A dense ring of the trans-Neptunian object Quaoar outside its Roche limit.

Planetary rings are observed not only around giant planets1, but also around small bodies such as the Centaur Chariklo2 and the dwarf planet Haumea3. Up to now, all known dense rings were located close enough to their parent bodies, being inside the Roche limit, where tidal forces prevent material with reasonable densities from aggregating into a satellite. Here we report observations of an inhomogeneous ring around the trans-Neptunian body (50000) Quaoar. This trans-Neptunian object has an estimated radius4 of 555 km and possesses a roughly 80-km satellite5 (Weywot) that orbits at 24 Quaoar radii6,7. The detected ring orbits at 7.4 radii from the central body, which is well outside Quaoar's classical Roche limit, thus indicating that this limit does not always determine where ring material can survive. Our local collisional simulations show that elastic collisions, based on laboratory experiments8, can maintain a ring far away from the body. Moreover, Quaoar's ring orbits close to the 1/3 spin-orbit resonance9 with Quaoar, a property shared by Chariklo's2,10,11 and Haumea's3 rings, suggesting that this resonance plays a key role in ring confinement for small bodies.

Allogeneic donor split skin grafts for treatment of refractory ulcers in cutaneous chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation-a retrospective analysis on seven patients.

Refractory skin ulcers due to severe chronic graft-versus-host disease (cGVHD) remain to be associated with significant morbidity and mortality.We performed an allogeneic donor skin transplantation in seven adult patients after allogeneic hematopoietic stem cell transplantation for cGVHD-associated refractory skin ulcers. While four patients received a split skin graft (SSG), in one patient, a full thickness skin graft for two small refractory ulcers of the ankle was performed, and one patient received in vitro expanded donor keratinocyte grafts derived from hair roots of the original unrelated donor. In one additional patient, a large deep fascial defect of the lower leg was covered with an autologous greater omentum free graft before coverage with an allogeneic SSG. An additional patient was treated with an autologous scrotal skin graft for a refractory ulcer associated with deep sclerosis of cGVHD after unrelated donor transplantation.All skin grafts engrafted and resulted in permanent coverage of the grafted ulcers without any signs of immunological mediated damage. In the patient receiving in vitro expanded keratinocyte grafts, two localized ulcers were permanently covered by donor skin while this approach failed to cover extensive circular ulcers of the lower legs.Allogeneic donor skin grafts are a valuable treatment option in refractory ulcers due to cGVHD but are restricted mainly to related donors while keratinocyte grafts from unrelated donors remain experimental. In male patients lacking a related donor, autologous scrotal skin graft may be an alternative option.

Altered immune reconstitution of B and T cells precedes the onset of clinical symptoms of chronic graft-versus-host disease and is influenced by the type of onset.

We analyzed lymphocyte subpopulations and cytokines 3 months after allogeneic hematopoietic stem cell transplantation aiming to identify predictive cellular and serum markers for chronic graft-versus-host disease (cGVHD). Samples of 49 patients (pts) (no cGVHD (n = 14), subsequent quiescent onset (n = 16), de novo onset of cGVHD (n = 19)) were analyzed in the absence of active GVHD by flow cytometry and enzyme-linked immunosorbent assay. All mean absolute cell counts are presented as cells per microliter; relative cell counts are presented as percentage of lymphocytes. Pts with subsequent de novo cGVHD had significantly higher relative and absolute counts of CD4+ T cells including higher absolute counts of CD4+ memory T cells (22.36%; 206.55/µl; 136/µl, respectively) compared to pts with subsequent quiescent onset of cGVHD (12.41%; 83.42/µl; 54.3/µl) and pts without cGVHD (10.55%) with regard to relative counts of CD4+ T cells. Similarly, significantly more relative and absolute regulatory T cell numbers (CD4+FOXP3+) were detected in pts with de novo onset of cGVHD (3.08% and 24.63/µl) compared to those in pts without (1.25% and 9.06/µl) or with quiescent onset of cGVHD (1.15% and 6.91/µl). Finally, relative B cell counts, including naïve and memory B cells, were also significantly decreased in pts developing quiescent cGVHD (0.85, 0.73, 0.12% resp.) when compared to pts with de novo onset (5.61, 5.24, 0.38%). The results demonstrate that alterations in immune reconstitution are already present before onset of clinical symptoms and differ between de novo and quiescent onset of disease.

Mesenchymal Stromal Cells Protect Endothelial Cells from Cytotoxic T Lymphocyte-Induced Lysis.

The integrity of the vasculature plays an important role in the success of allogeneic organ and haematopoietic stem cell transplantation. Endothelial cells (EC) have previously been shown to be the target of activated cytotoxic T lymphocytes (CTL) resulting in extensive cell lysis. Mesenchymal stromal cells (MSC) are multipotent cells which can be isolated from multiple sites, each demonstrating immunomodulatory capabilities. They are explored herein for their potential to protect EC from CTL-targeted lysis. CD8(+) T cells isolated from human PBMC were stimulated with mitotically inactive cells of a human microvascular endothelial cell line (CDC/EU.HMEC-1, further referred to as HMEC) for 7 days. Target HMEC were cultured in the presence or absence of MSC for 24 h before exposure to activated allogeneic CTL for 4 h. EC were then analysed for cytotoxic lysis by flow cytometry. Culture of HMEC with MSC in the efferent immune phase (24 h before the assay) led to a decrease in HMEC lysis. This lysis was determined to be MHC Class I restricted linked and further analysis suggested that MSC contact is important in abrogation of lysis, as protection is reduced where MSC are separated in transwell experiments. The efficacy of multiple sources of MSC was also confirmed, and the collaborative effect of MSC and the endothelium protective drug defibrotide were determined, with defibrotide enhancing the protection provided by MSC. These results support the use of MSC as an adjuvant cellular therapeutic in transplant medicine, alone or in conjunction with EC protective agents such as defibrotide.

Extracorporeal photopheresis in 62 patients with acute and chronic GVHD: results of treatment with the COBE Spectra System.

In this retrospective analysis, 30 patients with acute GVHD (aGVHD) and 32 patients with chronic GVHD (cGVHD) treated with extracorporeal photopheresis (ECP) performed by the COBE Spectra System were evaluated. After 3 months of ECP treatment, a CR and PR were observed in 9 (30%) and 6 (20%) patients with aGVHD and in 2 (6%) and 12 (38%) patients with cGVHD. In 16 (53%) patients with aGVHD and 9 (28%) with cGVHD ECP treatment was already stopped after 3 months. One (3%) patient with aGVHD and 7 (22%) patients with cGVHD received new additional immunosuppressive therapy started during the first 3 months of ECP treatment and were classified as 'nonresponder' with regard to ECP. Of these patients a PR was achieved in one patient with aGVHD and in three patients with cGVHD. Steroids could be tapered by 50 in 83% of patients with aGVHD and in 29% of patients with cGVHD after 3 months of ECP treatment. Patients with aGVHD achieving a CR or PR showed a significant improved OS after allo-SCT (P=0.019). ECP is associated with significant response rates and successful reduction of steroids in patients with GVHD.

Vaccination against pandemic H1N1 (2009) in patients after allogeneic hematopoietic stem cell transplantation: a retrospective analysis.

PURPOSE: Limited data are available on immunologic responses to primary pandemic H1N1 (2009) vaccination in recipients of allogeneic hematopoietic stem cell transplantation (HSCT) recipients. In 2009 serologic responses to either pandemic H1N1 (2009) vaccine (n = 36) or pandemic H1N1 (2009) infection (n = 2) were studied in 38 HSCT recipients. METHODS: Responses were measured with a standard hemagglutination-inhibition assay. Fourteen patients had active chronic graft-versus-host disease (cGvHD) at the time of vaccination/infection and seven patients had cGvHD in remission; 11 patients had no immunosuppressive therapy, and 27 patients were on immunosuppressive therapy. Nineteen patients (53%) responded to pandemic H1N1 (2009) vaccination. Two patients had pandemic H1N1 (2009) infection without prior vaccination, and one patient had severe pandemic H1N1 (2009) infection with acute respiratory distress syndrome despite prior single vaccination. RESULTS: Non-responders to pandemic H1N1 (2009) vaccination more often had cGvHD (65 vs. 53%) and received second- or third-line therapy (53 vs. 11%), while responders mostly had first-line therapy for cGvHD. While vaccine responders had no or single agent immunosuppressive therapy, non-responders frequently received moderate or intense immunosuppressive therapy. All vaccine recipients previously treated with rituximab were non-responders. CONCLUSIONS: In summary, the overall response to pandemic H1N1 (2009) vaccination in HSCT recipients was modest. Patients receiving combined immunosuppressive therapy for steroid-refractory cGvHD barely responded to pandemic H1N1 (2009) vaccination.

Longitudinal monitoring of pediatric cystic fibrosis lung disease using nitrite in exhaled breath condensate.

Cystic fibrosis (CF) lung disease is characterized by airway inflammation and airway infection. Nitrites in exhaled breath condensate (EBC-NO(2)(-)) have been shown to be increased in children and adults with CF compared to healthy controls suggesting its use as a measure of airway inflammation. This longitudinal study aimed to evaluate if repeated measurements of EBC-NO(2)(-) are helpful in monitoring CF lung disease activity in children. Thirty-two children with mild CF lung disease (age 10.6 +/- 3.3 years) were recruited in two study centers. Follow-up visits occurred every 3 months over a period of 1 year with a total of five visits. Each visit included a clinical assessment incorporating a modified Shwachman-Kulczycki (SK) score, spirometry, an oropharyngeal swab, or sputum sample for bacterial analysis and an EBC sample analyzed for NO(2)(-) using a spectrophotometric assay. Furthermore at the first and the last visit a chest radiograph was done and scored (Chrispin-Norman (CN) score). There was no correlation of EBC-NO(2)(-) and parameters of spirometry, SK-score, or CN-score. Furthermore, increased EBC-NO(2)(-) levels did not predict subsequent pulmonary exacerbations. We conclude that repeated measurements of EBC-NO(2)(-) are not helpful in the longitudinal monitoring of mild CF lung disease in children.

[Prognosis of the facial profile line using the finite element method]. / Zur Prognose des Profilverlaufes bei interdisziplinären Therapieplanungen mit der Finite-Elemente-Methode.

AIM: The aim of the present study was to verify how realistic the prediction of the clinical appearance of the patient's profile is by using the finite element method to simulate orthodontic and surgical intervention. MATERIAL AND METHOD: This single-case study explains step by step interdisciplinary treatment planning in a case with angle class III. Orthodontic and surgical procedures can be simulated and visualized using the lateral cephalogram and the Onyx Ceph software. The facial profile line is calculated over the skeletal surface using the finite element method. The morphing feature of the Onyx Ceph software is used to create an image of the predicted appearance of the patient's profile using a preoperative lateral photograph. RESULTS: The comparison of the simulated profile and the clinical result after bimaxillary surgery showed high concordance. CONCLUSION: The finite element method represents a useful tool for the prediction of the postoperative appearance in patients undergoing fixed orthodontic appliance and orthognathic surgery.

Fluoride uptake and distribution in enamel and dentin after application of different fluoride solutions.

The aim of this in vitro study was to examine the fluoride accumulation in enamel and dentin after short- and long-term application of four fluoride solutions, including a casein-based fluoride preparation. Cubical enamel and dentin specimens were cut out from extracted, caries-free, human third molars. The buccal surface of each specimen was moistened for 5 min or 24 h with 10 microl of the control or one of the four test solutions Olaflur, Oleaflur, sodium fluoride, or experimental fluoride containing hydrolyzed casein. The specimens were ground in 20- microm steps and the fluoride content was determined in each enamel and dentin layer. After application of the fluoride solutions, significantly more fluoride was associated with the superficial layer up to 20 microm. The values were 3-4 times higher in enamel and 4-8 times higher in dentin after 5-min application time and 10-24 times higher than the initial fluoride content in both hard tooth tissues after 24-h application time. Focusing on the experimental solution, the fluoride levels in enamel and dentin were somewhere in the order of the values of sodium and amine fluoride solutions. However, a tendency towards higher values could be observed after application of the experimental solution.

Role of prostaglandins in regulation of pancreatic enzyme secretion by various diets.

We have demonstrated by the use of isolated rat pancreatic acini that exogenous prostaglandins of the E type inhibit secretagogue-stimulated amylase secretion. We here studied whether the pancreas is a source of prostaglandin synthesis and whether prostaglandins mediate regulation of pancreatic enzyme secretion by various diets. Prostaglandin E2 was measured by enzyme immunoassay in pancreatic acini from either normal animals or after 10 days of feeding with different diets. Acini were prepared by collagenase digestion. Amylase secretion was measured after stimulation with cholecystokinin in the presence or absence of indomethacin, an inhibitor of prostaglandin synthesis. Prostaglandin E2 concentration in pancreatic acini was comparable to other organs such as kidney and liver. Feeding a diet enriched in proteins caused an increase of cholecystokinin-stimulated maximal amylase secretion and a decrease of prostaglandin E2 concentration. Incubation of acini with indomethacin caused a decrease in prostaglandin E2 concentration and an increase in cholecystokinin stimulated amylase secretion. We conclude that regulation of pancreatic enzyme secretion by diets may be mediated by prostaglandins.

Cyclooxygenase-2 transcription is stimulated and amylase secretion is inhibited in pancreatic acinar cells after induction of acute pancreatitis.

Cyclooxygenases as the key enzymes of prostaglandin synthesis have an important role in regulation of inflammation. We describe that Cox-1 and Cox-2 are synthesized in rat pancreatic acinar cells. Upon induction of pancreatitis, Cox-2 mRNA increases while Cox-1 expression remains constant. However, the cyclooxygenase inhibitor indomethacin has no influence by a feed-back mechanism on the expression of the two isoforms. We have previously shown that prostaglandins of the E-type inhibit cholecytoskinin-stimulated amylase secretion. Consistent with this observation, we find here that pancreatitis inhibits CCK-stimulated amylase secretion from isolated acini. In agreement with this result, the effect is neutralized by indomethacin inhibition of prostaglandin synthesis. In summary, we have found that both cyclooxygenases are synthesized in pancreatic acinar cells and that their expression is differentially regulated which in turn influences amylase secretion.

Phenotypic and genetic characterization of the bacteriophage abortive infection mechanism AbiK from Lactococcus lactis.

The natural plasmid pSRQ800 isolated from Lactococcus lactis subsp. lactis W1 conferred strong phage resistance against small isometric phages of the 936 and P335 species when introduced into phage-sensitive L. lactis strains. It had very limited effect on prolate phages of the c2 species. The phage resistance mechanism encoded on pSRQ800 is a temperature-sensitive abortive infection system (Abi). Plasmid pSRQ800 was mapped, and the Abi genetic determinant was localized on a 4.5-kb EcoRI fragment. Cloning and sequencing of the 4.5-kb fragment allowed the identification of two large open reading frames. Deletion mutants showed that only orf1 was needed to produce the Abi phenotype. orf1 (renamed abiK) coded for a predicted protein of 599 amino acids (AbiK) with an estimated molecular size of 71.4 kDa and a pI of 7.98. DNA and protein sequence alignment programs found no significant homology with databases. However, a database query based on amino acid composition suggested that AbiK might be in the same protein family as AbiA. No phage DNA replication nor phage structural protein production was detected in infected AbiK+ L. lactis cells. This system is believed to act at or prior to phage DNA replication. WHen cloned into a high-copy vector, AbiK efficiency increased 100-fold. AbiK provides another powerful tool that can be useful in controlling phages during lactococcal fermentations.

Expression of a Lactococcus lactis Phage Resistance Mechanism by Streptococcus thermophilus.

The 7.8-kb lactococcal plasmid pSRQ700 encodes the LlaII restriction/modification system which recognizes and cleaves the sequence 3(prm1)-GATC-5(prm1). When the plasmid pSRQ700 is introduced into a phage-sensitive Lactococcus lactis strain, strong phage resistance is conferred by the LlaII system. In this report, we show that pSRQ700 cannot replicate in Streptococcus thermophilus. However, if cloned into the vector pNZ123, the native LlaII system is expressed and strong phage resistance is conferred to various industrial S. thermophilus strains. Resistance against phages isolated from yogurt and mozzarella wheys was observed. To our knowledge, this is the first report of increased phage resistance in S. thermophilus.

Failure in school, family conflicts, and psychosomatic disorders in adolescence.

Adolescence is considered to be a transitory phase in the life course. It is hypothesized that failure in school, which carries the risk of an occupational and social "downward mobility" in the future life course in comparison to the family of origin, can function as a social "stressor" which has detrimental effects on the social and emotional climate within the family and manifests itself in symptoms of stress such as psychosomatic disorders. The results are based on a questionnaire survey carried out with a representative sample of 1717 students aged 13-16 in West Germany. The data support the hypotheses: psychosomatic symptom frequency is reinforced when adolescents experience failure in school and social and emotional conflict in their relationships with parents. Multivariate analysis shows that these effects are interconnected: failure in school has a direct effect on the frequency of psychosomatic disorders, and an indirect effect by influencing social and emotional conflicts in the family. The underlying causes for the tensions between adolescents and their parents are conceived in the social and economic opportunity structures of the society.

Explanation of the pseudohypoaldosteronism (PHA)-stress syndrome with an artificial aldosterone receptor model.

A receptor for aldosterone was studied in the cytosol of rectal mucosa of two sisters (M.A., M.B.) with the clinical manifestations of pseudohypoaldosteronism (PHA). Compared to age matched controls the patients showed a decreased affinity for aldosterone (M.A. Kd1: 0.18 nM, Kd2: 4.55 nM; Nmax1: 0.185 fmol/mg cytosol protein (CP), Nmax2: 3.12 fmol/mg CP, respectively). In an attempt to find an explanation for the phenomenon of stress-induced electrolyte imbalance in PHA patients an experimental set up was designed, using aldosterone antibody material as artificial aldosterone receptor. Specific binding was evaluated in addition with and without a 25-100-fold molar excess of dexamethasone (DEX) in order to overcome the glucocorticoid affinity of the aldosterone receptor, a phenomenon proposed to be the cause for the severe consequences of stress in some patients with PHA. The aldosterone antiserum showed two binding sites, similar to the natural receptor (Kd1: 0.15 nM, Kd2: 1.30 nM; Nmax: 30 fmol/mg CP and 130 fmol/mg CP, respectively). Under the influence of DEX the high affinity binding site (Kd1) was occupied by the glucocorticoidanalogon (Kd: 1.30 nM; Nmax: 125 fmol/mg CP). In conclusion, in stress situations, with increased quantities of glucocorticoid circulating, the high affinity binding site of the aldosterone receptor might be occupied by the glucocorticoids, while the low affinity binding site in PHA patients might not have sufficient binding capacity to maintain the electrolyte balance.