ABSTRACT
OBJECTIVE: Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) infection may yield a hypercoagulable state with fibrinolysis impairment. We conducted a single-center observational study with the aim of analyzing the coagulation patterns of intensive care unit (ICU) COVID-19 patients with both standard laboratory and viscoelastic tests. The presence of coagulopathy at the onset of the infection and after seven days of systemic anticoagulant therapy was investigated. PATIENTS AND METHODS: Forty consecutive SARS-CoV-2 patients, admitted to the ICU of a University hospital in Italy between 29th February and 30th March 2020 were enrolled in the study, providing they fulfilled the acute respiratory distress syndrome criteria. They received full-dose anticoagulation, including Enoxaparin 0.5 mg·kg-1 subcutaneously twice a day, unfractionated Heparin 7500 units subcutaneously three times daily, or low-intensity Heparin infusion. Thromboelastographic (TEG) and laboratory parameters were measured at admission and after seven days. RESULTS: At baseline, patients showed elevated fibrinogen activity [rTEG-Ang 80.5° (78.7 to 81.5); TEG-ACT 78.5 sec (69.2 to 87.9)] and an increase in the maximum amplitude of clot strength [FF-MA 42.2 mm (30.9 to 49.2)]. No alterations in time of the enzymatic phase of coagulation [CKH-K and CKH-R, 1.1 min (0.85 to 1.3) and 6.6 min (5.2 to 7.5), respectively] were observed. Absent lysis of the clot at 30 minutes (LY30) was observed in all the studied population. Standard coagulation parameters were within the physiological range: [INR 1.09 (1.01 to 1.20), aPTT 34.5 sec (29.7 to 42.2), antithrombin 97.5% (89.5 to 115)]. However, plasma fibrinogen [512.5 mg·dl-1 (303.5 to 605)], and D-dimer levels [1752.5 ng·ml-1 (698.5 to 4434.5)], were persistently increased above the reference range. After seven days of full-dose anticoagulation, average TEG parameters were not different from baseline (rTEG-Ang p = 0.13, TEG-ACT p = 0.58, FF-MA p = 0.24, CK-R p = 0.19, CKH-R p = 0.35), and a persistent increase in white blood cell count, platelet count and D-dimer was observed (white blood cell count p < 0.01, neutrophil count p = 0.02, lymphocyte count p < 0.01, platelet count p = 0.13 < 0.01, D-dimer levels p= 0.02). CONCLUSIONS: SARS-CoV-2 patients with acute respiratory distress syndrome show elevated fibrinogen activity, high D-dimer levels and maximum amplitude of clot strength. Platelet count, fibrinogen, and standard coagulation tests do not indicate a disseminated intravascular coagulation. At seven days, thromboelastographic abnormalities persist despite full-dose anticoagulation.
Subject(s)
Anticoagulants/therapeutic use , Blood Coagulation Disorders/blood , COVID-19/blood , Respiratory Distress Syndrome/blood , Thrombelastography , Aged , Aged, 80 and over , Antithrombins/blood , Blood Coagulation Disorders/drug therapy , Blood Coagulation Tests , Enoxaparin/therapeutic use , Female , Fibrin Fibrinogen Degradation Products/metabolism , Fibrinogen/metabolism , Heparin/therapeutic use , Humans , International Normalized Ratio , Leukocyte Count , Lymphocyte Count , Male , Middle Aged , Neutrophils , Partial Thromboplastin Time , Platelet Count , Prospective Studies , SARS-CoV-2 , Treatment Outcome , COVID-19 Drug TreatmentABSTRACT
Radioprotection of the eye lens of medical staff involved in Surgical procedures is a subject of international debates since ICRP recommended, on 2011, a lower equivalent dose limit for the lens of the eye. In this work we address the effectiveness of different models of X-ray protective eyewear by relating actual dosimetry measurements to an ad hoc developed mathematical model, in order to disentangle the contribution of geometrical factors and shield capabilities. Phantom irradiation was carried out in fixed exposure conditions in angiographic room: we found that measured Dose Reduction Factors (DRF) strongly depend on the ergonomics of the investigated eyewear. Actually a very poor DRF was observed in the case of a glass model in spite of its high nominal attenuation, whereas a protective tool with low shielding capabilities such a visor resulted much more effective as a consequence of is shape (i.e. extended geometric protection of the eye lens). Our work highlights the need of the introduction of a specific parameter to quantify the effectiveness of the protection tools and able to predict their DRF by taking into account the geometry of the clinical condition of exposure. Aiming at making steps forward the standardization of the guidelines concerning the features of eye protective tools, we developed a simple mathematical model describing the eye lens irradiation geometry which allows the introduction, for each eyewear, of a comprehensive parameter, the Eye Protection Effectiveness (EPE), that, for any defined clinical irradiation condition and glass shielding capabilities and shape, defines the overall effective X-ray protection of the eyewear.
Subject(s)
Eye Injuries/prevention & control , Lens, Crystalline/radiation effects , Radiation Injuries/prevention & control , Radiation Protection/methods , Radiography/instrumentation , Eye Protective Devices , Hospitals , Humans , Models, Theoretical , Phantoms, Imaging , Radiation Dosage , Radiation Exposure/prevention & control , Scattering, Radiation , X-RaysABSTRACT
OBJECTIVES: To evaluate the prevalence and therapeutic relevance of drug resistance among isolates from ART-experienced HIV-1-infected patients over the past two decades in Italy. METHODS: Dynamics of resistance to one, two and three or more antiretroviral classes were evaluated from 1999-2018. Virological success (VS) after the latest therapy switch was evaluated according to cumulative class resistance and cumulative genotypic susceptibility score (Stanford HIV_DB algorithm). RESULTS: Among 13 663 isolates (from 6739 patients), resistance to at least one drug class decreased sharply from 1999 to 2010 (≤2001, 84.6%; 2010, 43.6%; P < 0.001), then remained relatively constant at â¼40% during 2010-18, with the proportion of resistance to three or more classes also stable (â¼5%). After 2008, integrase inhibitor resistance slightly increased from 5.6% to 9.7% in 2018 and contributed to resistance, particularly in isolates with resistance to three or more classes (one class, 8.4%; two classes, 15.3%; three or more classes, 34.7%, P < 0.001). Among 1827 failing patients with an available follow-up, by 1 year after genotype-guided therapy start the probability of VS was 87.6%. Patients with cumulative resistance to three or more classes and receiving a poorly active regimen showed the lowest probability (62.6%) of VS (P < 0.001) compared with all other patients (≥81.8%). By Cox regression analysis, cumulative MDR and receiving poorly active antiretroviral regimens were associated with a lower hazard of VS compared with those without resistance. CONCLUSIONS: A dramatic drop of HIV-1 drug resistance at failure has been achieved over the last two decades in Italy; resistance to three or more classes is low but present among currently failing patients. Its management still requires a rational and careful diagnostic and therapeutic approach.
Subject(s)
Anti-HIV Agents , HIV Infections , HIV-1 , Anti-HIV Agents/pharmacology , Anti-HIV Agents/therapeutic use , Antiretroviral Therapy, Highly Active , Drug Resistance, Viral/genetics , Genotype , HIV Infections/drug therapy , HIV Infections/epidemiology , HIV-1/genetics , Humans , Italy/epidemiology , Treatment FailureABSTRACT
Background: Transmitted drug-resistance (TDR) remains a critical aspect for the management of HIV-1-infected individuals. Thus, studying the dynamics of TDR is crucial to optimize HIV care. Methods: In total, 4323 HIV-1 protease/reverse-transcriptase sequences from drug-naive individuals diagnosed in north and central Italy between 2000 and 2014 were analysed. TDR was evaluated over time. Maximum-likelihood and Bayesian phylogenetic trees with bootstrap and Bayesian-probability supports defined transmission clusters. Results: Most individuals were males (80.2%) and Italian (72.1%), with a median (IQR) age of 37 (30-45) years. MSM accounted for 42.2% of cases, followed by heterosexuals (36.4%). Non-B subtype infections accounted for 30.8% of the overall population and increased over time (<2005-14: 19.5%-38.5%, P < 0.0001), particularly among Italians (<2005-14: 6.5%-28.8%, P < 0.0001). TDR prevalence was 8.8% and increased over time in non-B subtypes (<2005-14: 2%-7.1%, P = 0.018). Overall, 467 transmission clusters (involving 1207 individuals; 27.9%) were identified. The prevalence of individuals grouping in transmission clusters increased over time in both B (<2005-14: 12.9%-33.5%, P = 0.001) and non-B subtypes (<2005-14: 18.4%-41.9%, P = 0.006). TDR transmission clusters were 13.3% within the overall cluster observed and dramatically increased in recent years (<2005-14: 14.3%-35.5%, P = 0.005). This recent increase was mainly due to non-B subtype-infected individuals, who were also more frequently involved in large transmission clusters than those infected with a B subtype [median number of individuals in transmission clusters: 7 (IQR 6-19) versus 4 (3-4), P = 0.047]. Conclusions: The epidemiology of HIV transmission changed greatly over time; the increasing number of transmission clusters (sometimes with drug resistance) shows that detection and proper treatment of the multi-transmitters is a major target for controlling HIV spread.
Subject(s)
Drug Resistance, Viral/genetics , HIV Infections/transmission , HIV Infections/virology , HIV-1/drug effects , Adult , Anti-HIV Agents/therapeutic use , Bayes Theorem , Female , Genotype , HIV Infections/drug therapy , HIV Infections/epidemiology , HIV Protease/genetics , HIV Reverse Transcriptase/genetics , HIV-1/classification , Humans , Italy/epidemiology , Male , Middle Aged , Molecular Dynamics Simulation , Phylogeny , PrevalenceABSTRACT
OBJECTIVES: We evaluated the virological response in patients starting a regimen based on darunavir/ritonavir (DRV/r), which is currently the most widely used ritonavir-boosted protease inhibitor. METHODS: Data from 206 drug-naïve and 327 PI-experienced patients starting DRV/r 600/100 mg twice daily (DRV600) or 800/100 mg once daily (DRV800) were examined. The probabilities of virological success (VS) and virological rebound (VR) were evaluated in survival analyses. Baseline DRV/r resistance and its evolution at failure were also examined. RESULTS: DRV600 was preferentially administered in patients with complex requirements (older age, higher viraemia, lower CD4 cell count and DRV/PI resistance) compared with DRV800. By 12 months, the probability of achieving VS was 93.2% and 84.3% in drug-naïve and PI-experienced patients, respectively. The higher the baseline viraemia, the longer was the time required to achieve VS, both in drug-naïve patients [>500 000 HIV-1 RNA copies/mL: median [interquartile range (IQR)] 6.1 (5.1-10.3) months; 100 000-500 000 copies/mL: median (IQR) 4.9 (3.8-6.1) months; <100 000 copies/mL: median (IQR) 3.9 (3.5-4.8) months; P < 0.001] and in PI-experienced patients [≥100 000 copies/mL: median (IQR) 7.2 (5.7-11.6) months; <100 000 copies/mL: median (IQR) 2.8 (2.4-3.3) months; P < 0.001]. In PI-experienced patients, the probability of VR was higher for higher viraemia levels (22.3% for ≥100 000 copies/ml vs. 9.7% for <100 000 copies/mL; P = 0.007). Baseline resistance did not affect the virological response. At failure, a high percentage of patients maintained virus susceptible to all PIs (drug-naïve: 95%; PI-experienced: 80%). Despite being used more often in patients with more complex requirements, DRV600 performed as well as DRV800. CONCLUSIONS: In clinical practice, use of DRV/r (with its flexible dosage) results in high rates of virological response. These data support the use of PI/r in patients whose characteristics require potent drugs with a high genetic barrier.
Subject(s)
Anti-HIV Agents/administration & dosage , Darunavir/administration & dosage , Drug Resistance, Viral , HIV Infections/drug therapy , HIV-1/drug effects , HIV-1/isolation & purification , Viral Load , Adolescent , Adult , Female , HIV Infections/virology , Humans , Male , Middle Aged , Ritonavir/administration & dosage , Treatment Failure , Young AdultABSTRACT
OBJECTIVES: Integrase drug resistance monitoring deserves attention because of the increasing number of patients being treated with integrase strand-transfer inhibitors. Therefore, we evaluated the integrase genotyping success rate at low-level viraemia (LLV, 51-1000 copies/mL) and resistance in raltegravir-failing patients. METHODS: An integrase genotypic resistance test (GRT) was performed on 1734 HIV-1 samples collected during 2006-13. Genotyping success rate was determined according to the following viraemia levels: 51-500, 501-1000, 1001-10â000, 10â001-100â000 and >100â000 copies/mL. The reproducibility of integrase GRT was evaluated in 41 plasma samples processed in duplicate in two reference centres. The relationship between LLV and resistance prevalence was evaluated in a subset of 120 raltegravir-failing patients. RESULTS: Overall, the integrase genotyping success rate was 95.7%. For viraemia levels 51-500 and 501-1000 copies/mL, the rate of success was 82.1% and 94.0%, respectively. GRT was reproducible, producing sequences with a high similarity and an equal resistance profile regardless of the sequencing centre or viraemia level. Resistance was detected both at LLV and at viraemia >1000 copies/mL (51-500 copies/mLâ=â18.2%; 501-1000â=â37.5%; 1001-10â000â=â53.7%; 10â001-100â000â=â30.0%; and >100â000â=â30.8%). At viraemia ≤500 copies/mL, Q148H/K/R and N155H had the same prevalence (9.1%), while the Y143C/H/R was completely absent. At early genotyping (within 3 months of raltegravir treatment), Q148H/K/R and N155H mutations were detected regardless of the viraemia level, while Y143C/H/R was observed only in samples with viraemia >1000 copies/mL. CONCLUSIONS: Our findings prove the reliability of HIV-1 integrase genotyping and reinforce the concept that this assay may be useful in the management of failures even at LLV.
Subject(s)
Genotyping Techniques/methods , HIV Infections/virology , HIV Integrase/genetics , HIV-1/genetics , Microbial Sensitivity Tests/methods , Mutation, Missense , Adult , Female , HIV Infections/drug therapy , HIV-1/isolation & purification , Humans , Male , Middle Aged , Reproducibility of Results , Retrospective Studies , Sensitivity and Specificity , Viral Load , Viremia/virologyABSTRACT
Through this study we evaluated whether the HIV-1 tropism determined by genotypic analysis correlates with HIV-1 markers, such as CD4 cell count and plasma HIV-RNA. The analysis was performed on 1221 HIV-1 B-subtype infected patients with an available V3 sequence (all maraviroc naive). Of them, 532 were antiretroviral therapy (ART) naive and 689 ART experienced. Tropism determination was performed by using the geno2pheno (co-receptor) algorithm set at a false-positive rate (FPR) of 10% and 2%. Potential associations of FPR with CD4 cell count and viraemia were evaluated. Association of V3 mutations with genotypic-determined tropism was also evaluated according to different FPR ranges. About 26% of patients (either ART naive or ART experienced) were infected by X4-tropic viruses (using the classical 10% FPR cut-off). However, a significantly lower proportion of ART-naive patients had FPR ≤ 2% in comparison with ART-experienced patients (4.9% vs. 12.6%, respectively, p <0.001). The risk of advanced HIV-1 infection (with CD4 cell count ≤ 200 cells/mm(3)) was significantly greater in X4-infected patients, either ART-naive (OR (95% CI)), 4.2 (1.8-9.2); p 0.0006) or ART-experienced (2.3 (1.4-3.6); p 0.0003), with FPR set at 2% (but not at 10%). This finding was confirmed by multivariable logistic analysis. No relationship was found between viraemia and FPR ≤2%. Some X4-related mutations were significantly associated with FPR ≤2% (ART-naive patients, S11R, Y21V, G24K and G24R, p ≤0.001; ART-experienced patients, Y7K, S11R, H13Y, p ≤0.002). In conclusion, these findings show that within the context of genotypically-assessed CXCR4 tropism, FPR ≤2% defines (far better than 10%-FPR) a viral population associated with low CD4 rank, with potentially greater cytopathic effect, and with more advanced disease.
Subject(s)
CD4-Positive T-Lymphocytes/virology , False Positive Reactions , HIV Infections/virology , HIV-1/pathogenicity , Receptors, HIV/genetics , Viral Tropism , Virology/methods , Adult , Antiretroviral Therapy, Highly Active/methods , CD4 Lymphocyte Count , Female , HIV Infections/drug therapy , HIV Infections/immunology , Humans , Male , Middle Aged , Receptors, HIV/metabolism , Viral LoadABSTRACT
Presence of drug-resistance mutations in drug-naïve hepatitis B virus (HBV) infected patients can seriously compromise response to antiviral treatment. Therefore, our study was aimed at defining the prevalence of HBV drug-resistance in a population of 140 patients, all infected with HBV-D-genotype (the most common HBV-genotype in Eastern Europe, Mediterranean countries and Middle East) and naïve to antiviral therapy. HBV reverse-transcriptase (RT) region was sequenced and analyzed for 20 mutations, confirmed by in vitro studies as associated with resistance to nucleos(t)ide HBV-RT inhibitors (rtL80I/V-rtI169T-rtV173L-rtL180M-rtA181T/V/S-rtT184A/S/G/C-rtA194T-rtS202C/G/I-rtM204V/I-rtN236T-rtM250V). Amino acid changes at other six RT positions, potentially associated with resistance, were also analyzed (rtV84M-rtV191I-rtV207L-rtV214A-rtQ215S-rtI233V). Overall, only 2/140 (1.4%) patients carried primary drug-resistance mutations [rtA181V (0.7%), and rtA194T (0.7%)], while 3/140 (2.1%) patients harbored the secondary mutations rtV173L (1.4%) and rtL180M (0.7%). Additionally, five polymorphic mutations, with a suggested role in drug resistance, were detected [rtQ215S (12.8%), rtI233V (4.3%), rtV214A (3.6%), rtV191I (0.7%), rtV207L (0.7%)]. Notably, no YMDD mutations, namely rtM204V/I, were found. Taken together, the rate of important drug resistance mutations in naïve HBV D-genotype infected patients is today very low, and suggests the potential full efficacy of new-generation antiviral drugs used in first line therapy. Whether such low rate can be extrapolated to non HBV-D subtypes, requires a detailed investigation to be performed in a different cohort of patients.
Subject(s)
Antiviral Agents/pharmacology , Drug Resistance, Viral , Hepatitis B virus/drug effects , Hepatitis B virus/isolation & purification , Hepatitis B, Chronic/virology , Mutation, Missense , Adult , Amino Acid Substitution , DNA Mutational Analysis , DNA, Viral/chemistry , DNA, Viral/genetics , Europe, Eastern , Genotype , Hepatitis B virus/classification , Hepatitis B virus/genetics , Humans , Mediterranean Region , Middle Aged , Middle East , Molecular Sequence Data , Prevalence , RNA-Directed DNA Polymerase/genetics , Sequence Analysis, DNA , Viral Proteins/geneticsABSTRACT
Most commercial HIV-1 genotyping assays are hampered by high cost in resource-limited settings. Moreover, their performance might be influenced over time by HIV genetic heterogeneity and evolution. An in-house genotyping protocol was developed, and its sequencing performance and reproducibility were compared to that of ViroSeq™. One hundred ninety plasma samples from HIV-1-infected subjects in Cameroon, a resource-limited setting with a high HIV genetic variability, were processed for pol gene sequencing with an in-house protocol, ViroSeq™, or both. Only non-B subtypes were found. The in-house sequencing performance was 98.7% against 92.1% with ViroSeq™. Among 36 sequence pairs obtained using both assays, the overall rate of discordant amino acid positions was negligible (0.24%). With its high sensitivity and reproducibility, as well as its affordable cost (about half of ViroSeq™: 92 euros vs. 217 euros), this in-house assay is a suitable alternative for HIV-1 genotyping in resource-limited and/or in high-genetic-diversity settings.
Subject(s)
Genetic Techniques , HIV Infections/virology , HIV Reverse Transcriptase/genetics , HIV-1/genetics , HIV-1/isolation & purification , Adult , Aged , Cameroon/epidemiology , Female , Genotype , HIV-1/classification , HIV-1/enzymology , Humans , Male , Middle Aged , Molecular Sequence Data , PhylogenyABSTRACT
BACKGROUND: The use of biomarkers has been demonstrated useful in many acute diseases both for diagnosis, prognosis and risk stratification. OBJECTIVES: The purpose of this review is to analyze several biomarkers of potential use in patients referring to Emergency Department with acute dyspnea. STATE OF THE ART: The role of natriuretic peptides has a proven utility in the diagnosis, risk stratification, patient management and prediction of outcome in acute and chronic heart failure (HF). New immunoassays are available for the detection of mid-region prohormones in patients with acute dyspnea such as Mid-region pro-adrenomedullin (MR-proADM) and Mid-region pro-atrial natriuretic peptide (MR-proANP). Also procalcitonin, copeptin and D-dimer, which are markers of inflammation, bacterial infections and sepsis, seem to be useful in the differential diagnosis of dyspnea. Conventional and high-sensitivity troponins are fundamental, not only in the diagnosis of acute coronary syndromes, but also as indicators of mortality in patients with acute decompensated heart failure. PERSPECTIVES: Further studies with randomized controlled clinical trials will be needed to prove the theoretical clinical advantages offered by a shortness of breath biomarkers in terms of diagnostic, prognostic, cost effective work-up and management of patients with acute dyspnea. CONCLUSIONS: A multimarker pannel approach performed by rapid and accurate assays could be useful for emergency physicians to promptly identify different causes of dyspnea thus managing to improve diagnosis, treatment and risk stratification.
Subject(s)
Biomarkers/blood , Dyspnea/diagnosis , Acute Disease , Adrenomedullin/blood , Atrial Natriuretic Factor/blood , Calcitonin/blood , Calcitonin Gene-Related Peptide , Dyspnea/blood , Fibrin Fibrinogen Degradation Products/analysis , Humans , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Protein Precursors/blood , Troponin T/bloodABSTRACT
BACKGROUND: Treatment guidelines for multi-experienced HIV patients have recently evolved from aiming to preserve immunity to achieving virological success, largely due to the availability of new antiretroviral drugs and drug classes. To assess the role of viral suppression on clinical progression following a genotypic resistance test (GRT), we have examined a database on patients failing to respond to combined antiretroviral therapy (cART). METHODS: Patients undergoing a GRT after failure to respond to cART between January 1999 and May 2006 were followed up to December 2006. Time-to-death or a new AIDS event/death were considered to be analysis end-points. Viral suppression (< 50 copies/ml [c/ml]) after GRT, a time-dependent covariate, was tested as predictor of disease progression. RESULTS: Overall, 1,389 patients were included in this observational study. After the GRT, patients were followed up to 72 months (median 28 months, IQ range 13-51 months). During the follow-up, 124 patients (9%) died, and 86 (6%) experienced a new AIDS event. 774 patients (56%) achieved < 50 c/ml HIV-RNA. The results of an adjusted Cox model showed that undetectable HIV-RNA after the GRT was significantly associated with a lower risk of death (hazard ration [HR] 0.46, 95% confidence interval [CI] 0.27-0.76) and AIDS/death (HR 0.43, 95% CI 0.28-0.65). The adjusted hazard ratios suggested a twofold risk reduction. A threefold risk reduction of death related to achieved undetectable viral load was found in patients with resistance to more than one drug class and with CDC-C diagnosis; a fourfold reduction was found in patients with < 200 CD4+/mm(3). CONCLUSIONS: Maximal viral suppression has a large impact on HIV progression, particularly in heavily pre-treated individuals. Our findings support the latest treatment guidelines, which have rapidly evolved from an initial lack of indication to suggestions, and finally to strong recommendations for achieving the goal of suppressing viremia.
Subject(s)
Anti-HIV Agents/therapeutic use , Anti-Retroviral Agents/therapeutic use , Drug Resistance, Viral/genetics , HIV Infections/drug therapy , HIV-1/genetics , Viremia/drug therapy , Adult , Antiretroviral Therapy, Highly Active , Cohort Studies , Disease Progression , Drug Resistance, Multiple, Viral/genetics , Female , Genotype , HIV Infections/mortality , HIV Infections/virology , HIV-1/drug effects , Humans , Italy , Longitudinal Studies , Male , Retrospective Studies , Treatment Failure , Viral Load , Viremia/mortality , Viremia/virologyABSTRACT
The purpose of this study was to evaluate and compare the physical characteristics of five clinical systems for digital mammography (GE Senographe 2000D, Lorad Selenia M-IV, Fischer Senoscan, Agfa DM 1000, and IMS Giotto) currently in clinical use. The basic performances of the mammography systems tested were assessed on the basis of response curve, modulation transfer function (MTF), noise power spectrum, noise equivalent quanta (NEQ), and detective quantum efficiency (DQE) in an experimental setting closely resembling the clinical one. As expected, all the full field digital mammography systems show a linear response curve over a dynamic range from 3.5 to 500 microGy (0.998Subject(s)
Mammography
, Radiographic Image Enhancement
, Humans
, Quality Control
, Radiographic Image Interpretation, Computer-Assisted
, Reproducibility of Results
, Sensitivity and Specificity
ABSTRACT
Phototimer set-up is a critical procedure for dose and image quality optimisation in computed radiography (CR) systems. While a conventional radiography automatic exposure control device (AEC) can be calibrated in order to gain a constant optical density on the film independent of beam quality and patient size, CR detectors present a high dynamic range which allows a much larger dose interval, but with different image quality levels. CR leads to a less frequent exam repetition, but may produce quite noisy images if the exposure level on the plate is not correct. The aim of this work is to evaluate the performance of a CR plate (Agfa MD40) in order to optimally calibrate an AEC device. The plate response has been characterised in terms of digital signal, exposure on the plate and signal-to-noise ratio for different beam qualities, in a patient of standard size.
Subject(s)
Phosphorus/chemistry , Radiographic Image Enhancement/methods , Radiographic Image Interpretation, Computer-Assisted/methods , Radiography/instrumentation , Radiography/methods , X-Ray Film , X-Ray Intensifying Screens , Calibration , Dose-Response Relationship, Radiation , Humans , Light , Radiation Dosage , Radiographic Image Enhancement/instrumentation , Radiographic Image Interpretation, Computer-Assisted/instrumentation , Technology, RadiologicABSTRACT
The evaluation of resistance test perception by clinicians over the years 1999--2003 was assessed in an Italian cohort. The results on 2233 samples from 1416 HIV-1 infected patients show an increase in HIV-1 drug resistance test requests over time, with a plateau reached in the last three years. CD4-cell count at the time of genotype request progressively increased. In particular, the median CD4 cell count of drug-treated patients increased from 221x10(6) cells/l [interquartile range (IQR): 109-368] in 1999 to 296x10(6) cells/l (IQR: 166-478) in 2003 (p<0.0001). At the same time, plasma HIV-RNA level progressively decreased from a median of 103,500 copies/ml (IQR: 37,250-260,000) in 1999 to 9,444 copies/ml (IQR: 2,086-41,281) in 2003 (p<0.0001). Overall, data suggest that the genotype test is increasingly considered, and requested also for patients at earlier stages of drug history and/or at less severe disease stage.
Subject(s)
Anti-HIV Agents/pharmacology , Drug Monitoring , Drug Resistance, Viral/genetics , HIV Infections/virology , HIV-1/drug effects , HIV-1/genetics , CD4 Lymphocyte Count , Drug Monitoring/methods , Drug Monitoring/trends , Genotype , HIV Infections/drug therapy , HIV-1/isolation & purification , Humans , ViremiaABSTRACT
The European Council Directive 97/43 introduces diagnostic reference levels (DRL) for all medical examinations involving ionising radiation. Each department has to evaluate patient dose and to compare that value with the DRL adopted by its member state. Italian law, applying the Directive, states that reference levels must be measured every 2 years. Quantities that must be measured are entrance surface dose or air kerma, or other dosimetric quantities. In our work, clinical measurements on patients were made by positioning a thermoluminescence dosemeter (TLD) over the skin of a statistically significant number of patients for each projection of each examination. As there is no national guideline for these measurements in Italy, the aim of this work was to establish a method based both on European publications and on clinical experience. Three different modalities were considered: conventional radiography, computed radiography and mammography. Accordingly, differently shaped types of TLD were required, especially for mammography where the beam energy is lower.
Subject(s)
Radiology/methods , Thermoluminescent Dosimetry , Automation , Humans , Reproducibility of Results , Thermoluminescent Dosimetry/methodsABSTRACT
We report the case of a woman with axonal sensory and autonomic neuropathy lasting several months who improved in association with steroid administration. During the course of her disease and in the follow-up, the patient underwent repeated cerebrospinal fluid (CSF) examinations, neurophysiological somatic, autonomic nervous system studies and sural nerve biopsy. Clinical and laboratory assessments demonstrated the occurrence of a monophasic, chronic sensory and autonomic neuropathy. A sural nerve biopsy suggested an axonopathy. After a progressive worsening of symptoms lasting about 6 months, steroid treatment was started and within 6 months a complete recovery, with normalization of the CSF findings, was observed. Although the 'chronic inflammatory neuropathies' are still debated entities, the features of this chronic, exclusively sensory and autonomic neuropathy are new, and the occurrence of a high protein level in the CSF, together with the favorable outcome associated with steroid treatment, suggests that our case might be another variant in this debated area.
Subject(s)
Autonomic Nervous System Diseases/pathology , Axons/pathology , Peripheral Nerves/pathology , Polyneuropathies/pathology , Sensation Disorders/pathology , Autonomic Nervous System Diseases/drug therapy , Axons/drug effects , Biopsy , Chronic Disease , Female , Humans , Inflammation/drug therapy , Middle Aged , Peripheral Nerves/drug effects , Peripheral Nerves/physiopathology , Polyneuropathies/drug therapy , Prednisone/administration & dosage , Sensation Disorders/drug therapySubject(s)
Humans , Male , Female , Middle Aged , Brain Ischemia/drug therapy , Streptokinase/adverse effects , Streptokinase/therapeutic use , Calcium Channel Blockers/therapeutic use , Nimodipine/therapeutic use , Brain Ischemia/epidemiology , Acute Disease , Clinical Trials as Topic , Clinical Trials as Topic/trends , Fibrinolytic Agents/adverse effects , Fibrinolytic Agents/therapeutic use , Gangliosides/therapeutic useABSTRACT
Heart rate (HR) variability is a noninvasive index of the neural activity of the heart. Although also dependent on the sympathetic activity of the heart, HR variability is mainly determined by the vagal outflow of the heart. Several HR abnormalities have been described in patients with congestive heart failure (CHF); however, there are no data on HR variability in CHF patients. In the present study HR variability was assessed in 20 CHF patients and 20 control subjects from 24-hour Holter tapes. HR variability was evaluated by calculating the mean hourly HR standard deviation and by analyzing the 24-hour RR histogram. Mean hourly HR standard deviation was markedly and significantly reduced in CHF patients both over the 24-hour period (97.5 +/- 41 vs 233.2 +/- 26 ms, p less than 0.001) as well as during most of the individual hours examined. The 24-hour RR histogram of CHF patients had a different shape and had a decreased variation compared to control subjects (total variability 356 +/- 102 vs 757 +/- 156 ms, p less than 0.001). Thus, CHF patients with depressed ejection fraction (less than 30%) have a low HR variability compared to normal individuals. This result can be interpreted as adjunctive evidence for decreased parasympathetic activity to the heart during CHF.