243 research outputs found

    Correlation of histopathologic and dynamic tissue perfusion measurement findings in transplanted kidneys

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    BACKGROUND: Cortical perfusion of the renal transplant can be non-invasively assessed by color Doppler ultrasonography. We performed the Dynamic Tissue Perfusion Measurement (DTPM) of the transplant’s renal cortex using color Doppler ultrasonography (PixelFlux technique), and compared the results with the histopathological findings of transplant biopsies. METHODS: Ninety-six DTPM studies of the renal transplant’s cortex followed by transplant biopsies were performed in 78 patients. The cortical perfusion data were compared with the parameter of peritubular inflammatory cell accumulation (PTC 0 to 3) based on Banff-classification system. RESULTS: A significant decrease of cortical perfusion could be demonstrated as the inflammatory cells accumulation in peritubular capillaries increased. Increasing peritubulitis caused a perfusion loss from central to distal layers of 79% in PTC 0, of 85% in PTC 1, of 94% in PTC 2, and of 94% in PTC 3. Furthermore, the perfusion loss due to peritubular inflammation was more prominent in the distal cortical layer. The extent of perfusion decline with increasing peritubulitis (from PTC 0 to PTC 3) was 64% in proximal 20% cortical layer (p20), 63% in proximal 50% cortical layer (p50), increased to 76% in distal 50% cortical layer (d50), and peaked at 90% in the distal 20% cortical layer (d20). For those without peritubulitis (PTC 0), the increase in the the Interstitial Fibrosis/Tubular Atrophy (IF/TA) score was accompanied by a significantly increased cortical perfusion. A Polyomavirus infection was associated with an increased cortical perfusion. CONCLUSIONS: Our study demonstrated that the perfusion of the renal transplant is associated with certain pathological changes within the graft. DTPM showed a significant reduction of cortical perfusion in the transplant renal cortex related to peritubular capillary inflammation

    Distinguishing the Visual Working Memory Training and Practice Effects by the Effective Connectivity During n-back Tasks: A DCM of ERP Study

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    Visual working memory (WM) training and practice can result in improved task performance and increased P300 amplitude; however, only training can yield N160 enhancements. N160 amplitudes are related to the spatial attention, the detection of novelty and the inhibitory control, while P300 amplitudes are related to the selective attention. Therefore, it could be speculated that the mechanisms underlying N160 and P300 production may differ to accommodate to their functions. Based on the different N160 engagements and different functional roles of N160 and P300, we hypothesized that the effects of visual WM training and practice can be dissociated by their brain effective connectivity patterns. We compared different neural connectivity configurations for the main task-related brain activities including N160 and P300 during the visual three-back task in subjects after visual WM training (the WM group) and after repetitive task practice (the control group). The behavioral result shows significantly greater improvement in accuracy after training and suggests that visual WM training can boost the learning process of this simple task. The N160 peak amplitude increased significantly after training over the anterior and posterior brain areas but decreased after practice over the posterior areas, indicating different mechanisms for mediating the training and practice effects. In support of our hypothesis, we observed that visual WM training alters the frontal-parietal connections, which comprise the executive control network (ECN) and the dorsal attention network (DAN), whereas practice modulates the parietal-frontal connections underpinning P300 production for selective attention. It should be noted that the analytic results in this study are conditional on the plausible models being tested and the experimental settings. Studies that employ different tasks, devices and plausible models may lead to different results. Nevertheless, our findings provide a reference for distinguishing the visual WM training and practice effects by the underlying neuroplasticity

    A General Phase Matching Condition for Quantum Searching Algorithm

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    A general consideration on the phase rotations in quantum searching algorithm is taken in this work. As four phase rotations on the initial state, the marked states, and the states orthogonal to them are taken account, we deduce a phase matching condition for a successful search. The optimal options for these phase are obtained consequently.Comment: 3 pages, 3 figure

    Serum leptin is associated with cardiometabolic risk and predicts metabolic syndrome in Taiwanese adults

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    <p>Abstract</p> <p>Background</p> <p>Leptin is associated with cardiovascular disease (CVD); however, few studies have assessed its relationship with metabolic syndrome, especially in an Asian population. Therefore, the aim of the present study was to assess leptin levels and evaluate its association with CVD and metabolic syndrome.</p> <p>Methods</p> <p>In 2009, 957 subjects, who underwent a routine physical examination and choose leptin examination, were selected to participate. Participants (269 females and 688 males) were stratified according to leptin level quartiles. Metabolic syndrome was defined by NCEP ATP III using waist circumference cutoffs modified for Asian populations, and CVD risk was determined using the Framingham Heart Study profile.</p> <p>Results</p> <p>Leptin levels were correlated with CVD risk in men and women. With the exception of fasting plasma glucose, increased leptin levels were observed as factors associated with metabolic syndrome increased in both males and females. After adjusting for age, an association between leptin levels and metabolic syndrome was observed. After adjusting for age alone or with tobacco use, subjects in the highest leptin quartile had a higher risk of having metabolic syndrome than those in the lowest quartile (OR = 6.14 and 2.94 for men and women, respectively). After further adjustment for BMI, metabolic syndrome risk remained significantly increased with increasing leptin quartiles in men. Finally, increased leptin levels were a predictor of metabolic syndrome in men and women.</p> <p>Conclusions</p> <p>Serum leptin levels are correlated with CVD risk and metabolic syndrome. Analysis of leptin as part of routine physical examinations may prove beneficial for early diagnosis of metabolic syndrome.</p

    Trogodišnji trend promjena tjelesne pripremljenosti i indeksa tjelesne mase u učenika u dobi od 12 do 16 godina s ekstremnim indeksima tjelesne mase

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    The aim of this study was to investigate a three-year development in BMI and physical fitness of schoolchildren aged 12-16 years with extreme weight status. Taiwan Physical Fitness Test Battery, assessing aerobic fitness (1600-meter walk/run test), power (standing long jump), muscular endurance (sit-up), and flexibility (sit-and-reach) in 16,945 boys, was implemented in September from the year 2006 till 2008. Overweight and underweight were defined by the baseline BMI data values that fall within the highest and lowest 5% of their age population, whereas the BMI data values that fall within one standard deviation of the mean was considered “normal” in this study. The results showed that BMI of schoolchildren in 2006 was ~2–3 kg/m2 above the national average reported in 1993. All physical fitness components in the overweight group were substantially poorer than those in the normal group. Yet, these fitness parameters were improved over the three years in all groups. BMI in the underweight group increased at a faster rate than that in the normal and overweight groups. No difference was found in the jumping distance between the underweight and normal groups. Aerobic fitness in the underweight group was superior but flexibility and muscular endurance were slightly lower than those in the normal group. BMI of Taiwan schoolchildren increased substantially from 1993 to 2006 but leveled off from 2006 to 2008. Underweight schoolchildren during the growing period should not a priori be considered as physically weaker or unfit individuals.Cilj je ovog istraživanja bio ustanoviti trogodišnji trend razvoja indeksa tjelesne mase (ITM) i tjelesne pripremljenosti u učenika, u dobi između 12 i 16 godina, s ekstremnim vrijednostima tjelesne težine. Tajvanski sklop testova za tjelesnu pripremljenosti (Taiwan Physical Fitness Test Battery), koja uključuje procjenu aerobne pripremljenosti (test hodanja/ trčanja na 1600 metara), eksplozivne snage (skok u dalj s mjesta), mišićne izdržljivosti (podizanje trupa iz ležanja na leđima) i fleksibilnosti (sjed-i-dohvat), primijenjen je od 2006 do 2008 godine u mjesecu rujnu na uzorku od 16.945 dječaka. Preteški (overweight) i prelagani (underweight) ispitanici bili su definirani prema inicijalnoj vrijednosti ITM-a za dobnu skupinu populacije ispitanika kao oni koji se ubrajaju među 5% s najvišim odnosno najnižim vrijednostima ITM. Ispitanici koji su se nalazili unutar jedne standardne devijacije smatrali su se „normalnima“. Rezultati su pokazali da je ITM tajvanskih učenika u 2006. godini bio za ~2–3kg/m2 veći od nacionalnog prosjeka objavljenog 1993. godine. Sve varijable tjelesne pripremljenosti u grupi prekomjerno teških bile su značajno lošije u odnosu na rezultate koje su postigli ispitanici u normalnoj grupi. Ipak, rezultati su se u svim mjerenim varijablama u svim grupama poboljšali tijekom 3 godine mjerenja. ITM je u grupi nedovoljno teških porastao većom brzinom nego u grupama normalnih i prekomjerno teških učenika. Nije utvrđena značajna razlika u rezultatima skoka u dalj s mjesta između grupa nedovoljno teških i normalnih ispitanika. Nedovoljno teški ispitanici imali su najbolje rezultate u aerobnoj izdržljivosti u odnosu na ostale grupe, dok su u fleksibilnosti i mišićnoj izdržljivosti bili nešto slabiji nego ispitanici u normalnoj grupi. ITM je u tajvanske djece značajno porastao u razdoblju od 1993. do 2006. godine, ali je i stagnirao u razdoblju od 2006. do 2008. godine. Nedovoljno teška djeca ne bi se smjela a priori smatrati fizički slabijom ili nespremnom tijekom perioda odrastanja

    Increased CD4+CD25+ regulatory T cells correlate with poor short-term outcomes in hepatitis B virus-related acute-on-chronic liver failure patients

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    BackgroundThe roles of CD4+CD25+ regulatory T cells (Treg) in chronicity of hepatitis B virus (HBV) infection have been confirmed. We aimed to explore alteration of Treg in patients with HBV-related acute-on-chronic liver failure (ACLF).MethodsThirty-two HBV-related ACLF patients, 44 chronic hepatitis B patients, and 41 healthy controls were recruited. We detected frequencies of peripheral Treg and intrahepatic forkhead winged helix transcription factor (Foxp3)+ cells. Inhibitory activity of Treg was assessed by functional suppression assays. Serum interferon-γ and interleukin-10 were also determined.ResultsPeripheral Treg and intrahepatic Foxp3+ cells were more markedly increased in ACLF than chronic hepatitis B and controls (all p < 0.001), and the Foxp3+ cells located predominantly in the portal areas. The Treg frequency was positively correlated with HBV DNA load, international normalized ratio, model of end stage liver disease score, and serum interleukin-10 level in ACLF patients. Functional assays in vitro demonstrated that ACLF patients exhibited higher suppressive effects of Treg on proliferations of autologous CD4+CD25− T cells than controls. On logistic regression, prolonged international normalized ratio and higher peripheral Treg frequency predicted 30-day survival of ACLF.ConclusionThe patients with HBV-related ACLF exhibit increased amounts of Treg, of which redistribution from periphery to liver seems to modulate liver inflammation. Higher Treg amounts are associated with more severe liver disease in ACLF, and its level in combination with international normalized ratio may assist prediction of short-term outcomes of HBV-related ACLF

    Selection and environmental adaptation along a path to speciation in the Tibetan frog Nanorana parkeri.

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    Tibetan frogs, Nanorana parkeri, are differentiated genetically but not morphologically along geographical and elevational gradients in a challenging environment, presenting a unique opportunity to investigate processes leading to speciation. Analyses of whole genomes of 63 frogs reveal population structuring and historical demography, characterized by highly restricted gene flow in a narrow geographic zone lying between matrilines West (W) and East (E). A population found only along a single tributary of the Yalu Zangbu River has the mitogenome only of E, whereas nuclear genes of W comprise 89-95% of the nuclear genome. Selection accounts for 579 broadly scattered, highly divergent regions (HDRs) of the genome, which involve 365 genes. These genes fall into 51 gene ontology (GO) functional classes, 14 of which are likely to be important in driving reproductive isolation. GO enrichment analyses of E reveal many overrepresented functional categories associated with adaptation to high elevations, including blood circulation, response to hypoxia, and UV radiation. Four genes, including DNAJC8 in the brain, TNNC1 and ADORA1 in the heart, and LAMB3 in the lung, differ in levels of expression between low- and high-elevation populations. High-altitude adaptation plays an important role in maintaining and driving continuing divergence and reproductive isolation. Use of total genomes enabled recognition of selection and adaptation in and between populations, as well as documentation of evolution along a stepped cline toward speciation
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