Brain Charts for the Rhesus Macaque Lifespan.

Recent efforts to chart human brain growth across the lifespan using large-scale MRI data have provided reference standards for human brain development. However, similar models for nonhuman primate (NHP) growth are lacking. The rhesus macaque, a widely used NHP in translational neuroscience due to its similarities in brain anatomy, phylogenetics, cognitive, and social behaviors to humans, serves as an ideal NHP model. This study aimed to create normative growth charts for brain structure across the macaque lifespan, enhancing our understanding of neurodevelopment and aging, and facilitating cross-species translational research. Leveraging data from the PRIMatE Data Exchange (PRIME-DE) and other sources, we aggregated 1,522 MRI scans from 1,024 rhesus macaques. We mapped non-linear developmental trajectories for global and regional brain structural changes in volume, cortical thickness, and surface area over the lifespan. Our findings provided normative charts with centile scores for macaque brain structures and revealed key developmental milestones from prenatal stages to aging, highlighting both species-specific and comparable brain maturation patterns between macaques and humans. The charts offer a valuable resource for future NHP studies, particularly those with small sample sizes. Furthermore, the interactive open resource (https://interspeciesmap.childmind.org) supports cross-species comparisons to advance translational neuroscience research.

Melanoma sentinel node biopsy and prediction models for relapse and overall survival.

BACKGROUND: To optimise predictive models for sentinal node biopsy (SNB) positivity, relapse and survival, using clinico-pathological characteristics and osteopontin gene expression in primary melanomas. METHODS: A comparison of the clinico-pathological characteristics of SNB positive and negative cases was carried out in 561 melanoma patients. In 199 patients, gene expression in formalin-fixed primary tumours was studied using Illumina's DASL assay. A cross validation approach was used to test prognostic predictive models and receiver operating characteristic curves were produced. RESULTS: Independent predictors of SNB positivity were Breslow thickness, mitotic count and tumour site. Osteopontin expression best predicted SNB positivity (P=2.4 × 10⁻7), remaining significant in multivariable analysis. Osteopontin expression, combined with thickness, mitotic count and site, gave the best area under the curve (AUC) to predict SNB positivity (72.6%). Independent predictors of relapse-free survival were SNB status, thickness, site, ulceration and vessel invasion, whereas only SNB status and thickness predicted overall survival. Using clinico-pathological features (thickness, mitotic count, ulceration, vessel invasion, site, age and sex) gave a better AUC to predict relapse (71.0%) and survival (70.0%) than SNB status alone (57.0, 55.0%). In patients with gene expression data, the SNB status combined with the clinico-pathological features produced the best prediction of relapse (72.7%) and survival (69.0%), which was not increased further with osteopontin expression (72.7, 68.0%). CONCLUSION: Use of these models should be tested in other data sets in order to improve predictive and prognostic data for patients.

Left dorsolateral prefrontal cortex supports context-dependent prioritisation of off-task thought.

When environments lack compelling goals, humans often let their minds wander to thoughts with greater personal relevance; however, we currently do not understand how this context-dependent prioritisation process operates. Dorsolateral prefrontal cortex (DLPFC) maintains goal representations in a context-dependent manner. Here, we show this region is involved in prioritising off-task thought in an analogous way. In a whole brain analysis we established that neural activity in DLPFC is high both when 'on-task' under demanding conditions and 'off-task' in a non-demanding task. Furthermore, individuals who increase off-task thought when external demands decrease, show lower correlation between neural signals linked to external tasks and lateral regions of the DMN within DLPFC, as well as less cortical grey matter in regions sensitive to these external task relevant signals. We conclude humans prioritise daydreaming when environmental demands decrease by aligning cognition with their personal goals using DLPFC.

Vasopressin-induced activation of protein kinase C in renal epithelial cells.

Recent studies indicate that the actions of arginine vasopressin (AVP) and other agonists that stimulate electrogenic sodium transport in renal epithelial A6 cells are linked to a Ca(2+)-mobilizing signal transduction mechanism that involves generation of inositol trisphosphate. Since diacylglycerol is the other product in this pathway, studies were performed to determine the possible role of PKC in the stimulation of sodium transport. AVP induced a biphasic increase in diacylglycerol generation, characterized by an initial rapid rise and then a sustained elevation, and PKC activation, reflected by phosphorylation of a specific 80 kDa myristoylated alanine-rich PKC substrate (MARCKS). To determine the PKC isoform(s) involved in this process, immunoblot analysis was performed using antisera that recognize both classical PKC isoforms, XPKC-I and XPCK-II, cloned from Xenopus oocytes. The transcripts of both isoforms were expressed in the A6 cell. Since protein recognized by antisera was translocated from cytosol to the particulate fraction after exposure to AVP, one or both isoforms were activated in the A6 cell. Further studies showed that cyclohexyladenosine and insulin, additional agonists of sodium transport in A6 cells, also stimulated phosphorylation of MARCKS. These results argue that Ca(2+)-dependent PKC is involved in the action of AVP, and that of other agonists, which stimulate sodium transport.

Protein kinase C isoforms in human neutrophil cytoplasts.

Granule-poor human neutrophil cytoplasts, prepared without heat or cytochalasin B treatment so as to preserve both motile function and activatable respiratory burst oxidase, were investigated for their content of several isoforms of protein kinase C (PKC). Immunoblotting with isoform-specific rabbit antibodies (Abs) to PKC revealed that both the alpha-specific and the beta(I and II)- specific Abs recognized a protein band of 78 kd comigrating with PKC from rat brain cytosol. The gamma-specific antiserum did not detect any protein of this molecular mass. The cytoplast beta-PKC band was more readily detected than the cytoplast alpha-PKC band. Antibodies to beta I- or beta-II- specific PKC sequences showed the beta II subtype to be the predominant form of beta-PKC, although some beta I was also found. The identity of the 78-kd cytoplast bands as PKC was established by the fact that phorbol ester treatment of intact cytoplasts induced translocation of the bands from cytosol to membrane fractions. However, whereas PKC specific activity was similar in cytoplast lysates and brain cytosol, immunoreactivity of cytoplast alpha- and beta-PKC bands was considerably less than that of rat brain. Hydroxylapatite chromatography of partially purified cytoplast PKC revealed two major peaks of PKC activity precisely coeluting with brain alpha- and beta-PKC and displaying comparable enzymatic activities despite the relatively weak immunoreactivity of cytoplast alpha- and beta-PKC. To our knowledge, this is the first demonstration that human neutrophil-derived cytoplasts contain alpha, beta I, and beta II forms of PKC and that each isoform translocates from cytosol to membrane upon exposure to phorbol ester at concentrations that induce superoxide production. In addition, our evidence raises the possibility that cytoplasts may also possess other isoforms of PKC that we are unable to detect with our alpha, beta, and gamma antibodies. Finally, the granule-poor cytoplasts seem a particularly useful preparation in which to examine the role of individual PKC isoforms in neutrophil activation.

Glucose and the wandering mind: not paying attention or simply out of fuel?

RATIONALE/OBJECTIVES: The impact of raising glycaemia by ingestion of a glucose drink has revealed cognitive facilitation, particularly for memory and attention. This study aimed to extend current knowledge by examining, for the first time, whether glucose load also moderates task-related (TRT) and task-unrelated thoughts (TUT) during activities that vary in their requirement for sustained attention. METHOD: A 2 (25 g glucose vs. placebo) × 2 (fast vs. slow version of the Sustained Attention to Response Task (SART)) repeated measures, counterbalanced design was used with 16 healthy adults. Self-report questionnaires probed participants' levels of TRT and TUT during SART performance. Prior to testing, the Short Imaginal Processes Inventory (SIPI) was also administered to help pinpoint the nature of thought processes during the task before and after treatment. RESULTS: Analysis of variance revealed no significant effect of treatment; however, we report a pattern of results that is consistent with glucose facilitation effects on task accuracy for more demanding attention tasks (d = 0.56). Additionally, glucose improved the monitoring and task reflection as measured by TRT (d = 0.33) in the more demanding task but no effect on TUT. Probing the nature of thought processes further, we also report two novel correlations (in the placebo) between fears of failure (indexed by the SIPI) and the number of TUT episodes and perceived poor attention control (indexed by the SIPI) and number of TUT and speculate that glucose may act to buffer against TUT episodes under externally demanding situations. CONCLUSIONS: These data extend previous research examining the glucose facilitation effect to the processing of internal thought processes.

The preparation of freeze-thaw density gradients with homogeneous solute concentrations.

A simple and effective method is described for preparing freeze-thaw density gradients which is free of the problems of uneven solute distribution. It consists of blending aqueous freeze-thaw gradients with hypertonic diluent. The routine application of this system for separations of murine lymphosarcoma cell populations is described.

CD40 ligation for immunotherapy of solid tumours.

Tumour vaccines provide an important focus of current cancer research and are often based on the premise that although T-cells do respond naturally to certain tumours, this is usually weak and therefore ineffective at controlling disease. An integral and necessary part of a T-cell immune response involves triggering of CD40 on antigen-presenting cells (APC) by its ligand, CD154, on responding T helper (Th) cells. Furthermore, cytotoxic responses to tumours may fail because the Th-cell response is inadequate and unable to provide CD40 stimulation of APC. Growing evidence shows that stimulating APC with soluble CD40L or an agonistic anti-CD40 mAb can, at least in part, replace the need for Th cells and generate APC that are capable of priming cytotoxic T lymphocytes (CTL). The aim of this study was to investigate whether a range of solid tumours (CD40(-)) could be treated with anti-CD40 mAb. It was found that this treatment was effective, and correlated with the intrinsic immunogenicity and aggressiveness of the tumours. The mAb could be delivered locally or at a distal site, but increased antigen load provided by irradiated tumour cells added little to the effectiveness of the treatment. T-cells were required since cytokine (interferon-gamma) and CTL activity were demonstrated following treatment and the therapeutic efficacy was lost in nude mice. In addition, depletion of CD8(+) cells abrogated protection whilst depletion of CD4(+) cells had no effect. This study demonstrates that solid CD40(-) tumours are sensitive to anti-CD40 mAb therapy and that the response bypasses the need for Th cells.

Electrophysiologic and antiarrhythmic activities of 4-amino-N-[2-(diethylamino)ethyl]-3,5-dimethylbenzamide, a sterically hindered procainamide analogue.

Procainamide is a widely used antiarrhythmic that is fraught with therapeutic limitations such as a short half-life, production of autoimmune antibodies and a lupus-like syndrome, and complex pharmacokinetics. We synthesized the congeners of procainamide possessing one or two methyl substituents ortho to the 4-amino moiety (compounds 4 and 5, respectively), in order to sterically encumber the 4-amino substituent and prevent or diminish the rate of metabolic N-acetylation. Moreover, we anticipated that this structural alteration might eliminate the autoimmune toxicities associated with procainamide. Like procainamide, the two methylated analogues significantly reduced the rate of rise and amplitude of the action potential when studied in isolated canine Purkinje fibers. Whereas procainamide caused no significant change in action potential duration (APD), both methylated congeners significantly reduced APD at 70% and 95% repolarization. Moreover, the dimethylated congener was significantly more efficacious than procainamide in reducing ERP (effective refractory period) and increasing the ERP/APD70. The ability of these compounds to block ouabain-induced arrhythmias was studied in anesthetized dogs. Addition of two methyl groups ortho to the amine produced an increase in potency: The conversion doses for procainamide and the monomethyl and dimethyl congeners were 19.0, 18.3, and 14.3 mg/kg, respectively, following iv administration. After iv administration to rats, procainamide was extensively metabolized to N-acetylprocainamide and displayed a half-life of 0.4 h. In contrast, dimethylprocainamide was not metabolized by N-acetylation, had a half-life of 1.4 h, and provided greater peak plasma concentrations. Thus, addition of methyl substituents ortho to the 4-amino group of procainamide alters the electrophysiological characteristics of the compound, increases its potency against ouabain-induced arrhythmias in vivo, increases its plasma half-life, and prevents N-acetylation.

Calcium ion as intracellular messenger and cellular toxin.

Ca2+ serves a nearly universal intracellular messenger function in cell activation, but excess Ca2+ is also a cellular toxin. The possibility of Ca2+ intoxication is minimized by an elaborate autoregulatory system in which changes in Ca2+ influx rate across the plasma membrane are rapidly compensated for by parallel changes in Ca2+ efflux rate. By this mean, cellular Ca2+ homestasis is maintained so that minimal changes in total cell calcium and cytosolic Ca2+ concentration occur during sustained Ca2(+)-mediated responses. Rather than a sustained increase in cytosolic Ca2+ concentration, it is the localized cycling of Ca2+ across the plasma membrane that is the critically important Ca2+ messenger during the sustained phase of cellular responses mediated via surface receptors linked to the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2). PIP2 hydrolysis gives rise to inositol(1,4,5)trisphosphate (IP3) and diacylglycerol (DAG). The IP3 acts to release Ca2+ from an intracellular pool, thereby causing a transient rise in cytosolic Ca2+ concentration. This transient Ca2+ signal activates calmodulin-dependent protein kinases transiently, and hence, causes the transient phosphorylation of a subset of cellular proteins that mediate the initial phase of the response. The DAG brings about the association of protein kinase C (PKC) with the plasma membrane where a receptor-mediated increase in Ca2+ cycling across the membrane regulates PKC activity. The sustained phosphorylation of a second subset of proteins by PKC mediates the sustained phase of the response. Hence, Ca2+ serves as a messenger during both phases of the cellular response, but its cellular sites of action, its mechanisms of generation, and its molecular targets differ during the initial and sustained phases of the response.(ABSTRACT TRUNCATED AT 250 WORDS)

Adriamycin and daunomycin dose-dependent effects upon contractions of isolated rat myocytes.

Chemotherapeutic usefulness of adriamycin (ADR) and daunomycin (DAU), members of a large class of antitumor anthracyclines, is limited by a unique cardiotoxicity. Using spontaneously beating isolated myocytes from adult rat hearts, we have observed a relatively unique effect of these agents upon maximal contraction times. ADR and DAU induce cessation of beating in an identical dose-dependent manner, while two related anthracyclines exhibit similar inhibitory effects but at different concentrations. Other cytotoxic and antitumor agents tested failed to significantly affect maximal contraction times. This system may be useful in the evaluation of anthracycline analogs for cardiotoxic potential relative to ADR and DAU, as well as in studying the mechanisms of that toxicity. It may also prove useful in selective examination of the direct effects of other agents upon myocardial cells.

Electrophysiological effects of flecainide enantiomers in canine Purkinje fibres.

Since flecainide is a chiral class I antiarrhythmic agent, we examined the basic electrophysiological effects of its enantiomers (10-(6) - 3 x 10(-5) mol/l) in isolated canine Purkinje fibres using standard microelectrode techniques. Frequency-dependent block was studied by pacing at cycle lengths of 300 and 2000 ms. Both enantiomers produced a marked, concentration-dependent decrease in maximum upstroke velocity (Vmax), with greater depression occurring at a cycle length of 300 ms. The concentration causing a 50% decrease in Vmax (EC50) at this pacing rate were 5.0 +/- 0.6 x 10(-6) mol/l for (+)-flecainide and 6.2 +/- 0.8 x 10(-6) mol/l for (-)-flecainide, and were not significantly different. Both enantiomers also produced a concentration- and frequency-dependent decrease in action potential amplitude and an increase in conduction time with no significant differences between the enantiomers. However, at the highest concentration studied (3 x 10(-5) mol/l), none of the nine tissues exposed to (+)-flecainide could be paced at 300 ms cycle length while five of eight tissues exposed to (-)-flecainide could be paced, suggesting the possibility of a small difference between the effects of the enantiomers on membrane responsiveness. The effect of the enantiomers on action potential duration (APD) also depended on pacing rate. At the longer cycle length, ADP50 was shortened to a maximum of 61 +/- 7% and 67 +/- 7% from baseline by (+)- and (-)-flecainide, respectively, whereas APD95 was shortened by 30 +/- 6% and 32 +/- 3% from baseline by (+)- and (-)-flecainide, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Modification by glibenclamide of the electrophysiological consequences of myocardial ischaemia in dogs and rabbits.

Glibenclamide has been shown to block ATP-dependent K+ channels in the heart and prevent the shortening of cardiac action potentials caused by hypoxia in vitro. The present study examines the ability of glibenclamide to modify the effect of acute ischaemia on monophasic action potential duration in pentobarbital-anaesthetized rabbits, and on monophasic action potential duration and ventricular fibrillation threshold in pentobarbital-anaesthetized dogs. Left ventricular endocardial monophasic action potential duration was measured using a contact electrode catheter, and ventricular fibrillation threshold was measured by the single pulse method. Ischaemia was produced in rabbits by occluding the circumflex coronary for 5 min and in dogs by occluding the left anterior descending coronary artery for 40 min. In rabbits, glibenclamide (0.3-3 mg/kg, i.v.) had no effect on baseline monophasic action potential duration, but attenuated action potential shortening during ischaemia in a dose-related manner. In dogs, monophasic action potential duration did not shorten during ischaemia in the vehicle group, but tended to increase in the glibenclamide group (0.5 mg/kg, i.v.) both before and during ischaemia (7 +/- 5% and 14 +/- 8%, respectively, NS). Likewise, ventricular effective refractory period was significantly increased by glibenclamide prior to ischaemia (5 +/- 1%). Ventricular fibrillation threshold tended to increase during 40 min of ischaemia in vehicle-treated dogs (40 +/- 29%, NS), but was unchanged during ischaemia in the glibenclamide-treated dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Monocyte-derived giant cell formation in patients with breast cancer.

Recent reports of monocyte-derived giant cell formation in breast cancer and associated retroviral findings have attracted much interest in the scientific literature and with the media, revitalising hypotheses of a viral role in the aetiology of the disease. We describe an assay developed to investigate further the giant cell forming phenomenon and report results which conflict with earlier work. We observed a smaller proportion of patients with breast cancer forming giant cells than in previous reports. Conversely, a much larger proportion of controls formed giant cells. Using our assay to calculate a fusion index the formation of giant cells, as defined in earlier work, was found to be a poor indicator of the degree of cell fusion in our samples. We discuss our experiences with the assay and suggest the calculation of a fusion index as a more comparable and quantitative measurement of cell fusion.

Analysis of the PKC-gamma-related immunocrossreactive region of a novel leukocyte protein gamma-rp.

The newly discovered gamma-PKC-related-protein of human leukocytes (gamma-rp) crossreacts with a polyclonal antibody preparation originally designed to be specific for PKC-gamma (gammaMb-Ab). As this antibody is currently the only suitable probe for gamma-rp, we sought to characterize the binding of the two proteins. We determined that the gamma Mg-Ab does not recognize the native form of gamma-rp. However, with denaturing immunoblots of gamma-rp, we found that 1) the crossreactive gamma-rp epitope differs somewhat from that of classic rat brain PKC-gamma, but probably only to the degree of the rat/human PKC species difference; 2) the previously reported doublet bands of gamma-rp represent a single protein with cell-stimulus inducible modifications; 3) antibodies present in the gammaMg-Ab pool bind to two separate sites within the gamma-rp epitope; 4) access to one binding site is conformationally restricted, even after protein denaturation; 5) agonist-induced modification of gamma-rp does not significantly affect the total amount of gamma Mg-Ab that it can bind, but 6) does significantly affect the rate of antibody binding to one site. This investigation defines the appropriate experimental use of our antibody, and the significance of these findings for the future study and cloning of gamma-rp is discussed.

An apparently novel protein of human leukocytes, reactive with an antibody to protein kinase C-gamma, is rapidly modified upon cell activation: initial characterization in neutrophils and their cytoplasts.

On immunoblots of human neutrophil cytoplasts (U-CYT), a previously undescribed 97 kDa protein was revealed by intense and selective reaction with an antibody that was initially raised to recognize PKC-gamma. Denoted "gamma-rp" for gamma-related protein, this acidic cytosolic protein somewhat resembled the classic forms of PKC in several biochemical respects. Appearing as a doublet on low-percentage SDS-PAGE gels, both its mobility and staining pattern were rapidly altered by treatment of U-CYT with either phorbol ester or chemotactic peptide. Whole neutrophil gamma-rp was detectable only after TCA precipitation of intact cells. It was also detectable in human platelets, lymphocytes, and neutrophil-like differentiated HL60 cells, but not in fibroblasts, erythrocytes, monocytes, or monocyte-like differentiated HL60 cells. Our data suggest that gamma-rp merits further study as a potential participant in cellular activation, and as a possible structural or functional relative of PKC.

Hepatozoon canis infection in dogs: clinical, radiographic, and hematologic findings.

Hepatozoon canis gametocytes were identified in circulating neutrophils of 3 dogs from different parts of Texas. Clinical signs included intermittent fever, stiffness, and inappetence. The dogs had marked neutrophilic leukocytosis (35,000--51,000/mm3). Parasitemia varied from less than 1% to 60% of the circulating neutrophils. Two of the dogs had periosteal new born reaction on the vertebrae, ilia, ribs, and bones of the limbs proximal to the carpus and tarsus. There was no evidence that specific drug therapy was of value, although use of corticosteroids, aspirin, and antimicrobial agents was accompanied by clinical improvement.

Mastalgia; is this commonly associated with operable breast cancer?

A detailed analysis by questionnaire of breast pain in 460 newly referred patients at a specialized breast clinic revealed that only 1.5% of patients with pain had an early breast cancer. Of all 44 cancers 8 were painful but only 4 considered early. All these had nipple retraction. We conclude that although breast pain is rarely associated with cancer, localized pain must be fully investigated to exclude this diagnosis.

Intra-arterial thrombolysis should be the initial treatment of the acutely ischaemic lower limb.

We review and discuss the initial management of acute arterial occlusion. Thrombolytic therapy has been available for over 25 years but has failed to gain universal acceptance in the initial management of this condition. Support for the use of initial thrombolytic therapy in all patients is based on the following arguments. It may be difficult to distinguish clinically between an embolic or a thrombotic occlusion, and inappropriate surgery in the latter may have disastrous consequences. Therefore, arteriography should be performed in all patients. It is then easy to place a catheter for thrombolytic therapy. This therapy allows treatment of associated medical problems before definitive surgery, and it may enable a more accurate assessment of the obstruction and better planning of surgery after dissolution of some of the occluding thrombus. Recanalisation may make reconstructive surgery easier and, finally, the results with initial thrombolysis are better than with surgery alone. The case against the motion is that expeditious surgery is in the patient's best interest, particularly in embolus, and when there is ischaemic damage to the limb. Furthermore, the reports of thrombolysis currently available are uncontrolled and do not demonstrate convincingly that the results of thrombolytic therapy are superior to surgery alone.

Early experience with B mode ultrasound mapping of the long saphenous vein prior to femorodistal bypass.

B mode ultrasound was used to assess and map the long saphenous vein in 20 limbs prior to femorodistal bypass. The assessment was compared with operative findings. Eighteen of 19 adequate veins and 8 of 9 anatomical abnormalities or major divisions were correctly identified. B mode ultrasound allows accurate marking of the vein, facilitating dissection, alerts the surgeon to possible difficulties and is an ideal non-invasive technique for preoperative assessment of the long saphenous vein.