Stress exposure modulates peptidergic innervation and degranulates mast cells in murine skin

Stress is said to induce itchiness of the skin, exacerbate inflammatory skin diseases, and inhibit wound healing. Neuropeptides such as substance P (SP) may play a role in these processes. Recently, we were able to show that both stress or SP are associated with neurogenic inflammation and increased apoptosis in the murine hair follicle. Moreover, peptidergic cutaneous innervation is subject to lifelong plasticity due to its association with the cyclic growth of hair follicles. However, peripheral neuronal plasticity has never been reported in altered interactions between the nervous and immune systems under perceived stress. Here, we show for the first time plasticity of the cutaneous peptidergic innervation in response to stress. After exposure to sonic stress, the number of SP+ nerve fibers in the back skin of C57BL/6 mice with their hair follicles in the resting phase of the hair cycle (telogen-low numbers of nerve fibers) increased significantly. Such nerve fibers contacted mast cells more frequently. At the same time, the percentage of degranulated mast cells increased significantly associated with a rise in apoptotic cells in the skin. Increased numbers of peptidergic nerve fibers correlated with increased numbers of growth-associated protein 43 (Gap-43)+ nerve fibers, which is a marker for growing nerves. Thus, neuronal plasticity and increased neuro-immune interaction occur under stress and may alter inflammatory skin diseases and trophic functions in the skin where neurogenic inflammation plays a part.     

Current challenges and concepts in the preparation of root canal systems: a review

Nickel-titanium rotary instruments are important adjuncts in endodontic therapy. This review attempts to identify factors that influence shaping outcomes with these files, such as preoperative root-canal anatomy and instrument tip design. Other, less significant factors include operator experience, rotational speed, and specific instrument sequence. Implications of various working length definitions and desired apical widths are correlated with clinical results.Despite the existence of one ever-present risk factor, dental anatomy, shaping outcomes with nickel-titanium rotary instruments are mostly predictable. Current evidence indicates that wider apical preparations are feasible. Nickel-titanium rotary instruments require a preclinical training period to minimize separation risks and should be used to case-related working lengths and apical widths. However, and despite superior in vitro results, randomized, clinical trials are required to evaluate outcomes when using nickel-titanium instruments.     

Hematopoietic stem cell transplantation for mucopolysaccharidoses and leukodystrophies

The only effective treatment for selected metabolic diseases is a successful allogeneic hematopoietic stem cell transplantation (HCT). Best results with HCT are obtained when performed early in the course of the disease. Hence, timely identification and referral are critical. Also, early identification of affected patients during the newborn period via screening may be invaluable, particularly for the infantile onset rapidly progressive forms of diseases. Rapid availability of a donor graft is often crucial for these patients. Preliminary experience suggests that results after umbilical cord blood (UCB) transplant may be comparable to those after marrow transplants. UCB grafts have certain benefits of rapid availability and even reduced risk of GvHD. Hence, UCB transplant represents an alternative to marrow HCT. Related haploidentical HCT, possibly with very high doses of CD34+ cells, may also represent an option. However, expertise has been developed in very few transplant centers and no large reports are available of its use for patients with inherited metabolic diseases.     

Issues arising from the prenatal diagnosis of some rare trisomy mosaics--the importance of cryptic fetal mosaicism

OBJECTIVES: To add to the knowledge of fetal mosaicism, confined placental mosaicism (CPM), and uniparental disomy (UPD), in rare trisomies detected at prenatal diagnosis. METHODS: The origin of rare trisomy mosaics, mostly (8/11) seen in amniocytes, was examined in 11 cases by follow-up karyotyping and the study of microsatellite inheritance. RESULTS: Of the rare trisomies presented, three were mosaic trisomy 16 (two of which were CPM), and the remainder comprised single cases of mosaic trisomies of 8, 9, 10, 11, 12, 14, 5 and 15--the last two being CPM. Cases varied in parental derivation and meiotic versus post-zygotic origin but no case involved UPD. There was evidence for cryptic fetal mosaicism in three cases (5, 7, 11)--involving chromosomes 11, 14 and 16. CONCLUSIONS: These cases contribute further data to phenotypes associated with rare trisomies and the relative influences on the phenotype of CPM, UPD and fetal mosaicism. From sparse published data, we estimate that approximately 10% of apparent CPM cases for a rare trisomy (i.e. aneuploid CVS, normal amniocytes) may actually be cryptic fetal mosaics undetected in cultured amniocytes. In many cases, this cryptic mosaicism may be of limited clinical significance, but in others, the associated phenotypic effects may be obvious. There is no general approach to resolve this issue; the finding of even a few similar aneuploid cells in different amniocyte culture vessels may be clinically significant. It may be useful to study such an amniocyte culture with FISH with the relevant centromeric probe. Careful follow-up is recommended, particularly for infants where apparent correction of autosomal trisomy has occurred.     

Psychological effects of occupational exposure to organic solvent mixtures on printers

PURPOSE: Neuropsychiatric symptoms associated with long-term exposure to organic solvents have been investigated for a long time in many occupational studies. The aim of our study was to identify preclinical effects of low-level chronic solvent exposure on the cognitive performance of silk-screen printers. METHODS: A cross-sectional study was conducted including 38 printers which were exposed to organic solvent mixtures and 45 controls without neurotoxic exposure. The psychometric test battery included nine tests and two questionnaires. RESULTS: The sum of scales or the total score of the PNF was also significantly (p <0.001) higher in the exposed group than in the non-exposed. The printers performed worse in some psychometric tests than did controls. Cross validation with the psychometric performances resulted in 69.6% of participants being correctly classified (55.9% printers and 80% controls). Highly significant differences (p<0.001) between both groups of exposed and non-exposed workers were found for the mean values of the multidimensional psychometric score. CONCLUSIONS: These results of our study proved not only that chronic exposure to organic solvent mixtures could induce a psychological effect but also that the psychological/psychometrical tests performed in this study were capable of predicting neurotoxicity.