388 research outputs found
LongË—term obsidian circulation in quebrada del toro (Salta), Northwestern Argentina
Este trabajo describe los resultados de los análisis de fluorescencia de rayos X (XRF) realizados sobre 30 muestras de obsidiana de sitios de Quebrada del Toro (Salta, Argentina), que cubren un lapso de alrededor de 2000 años de ocupación (ca. 2500Ë—500 AP). Establecida la procedencia de las muestras se discuten los patrones de distribución de esta materia prima observados entre los diferentes sitios y perÃodos considerados. Los resultados alcanzados permiten argumentar el uso relativamente sostenido en el tiempo de las canteras de Alto Tocomar, Laguna BlancaË—Zapaleri y OnaË—Las Cuevas (aunque esta última está ausente durante un intervalo de alrededor de 500 años), y algunas variaciones temporales en el uso de fuentes menores. Estos resultados proveen información para discutir el acceso y consumo de obsidianas desde una perspectiva de larga duración. Estas prácticas son evaluadas en el marco de los procesos de cambio ocurridos en el rango cronológico abordado, caracterizados por importantes transformaciones en los sistemas sociopolÃticos y económicos.Fil: de Feo, Maria Eugenia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División ArqueologÃa; ArgentinaFil: Soria, Silvia Susana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta. Instituto de Investigaciones en Ciencias Sociales y Humanidades. Universidad Nacional de Salta. Facultad de Humanidades. Instituto de Investigaciones en Ciencias Sociales y Humanidades; ArgentinaFil: Macoritto Torcivia, Claudia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Salta. Instituto de Investigaciones en Ciencias Sociales y Humanidades. Universidad Nacional de Salta. Facultad de Humanidades. Instituto de Investigaciones en Ciencias Sociales y Humanidades; Argentin
Qualitative and Semiquantitative Parameters of 18F-FDG-PET/CT as Predictors of Malignancy in Patients with Solitary Pulmonary Nodule
This study aims to evaluate the reliability of qualitative and semiquantitative parameters of 18F-FDG PET-CT, and eventually a correlation between them, in predicting the risk of malignancy in patients with solitary pulmonary nodules (SPNs) before the diagnosis of lung cancer. A total of 146 patients were retrospectively studied according to their pre-test probability of malignancy (all patients were intermediate risk), based on radiological features and risk factors, and qualitative and semiquantitative parameters, such as SUVmax, SUVmean, TLG, and MTV, which were obtained from the FDG PET-CT scan of such patients before diagnosis. It has been observed that visual analysis correlates well with the risk of malignancy in patients with SPN; indeed, only 20% of SPNs in which FDG uptake was low or absent were found to be malignant at the cytopathological examination, while 45.45% of SPNs in which FDG uptake was moderate and 90.24% in which FDG uptake was intense were found to be malignant. The same trend was observed evaluating semiquantitative parameters, since increasing values of SUVmax, SUVmean, TLG, and MTV were observed in patients whose cytopathological examination of SPN showed the presence of lung cancer. In particular, in patients whose SPN was neoplastic, we observed a median (MAD) SUVmax of 7.89 (±2.24), median (MAD) SUVmean of 3.76 (±2.59), median (MAD) TLG of 16.36 (±15.87), and a median (MAD) MTV of 3.39 (±2.86). In contrast, in patients whose SPN was non-neoplastic, the SUVmax was 2.24 (±1.73), SUVmean 1.67 (±1.15), TLG 1.63 (±2.33), and MTV 1.20 (±1.20). Optimal cut-offs were drawn for semiquantitative parameters considered predictors of malignancy. Nodule size correlated significantly with FDG uptake intensity and with SUVmax. Finally, age and nodule size proved significant predictors of malignancy. In conclusion, considering the pre-test probability of malignancy, qualitative and semiquantitative parameters can be considered reliable tools in patients with SPN, since cut-offs for SUVmax, SUVmean, TLG, and MTV showed good sensitivity and specificity in predicting malignancy
Radiolabeled dendrimer coated nanoparticles for radionuclide imaging and therapy: a systematic review
Background: Dendrimers are nanoscale-size polymers with a globular structure. They
are composed of an internal core and branching dendrons with surface active groups which can
be functionalized for medical applications. Different complexes have been developed for imaging
and therapeutic purposes. This systematic review aims to summarize the development of newer
dendrimers for oncological applications in nuclear medicine. Methods: An online literature search
was conducted on Pubmed, Scopus, Medline, Cochrane Library, and Web Of Science databases
selecting published studies from January 1999 to December 2022. The accepted studies considered
the synthesis of dendrimer complexes for oncological nuclear medicine imaging and therapy. Results:
111 articles were identified; 69 articles were excluded because they did not satisfy the selection criteria.
Thus, nine duplicate records were removed. The remaining 33 articles were included and selected for
quality assessment. Conclusion: Nanomedicine has led researchers to create novel nanocarriers with
high affinity for the target. Dendrimers represent feasible imaging probes and therapeutic agents
since, through the functionalization of external chemical groups and thanks to the possibility to carry
pharmaceuticals, it can be possible to exploit different therapeutic strategies and develop a useful
weapon for oncological treatments
PET imaging of neuro-inflammation with tracers targeting the translocator protein (TSPO), a systematic review: from bench to bedside
Parkinson’s disease is the second most common neurodegenerative disorder, affecting
2–3% of the population of patients >65 years. Although the standard diagnosis of PD is clinical,
neuroimaging plays a key role in the evaluation of patients who present symptoms related to
neurodegenerative disorders. MRI, DAT-SPECT, and PET with [18F]-FDG are routinely used in the
diagnosis and focus on the investigation of morphological changes, nigrostriatal degeneration or
shifts in glucose metabolism in patients with parkinsonian syndromes. The aim of this study is to
review the current PET radiotracers targeting TSPO, a transmembrane protein that is overexpressed
by microglia in another pathophysiological process associated with neurodegenerative disorders
known as neuroinflammation. To the best of our knowledge, neuroinflammation is present not only
in PD but in many other neurodegenerative disorders, including AD, DLB, and MSA, as well as
atypical parkinsonian syndromes. Therefore, in this study, specific patterns of microglial activation in
PD and the differences in distribution volumes of these radiotracers in patients with PD as compared
to other neurodegenerative disorders are reviewed
Fibroblast activation protein inhibitor (FAPI)-based theranostics-where we are at and where we are heading: a systematic review
Cancer is the leading cause of death around the globe, followed by heart disease and stroke, with the highest mortality to this day. We have reached great levels of understanding of how these various types of cancer operate at a cellular level and this has brought us to what we call "precision medicine" where every diagnostic examination and the therapeutic procedure is tailored to the patient. FAPI is among the new tracers that can be used to assess and treat many types of cancer. The aim of this review was to gather all the known literature on FAPI theranostics. A MEDLINE search was conducted on four web libraries, PUBMED, Cochrane, Scopus, and Web of Sciences. All of the available articles that included both diagnoses and therapy with FAPI tracers were collected and put through the CASP (Critical Appraisal Skills Programme) questionnaire for systematic reviewing. A total of 8 records were deemed suitable for CASP review, ranging from 2018 to November 2022. These studies were put through the CASP diagnostic checklist, in order to assess the goal of the study, diagnostic and reference tests, results, descriptions of the patient sample, and future applications. Sample sizes were heterogeneous, both for size as well as for tumor type. Only one author studied a single type of cancer with FAPI tracers. Progression of disease was the most common outcome, and no relevant collateral effects were noted. Although FAPI theranostics is still in its infancy and lacks solid grounds to be brought into clinical practice, it does not show any collateral effects that prohibit administration to patients, thus far, and has good tolerability profiles
Role of Functional Neuroimaging with 123I-MIBG and 123I-FP-CIT in De Novo Parkinson's Disease: A Multicenter Study
Background: Parkinson's disease is a progressive neurodegenerative disorder, with incidence and prevalence rates of 8-18 per 100,000 people per year and 0.3-1%, respectively. As parkinsonian symptoms do not appear until approximately 50-60% of the nigral DA-releasing neurons have been lost, the impact of routine structural imaging findings is minimal at early stages, making Parkinson's disease an ideal condition for the application of functional imaging techniques. The aim of this multicenter study is to assess whether 123I-FP-CIT (DAT-SPECT), 123I-MIBG (mIBG-scintigraphy) or an association of both exams presents the highest diagnostic accuracy in de novo PD patients. Methods: 288 consecutive patients with suspected diagnoses of Parkinson's disease or non- Parkinson's disease syndromes were analyzed in the present Italian multicenter retrospective study. All subjects were de novo, drug-naive patients and met the inclusion criteria of having undergone both DAT-SPECT and mIBG-scintigraphy within one month of each other. Results: The univariate analysis including age and both mIBG-SPECT and DAT-SPECT parameters showed that the only significant values for predicting Parkinson's disease in our population were eH/M, lH/M, ESS and LSS obtained from mIBG-scintigraphy (p < 0.001). Conclusions: mIBG-scintigraphy shows higher diagnostic accuracy in de novo Parkinson's disease patients than DAT-SPECT, so given the superiority of the MIBG study, the combined use of both exams does not appear to be mandatory in the early phase of Parkinson's disease
Subtle changes in central dopaminergic tone underlie bradykinesia in essential tremor
Introduction: In this research, our primary objective was to explore the correlation between basal ganglia dopaminergic neurotransmission, assessed using 123I-FP-CIT (DAT-SPECT), and finger movements abnormalities in patients with essential tremor (ET) and Parkinson's disease (PD). Methods: We enrolled 16 patients with ET, 17 with PD, and 18 healthy controls (HC). Each participant underwent comprehensive clinical evaluations, kinematic assessments of finger tapping. ET and PD patients underwent DAT-SPECT imaging. The DAT-SPECT scans were subjected to both visual and semi-quantitative analysis using DaTQUANT®. We then investigated the correlations between the clinical, kinematic, and DAT-SPECT data, in patients. Results: Our findings confirm that individuals with ET exhibited slower finger tapping than HC. Visual evaluation of radiotracer uptake in both striata demonstrated normal levels within the ET patient cohort, while PD patients displayed reduced uptake. However, there was notable heterogeneity in the quantification of uptake within the striata among ET patients. Additionally, we found a correlation between the amount of radiotracer uptake in the striatum and movement velocity during finger tapping in patients. Specifically, lower radioligand uptake corresponded to decreased movement velocity (ET: coef. = 0.53, p-adj = 0.03; PD: coef. = 0.59, p-adj = 0.01). Conclusion: The study's findings suggest a potential link between subtle changes in central dopaminergic tone and altered voluntary movement execution, in ET. These results provide further insights into the pathophysiology of ET. However, longitudinal studies are essential to determine whether the slight reduction in dopaminergic tone observed in ET patients represents a distinct subtype of the disease or could serve as a predictor for the clinical progression into PD
The prognostic value of 123I-mIBG SPECT cardiac imaging in heart failure patients: a systematic review
This systematic review aimed to evaluate the prognostic value of Iodine123 Metaiodobenzylguanidine
(123I-mIBG) SPECT myocardial imaging in patients with heart failure (HF) and to
assess whether semi-quantitative SPECT scores can be useful for accurate risk stratification
concerning arrhythmic event (AE) and sudden cardiac death (SCD) in this cohort. A systematic
literature search of studies published until November 2020 regarding the application of 123ImIBG
SPECT in HF patients was performed, in Pubmed, Scopus, Medline, Central (Cochrane
Library) and Web Of Science databases, including the words ‘‘MIBG’’, ‘‘metaiodobenzylguanidine’’,
‘‘heart’’, ‘‘spect’’, and ‘‘tomographic’’. The included studies had to correlate 123ImIBG
SPECT scores with endpoints such as overall survival and prevention ofAE and SCD inHF
patients. According to the sixteen studies included, the analysis showed that 123I-mIBG SPECT
scores, such as summed defect score (SDS), regional wash-out (rWO), and regional myocardial
tracer uptake, could have a reliable prognostic value in patients with HF. An increased SDS or
rWO, as well as a reduced 123I-mIBGmyocardial uptake, have proven to be effective in predicting
AE- and SCD-specific risk in HF patients. Despite achieved results being promising, a more
reproducible standardized method for semi-quantitative analysis and further studies with larger
cohort are needed for 123I-mIBG SPECT myocardial imaging to be as reliable and, thus, accepted
as the conventional 123I-mIBG planar myocardial imaging
PET criteria by cancer type from imaging interpretation to treatment response assessment: beyond FDG PET score
Background: in recent years, the role of positron emission tomography (PET) and
PET/computed tomography (PET/CT) has emerged as a reliable diagnostic tool in a wide variety of
pathological conditions. This review aims to collect and review PET criteria developed for interpretation
and treatment response assessment in cases of non-[18F]fluorodeoxyglucose ([18F]FDG) imaging
in oncology. Methods: A wide literature search of the PubMed/MEDLINE, Scopus and Google
Scholar databases was made to find relevant published articles about non-[18F]FDG PET response
criteria. Results: The comprehensive computer literature search revealed 183 articles. On reviewing
the titles and abstracts, 149 articles were excluded because the reported data were not within the
field of interest. Finally, 34 articles were selected and retrieved in full-text versions. Conclusions:
available criteria are a promising tool for the interpretation of non-FDG PET scans, but also to assess
the response to therapy and therefore to predict the prognosis. However, oriented clinical trials are
needed to clearly evaluate their impact on patient management
Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy
IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical
attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced
colorectal cancers at diagnosis.
OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced
oncologic stage and change in clinical presentation for patients with colorectal cancer.
DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all
17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December
31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period),
in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was
30 days from surgery.
EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery,
palliative procedures, and atypical or segmental resections.
MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer
at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as
cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding,
lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery,
and palliative surgery. The independent association between the pandemic period and the outcomes
was assessed using multivariate random-effects logistic regression, with hospital as the cluster
variable.
RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years)
underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142
(56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was
significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR],
1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic
lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03).
CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the
SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients
undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for
these patients
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