathione supplementation in vitro increases T cell proliferation and suppresses the spontaneous release of tumor necrosis factor-alpha from peripheral blood mononuclear cells, in HIV-infected patients receiving HAART. Our findings suggest that therapeutic intervention aimed at normalization of oxidative disturbances in HIV infection could be of interest, in addition to HAART.     

Effects of acupuncture on skin and muscle blood flow in healthy subjects

In 14 healthy female subjects, the effects of needle stimulation (acupuncture) on skin and muscle blood flow were investigated using a non-invasive custom-designed probe and photoplethysmography (PPG). In randomised order, 2–7 days apart, three modes of needle stimulation were performed on the anterior aspect of the tibia: superficial insertion (SF), insertion into the anterior tibial muscle (Mu), and insertion into the muscle including manipulation of the needle in order to elicit a distinct sensation of distension, heaviness or numbness (DeQi). Before intervention, the subjects rested for 30 min. After the intervention, the needle was left in situ for 20 min. Blood flow recordings were performed intermittently from 10 min prior to the intervention to the end of the trial. In a fourth session, serving as control, corresponding measurements were performed without any needle stimulation. Area under curve was calculated for 5-min periods prior to and after stimulation, respectively, and for the remaining 15-min period after stimulation. Compared to the control situation, muscle blood flow increased following both Mu and DeQi for 20 min, with the latter being more pronounced for the initial 5 min. Skin blood flow increased for 5 min following DeQi. However, no increase was found following SF. The DeQi stimulation was preceded by higher visual analogue scale ratings of anxiety prior to stimulation, which might have influenced skin blood flow to some extent. The results indicate that the intensity of the needling is of importance, the DeQi stimulation resulting in the most pronounced increase in both skin and muscle blood flow.     

Oxygen radical production in neutrophils interacting with platelets and surface-immobilized plasma proteins: role of tyrosine phosphorylation

The interaction between neutrophil granulocytes and platelets is considered to play an important role in the inflammatory process induced by an implanted foreign material. However, the cellular mechanisms involved remain incompletely understood. We used a luminol-dependent chemiluminescence (CL) technique to analyze the generation of reactive oxygen species (ROS) in human neutrophils interacting with different plasma protein-coated surfaces in the presence or absence of unstimulated or stimulated platelets. The role of tyrosine phosphorylation in the regulation of NADPH oxidase activity was evaluated with quantitative fluorescence microscopy and the specific tyrosine kinase inhibitor genistein. We found that the ROS-production is 2 to 3 times higher in neutrophils on immunoglobulin G (IgG)-coated surfaces than in cells interacting with albumin- or fibrinogen-coated surfaces. Incubation with superoxide dismutase and catalase revealed that about 45% of the ROS was released extracellularly on IgG surfaces whereas corresponding values were 90% and 85% in neutrophils interacting with albumin and fibrinogen, respectively. The presence of platelets markedly increased the extracellular generation of ROS, mainly in neutrophils interacting with IgG- or fibrinogen-coated surfaces whereas the intracellular production was only modestly affected. Quantitative fluorescence microscopy of neutrophils stained with FITC-conjugated anti-phosphotyrosine antibodies showed a correlation between tyrosine phosphorylation, cell spreading, and ROS production. Platelets markedly amplified the anti-phosphotyrosine staining on both fibrinogen- and IgG-coated surfaces whereas the low level of tyrosine phosphorylation in neutrophils on albumin-coated surfaces was not further elevated by platelets. Furthermore, the tyrosine kinase inhibitor genistein inhibited both extra- and intracellular ROS production in neutrophils regardless of the presence of platelets. We demonstrate that plasma protein coating and the presence of platelets are crucial for the inflammatory response of adhering neutrophils and that the oxidative response correlates with the extent of tyrosine phosphorylation of proteins in focal contacts.