16 research outputs found
Accuracy of self-assessment of real-life functioning in schizophrenia
A consensus has not yet been reached regarding the accuracy of people with schizophrenia in self-reporting their real-life functioning. In a large (n=618) cohort of stable, community-dwelling schizophrenia patients we sought to: (1) examine the concordance of patients' reports of their real-life functioning with the reports of their key caregiver; (2) identify which patient characteristics are associated to the differences between patients and informants. Patient-caregiver concordance of the ratings in three Specific Level of Functioning Scale (SLOF) domains (interpersonal relationships, everyday life skills, work skills) was evaluated with matched-pair t tests, the Lin's concordance correlation, Somers' D, and Bland-Altman plots with limits of agreement (LOA). Predictors of the patient-caregiver differences in SLOF ratings were assessed with a linear regression with multivariable fractional polynomials. Patients' self-evaluation of functioning was higher than caregivers' in all the evaluated domains of the SLOF and 17.6% of the patients exceeded the LOA, thus providing a self-evaluation discordant from their key caregivers. The strongest predictors of patient-caregiver discrepancies were caregivers' ratings in each SLOF domain. In clinically stable outpatients with a moderate degree of functional impairment, self-evaluation with the SLOF scale can become a useful, informative and reliable clinical tool to design a tailored rehabilitation program
The interplay among psychopathology, personal resources, context-related factors and real-life functioning in schizophrenia: stability in relationships after 4 years and differences in network structure between recovered and non-recovered patients
Improving real-life functioning is the main goal of the most advanced integrated treatment programs in people with schizophrenia. The Italian Network for Research on Psychoses previously explored, by using network analysis, the interplay among illness-related variables, personal resources, context-related factors and real-life functioning in a large sample of patients with schizophrenia. The same research network has now completed a 4-year follow-up of the original sample. In the present study, we used network analysis to test whether the pattern of relationships among all variables investigated at baseline was similar at follow-up. In addition, we compared the network structure of patients who were classified as recovered at follow-up versus those who did not recover. Six hundred eighteen subjects recruited at baseline could be assessed in the follow-up study. The network structure did not change significantly from baseline to follow-up, and the overall strength of the connections among variables increased slightly, but not significantly. Functional capacity and everyday life skills had a high betweenness and closeness in the network at follow-up, as they had at baseline, while psychopathological variables remained more peripheral. The network structure and connectivity of non-recovered patients were similar to those observed in the whole sample, but very different from those in recovered subjects, in which we found few connections only. These data strongly suggest that tightly coupled symptoms/dysfunctions tend to maintain each other's activation, contributing to poor outcome in schizophrenia. Early and integrated treatment plans, targeting variables with high centrality, might prevent the emergence of self-reinforcing networks of symptoms and dysfunctions in people with schizophrenia
The interplay among psychopathology, personal resources, context-related factors and real-life functioning in schizophrenia: stability in relationships after 4 years and differences in network structure between recovered and non-recovered patients
Improving real-life functioning is the main goal of the most advanced integrated treatment programs in people with schizophrenia. The Italian Network for Research on Psychoses previously explored, by using network analysis, the interplay among illness-related variables, personal resources, context-related factors and real-life functioning in a large sample of patients with schizophrenia. The same research network has now completed a 4-year follow-up of the original sample. In the present study, we used network analysis to test whether the pattern of relationships among all variables investigated at baseline was similar at follow-up. In addition, we compared the network structure of patients who were classified as recovered at follow-up versus those who did not recover. Six hundred eighteen subjects recruited at baseline could be assessed in the follow-up study. The network structure did not change significantly from baseline to follow-up, and the overall strength of the connections among variables increased slightly, but not significantly. Functional capacity and everyday life skills had a high betweenness and closeness in the network at follow-up, as they had at baseline, while psychopathological variables remained more peripheral. The network structure and connectivity of non-recovered patients were similar to those observed in the whole sample, but very different from those in recovered subjects, in which we found few connections only. These data strongly suggest that tightly coupled symptoms/dysfunctions tend to maintain each other's activation, contributing to poor outcome in schizophrenia. Early and integrated treatment plans, targeting variables with high centrality, might prevent the emergence of self-reinforcing networks of symptoms and dysfunctions in people with schizophrenia
The association between insight and depressive symptoms in schizophrenia: Undirected and Bayesian network analyses
Background. Greater levels of insight may be linked with depressive symptoms among patients with schizophrenia, however, it would be useful to characterize this association at symptom-level, in order to inform research on interventions. Methods. Data on depressive symptoms (Calgary Depression Scale for Schizophrenia) and insight (G12 item from the Positive and Negative Syndrome Scale) were obtained from 921 community-dwelling, clinically-stable individuals with a DSM-IV diagnosis of schizophrenia, recruited in a nationwide multicenter study. Network analysis was used to explore the most relevant connections between insight and depressive symptoms, including potential confounders in the model (neurocognitive and social-cognitive functioning, positive, negative and disorganization symptoms, extrapyramidal symptoms, hostility, internalized stigma, and perceived discrimination). Bayesian network analysis was used to estimate a directed acyclic graph (DAG) while investigating the most likely direction of the putative causal association between insight and depression. Results. After adjusting for confounders, better levels of insight were associated with greater self-depreciation, pathological guilt, morning depression and suicidal ideation. No difference in global network structure was detected for socioeconomic status, service engagement or illness severity. The DAG confirmed the presence of an association between greater insight and self-depreciation, suggesting the more probable causal direction was from insight to depressive symptoms. Conclusions. In schizophrenia, better levels of insight may cause self-depreciation and, possibly, other depressive symptoms. Person-centered and narrative psychotherapeutic approaches may be particularly fit to improve patient insight without dampening self-esteem
The induction of cyclic nucleotide phosphodiesterase 4 gene (PDE4D) impairs memory in a water maze task
In this study, the effects on memory of intraperitoneal post-training administration of cyclic nucleotide phosphodiesterase (PDE)
inhibitors, DC-TA 46 and rolipram, were tested using a visible/hidden-platform water maze task. The effects of these compounds on cyclic
nucleotide levels in the hippocampal formation (HF) and striatum (CP) were also assessed, by enzymatic immunoassay (EIA). The results
obtained from rats trained in the visible-platform task were not significantly different from controls. On the contrary, the animals trained in
the hidden-platform water maze task showed a memory impairment, when injected with DC-TA 46 at maximal dose of 20 mg/kg and with
rolipram at 3 and 30 mg/kg doses. The effects of these drugs on cyclic nucleotide levels in HF and CP were observed at 30 min and at 24 h
after drug administration. Thirty minutes after drug injection, we observed an increase of cAMP level, both in HF and in CP. Twenty-four
hours after the retention test, we observed that in CP the cAMP intracellular level remained high, while in the HF at effective doses both
inhibitors induced cAMP PDE activity, determining a decrease of cyclic nucleotide. Semi-quantitative RTâPCR analysis, together with
Western blot immunodetection, showed a mRNA and protein induction of PDE4D PDE isoforms, that may account for the increase of PDE
activity observed. Our data suggest that, despite cyclic nucleotide increase at 30 min, the fundamental event causing memory impairment,
came from the subsequent long time decrease of cAMP levels, due to the post-translational PDE4D induction
Sleep to find your way: The role of sleep in the consolidation of memory for navigation in humans
Although a large body of evidence indicates that sleep plays an important role in learning and memory processes, the actual existence of a sleep-dependent spatial memory consolidation has been not firmly established. Here, by using a computerized 3D virtual navigation tool, we were able to show that topographical orientation in humans largely benefits from sleep after learning, while 10 h of wakefulness during the daytime do not exert similar beneficial effects. In particular, navigation performance enhancement needs sleep in the first post-training night, and no further improvements were seen after a second night of sleep. On the other hand, sleep deprivation hinders any performance enhancement and exerts a proactive disruption of spatial memory consolidation, since recovery sleep do not revert its effects. Spatial memory performance does not benefit from the simple passage of time, and a period of wakefulness between learning and sleep does not seem to have the role of stabilizing memory traces. In conclusion, our results indicate that spatial performance improvement is observed only when learning is followed by a period of sleep, regardless of the retention interval length. (c) 2008 Wiley-Liss, Inc
Vitamin D status as the major factor determining the circulating levels of parathyroid hormone: a study in normal subjects
We investigated the relative contribution of the major factors regulating calcium homeostasis in determining the circulating levels of PTH. We studied 137 males and 125 females who were healthy volunteers. Circulating PTH levels were determined by three different immunoradiometric assays (IRMA). The first one (PTH Sorin, PTH S) utilizes two affinity-purified polyclonal antibodies directed against the 1-34 and 39-84 sequence of the hormone. The two other IRMA share polyclonal anti-PTH (39-84) antibodies. The first assay (PTH Whole, PTH W) utilizes a second polyclonal antibody, directed against the 1-4 amino acid sequence. The second assay (PTH Total, PTH T) utilizes a second antibody specific for the 7-34 region. Concentrations of PTH fragments lacking the initial amino acid sequence (PTH N-truncated, PTH N-t) were determined by the difference of values between PTH T and PTH W. Vitamin D was the main explicative variable almost in every multiple linear regression model, both considering the group as a whole (PTH S: R-2=0.238, P < 0.0001; PTH W: R-2=0.08, P < 0.001; PTH T: R-2=0.145, P < 0.0001; PTH N-t: R-2=0.081, P < 0.009) and when considering men and women separately. In subjects with vitamin D insufficiency (n=53) [25(OH)D < 30 nmol/l], mean serum levels of parathyroid hormone were significantly higher (P < 0.001) than those in subjects of similar age with normal vitamin status (n=209) with all the assays employed. This study demonstrates the central role of 25(OH)D in regulating PTH secretion in physiological conditions
Design, realization, and characterization of a novel diamond detector prototype for FLASH radiotherapy dosimetry
PURPOSE: FLASH radiotherapy (RT) is an emerging technique in which beams with ultraâhigh dose rates (UHâDR) and dose per pulse (UHâDPP) are used. Commercially available active realâtime dosimeters have been shown to be unsuitable in such conditions, due to severe response nonlinearities. In the present study, a novel diamondâbased Schottky diode detector was specifically designed and realized to match the stringent requirements of FLASHâRT. METHODS: A systematic investigation of the main features affecting the diamond response in UHâDPP conditions was carried out. Several diamond Schottky diode detector prototypes with different layouts were produced at Rome Tor Vergata University in cooperation with PTWâFreiburg. Such devices were tested under electron UHâDPP beams. The linearity of the prototypes was investigated up to DPPs of about 26Â Gy/pulse and dose rates of approximately 1Â kGy/s. In addition, percentage depth dose (PDD) measurements were performed in different irradiation conditions. Radiochromic films were used for reference dosimetry. RESULTS: The response linearity of the diamond prototypes was shown to be strongly affected by the size of their active volume as well as by their series resistance. By properly tuning the design layout, the detector response was found to be linear up to at least 20Â Gy/pulse, well into the UHâDPP range conditions. PDD measurements were performed by three different linac applicators, characterized by DPP values at the point of maximum dose of 3.5, 17.2, and 20.6Â Gy/pulse, respectively. The very good superimposition of three curves confirmed the diamond response linearity. It is worth mentioning that UHâDPP irradiation conditions may lead to instantaneous detector currents as high as several mA, thus possibly exceeding the electrometer specifications. This issue was properly addressed in the case of the PTW UNIDOS electrometers. CONCLUSIONS: The results of the present study clearly demonstrate the feasibility of a diamond detector for FLASHâRT applications
Application of a novel diamond detector for commissioning of FLASH radiotherapy electron beams
PURPOSE: A diamond detector prototype was recently proposed by Marinelli et al. (Medical Physics 2022, https://doi.org/10.1002/mp.15473) for applications in ultrahighâdoseâperâpulse (UHâDPP) and ultrahighâdoseârate (UHâDR) beams, as used in FLASH radiotherapy (FLASHâRT). In the present study, such soâcalled flashDiamond (fD) was investigated from the dosimetric point of view, under pulsed electron beam irradiation. It was then used for the commissioning of an ElectronFlash linac (SIT S.p.A., Italy) both in conventional and UHâDPP modalities. METHODS: Detector calibration was performed in reference conditions, under (60)Co and electron beam irradiation. Its response linearity was investigated in UHâDPP conditions. For this purpose, the DPP was varied in the 1.2â11.9 Gy range, by changing either the beam applicator or the pulse duration from 1 to 4 Όs. Dosimetric validation of the fD detector prototype was then performed in conventional modality, by measuring percentage depth dose (PDD) curves, beam profiles, and output factors (OFs). All such measurements were carried out in a motorized water phantom. The obtained results were compared with the ones from commercially available dosimeters, namely, a microDiamond, an Advanced Markus ionization chamber, a silicon diode detector, and EBTâXD GAFchromic films. Finally, the fD detector was used to fully characterize the 7 and 9 MeV UHâDPP electron beams delivered by the ElectronFlash linac. In particular, PDDs, beam profiles, and OFs were measured, for both energies and all the applicators, and compared with the ones from EBTâXD films irradiated in the same experimental conditions. RESULTS: The fD calibration coefficient resulted to be independent from the investigated beam qualities. The detector response was found to be linear in the whole investigated DPP range. A very good agreement was observed among PDDs, beam profiles, and OFs measured by the fD prototype and reference detectors, both in conventional and UHâDPP irradiation modalities. CONCLUSIONS: The fD detector prototype was validated from the dosimetric point of view against several commercial dosimeters in conventional beams. It was proved to be suitable in UHâDPP and UHâDR conditions, for which no other commercial realâtime active detector is available to date. It was shown to be a very useful tool to perform fast and reproducible beam characterizations in standard clinical motorized water phantom setups. All of the previously mentioned demonstrate the suitability of the proposed detector for the commissioning of UHâDR linac beams for preclinical FLASHâRT applications