80 research outputs found

    Recognition of Ribosomal RNA Sites in DNA, I. Analysis of the E. coli System

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    The evidence recently presented of specific hybridization between bacterial ribosomal RNA and homologous DNA1-3 has indicated the possibility of a biochemical approach to the problem of the identification of ribosomal RNA sites in DNA. A difficulty in this approach is that while the specific role of the RNA in the hybridization is open to experimental test, the critical evidence of the unique involvement of presumptive DNA sites is not easily attainable

    FORAGING DISTANCE IN THE STINGLESS BEE Trigona thoracica

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    The foraging patterns of stingless bees are dependent on resource availability.Human alterations to natural areas will affect the condition of local habitats,and influence the bees' foraging behavior. In this study, we assessed thefamiliarity of Trigona thoracica with two distinct habitats. This studyinvestigates the familiarity of the stingless bee Trigona thoracica with twodistinct habitats. It has the dual purpose of comparing foraging distancebetween the intact forest and disturbed environments, and of evaluating theidea that bees create memory patterns for navigational purposes en route todestinations. We hypothesized that bees forage more frequently in thenatural environment than in the disturbed environment, and are thereforemore familiar with forested terrain. We also suspect that bees are able toform a visual memory in transport, and that they will integrate cues theyacquire in transition to guide themselves home from unfamiliar locations. Weselected a (medium-sized) colony of Trigona thoracica at the base of a Ficusmicrocarpa tree near the entrance to the Khao Chong Peninsular BotanicGardens. The nest was located in a relatively open area, adjacent to twodistinct environments: a densely wooded forest to the east and an altered,semi-natural environment along a highway to the west. One transect line wasplaced in each of these two areas, and three release points along the transectswere determined using GPS (East - Forest area: 350, 650, 1200m; West -Highway: 400, 800, 1200m).Outgoing bees were collected in plastic bags and tagged with paint markers,Collections ranging in size from sixteen to seventy bees were thentransported in an insect cage to designated release points either on foot or onmotorbike. At each location, two samples (covered and uncovered) werereleased at staggered times. The two transects were completed over thecourse of three days, with a total of twelve releases. On each day we hadsimilar sunny and dry weather conditions. On each day, the nest wasobserved from the first release to at least 1.25 hours after the last release; theactivity of marked bees (entering or exiting the hive) was recorded, as well asthe time of that activity. Percentage returns were calculated for each batch ofmarked bees released from each of the three releasing points on each transect,according to the recorded number of returns for each batch.There was no significant difference between the number of covered anduncovered bees that returned. This leads us to believe that the bees do notform memory when they are artificially transported, which may be due tofactors, which differ between artificial transport and normal flight behavior.Possible factors include the rate of movement, and the height of travel.Additionally, the mesh-and-plastic carrying cage may have skewed the bee'sexposure to sunlight and added an abnormal level of stress for the bee,altering the bee's ability to assess the solar pattern. These factors wouldcontribute to the bee's incapacity to use egocentric methods for homewardnavigation. We found that the bees are more familiar with the natural habitatthan the disturbed habitat. The forage distance was determined to be 3.676km in the forested area and 1.973 km along the highway

    Type 1 Interferon Induction of Natural Killer Cell Gamma Interferon Production for Defense during Lymphocytic Choriomeningitis Virus Infection

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    Natural killer (NK) cells are equipped to innately produce the cytokine gamma interferon (IFN-γ) in part because they basally express high levels of the signal transducer and activator of transcription 4 (STAT4). Type 1 interferons (IFNs) have the potential to activate STAT4 and promote IFN-γ expression, but concurrent induction of elevated STAT1 negatively regulates access to the pathway. As a consequence, it has been difficult to detect type 1 IFN stimulation of NK cell IFN-γ during viral infections in the presence of STAT1 and to understand the evolutionary advantage for maintaining the pathway. The studies reported here evaluated NK cell responses following infections with lymphocytic choriomeningitis virus (LCMV) in the compartment handling the earliest events after infection, the peritoneal cavity. The production of type 1 IFNs, both IFN-α and IFN-β, was shown to be early and of short duration, peaking at 30 h after challenge. NK cell IFN-γ expression was detected with overlapping kinetics and required activating signals delivered through type 1 IFN receptors and STAT4. It took place under conditions of high STAT4 levels but preceded elevated STAT1 expression in NK cells. The IFN-γ response reduced viral burdens. Interestingly, increases in STAT1 were delayed in NK cells compared to other peritoneal exudate cell (PEC) populations. Taken together, the studies demonstrate a novel mechanism for stimulating IFN-γ production and elucidate a biological role for type 1 IFN access to STAT4 in NK cells

    Endoscopic treatment of prepatellar bursitis

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    Operative treatment of prepatellar bursitis is indicated in intractable bursitis. The most common complication of surgical treatment for prepatellar bursitis is skin problems. For traumatic prepatellar bursitis, we propose a protocol of outpatient endoscopic surgery under local anaesthesia. From September 1996 to February 2001, 60 cases of failed nonoperative treatment for prepatellar bursitis were included. The average age was 33.5 ± 11.1 years (range 21–55). The average operation duration was 18 minutes. Two to three mini-arthroscopic portals were used in our series. No sutures or a simple suture was needed for the portals after operation. After follow-up for an average of 36.3 months, all patients are were symptom-free and had regained knee function. None of the population had local tenderness or hypo-aesthesia around their wound. Their radiographic and sonographic examinations showed no recurrence of bursitis. Outpatient arthroscopic bursectomy under local anaesthesia is an effective procedure for the treatment of post-traumatic prepatellar bursitis after failed conservative treatments. Both the cosmetic results and functional results were satisfactory

    In Vitro Study of the Effects of Angiostrongylus cantonensis Larvae Extracts on Apoptosis and Dysfunction in the Blood-Brain Barrier (BBB)

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    It has been hypothesized that blood-brain barrier (BBB) dysfunction in Angiostrongylus cantonensis infection might be due to the apoptosis of the hosts' BBB cells. Here, we evaluated this hypothesis through several methods, all based on an in vitro mouse BBB model consisting of primary culture brain microvascular endothelial cells (BMECs) and brain astrocytic cells (BACs). In the present study, a four-hour percolation and HRP permeability experiment showed that A. cantonensis larvae extracts can increase the permeability of the BBB. Apoptosis among BMECs and BACs after exposure to larvae extracts was monitored by TUNEL and annexin-V-FITC/PI double staining. A. cantonensis larvae extracts were found to induce apoptosis in both BMECs and BACs. For this reason, we concluded that the induction of apoptosis might participate in the BBB dysfunction observed during angiostrongyliasis. Improved fundamental understanding of how A. cantonensis induces apoptosis may lead to new approaches to the treatment or prevention of this parasitic disease

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    Predicting upper airway collapse sites found in drug-induced sleep endoscopy from clinical data and snoring sounds in patients with obstructive sleep apnea: a prospective clinical study

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    STUDY OBJECTIVES: The primary aim was to predict upper airway collapse sites found in drug-induced sleep endoscopy (DISE) from demographic, anthropometric, clinical examination, sleep study, and snoring sound parameters in patients with obstructive sleep apnea (OSA). The secondary aim was to identify the above-mentioned parameters that are associated with complete concentric collapse of the soft palate. METHODS: All patients with OSA who underwent DISE and simultaneous snoring sound recording were enrolled in this study. Demographic, anthropometric, clinical examination (viz., modified Mallampati classification and Friedman tonsil classification), and sleep study parameters were extracted from the polysomnography and DISE reports. Snoring sound parameters during DISE were calculated. RESULTS: One hundred and nineteen patients with OSA (79.8% men; age = 48.1 ± 12.4 years) were included. Increased body mass index was found to be associated with higher probability of oropharyngeal collapse (P < .01; odds ratio = 1.29). Patients with a high Friedman tonsil score were less likely to have tongue base collapse (P < .01; odd ratio = 0.12) and epiglottic collapse (P = .01; odds ratio = 0.20) than those with a low score. A longer duration of snoring events (P = .05; odds ratio = 2.99) was associated with a higher probability of complete concentric collapse of the soft palate. CONCLUSIONS: Within the current patient profile and approach, given that only a limited number of predictors were identified, it does not seem feasible to predict upper airway collapse sites found in DISE from demographic, anthropometric, clinical examination, sleep study, and snoring sound parameters in patients with OSA. CITATION: Huang Z, Bosschieter PFN, Aarab G, et al. Predicting upper airway collapse sites found in drug-induced sleep endoscopy from clinical data and snoring sounds in obstructive sleep apnea patients: a prospective clinical study. J Clin Sleep Med. 2022;18(9):2119-2131
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