Using an electron beam energy scan to characterise a silicon strip telescope Sacco, Donatella; Bulgheroni, Antonio; Risigo, Fabio ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2009, Letnik:
598, Številka:
3
Journal Article
Recenzirano
In 2006, a silicon telescope made of eight planes of strip detectors was exposed to an electron beam with available energies between 154 and 644
MeV. The study of the reconstructed tracks allowed the ...measurement of the effective single plane resolution which includes both intrinsic resolution and multiple scattering effects. A new method to extract the effective spatial resolution, based on the study of the track probability distribution, has been developed. The extrapolation to infinite energy has allowed to compute the intrinsic spatial resolution of the single detector plane. The method has been confirmed by preliminary results obtained with high energy muons at the CERN SPS.
Puberty is a crucial period of life during which dramatic hormonal changes induce notable modifications in linear growth, bone mass and body composition. These changes are associated with variations ...in some biochemical parameters such as markers of bone turnover and leptin, which may reflect changes in bone growth and fat mass, respectively. Children with growth hormone (GH) deficiency have reduced concentrations of bone markers, which increase during GH administration, while the levels of leptin decrease. There have been few studies analysing the behaviour of bone markers during puberty in GH-treated GH-deficient patients and no studies analysing the behaviour of leptin. Results from a longitudinal study showed that there was no change in serum osteocalcin, carboxy-terminal propeptide of type I procollagen, and cross-linked carboxy-terminal telopeptide of type I collagen levels during puberty in GH-treated GH-deficient children. Some studies have shown that changes in markers of bone turnover and leptin after short-term GH treatment may predict the growth response (at 6-12 months) to GH administration in GH-deficient children. At present, insufficient data are available for the clinical use of these parameters as markers of growth response during pubertal development and as predictors of long-term growth response to GH treatment in children with GH deficiency. Nevertheless, the use of more and possibly new markers might improve the accuracy of growth prediction models in the future.
There is limited information on full viral suppression and low-level HIV-RNA viremia in HIV-infected women at the end of pregnancy. We investigated HIV-RNA levels close to delivery in women on ...antiretroviral treatment in order to define rates of complete suppression, low-level viremia, and quantifiable HIV-RNA, exploring as potential determinants some clinical and viroimmunological variables. Plasma samples from a national study in Italy, collected between 2003 and 2012, were used. According to plasma HIV-RNA levels, three groups were defined: full suppression (target not detected), low-level viremia (target detected but <37 copies/ml), and quantifiable HIV-RNA (≥37 copies/ml). Multivariable logistic regression was used to define determinants of full viral suppression and of quantifiable HIV-RNA. Among 107 women evaluated at a median gestational age of 35 weeks, 90 (84.1%) had HIV-RNA <37 copies/ml. Most of them (59/90, 65.6%) had full suppression, with the remaining (31/90, 34.4%) showing low-level viremia (median: 11.9 copies/ml; IQR 7.4-16.3). Among the 17 women with quantifiable viral load, median HIV-RNA was 109 copies/ml (IQR 46-251), with only one case showing resistance (mutation M184V; rate: 9.1%). In multivariable analyses, women with higher baseline HIV-RNA levels and with hepatitis C virus (HCV) coinfection were significantly more likely to have quantifiable HIV-RNA in late pregnancy. Full viral suppression was significantly more likely with nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens and significantly less likely with higher HIV-RNA in early pregnancy. No cases of HIV transmission occurred. In conclusion, HIV-infected pregnant women showed a high rate of viral suppression and a low resistance rate before delivery. In most cases no target HIV-RNA was detected in plasma, suggesting a low risk of subsequent virological rebound and development of resistance. Women with high levels of HIV-RNA in early pregnancy and those who have concomitant HCV infection should be considered at higher risk of having quantifiable HIV-RNA at the end of pregnancy.
Summary Objectives increased incidence of acute coronary events, high rate of abnormal surrogate markers of atherosclerosis and increased amount of coronary calcium have been described in HIV ...infected population. To expand knowledge on coronary artery disease (CAD) in HIV patients, cardiac CT scan was performed in asymptomatic subjects with low cardiovascular (CV) risk. Methods A cross-sectional study using dual-source CT (MDCT) coronary angiography.was conducted in HIV-infected subjects with the following characteristics: Framingham Risk Score (FRS) ≤10, absence of metabolic syndrome, negative echocardiographic and ECG stress-test. A luminal narrowing exceeding 50% was defined as a clinically significant coronary stenosis. Calcium score was quantified using the Agatston Calcium Score method. Results Fifty-five subjects were enrolled. Significant coronary stenoses, requiring coronary angiography, were found in 16/55 (29.1%). At multivariate analysis older age was the only variable independently associated with the presence of significant luminal narrowing ( p = 0.011). Conclusions MDCT showed an unexpected, age-associated high rate of significant coronary stenosis in asymptomatic HIV positive subjects with low CV risk. These findings suggest that aggressive screening programs for coronary artery disease may be appropriate in this population; further studies are recommended to assess the appropriateness of MDCT for this purpose.
Abstract Integrase (IN) defective lentiviral vectors have a high safety profile and might prove useful as immunizing agents especially against HIV-1. However, IN defective SIV-based vectors must be ...developed in order to test their potential in the non-human primate models (NHP) of AIDS. To this aim we tested a novel SIV-based IN defective lentiviral vector for its ability to induce sustained immune responses in mice. BALB/c mice were immunized once intramuscularly with a SIV-based IN defective lentiviral vector expressing the model antigen enhanced green fluorescence protein (eGFP). Immune responses were evaluated 90 days after the injection and compared with those elicited with the IN competent counterpart. The IN defective vector was able to efficiently elicit specific and long-lasting polyfunctional immune responses as evaluated by enzyme-linked immunospot (ELISPOT) assays for interferon-γ (IFN-γ) in spleens, bone marrow (BM) and draining lymph nodes, and by intracellular staining (ICS) for IFN-γ, Interleukin-2 (IL-2) and tumor necrosis factor (TNF-α) in both splenocytes and BM cells without integration of the vector into the host genome. This is the first demonstration that an IN defective SIV-based lentiviral vector provides effective immunization, thus paving the way for the construction of IN defective vectors expressing SIV antigen(s) and test their efficacy against a SIV virus challenge in the NHP model of AIDS.
Degradation and detoxification of textile dyes are of interest due to the huge environmental impact of such chemicals. An isolate of Fusarium oxysporum was used to degrade and to detoxify a new ...chemical class of textile dyes called Glycoconjugate Azo Dye (GAD). After 6d of growth in a liquid batch culture, the fungus degraded the dye and the culture medium at the end of incubation period showed a ˜100% detoxification compared to the initial dye solution. Increasing the initial fungal inoculum, the dye was totally decolourized after 24h of incubation. The degradation ability was found to be common among various isolates of F. oxysporum suggesting this as a specific trait of this species. Degrading rate was enhanced in concomitancy to the glucose depletion and the beginning of the stationary phase of growth, suggesting that the shift from the primary to the secondary metabolism may be the trigger of the degradation pathway. The Daphnia magna acute toxicity test demonstrated a strong detoxification of GAD-4 by F. oxysporum, resulting in non-toxic metabolite production. Fusarium oxysporum could, therefore, be taken into consideration to develop new remediation strategies of textile effluents.
Lumbar bone mineral density (BMD) by dual energy x-ray absorptiometry was assessed in 46 (29 boys, 17 girls) treated patients with growth hormone deficiency (GHD) at final height, comparing the BMD ...results with normative data. Prevalence of fractures in patients during treatment and healthy controls (n = 100) during the corresponding time period was assessed. Lumbar BMD values at final height of fractured and fracture-free patients were compared between them.
Lumbar BMD corrected for bone area was significantly (P < 0.01) reduced (boys, −0.4 ± 0.8 Z score; girls, −0.5 ± 0.7 Z score), but lumbar BMD corrected for bone size (BMDvolume) did not differ P = not significant (NS); boys −0.2 ± 1.0 Z score; girls, −0.3 ± 1.0 Z score from normal mean. Approximately 22% of patients had reduced lumbar BMD (Z score, −1 to −2). The fact that patients had a complete or partial GHD did not influence lumbar BMD.
The prevalence of fractured patients did not differ (P = NS) from that of controls n = 7 (15.2%) and n = 24 (24.0%), respectively; odds ratio, 1.837. Lumbar BMDvolume of fractured patients was significantly (P < 0.02) lower than that of fracture-free (n = 39) patients (boys, 0.310 ± 0.005 and 0.351 ± 0.032 g/cm3, respectively; girls, 0.326 ± 0.027 and 0.382 ± 0.036 g/cm3, respectively). The percentage of the fractured patients with lumbar BMDvolume less than 1 sd of normal mean was significantly (P < 0.0001) higher than that of fracture-free patients n = 6 (85.7%) and n = 4 (10.3%), respectively; odds ratio, 26.092). The fractured patients also showed reduced lumbar BMD corrected for bone area and BMDvolume at the time of fractures (−1.6 ± 0.4 and −1.5 ± 0.2 Z score, respectively).
The results show that treated patients with GHD have normal mean values of lumbar BMDvolume at final height, but some patients have reduced lumbar BMD (Z score <1) with an increased susceptibility to fractures.
Cystic fibrosis (CF) patients present an increased risk of osteoporosis, and increased fracture rate. Several factors have been identified as modulators of bone metabolism and bone mineral density ...(BMD).
To evaluate BMD and serum markers of bone turnover and establish their relationships with serum concentrations of interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF)-alpha, IGF-I, IGF-II, IGF binding protein (IGFBP)-2, IGFBP-3, and parathyroid hormone (PTH) in young adult CF patients.
Seventeen young adult CF patients (4 M, 13 F; mean age: 26.6 +/- 1.1 years) were enrolled in the study and analysed as a whole and as two subgroups according to the Shwachman-Kulczycki score. BMD was assessed at the lumbar spine (L1-L4) by dual energy X-ray absorptiometry (DXA Hologic QDR 2000). Bone turnover was assessed by measuring serum levels of osteocalcin (OC) and serum carboxyterminal propeptide of type I collagen (PICP) as markers of bone formation, and serum cross-linked carboxyterminal telopeptide of type I collagen (ICTP) as a marker of bone resorption. Serum IGFs, IGFBPs, and cytokines were assayed using special commercial kits. Daily calcium intake and weekly physical activity were estimated by questionnaires. Forced expiratory volume in one second was used to assess pulmonary function.
Lumbar BMD was normal, although there was a tendency to be lower in the patients with a lower clinical score. Both OC and PICP were increased, whereas ICTP was normal. Lumbar BMD was positively correlated with pulmonary function. IL-6 and C-reactive protein (markers of inflammation) were inversely correlated with PICP. Serum ICTP levels were correlated with serum IGF-I levels. No significant relationship was detected among lumbar BMD, markers of bone turnover and PTH, IGF-I, IGF-II, IGFBP-2, IGFBP-3, TNF-alpha, IL-1beta, and body mass index Z-score.
Bone turnover is abnormal in CF patients. Young adult CF patients with satisfying clinical status and nutritional conditions have normal BMD and increased serum OC and PICP levels.
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