A

standard sound was presented 60% of the time, whereas t

A

standard sound was presented 60% of the time, whereas the remaining sounds deviated from the standard on one of four dimensions: duration, intensity, pitch, or location. The timing between stimuli was either periodic or aperiodic. Based on the sensory prediction hypothesis, the MMN for the patients should be abnormal across all four dimensions. in contrast, the timing hypothesis would predict a selective impairment of the duration MMN. Moreover, the timing hypothesis would also predict that the enhancement of the MMN observed in controls when the stimuli are presented periodically should be attenuated in the patients. Compared to controls, the patients exhibited a delayed latency in the MMN to duration deviants and a

similar trend for the intensity deviants, while pitch and check details location MMNs did not differ between groups. Periodicity had limited and somewhat inconsistent effects. The present results are at odds with a general role for the cerebellum Ganetespib price in sensory prediction and provide partial support for the timing hypothesis. (C) 2008 Elsevier Ltd. All rights reserved.”
“Objective: This study examined the effect on neointimal hyperplasia of adenovirus-mediated delivery of cellular repressor of EIA-stimulated genes (CREG) to the artery after balloon injury.

Methods. Sixty rabbits were randomized into three groups and underwent balloon injury in the left common carotid arteries. The injured arterial segment was isolated by two inflated balloon catheters. Saline or recombinant adenovirus expressing CREG or green fluorescent protein was injected into

the lumen of the isolated arterial segments and incubated for 30 minutes. Bortezomib order The rabbits were euthanized for immunohistochemistry, Western blotting, and morphometric analysis at 3, 7, 14, and 28 days after balloon injury and in vivo gene transfer (5 rabbits for each time point). Common carotid artery angiography was performed before euthanasia.

Results. Immunohistochemistry and Western blot analysis demonstrated that CREG expression was significantly down-regulated in the acute phase of vascular injury and was gradually restored in the resolution phase. The changes of CREG expression were in parallel with those of the smooth muscle cell (SMC) differentiation markers SM alpha-actin and SM myosin heavy chain in the injured arteries. Adenovirus-mediated CREG transfer markedly increased CREG expression in the injured artery. Consequently, morphometric analysis revealed an approximate 50% reduction in the neointima and the intima/media ratio in CREG-transferred arteries compared with the saline and green fluorescent protein controls. Assay with 5-bromo-2-deoxyuridine showed that CREG transfer significantly inhibited SMC proliferation. In contrast, endothelialization of the injured artery was not affected by CREG transduction as assessed by CD31 immunostaining.

Using purified G alpha(i) and G alpha(t), we examined the intrins

Using purified G alpha(i) and G alpha(t), we examined the intrinsic tryptophan fluorescence of these proteins, which reports conformational changes associated with activation and deactivation of G alpha proteins. In addition to the expected enhancement in tryptophan fluorescence intensity, activation of G alpha GDP proteins was accompanied by a modest but notable red shift in tryptophan emission maxima. We identified a cation-pi

interaction between tryptophan and arginine residues in the Switch II of G alpha(i) family proteins that mediates the observed red shift in emission maxima. Furthermore, amino-terminal myristoylation of G alpha(i) resulted in a less polar environment for tryptophan residues in the GTPase domain, consistent with an interaction between selleck the myristoylated amino terminus CHIR98014 and the GTPase domain of G alpha proteins. These results reveal unique insights into conformational changes which occur upon activation and deactivation of G proteins in solution.”
“Purpose: Urolithiasis after kidney transplantation can involve several contributing

factors and the treatment strategy is open to question. We determined the incidence and management of urolithiasis in kidney recipients.

Materials and Methods: We retrospectively reviewed a single center series of 3,000 kidney graft recipients during 32 years to identify those with urolithiasis. We analyzed data by the prevalence per decade, including perioperative procedures (preoperative assessment, anastomosis type and urinary drainage) and long-term followup (urinary stenosis, time to presentation, size, site, treatment type, renal function and survival).

Results: We identified 31 cases and noted a significant MYO10 decrease in incidence from 2.1% to 0.6% during the 3 decades. Excluding 4 cases of donor in situ stones the mean time to diagnosis was 8.5 years. Surgical risk factors were ureteral obstruction in 41% of cases, infravesical obstruction in 14% and urinary-digestive anastomosis in 14%.

A total of 12 cases (38%) were observed exclusively with 2 of spontaneous passage. With minor adaptations all mini-invasive procedures, including extracorporeal shock wave lithotripsy, endoscopy and percutaneous nephrolithotomy, were feasible in graft recipients. Antegrade procedures were facilitated by the ventral position of the graft. Eight patients (25%) were treated with open surgical ureteroureteral anastomosis.

Conclusions: Prevention with a perioperative Double-J (R) stent and early treatment of ureteral obstruction have decreased and stabilized the urolithiasis rate at around 0.6%. Careful surveillance or any currently available instrumental treatments of urinary stones can be valid options.”
“Tissue and nerve damage can result in chronic pain.

Experiments were performed in male Wistar rats under free-feeding

Experiments were performed in male Wistar rats under free-feeding and fasting conditions. We measured hypothalamic neuropeptides and monoamines by in situ hybridization and HPLC respectively as well as

plasmatic levels of relevant endocrine signals. OEA administration induced changes in hypothalamic monoaminergic activity and in the anorexigenic neuropeptide CART expressed in the paraventricular nucleus (PVN) but lacked effect on neuropeptides expression in nucleus arcuatus. In addition, OEA induced peripheral changes selleck chemicals llc in gut peptides, with marked effects on PYY and Chrelin. These results further suggest that anorexigenic properties of OEA are mediated by peripheral signals and by central alterations in neuropeptides expressed by feeding-involved hypothalamic structures receiving input from peripheral sensory systems, such as the PVN. (C) 2010 Elsevier Ltd. All rights reserved.”
“We prospectively studied the impact of several cytogenetic abnormalities (CAs) in patients with relapsed/refractory myeloma who received lenalidomide and dexamethasone (RD) with or without the addition of bortezomib (V). On

the basis of the presence of previous neuropathy, 50 patients were treated with RD and 49, without preexisting neuropathy, with VRD. The overall response rate was 63%, similar for RD and VRD. Poor risk cytogenetics were associated with lower response rates in RD (P = 0.01), but not in VRD (P = 0.219). The median progression-free survival (PFS) was similar for RD (9 months) and VRD (7 months). Ergoloid The median overall survival (OS) for all Tofacitinib patients was 16 months, with no differences between RD or VRD regimens. Poor risk cytogenetics, especially del17p, resistance to previous thalidomide, elevated lactate dehydrogenase (LDH) and presence of extramedullary disease were associated with inferior response to therapy and shorter PFS and OS. The impact of other CAs on OS was

more pronounced in RD. In conclusion, the presence of CAs is an important adverse prognostic factor for patients with relapsed/refractory myeloma, but resistance to previous thalidomide, elevated LDH and presence of extramedullary disease remain of major prognostic importance. The outcome of patients with del17p remains extremely poor even with VRD combination. Leukemia (2010) 24, 1769-1778; doi: 10.1038/leu.2010.175; published online 26 August 2010″
“The function of 5-HT6 receptors, one of the last additions to the large family of 5-HT receptors, is largely unknown due to the limited knowledge of their transduction mechanisms, lack of full centrally acting agonists and inconsistencies in the pharmacological and neurochemical effects of the antagonists. Recently, a new full agonist, ST1936, with nanomolar affinity for 5-HT6 receptors, has become available.

(J Thorac Cardiovasc Surg 2012;144:1167-75)”
“Background Th

(J Thorac Cardiovasc Surg 2012;144:1167-75)”
“Background. The same executive dysfunctions and alterations in neuroimaging tests (both functional and structural) have been found in obsessive-compulsive patients and their first-degree relatives. These neurobiological findings are considered to be intermediate markers of the disease. The aim of

our study was to assess verbal and non-verbal memory in unaffected first-degree relatives, in order to determine whether these neuropsychological functions constitute a new cognitive marker for obsessive-compulsive disorder see more (OCD).

Method. Recall and use of organizational strategies in verbal and non-verbal memory tasks were measured in 25 obsessive-compulsive patients, 25 unaffected first-degree relatives and 25 healthy volunteers.

Results.

First-degree relatives and healthy volunteers did not show differences on most measures of verbal memory. However, during the recall and processing of non-verbal information, deficits were found in first-degree relatives and patients compared with healthy volunteers.

Conclusions. The presence of the same deficits in the execution of non-verbal memory tasks in OCD patients and unaffected first-degree relatives suggests the influence of certain genetic and/or familial factors on this cognitive function in OCD and supports the hypothesis that deficits in non-verbal memory tasks could be considered as cognitive markers of the disorder.”
“Objective: The BIBF 1120 cell line effect of mechanical preconditioning on skeletal myoblasts in engineered tissue constructs was investigated to resolve issues associated with conduction block between skeletal myoblast cells and cardiomyocytes.

Methods: Murine skeletal myoblasts were used to generate engineered tissue constructs with or without application of mechanical strain. After in vitro myotube formation, engineered tissue constructs were co-cultured

for 6 days with viable embryonic heart slices. With the use of sharp electrodes, electrical coupling between engineered tissue constructs and embryonic heart slices was assessed in the presence or absence of pharmacologic agents.

Results: The isolation and expansion procedure for skeletal myoblasts resulted in high yields of homogeneously desmin-positive (97.1% +/- 0.1%) cells. Mechanical strain C-X-C chemokine receptor type 7 (CXCR-7) was exerted on myotubes within engineered tissue constructs during gelation of the matrix, generating preconditioned engineered tissue constructs. Electrical coupling between preconditioned engineered tissue constructs and embryonic heart slices was observed; however, no coupling was apparent when engineered tissue constructs were not subjected to mechanical strain. Coupling of cells from engineered tissue constructs to cells in embryonic heart slices showed slower conduction velocities than myocardial cells with the embryonic heart slices (preconditioned engineered tissue constructs vs embryonic heart slices: 0.04 +/- 0.02 ms vs 0.10 +/- 0.05 ms, P=.

Using fluorescent in situ hybridization to detect vRNA as well as

Using fluorescent in situ hybridization to detect vRNA as well as the live cell imaging of fluorescently labeled RNPs, we show that an early event in vRNA cytoplasmic trafficking involves accumulation near the microtubule organizing center in multiple cell types and viral strains. Here, RNPs colocalized with Rab11, a pericentriolar recycling endosome marker. Cytoplasmic RNP localization was perturbed by inhibitors of vesicular trafficking, microtubules, or the short interfering RNA-mediated depletion of Rab11. Green fluorescent protein (GFP)-tagged RNPs in see more living cells demonstrated

rapid, bidirectional, and saltatory movement, which is characteristic of microtubule-based transport, and also cotrafficked with fluorescent Rab11. Coprecipitation experiments showed an interaction between RNPs and the GTP-bound form of Rab11, potentially mediated via the PB2 subunit of the polymerase. We propose that influenza virus RNPs are routed from the nucleus to the pericentriolar recycling endosome (RE), where they access a Rab11-dependent vesicular transport pathway to the cell periphery.”
“As more adults take the stimulant medication methylphenidate to treat attention deficit hyperactivity disorder (ADHD) residual type, the risk arises with regard to exposure

during early development if people taking the medication become pregnant. We studied the neurobehavioral effects of methylphenidate learn more in zebrafish. Zebrafish offer cellular reporter systems, continuous visual access and molecular interventions such as morpholinos to help determine critical mechanisms underlying neurobehavioral teratogenicity. Previously, we had seen that persisting neurobehavioral impairment in zebrafish with developmental chlorpyrifos exposure was associated with disturbed dopamine

systems. Because methylphenidate is an indirect dopamine agonist, it was thought that it might also cause persistent behavioral impairment after developmental exposure. Zebrafish embryos were exposed to the ADHD stimulant medication methylphenidate Thymidylate synthase 0-5 days post fertilization (12.5-50 mg/l). They were tested for long-term behavioral effects as adults. Methylphenidate exposure (50 mg/l) caused significant increases in dopamine, norepinepherine and serotonin on day 6 but not day 30 after fertilization. In the novel tank diving test of predatory avoidance developmental methylphenidate (50 mg/l) caused a significant reduction in the normal diving response. In the three-chamber spatial learning task early developmental methylphenidate (50 mg/l) caused a significant impairment in choice accuracy. These data show that early developmental exposure of zebrafish to methylphenidate causes a long-term impairment in neurobehavioral plasticity.


“Background: The chronic kidney disease (CKD)-Epidemiology


“Background: The chronic kidney disease (CKD)-Epidemiology Collaboration (CKD-EPI) equation was developed to address the underestimation of measured glomerular filtration rate (GFR) by the Modification of Diet in Renal Disease (MDRD) equation at levels >60 mL/min/1.73 m(2).

Aim: To assess the impact of the CKD-EPI equation on the estimation of GFR in a large adult UK population (n = 561 400), particularly looking at the effect of age.

Design: Serum creatinine results (ID-MS-aligned enzymatic assay) were extracted from the pathology database during 1 year on adult (epsilon 18 years) patients from primary care.

Methods:

The first available creatinine GW4869 mw result from 174 448 people was used to estimate GFR using both equations and agreement assessed.

Results: Median CKD-EPI GFR was significantly higher than median MDRD GFR (82 vs. 76 mL/min/1.73 m(2), P < 0.0001). Overall mean bias between CKD-EPI

and MDRD GFR was 5.0%, ranging from 13.0% in the 18-29 years age group down to -7.5% in those aged epsilon 90 years. Although statistically AMN-107 solubility dmso significant at all age groups the difference diminished with age and the agreement in GFR category assignment increased. Age-adjusted population prevalence of CKD Stages 3-5 was lower by CKD-EPI than by MDRD (4.4% vs. 4.9%).

Conclusion: CKD-EPI produces higher GFR and lower CKD estimates, particularly among 18-59 year age groups with MDRD estimated GFRs of 45-59 mL/min/1.73 m(2) (Stage 3A). However, at ages > 70 years there is very

little difference between the equations, and among the very elderly CKD-EPI may actually increase CKD prevalence estimates.”
“Heat transfer in a biological system is a complex process and its analysis is difficult. Heterogeneous vascular architecture, blood flow in the complex network of arteries and veins, varying metabolic heat generation rates and dependence of tissue properties on its physiological condition contribute to this complexity. The understanding of heat transfer in human body is important for better insight of thermoregulatory mechanism and physiological conditions. Its understanding is also important for accurate prediction of thermal transport and temperature distribution during biomedical applications. During the last three decades, many attempts have been made Glycogen branching enzyme by researchers to model the complex thermal behavior of the human body. These models, viz., blood perfusion, countercurrent, thermal phase-lag, porous-media, perturbation, radiation, etc. have their corresponding strengths and limitations. Along with their biomedical applications, this article reviews various contextual issues associated with these models. After brief discussion of early bioheat models, the newly developed bioheat models are discussed in detail. Dependence of these models on biological properties, viz., thermophysical and optical properties are also discussed. (C) 2013 Elsevier Ltd. All rights reserved.

Immunohistochemical staining, Western blotting, and RT-PCR indica

Immunohistochemical staining, Western blotting, and RT-PCR indicated that down-regulation of GRs expression occurred in the hippocampus among TBI-rats which demonstrated reduced performance of check details learning and memory in Morris water maze. As the GRs expression bounced up, the cognitive function approached to normal. It is concluded that reduced expression of hippocampal GRs was closely associated with learning and memory deficits in TBI-rats. Hippocampal GRs was involved in the biochemical mechanisms of cognitive deficits after TBI. (c) 2012 Elsevier Ireland Ltd. All rights reserved.”
“An

infectious cDNA clone of a genotype 3 strain of hepatitis E virus adapted to growth in HepG2/C3A human hepatoma cells was constructed. This virus was unusual in that the hypervariable region of the adapted virus contained a 171-nucleotide insertion that encoded 58 amino acids of human S17 ribosomal protein. Analyses of virus from six serial passages indicated ASP2215 that genomes with this insert, although initially rare, were selected during the first passage, suggesting it conferred a significant growth advantage. RNA transcripts from this cDNA and the viruses

encoded by them were infectious for cells of both human and swine origin, the major host species for this zoonotic virus. Mutagenesis studies demonstrated that the S17 insert was a major factor in cell culture adaptation. Introduction of 54 synonymous mutations into the insert had no detectable effect, thus implicating protein, rather than RNA, as Lck the important component. Truncation of the insert by 50% decreased the levels of successful transfection by

similar to 3-fold. Substitution of the S17 sequence by a different ribosomal protein sequence or by GTPase-activating protein sequence resulted in a partial enhancement of transfection levels, whereas substitution with 58 amino acids of green fluorescent protein had no effect. Therefore, both the sequence length and the amino acid composition of the insert were important. The S17 sequence did not affect transfection of human hepatoma cells when inserted into the hypervariable region of a genotype 1 strain, but this chimeric genome acquired a dramatic ability to replicate in hamster cells.”
“We have designed and evaluated a novel strategy for screening large gene collections available as GATEWAY-adapted ORFeomes for soluble recombinant overexpression in Escherichia coli, called “”Screening Colonies of ORFeome Pools”" (SCOOP). From a large gene collection we could, without expensive multi-well based cloning and expression screening, determine which targets were suitable for large-scale expression and purification. Normalized bacterial overnight cultures of an ORF collection of entry clones derived from the Kaposi’s sarcoma associated herpesvirus (KSHV) were pooled and used for the isolation of plasmid DNA.

Consequently, the synthesis of RNA or proteins will soon terminat

Consequently, the synthesis of RNA or proteins will soon terminate. In this way, cells do not produce undesirable proteins and essentially save energy. This hypothesis is tested on the AT-rich Drosophila genome, where the detection Tideglusib purchase of frameshifted stop codons is even higher than the theoretical value. Using the binomial theorem, we establish the probability of reading a frameshifted stop codon within n steps. Since the genetic code is largely redundant, there is still space for some hidden secondary functions of this code. In particular, because stop codons do not contain cytosine, random C -> U and C -> T mutations in the third position of codons increase the number of hidden frameshifted

stops and simultaneously the same amino acids are coded. This evolutionary advantage is demonstrated on the genomes of several simple species, e.g. Escherichia coli. (c) 2012 Elsevier Ltd. All Temsirolimus ic50 rights reserved.”
“Background: The gene coding for the D2 dopamine receptor (DRD2) is considered to be one of the most pertinent candidate genes in schizophrenia. However, genetic studies have yielded conflicting results whereas the promising TaqIA variant/rs1800497 has been mapped in a novel gene, ANKK1.

Methods: We investigated eleven single nucleotide polymorphisms (SNPs) spanning the DRD2 and ANKK1 genes, using both a case-control association study comparing 144 independent patients to 142 matched healthy subjects, and

a transmission disequilibrium test in 108 trios. Etomidate This classical genetic study was coupled with a cladistic phylogeny-based association test of human variants, and with an interspecies evolution study of ANKK1.

Results: Case-control study, followed by a 108 trios family-based association analysis for replication, revealed an association between schizophrenia and the ANKK1 rs1800497 (p = 0.01, Odds Ratio = 1.5, 95% Confidence Interval = 1.1-2.2), and the intergenic rs2242592 (p = 2. 10(-4), OR = 1.8, 95%CI = 1.3-2.5). A significant SNP-SNP interaction

was also found (p<10(-5), OR = 2.0, 95%CI = 1.6-2.5). The phylogeny-based association test also identified an association between both these polymorphisms and schizophrenia. Finally, interspecies comparison of the sequences from chimpanzee, orangutan, rhesus macaque and human species suggested specific involvement of ANKK1 in the human lineage.

Conclusions: Intergenic rs2242592 appears to be involved in the genetic vulnerability to schizophrenia, whereas the ANKK1 rs1800497 appears to have a modifying rather than causative effect. Finally; ANKK1 may be a specific human lineage-trait involved in a specific human disease, schizophrenia. (C) 2010 Elsevier Inc. All rights reserved.”
“There is convincing evidence that nitric oxide (NO) may be a causative factor in the pathogenesis of migraine. We investigated the consequences of NO donors’ administration on meningeal processes related to the development of migraine pain in an animal model of meningeal nociception.

However, there are key differences in neurovascular relationships

However, there are key differences in neurovascular relationships that

must be considered when the canine prostate is used as a radical prostatectomy model.”
“Purpose: The knowledge of somatic mutations that arise in penile cancer is limited. We examined the dysregulation of components in the phosphatidylinositol 3-kinase and Ras pathways.

Materials and Methods: Using single stranded conformational. analysis and direct sequencing we performed mutational analysis of the PIK3CA, PTEN, HRAS, KRAS, NRAS and BRAF genes in 28 penile tumors.

Results: We identified somatic missense mutations in 11 of the 28 penile cancer samples (39%). In the PIK3CA gene 8 mutations (29%) were identified that were E542K or E545K. In the HRAS gene a G12S and a Q61L mutation were found (7%). The KRAS gene contained 1 mutation (3%), that is a G12S change. PIK3CA selleck chemicals mutations were found in all grades and stages, whereas HRAS and KRAS mutations were found in larger and more advanced tumors. The mutations were mutually exclusive, suggesting that dysregulation of either pathway is sufficient for the development and progression of penile carcinoma.

Conclusions: The high frequency of mutations in the PIK3CA, HRAS learn more and KRAS genes leads

us to believe that dysregulation of the phosphatidylinositol 3-kinase or Ras pathway is significant for the development and progression of penile carcinoma.”
“Purpose: Tissue engineered bladders are emerging as a potential treatment option in urological surgery. Although successful neobladders can be engineered with autologous cells on a biodegradable polymer scaffold, studies of the local and systemic effects on host tissue have not been extensively pursued. We examined such effects at predetermined

time points after implantation of tissue engineered neobladders in a canine cystoplasty model.

Materials and Methods: Eight dogs underwent trigone sparing cystectomies. Six dogs (experimental Isotretinoin group) received bladder augmentation with tissue engineered constructs produced from autologous urothelial and smooth muscle cells on a prefabricated polyglycolic acid polymer scaffold. Two beagles (control group) received bladder augmentation with the polyglycolic acid scaffold alone. Serial urodynamic studies, cystograms, peripheral blood smears, urinalysis, serum chemistry, complete blood count and electrolytes were done at predetermined time points postoperatively. The bladder, and local and distant organs were retrieved 6 months after surgery for analysis.

Results: Capacity and compliance of the engineered bladders reached normal levels by 6 months. Engineered bladders showed tissue composition similar to that of normal bladders. Infiltration of inflammatory cells was minimal and subsided with time. Am increase in the total systemic leukocyte count and in bacteriuria was evident initially at 1 week but they returned to normal levels by 1 month postoperatively.

(C) 2011 Elsevier Ltd All rights reserved “
“Bone problems

(C) 2011 Elsevier Ltd. All rights reserved.”
“Bone problems can have a highly deleterious impact on life and society, therefore understanding the mechanisms of bone repair is important. Lazertinib price In vivo studies show that bone repair processes in adults resemble normal development of the skeleton during embryogenesis, which can thus be used as a model. In addition, recent studies of skeletal stem cell biology have underlined several crucial molecular and

cellular processes in bone formation. Hedgehog, parathyroid hormone-related protein, Writ, bone morphogenetic proteins and mitogen-activated protein kinases are the main molecular players, and osteoclasts and mesenchymal stem cells are the main cells involved in these processes. However, questions remain regarding the precise mechanisms of bone formation, how the different molecular processes interact, and the real identity of regenerative cells. Here, we review recent studies of bone regeneration and repair. A better understanding of the underlying mechanisms is expected to facilitate the development of new strategies for improving bone repair.”
“BACKGROUND: Intraoperative measurements of cerebral blood flow are of interest during vascular neurosurgery. Near-infrared indocyanine green (ICG) fluorescence angiography was introduced for visualizing vessel patency intraoperatively. However, quantitative information has not been available.

OBJECTIVE: To report our experience

with a microscope with an integrated www.selleckchem.com/products/VX-809.html dynamic ICG fluorescence analysis system supplying semiquantitative information on blood flow.

METHODS: We recorded ICG fluorescence curves of cortex Casein kinase 1 and cerebral vessels using software integrated into the surgical microscope (Flow 800 software; Zeiss Pentero) in 30 patients undergoing

surgery for different pathologies. The following hemodynamic parameters were assessed: maximum intensity, rise time, time to peak, time to halfmaximal fluorescence, cerebral blood flow index, and transit times from arteries to cortex.

RESULTS: For patients without obvious perfusion deficit, maximum fluorescence intensity was 177.7 arbitrary intensity units (AIs; 5-mg ICG bolus), mean rise time was 5.2 seconds (range, 2.9-8.2 seconds; SD, 1.3 seconds), mean time to peak was 9.4 seconds (range, 4.9-15.2 seconds; SD, 2.5 seconds), mean cerebral blood flow index was 38.6 AI/s (range, 13.5-180.6 AI/s; SD, 36.9 seconds), and mean transit time was 1.5 seconds (range, 360 milliseconds-3 seconds; SD, 0.73 seconds). For 3 patients with impaired cerebral perfusion, time to peak, rise time, and transit time between arteries and cortex were markedly prolonged (>20, >9, and >5 seconds). In single patients, the degree of perfusion impairment could be quantified by the cerebral blood flow index ratios between normal and ischemic tissue. Transit times also reflected blood flow perturbations in arteriovenous fistulas.