UVB radiation interrupts cytokine-mediated support of an epidermal-derived dendritic cell line (XS52) by a dual mechanism

We have established long-term dendritic cell lines from the epidermis of newborn mice. These cell lines (XS series) proliferate maximally in response to granulocyte/macrophage-colony stimulating factor, as well as to CSF-1, which is produced by skin-derived NS fibroblast lines and by keratinocytes (albeit in smaller amounts). The purpose of this study was to examine the impact of UVB radiation on CSF-1-mediated interaction of dendritic cells with fibroblasts and keratinocytes. Exposure of NS cells to UVB radiation (unfiltered FS20 sunlamp) decreased CSF-1 production at mRNA and protein levels. Both changes occurred in a dose-dependent fashion, with 50 J/m2 causing a significant reduction. UVB radiation also downregulated CSF-1 mRNA expression by Pam 212 keratinocytes. UVB exposure of XS cells diminished the surface expression of CSF-1 receptors, with 50 J/m2 causing a significant reduction. Thus, UVB radiation interrupts CSF-1-mediated cell-cell interaction by a dual mechanism: downregulating CSF-1 production and abrogating CSF-1 receptor expression. Importantly, granulocyte/macrophage-colony stimulating factor receptor expression by XS cells was also inhibited by UVB radiation, once again, with 50 J/m2 producing significant inhibition. We propose that the resulting CSF-1 deficiency in epidermal microenvironment and unresponsiveness by dendritic cells to relevant growth factors may contribute to UVB-mediated loss of resident epidermal dendritic cells (i.e., Langerhans cells) in skin.     

Characterization of t(11;14) translocation in mantle cell lymphoma by fluorescent in situ hybridization

Characterization of chromosome abnormalities in leukemia and lymphoma have contributed to the understanding of the molecular basis of these neoplastic diseases. In addition, specific chromosomal aberrations have acquired diagnostic or prognostic value. The t(11;14)(q13;q32) chromosome translocation has been detected in mantle cell lymphomas. However, possibly due to the limits of conventional cytogenetic analysis and the presence of different breakpoints at the molecular level, it is possible that the true percentage of association is underestimated. In our study, we used a yeast artificial chromosome, spanning the entire area where the rearrangements occur on chromosome 11q13, to detect the presence of translocations by fluorescent in situ hybridization experiments. We detected BCL-1 translocations in eight of eight patients with clinical and immunological features of mantle cell lymphoma, suggesting that the t(11;14) translocation is a critical event in the pathogenesis of MCL and may be a primary element for the diagnosis. Since this translocation is associated with poor prognosis, its detection may help to make a correct diagnosis as well as to evaluate residual disease, which is critical to plan a rational chemotherapy regimen.     

Lumbosacral movement in the sit-and-reach and in Cailliet's protective-hamstring stretch

STUDY DESIGN: This study analyzed movement characteristics of subjects as they performed two different hamstring stretching activities. OBJECTIVES: The study determined if there were differences in lumbosacral movement as the subjects performed the two stretches. SUMMARY OF BACKGROUND DATA: Cailliet contends that his protective hamstring stretch is less apt to be stressful to the structures of the spine than is a more commonly done sit-and-reach stretching activity. No previous biomechanical investigation has tested his contention. METHODS: Lumbosacral movement was measured with an Ady-Hall lumbar monitor as 40 university students (20 males, 20 females) performed a popular sit-and-reach test and a sit-and-reach test that subscribed to Cailliet's protective hamstring stretch protocol. RESULTS: Lumbosacral movement was almost identical in the two stretching activities. CONCLUSIONS: If lumbosacral movement is the only criterion to consider in evaluating the safety of these two stretching activities, it makes little difference which activity is chosen. If moment of inertia were the dependent variable rather than lumbosacral movement, possibly one activity may be less stressful to the structures of the spine than the other.     

Survival of cylindrical implants in composite grafted maxillary sinuses

PURPOSE: This retrospective study investigated the survival of dental implants placed in the maxilla after composite grafting of the sinus and an average of 55 months of loading. PATIENTS AND METHODS: Maxillary sinuses of 88 patients were grafted with autogenous cancellous bone combined with dense hydroxyapatite particles. After an average healing period of 3.4 months, hydroxyapatite-coated titanium endosseous implants were placed. A total of 388 implants were placed in grafted sinus floors, and 82 were placed in onlay grafted nonsinus position in the canine region. The implants were loaded with overdentures and fixed bridges 4 months (mean) after implantation, with a follow-up for a mean of 55 months. RESULTS: The cumulative implant survival was calculated according to the Kaplan-Meier method. Implant survival from the time of loading was 89% in full reconstructed cases and 90% in partially edentulous cases. The overall cumulative implant survival rate, including the loss in the surgical stage, was 82%. CONCLUSION: Implant loss in composite grafted maxillae after 70 months of follow-up was similar to loss in nongrafted maxillae.     

Ultrasound-guided cryotherapy for retinal tears in patients with vitreous hemorrhage

BACKGROUND AND OBJECTIVE: The goal was to utilize ultrasound-guided cryotherapy as an immediate, low-risk, noninvasive, precise method of treating retinal tears obscured by vitreous hemorrhage. PATIENTS AND METHODS: Eleven patients with sudden onset of vitreous hemorrhage were referred for diagnosis and management. Ophthalmoscopy with scleral depression was unsuccessful at localizing peripheral retinal tears, and all of the patients were examined with ultrasound using the techniques of standardized echography. The cryoprobe was positioned for cryotherapy using both transverse and longitudinal B-scan approaches following the indentation of the globe as it appeared on the oscilloscope. RESULTS: On follow-up examination after the vitreous hemorrhage cleared, 10 of the 11 tears were examined by ophthalmoscopy and were thought to have been adequately treated. One patient had a retinal detachment after remaining stable for 3 months. Two patients were treated with laser to enhance the cryotherapy seal. One patient was observed by another physician and underwent vitrectomy due to vitreous hemorrhage that persisted 2 months following cryotherapy. After vitrectomy, the physician reported a successful cryotherapy reaction at the treated tear. One final patient in the series required vitrectomy and scleral buckle before the hemorrhage had cleared, and the treatment did not appear to be complete. CONCLUSION: Ultrasound-guided cryotherapy provides a noninvasive, inexpensive treatment alternative for retinal tears obscured by vitreous hemorrhage.     

Infection by Mycobacterium tuberculosis promotes human alveolar macrophage apoptosis

The effect of Mycobacterium tuberculosis infection on the viability of healthy (control) human alveolar macrophages was evaluated by staining with ethidium homodimer and calcein to discriminate live from dead cells. Infection with M. tuberculosis H37Ra or H37Rv increased macrophage mortality at 6 days from the control level of 3.8% +/- 0.7% to 28.7% +/- 6.9% or 12.6% +/- 3.1%, respectively (P < 0.001 for comparisons of all conditions). A role for tumor necrosis factor alpha (TNF-alpha) in the M. tuberculosis-induced cytolysis of alveolar macrophages was demonstrated by increased cytotoxicity following the addition of exogenous TNF-alpha to the cultures and by enhancement of macrophage survival when M. tuberculosis-infected alveolar macrophages were treated with pentoxifylline or anti-TNF-alpha antibody. The cytolytic mechanism was determined to be apoptosis by the demonstration of a characteristic internucleosomal ladder of genomic DNA by agarose gel electrophoresis, by finding nuclear fragmentation and condensation by electron microscopy, and by in situ terminal transferase-mediated nick end labeling of fragmented DNA in alveolar macrophages infected with M. tuberculosis in vitro. The latter technique was employed to reveal extensive apoptosis within caseating granulomas from lung tissue samples from clinical tuberculosis cases. The induction of apoptosis in alveolar macrophages by M. tuberculosis may play a role in the macrophage-pathogen interaction of tuberculosis in vivo.     

Oxytocin blocks the development of heroin-enkephalin cross-tolerance in mice

The development of cross-tolerance to an analgesic effect has been observed between a mu-receptor agonist, heroin, and a delta-receptor agonist, Met2-Pro5-enkephalinamide. Repeated treatments with heroin twice a day for 4 days resulted in a decreased nociceptive effect to enkephalin on day 5. The enkephalin dose-response line was shifted to the right, considered a sign of the development of cross-tolerance. Peripheral treatment with oxytocin blocked the development of heroin-enkephalin cross-tolerance. A similar effect was observed after intracerebroventricular administration of oxytocin, supporting our assumption that oxytocin blocks the development of heroin-enkephalin cross-tolerance via CNS mechanisms.