2,184 research outputs found
Abnormal phosphomonoester signals in 31P MR spectra from patients with hepatic lymphoma. A possible marker of liver infiltration and response to chemotherapy.
Hepatic infiltration by lymphoma can be difficult to detect by conventional methods. We have studied 22 patients in vivo 31P magnetic resonance spectroscopy of the liver and compared the results with the clinical staging and assessment of liver involvement by computed tomography (CT), ultrasound (US), and liver function tests (LFTs). We find that the phosphomonoester (PME) to ATP, and the PME to Pi ratios are the best indication of liver involvement as in all the patients with liver involvement apparent on CT or US, these ratios were elevated (greater than 2 s.d. above the control mean). Of the patients with deranged LFTs but normal CT or US, five out of nine showed increased PME/ATP and PME/Pi ratios, and in the patients with normal LFTs and normal CT or US, three out of eight patients had raised PME ratios. Extracts of lymphomatous lymph nodes contain high concentrations of phosphoethanolamine which suggests that this compound is responsible for the increase in the PME peak. Eleven patients were studied again after chemotherapy, and those with initially raised PME/ATP and PME/Pi ratios all showed a decrease in these ratios towards normal. The patients with initially normal ratios showed no changes
Functional network changes and cognitive control in schizophrenia
Cognitive control is a cognitive and neural mechanism that contributes to managing the complex demands of day-to-day life. Studies have suggested that functional impairments in cognitive control associated brain circuitry contribute to a broad range of higher cognitive deficits in schizophrenia. To examine this issue, we assessed functional connectivity networks in healthy adults and individuals with schizophrenia performing tasks from two distinct cognitive domains that varied in demands for cognitive control, the RiSE episodic memory task and DPX goal maintenance task. We characterized general and cognitive control-specific effects of schizophrenia on functional connectivity within an expanded frontal parietal network (FPN) and quantified network topology properties using graph analysis. Using the network based statistic (NBS), we observed greater network functional connectivity in cognitive control demanding conditions during both tasks in both groups in the FPN, and demonstrated cognitive control FPN specificity against a task independent auditory network. NBS analyses also revealed widespread connectivity deficits in schizophrenia patients across all tasks. Furthermore, quantitative changes in network topology associated with diagnostic status and task demand were observed. The present findings, in an analysis that was limited to correct trials only, ensuring that subjects are on task, provide critical insights into network connections crucial for cognitive control and the manner in which brain networks reorganize to support such control. Impairments in this mechanism are present in schizophrenia and these results highlight how cognitive control deficits contribute to the pathophysiology of this illness
Biological responses to a resumption in river flow in a freshwaterdeprived, permanently open Southern African estuary
The Kariega Estuary is a freshwater-deprived system due to numerous impoundments in the catchment. This system has had little or no horizontal salinity gradient over the last 15 years, with hypersaline conditions sometimes predominating in the upper reaches. Following high rainfall events in the catchment during the spring of 2006, including a flood event (approximate 1:10 year) in August 2006, a series of riverine pulses entered the estuary and a horizontal salinity gradient was established. This study examined the influence of this freshwater pulse on four components of the biota within the estuary, namely the zooplankton, and larval, littoral and demersal fishes. The study demonstrated that in three of these components elevated densities were recorded following the riverine input, with only the littoral fishes retaining an almost constant density. In addition, changes in the relative contributions of the estuarine utilisation classes for all three fish groups examined indicated that freshwater input into these systems positively influences the abundances. This has significant implications for water managers as it demonstrates the importance of an Ecological Reserve (defined as ‘the water required to protect the aquatic ecosystems of the water resource’) for this system.Keywords: biotic response, freshwater pulse, river inflow, Kariega Estuar
Ambivalence in emotion-focused therapy for depression: the maintenance of problematically dominant self-narratives
Objective: Ambivalence can be understood as a cyclical movement between an emerging narrative novelty—an Innovative Moment (IM)—and a return to a problematically dominant self-narrative. The return implies that the IM, with its potential for change is devalued right after its emergence. Our goal is to test the hypothesis that the probability of the client expressing such form of ambivalence decreases across treatment in good-outcome cases but not in poor-outcome cases. Method: Return-to-the-Problem Markers (RPMs) signaling moments of devaluation of IMs were coded in passages containing IMs in six clients with major depression treated with emotion-focused therapy: three good-outcome cases and three poor-outcome cases. Results: The percentage of IMs with RPMs decreased across therapy in good-outcome cases, whereas it remained unchanged and high in the poor-outcome cases. Conclusions: These results were consistent with the theoretical suggestion that therapeutic failure may be associated with this form of ambivalence.Obiettivo: L'ambivalenza può essere considerata come un movimento ciclico tra un nuovo elemento narrativo emergente - Innovative Moment (IM) - e il ritorno ad una auto-narrazione problematica dominante. Il ritorno implica che il IM perde il proprio potenziale di favorire un cambiamento nel momento in cui emerge. Il nostro obiettivo è quello di verificare l'ipotesi che la probabilità che il paziente possa esprimere tale forma di ambivalenza diminuisce nel corso di un trattamento che ha un buon esito, ma non nei casi con esito negativo. Metodo: in sei pazienti affetti da depressione maggiore trattati con terapia focalizzata sulle emozioni, sono stati codificati i passaggi contenenti IM utilizzando il Return-to-the-Problem Markers (RPMs) che segnala i passaggi in cui IM vengono svalutati: tre casi con buon esito e tre con esito negativo. Risultati: La percentuale di IM con gli RPM diminuiva nel corso delle terapie dei casi con buon esito, mentre è rimasto invariato ed elevato nei casi con scarso esito. Conclusioni: Questi risultati sono coerenti con il presupposto teorico che il fallimento terapeutico possa essere associato a questa forma di ambivalenza.Objetivo: A ambivalência pode ser entendida como um movimento cíclico entre uma novidade narrativa emergente – um Momento de Inovação (MI) – e um retorno à narrativa problemática dominante. O retorno implica que o MI, com o seu potencial para a mudança, seja desvalorizado logo após a sua emergência. O nosso objetivo é testar a hipótese de que a probabilidade do cliente expressar tal forma de ambivalência diminui ao longo do tratamento em casos de sucesso mas não em casos de insucesso terapêutico. Método: Marcadores de Retorno ao Problema (MRP) que assinalam momentos de desvalorização dos MIs foram codificados em passagens contendo MIs em seis casos de clientes com depressão major tratados com terapia focada nas emoções: três casos de sucesso e três casos de insucesso. Conclusões: Estes resultados foram consistentes com as sugestões teóricas de que o insucesso terapêutico poderá estar associado a esta forma de ambivalência.Ziel: Ambivalenz kann als zyklische Bewegung zwischen einer emergenten narrativen Neuheit – einem Innovative Moment (IM) – und einer Rückkehr zu einer problematischen dominanten Selbst-Erzählung verstanden werden. Diese Rückkehr impliziert, dass der IM mit seinem Potential für Veränderung direkt nach seinem Auftauchen abgewertet wird. Unser Ziel ist die Hypothese zu testen, dass die Wahrscheinlichkeit, dass der Klient eine solche Form der Ambivalenz zeigt, bei Fällen mit gutem Therapieergebnis über die Behandlung abnimmt, aber nicht in Fällen mit schlechtem Ergebnis. Methode: Rückkehr-zu-dem-Problem Marker (RPMs), die Momente signalisieren, in denen IMs abgewertet werden, wurden in Passagen, die IMs beinhalten, von sechs Klienten mit Major Depression, die mit emotionsfokussierter Therapie behandelt wurden, kodiert: 3 Fälle mit gutem und 3 Fälle mit schlechtem Therapieergebnis. Ergebnisse: Der Prozentsatz von IMs mit RPMs verringerte sich bei Fällen mit gutem Ergebnis über die Therapie hinweg, wohingegen er in den Fällen mit schlechtem Ergebnis unverändert und hoch blieb. Schlussfolgerung: Die Ergebnisse waren mit dem theoretischen Vorschlag konsistent, dass therapeutischer Misserfolg mit dieser Form der Ambivalenz assoziiert ist.目標:矛盾可以視為是種擺盪在新產生的新穎敘說—創意時刻(IM)—和回復到一種有問題的支配性自我敘說之間的循環動作。回復意味著潛藏改變契機的IM,其價值在出現後即被摒棄。我們的目標是檢視以下假設的可能性:「在具良好成效的案例中,案主在治療歷程中表達這種形式的矛盾會降低;而在不良成效的案例中則否」。方法:在六位具有嚴重憂鬱症患者的IM段落中,找到顯示IM價值降低時刻的故態復萌標記(RPMs)並加以編碼。這六位患者均接受情緒焦點治療,其中三位為具良好成效案例,另外三位為不良成效案例。結果:在具良好成效案例中,IM當中具有RPM的比率降低;而在不良成效的案例中,RPM的比率維持不變或更高。結論:此結果與理論假設一致,即假設治療的失敗可能與這種形式的矛盾有關
Contribution of glycogen in supporting axon conduction in the peripheral and central nervous systems: the role of lactate
The role of glycogen in the central nervous system is intimately linked with the glycolytic pathway. Glycogen is synthesized from glucose, the primary substrate for glycolysis, and degraded to glucose-6-phosphate. The metabolic cost of shunting glucose via glycogen exceeds that of simple phosphorylation of glucose to glucose-6-phosphate by hexokinase; thus, there must be a metabolic advantage in utilizing this shunt pathway. The dogmatic view of glycogen as a storage depot persists, based on initial descriptions of glycogen supporting neural function in the face of aglycemia. The variable latency to conduction failure, dependent upon tissue glycogen levels, provided convincing evidence of the role played by glycogen in supporting neural function. Glycogen is located predominantly in astrocytes in the central nervous system, thus for glycogen to benefit neural elements, intercellular metabolic communication must exist in the form of astrocyte to neuron substrate transfer. Experimental evidence supports a model where glycogen is metabolized to lactate in astrocytes, with cellular expression of monocarboxylate transporters and enzymes appropriately located for lactate shuttling between astrocytes and neural elements, where lactate acts as a substrate for oxidative metabolism. Biosensor recordings have demonstrated a significant steady concentration of lactate present on the periphery of both central white matter and peripheral nerve under unstimulated baseline conditions, indicating continuous cellular efflux of lactate to the interstitium. The existence of this lactate pool argues we must reexamine the “on demand” shuttling of lactate between cellular elements, and suggests continuous lactate efflux surplus to immediate neural requirements
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