Sequence distribution of poly(ether-sulfone)/poly(ether-ketone) copolymers by mass spectrometry and 13C NMR

The sequence distributions of four poly(ether-sulfone)/poly(ether-ketone) (PES/PEK) copolymer samples were determined by means of fast atom bombardment mass spectrometry (FAB-MS) and by ¹³C NMR spectroscopy. The controlled partial degradation of the copolymer chains to produce oligomers suitable of FAB-MS analysis was performed with sodium methoxide in dimethyl sulfoxide solution at 130°C, and the experimental conditions were optimized. The sequential arrangements of ether-sulfone/ether-ketone units present in these materials were estimated by a best-fit minimization method using the MACO4 computer program which compares the experimental FAB-MS spectral intensities with theoretical intensities. Random PES/PEK copolymer samples showed quite the same sequence arrangements as expected from monomer feed-ratios used in the syntheses. Instead, a PES/PEK copolymer sample expected to be exactly alternating (from the synthesis procedure) showed 44% of random sequences owing to the transetherification reaction which occurred in the synthesis. The results of sequential analysis obtained from ¹³C NMR data compare well with the data obtained by the FAB-MS analysis.     

Characterization of the Ca2+ responses evoked by ATP and other nucleotides in mammalian brain astrocytes

1. This study was aimed at characterizing ATP-induced rises in cytosolic free calcium ion, [Ca²⁺]_i, in a population of rat striatal astrocytes loaded with the fluorescent Ca²⁺ probe Fura2, by means of fluorescence spectrometry.
2. ATP triggered a fast and transient elevation of [Ca²⁺]_i in a concentration-dependent manner. The responses of the purine analogues 2-methylthio-ATP (2-meSATP), adenosine-5′-O-(2-thiodiphosphate) (ADPβS), as well as uridine-5′-triphosphate (UTP) resembled that of ATP, while α,β-methylene-ATP (α,β-meATP) and β,γ-methylene-ATP (β,γ-meATP) were totally ineffective.
3. Suramin (50 μM) had only a minor effect on the ATP response, whereas pyridoxal phosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS) (5 μM) significantly depressed the maximum response.
4. Extracellular Ca²⁺ did not contribute to the observed [Ca²⁺]_i rise: removing calcium from the extracellular medium (with 1 mM EGTA) or blocking its influx by means of either Ni²⁺ (1 mM) or Mn²⁺ (1 mM) did not modify the nucleotide responses.
5. Furthermore, after preincubation with 10 μM thapsigargin, the nucleotide-evoked [Ca²⁺]_i increments were completely abolished. In contrast, 10 mM caffeine did not affect the responses, suggesting that thapsigargin-, but not caffeine/ryanodine-sensitive stores are involved.
6. Both application of the G-protein blocker guanosine-5′-O-(2-thiodiphosphate) (GDPβS) (1 mM) and preincubation with pertussis toxin (PTx) (350 ng ml⁻¹) partially inhibited the nucleotide-mediated responses. Moreover, the phospholipase C (PLC) inhibitor U-73122, but not its inactive stereoisomer U-73343 (5 μM), significantly reduced the ATP-evoked [Ca²⁺]_i rise.
7. In conclusion, our results suggest that, in rat striatal astrocytes, ATP-elicited elevation of [Ca²⁺]_i is due solely to release from intracellular stores and is mediated by a G-protein-linked P2Y receptor, partially sensitive to PTx and coupled to PLC.

     

Image-guided core breast biopsy: a suitable method for preoperative biological characterization of small (pT1) breast carcinomas

Multiple prognostic indicators, namely histological grade and immunostaining for estrogen (ER) and progesterone receptors (PgR), MIB 1, bc1-2, and p53, were retrospectively determined on preoperative core biopsies from 75 patients with pT 1 breast carcinoma. The association of the preoperatively evaluated factors with those on the corresponding resected tumors (i.e. nodal status, histological grade, presence or absence of vascular invasion and necrosis) was assessed. In univariate analysis, histological grade on resected tumors was significantly associated with histological grade on core biopsy, p53 expression, MIB1 immunostaining. An inverse association was found between postoperative histologic grade and ER, PgR, and bc1-2. Necrosis was significantly associated with grade, p53, MIB1, and inversely with ER, PgR, and bc1-2. Nodal involvement and vascular invasion were significantly associated with MIB1. In multivariate analysis, histological grade and ER were the only independent core biopsy variables associated with postoperative histological grade and necrosis, respectively. This study showed that image-guided core biopsy is a suitable method that can be used to reveal some characteristics of the tumor biology in a preoperative stage.     

Impact of hepatitis C virus infection on clinical features, quality of life and survival of patients with lymphoplasmacytoid lymphoma/immunocytoma

Background: The non-Hodgkins lymphoma (NHL) subgroup most frequentlyassociated with hepatitis C virus (HCV) infection is the lymphoplasmacytoidlymphoma/immunocytoma (Lp-Ic). We have assessed the impact of the infectionon the clinical features, quality of life and survival of HCV+ve Lp-Icpatients as compared to its impact in HCV–ve patients.Patients and methods: Seventy patients with Lp-Ic consecutively observedover a six-year period were studied. Clinical, virological andhistopathological features were recorded at diagnosis. Quality of life wasassessed using a scoring system including disease-related symptoms,performance status, working ability, hospital admissions and therapiesrequired.Results: Eighteen patients (26%) with HCV infection wereidentified. Significant differences between those patients and theHCV–ve group included number of symptomatic patients, Hb levels, serumprotein levels, entity of the IgM monoclonal component, number of patientswith cryoglobulins and with organ (liver, kidney) involvement, and entityand pattern of bone marrow infiltration. Survival rates were similar (P =0.8383), but the quality-of-life score was significantly worse for theHCV+ve patients (P = 0.002). All anti-HCV Ab+ve patients tested positive forHCV RNA; genotype 2ac was detected in a significant proportion of cases.Conclusions: This study confirms that HCV infection is present in aboutone-third of patients with Lp-Ic. HCV infection does not seem to affect theoverall survival of patients with Lp-Ic, but it affects the clinicalexpression of the disease, so that the overall quality of life of HCV+vepatients is significantly worse.     

Stress and conflict conditions leading to and maintaining voluntary alcohol consumption in rats

Four experiments were conducted to investigate the effects of unavoidable shock, conflict conditions, taste, and food deprivation on the voluntary consumption of alcohol by rats. Experiment 1 showed that when rats were given unavoidable shocks for one hour every day, those living in their home cages consumed greater amounts of a 5% ethanol solution than did rats living in the shock chambers. Experiment 2 revealed that this increased alcohol consumption was maintained and further elevated when these same rats were subjected to conflict, and it did not decrease when the conflict conditions were terminated. When the unavoidable shock conditions were repeated in Experiment 3 with naive rats and the fluid choice consisted of a plain sucrose solution and one containing alcohol, rats in both the shock box and safety cage living conditions consumed very little of the sucrose-plus-alcohol solution. Rats living in the aversive environment even decreased consumption of the plain sucrose solution. Experiment 4 showed that simple food deprivation can also result in an increased intake of an alcohol solution. The tension reduction hypothesis cannot account for these results: they demonstrate that deprivation can influence alcohol consumption, and indicate that an aversive environment can interfere with drinking of any solution. The results also demonstrate both the positive and negative properties that alcohol can have.     

An Italian matrix sentence test for the evaluation of speech intelligibility in noise

Objective: Development of an Italian matrix sentence test for the assessment of speech intelligibility in noise. Design: The development of the test included the selection, recording, optimization with level adjustment, and evaluation of speech material. The training effect was assessed adaptively during the evaluation measurements with six lists of 20 sentences, using open- and closed-set response formats. Reference data were established for normal-hearing listeners with adaptive measurements. Equivalence of the test lists was investigated using the open-set response format at three signal-to-noise ratios (SNRs). Study sample: A total of 55 normal-hearing Italian mother-tongue listeners. Results: The evaluation measurements at fixed SNRs resulted in a mean speech reception threshold (SRT) of ? 7.3 ± 0.2 dB SNR and slope of 13.3 ± 1.2 %/dB. The major training effect of 1.5 dB was observed for the first two consecutive measurements. Mean SRTs of ? 6.7 ± 0.7 dB SNR and ? 7.4 ± 0.7 dB SNR were found from the third to the sixth adaptive measurement for open- and closed-set test response formats, respectively. Conclusions: A good agreement has been found between the SRTs and slope and those of other matrix tests. Since sentences are difficult to memorize, the Italian matrix test is suitable for repeated measurements.     

Efficacy of cardiac resynchronization therapy in very old patients: the Insync/Insync ICD Italian Registry.

AIMS: To assess the effects of cardiac resynchronization therapy (CRT) in > or =80-year-old patients vs. patients <80 years, in terms of clinical, functional, and echocardiographic parameters after 12 month of CRT, survival, and incidence of arrhythmic events. METHODS AND RESULTS: The study population consisted of 1181 CRT patients (85 were > or =80 years old). They were enrolled in a national observational registry and underwent baseline evaluation and periodical follow-up visits. In the overall population, New York Heart Association class and ejection fraction (EF) improved and ventricular diameters decreased. Similar changes were observed in the two groups. In the study population, 157 patients died, 144 (13%) in the <80 years group and 13 (15%) in the > or =80 years group. There was a higher all-cause mortality (log-rank test, P = 0.015) among > or =80 years patients, with a trend towards higher sudden cardiac death (SCD) (P = 0.057), but similar non-SCD (P = 0.293). Using the combined endpoint of SCD or appropriate shock from a defibrillator for ventricular fibrillation, no significant differences resulted between groups (P = 0.455). In both groups, lower EF was associated with higher mortality. CONCLUSION: Cardiac resynchronization therapy demonstrated similar efficacy in patients aged > or =80 years and in those under 80, in terms of clinical and functional parameters and reverse remodelling. Similarly, CRT resulted in comparable effects on death for heart failure and on SCD.