A phenotype of early infancy predicts reactivity of the amygdala in male adults.

One of the central questions that has occupied those disciplines concerned with human development is the nature of continuities and discontinuities from birth to maturity. The amygdala has a central role in the processing of novelty and emotion in the brain. Although there is considerable variability among individuals in the reactivity of the amygdala to novel and emotional stimuli, the origin of these individual differences is not well understood. Four-month old infants called high reactive (HR) demonstrate a distinctive pattern of vigorous motor activity and crying to specific unfamiliar visual, auditory and olfactory stimuli in the laboratory. Low-reactive infants show the complementary pattern. Here, we demonstrate that the HR infant phenotype predicts greater amygdalar reactivity to novel faces almost two decades later in adults. A prediction of individual differences in brain function at maturity can be made on the basis of a single behavioral assessment made in the laboratory at 4 months of age. This is the earliest known human behavioral phenotype that predicts individual differences in patterns of neural activity at maturity. These temperamental differences rooted in infancy may be relevant to understanding individual differences in vulnerability and resilience to clinical psychiatric disorder. Males who were HR infants showed particularly high levels of reactivity to novel faces in the amygdala that distinguished them as adults from all other sex/temperament subgroups, suggesting that their amygdala is particularly prone to engagement by unfamiliar faces. These findings underline the importance of taking gender into account when studying the developmental neurobiology of human temperament and anxiety disorders. The genetic study of behavioral and biologic intermediate phenotypes (or 'endophenotypes') indexing anxiety-proneness offers an important alternative to examining phenotypes based on clinically defined disorder. As the HR phenotype is characterized by specific patterns of reactivity to elemental visual, olfactory and auditory stimuli, well before complex social behaviors such as shyness or fearful interaction with strangers can be observed, it may be closer to underlying neurobiological mechanisms than behavioral profiles observed later in life. This possibility, together with the fact that environmental factors have less time to impact the 4-month phenotype, suggests that this temperamental profile may be a fruitful target for high-risk genetic studies.

Prevalence, diversity, and interaction patterns of avian haemosporidians in a four-year study of blackcaps in a migratory divide.

Migratory birds contribute to the movement of avian parasites between distant locations, thereby influencing parasite distribution and ecology. Here we analyse the prevalence, diversity and interaction patterns of Haemosporida parasites infecting Blackcap (Sylvia atricapilla) populations in a recently established migratory divide of southwestern Germany across 4 years. We hypothesize that the temporal and spatial isolation provided by 2 sympatric Blackcap breeding populations (migratory divide) might modify ecological interactions and thus create differences in the structure of the parasite community according to migratory route. We used a fragment of the mitochondrial DNA cytochrome b gene to determine haemosporidian haplotypes. We detected an overall infection prevalence of 70.3% (348 out of 495 blackcaps sampled from 2006 to 2009), and prevalence rates were significantly different among years and seasons. We observed a total of 27 parasite haplotypes infecting blackcaps, from them 6 new rare Haemoproteus haplotypes were found in 2 mixed infections. H. parabelopolskyi haplotypes SYAT01 (35.7%) and SYAT02 (20.8%) comprised most of the infections. An association analysis suggests that SYAT01 and SYAT02 are interacting negatively, implying that they are either competing directly for host resources, or indirectly by eliciting a cross-immune response. Molecular data show no clear difference between the parasite communities infecting blackcaps with different migratory routes, despite some temporal and spatial isolation between the two sympatric blackcap populations.

Biomechanics of the sarcolemma and costameres in single skeletal muscle fibers from normal and dystrophin-null mice.

We studied the biomechanical properties of the sarcolemma and its links through costameres to the contractile apparatus in single mammalian myofibers of Extensor digitorum longus muscles isolated from wild (WT) and dystrophin-null (mdx) mice. Suction pressures (P) applied through a pipette to the sarcolemma generated a bleb, the height of which increased with increasing P. Larger increases in P broke the connections between the sarcolemma and myofibrils and eventually caused the sarcolemma to burst. We used the values of P at which these changes occurred to estimate the tensions and stiffness of the system and its individual elements. Tensions of the whole system and the sarcolemma, as well as the maximal tension sustained by the costameres, were all significantly lower (1.8-3.3 fold) in muscles of mdx mice compared to WT. Values of P at which separation and bursting occurred, as well as the stiffness of the whole system and of the isolated sarcolemma, were ~2-fold lower in mdx than in WT. Our results indicate that the absence of dystrophin reduces muscle stiffness, increases sarcolemmal deformability, and compromises the mechanical stability of costameres and their connections to nearby myofibrils.

The actin binding domain of ACF7 binds directly to the tetratricopeptide repeat domains of rapsyn.

Formation of the neuromuscular junction requires the release of agrin from the presynaptic terminal of motor neurons. Clustering of acetylcholine receptors (AChRs) on the postsynaptic sarcolemma is initiated by agrin-dependent activation of the muscle-specific kinase. While the postsynaptic scaffolding protein rapsyn is vital for high density AChR aggregation, little is known about the mechanism through which AChRs are immobilized on the postsynaptic membrane. Ultrastructural and immunohistochemical studies of rat skeletal muscle have suggested that AChRs are anchored to a membrane-associated cytoskeleton that contains spectrin-like proteins and is thus similar to that of the human erythrocyte [Bloch RJ, Bezakova G, Ursitti JA, Zhou D, Pumplin DW (1997) A membrane skeleton that clusters nicotinic acetylcholine receptors in muscle. Soc Gen Physiol Ser 52:177-195]. We are studying a protein of the spectrin superfamily, ACF7 (also known as MACF), as a postsynaptic cytoskeletal component of the neuromuscular junction. ACF7 has multiple cytoskeleton-binding domains, including an N-terminal actin-binding domain that, we postulate, may interact with rapsyn, the scaffolding protein that binds directly to AChRs. To test this hypothesis, we co-expressed fragments of these molecules in cultured fibroblasts and assessed their co-distribution and interaction using confocal microscopy and co-immunoprecipitation. We demonstrate that the actin-binding domain of ACF7 specifically interacts with the tetratricopeptide repeat domains of rapsyn. Furthermore, we show using surface plasmon resonance and blot overlay that the actin-binding domain of ACF7 binds directly to rapsyn. These results suggest that, in mammalian skeletal muscle, AChRs are immobilized in the membrane through rapsyn-mediated anchoring to an ACF7-containing network that in turn is linked to the actin cytoskeleton.

The tetratricopeptide repeat domains of rapsyn bind directly to cytoplasmic sequences of the muscle-specific kinase.

Clustering of acetylcholine receptors at the developing vertebrate neuromuscular junction is initiated by neural agrin, which stimulates the activity of the muscle-specific kinase (MuSK). Acetylcholine receptor clustering is also dependent on the postsynaptic scaffolding protein, rapsyn, which binds to acetylcholine receptors. Here, we address the possibility that MuSK and rapsyn bind directly to each other by coexpressing sequences of the cytoplasmic domain of MuSK with rapsyn in COS-7 cells and assaying for codistribution and biochemical interaction. Sequences constituting the bulk of the kinase domain can interact with rapsyn. This interaction is mediated by the tetratricopeptide repeat domains, but not the coiled coil or zinc finger domains, of rapsyn. This interaction does not require tyrosine phosphorylation of the MuSK sequences. Binding is direct, as indicated by blot overlay and surface plasmon resonance experiments. The sequence of the cytoplasmic domain of MuSK that most effectively codistributes with rapsyn confers the ability of an otherwise inactive receptor tyrosine kinase, TrkA, to associate with rapsyn. Our results support a model in which the tetratricopeptide repeat domains of rapsyn bind directly to the cytoplasmic portion of MuSK, which could thereby serve as an initial scaffold for the clustering of acetylcholine receptors.

Impact of activating killer immunoglobulin-like receptor genotype on outcome of unrelated donor-hematopoietic cell transplantation.

BACKGROUND: In a previous study we demonstrated that incompatibility regarding ligands for inhibitory killer immunoglobulin-like receptors (KIRs) is associated with a survival advantage following unrelated donor-hematopoietic cell transplantation (URD-HCT). The goal of the present analysis was to evaluate whether genotype of activating KIRs of the donor may have an impact on the outcome of URD-HCT. PATIENTS AND METHODS: Twenty-five URD-HCT recipients with hematological malignancies, mean age 27 years (range, 14-43 years), were included in the analysis. The conditioning regimen was myeloablative and based on chemotherapy alone (n = 20) or total body irradiation (n = 5). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine, methotrexate, and pretransplant antithymocyte globulin. Patients were grouped according to their donors' activating KIR genotype including two loci: KIR2DS1 and KIR2DS2. RESULTS: The presence of KIR2DS1 in the donor (n = 16/25) was not demonstrated to influence outcome. In contrast, the presence of KIR2DS2 (n = 13/25 donors) was associated with decreased probability of overall survival (0% vs 92%, P = .04) and disease-free survival (0% vs 92%, P = .046). The reason for failures in the KIR2DS2-positive group was chronic GVHD (n = 4), acute GVHD (n = 2), and relapse (n = 1). The cumulative incidence of nonrelapse mortality equaled 90% for the KIR2DS2-positive group and 8% for the KIR2DS2-negative group (P = .09). CONCLUSION: The presence of KIR2DS2 gene in the donor is associated with a high risk of mortality following URD-HCT, resulting mainly from the incidence of severe GVHD. Whether this effect is associated with the activity of natural killer cells or KIR-bearing T lymphocytes requires further investigation.

Antimicrobial activity of Polyscias filicifolia cell biomass extracts.

Antibacterial activity of extracts of Polyscias filicifolia biomass from bioreactor and callus was determined using the agar disc-diffusion method. The microorganisms Staphylococcus aureus (three strains) showed the highest sensitivity to extracts of P. filicifolia biomass from a bioreactor. The values were comparable with nitrofurantoine used as a standard. Micrococcus flavus, Sreptococcus pyogenes and S. agalatiae were less sensitive. The effect of P. filicifolia callus extract on the above bacteria was less pronounced than that of extracts of biomass from a bioreactor.

The Swiss catalogue of learning objectives.

PBL philosophy may challenge the need for explicit and specific educational objectives in medical education. From a practical point of view, however, such objectives are essential to achieve a close overlap between learning, teaching and assessment. Since the 1970s medical licensing in Switzerland has been based, among other things, on passing a uniform, centrally prepared MCQ exam for the graduates of all five Swiss medical schools. The need for a set of jointly developed learning, teaching and assessment objectives has become apparent. The Joint Conference of Swiss Medical Schools has therefore charged a small taskforce with the development of such a catalogue. This paper describes the background, process and results of this work.

Sequential analysis for quality control in the neonatal intensive care unit.

OBJECTIVE: This article describes a novel application of a statistical technique for continuous quality assurance in the NICU. METHODS: We used prospective analysis of rates of survival to 28 days of life, without major IVH in ELBW infants in a single tertiary NICU, before and after the introduction of an evidence-based treatment protocol. By using the CUSUM function, each infant's results were sequentially plotted, and significant changes in outcomes were noted when the plot crossed predetermined boundary lines. RESULTS: Significant changes in outcomes were evident with this method sooner than traditional analyses on the basis of year-end or other arbitrary intervals. The introduction of the ELBW protocol was temporally associated with significant improvement in intact short-term survival. CONCLUSION: Sequential analysis techniques are useful tools for ongoing quality assurance; deviations in outcomes may be detected more quickly, which should assist in the identification of improvements or decrements in performance of the NICU.

Peripherally inserted central catheters with distal versus proximal valves: prospective randomized trial.

PURPOSE: To evaluate whether peripherally inserted central catheters (PICCs) with a proximal valve have any advantage compared to those with a distal valve in regard to the incidence of occlusion, infection, or malfunction. MATERIALS AND METHODS: One hundred patients (mean age, 46 y) were randomized to receive either a distal-valved Bard Groshong catheter (n = 48) or a proximal-valved Catheter Innovations Pressure Activated Safety Valve catheter (n = 52). All catheters were 4-F, single-lumen PICCs. Catheters were placed under fluoroscopic (n = 82) or sonographic (n = 18) guidance. Most (91%) were placed for the administration of antibiotics. The placement procedure, maintenance, and weekly follow-up were the same for both catheters. RESULTS: Percutaneous placement with the catheter tip in the central veins was successful in all patients. Mean dwell time was 36 days. There were 12 (25%) occlusive or infectious complications in the distal valve catheter group and six (11.5%) in the proximal valve group (P = .08). There were 25 fractures in 17 distal valve catheters (35.4%) and three (5.8%) proximal valve catheter fractures (P < .01). CONCLUSION: There was a marked difference in durability between the valved catheters, in favor of the catheter with a proximal valve. There was also a trend for fewer occlusive and infectious complications with the proximal valve catheter.

Type III heart block with peripheral use of the Angiojet thrombectomy system.

The authors describe the occurrence of type III heart block in a patient undergoing a transjugular intrahepatic portosystemic shunt recanalization with use of the AngioJet thrombectomy system.

Caffeine promotes an ethanol-induced conditioned taste aversion: a dose-dependent interaction.

The present study examined whether caffeine administered within a dose range previously shown to promote ethanol drinking would also alter an ethanol-induced conditioned taste aversion (CTA). The results revealed a dose-dependent interaction between caffeine and ethanol where caffeine (2.5 and 10 mg/kg) promoted an ethanol-induced CTA at a low ethanol dose (1.0 g/kg) but had no effect in blocking CTA at the higher ethanol dose (1.5 g/kg). These results were found to be unrelated to an alteration in ethanol metabolism, as caffeine had no effect in altering blood ethanol levels at the doses tested. In agreement with the reward comparison hypothesis, the present results suggest that rather than attenuate ethanol's "aversive" effects, caffeine may have promoted an ethanol-induced CTA by increasing the reinforcing efficacy of ethanol.

Stent placement in the treatment of pulmonary artery stenosis secondary to fibrosing mediastinitis.

This article describes an initial experience with stent placement in three patients with severe pulmonary artery stenosis secondary to fibrosing mediastinitis. All three patients were severely symptomatic on admission and all three were asymptomatic after treatment and remained symptom-free approximately 1 year after treatment.

Oral gossypol in the treatment of patients with refractory metastatic breast cancer: a phase I/II clinical trial.

Gossypol has demonstrated in vitro effects on cell cycle regulation and anti-tumor activity against mammary carcinoma cell lines. This Phase I/II study assesses both the effect of gossypol on cell cycle regulatory proteins in vivo and the clinical effect. Twenty women with refractory metastatic breast cancer received oral gossypol at daily doses between 30 and 50 mg per day. Gossypol plasma levels were measured (n = 8) and the modulation of the retinoblastoma (Rb) gene protein and Cyclin D1 was assessed by serial biopsies (n = 4). Grade I-II toxicities with gossypol treatment included nausea in 30% of patients, fatigue 15%, emesis 15%, altered taste sensation 15% and diarrhea in 10% of patients. Two of the three patients receiving 50 mg/day experienced dose limiting dermatologic toxicity (grade III). One patient had a minor response and two patients had stable disease with > 50% decline in serial assessments of the serum tumor markers. Immunohistochemical analysis of cyclin D1 and Rb expression in serial biopsies of four patients revealed both a concurrent decrease in cyclin D1 expression and an increase in nuclear Rb expression in three patients. The maximal tolerated dose (MTD) of gossypol was 40 mg/day. Gossypol appears to affect the expression of Rb protein and cyclin D1 in breast cancer metastases at doses achievable, yet had negligible antitumor activity against anthracycline and taxane refractory metastatic breast cancer. The cell cycle regulatory effects of gossypol suggest a potential role for gossypol as a modulating agent in conjunction with other cell cycle specific compounds.

CT-guided transfemoral portocaval shunt creation.

A patient with superior vena cava (SVC) occlusion presented with severe ascites and urgent transjugular intrahepatic portosystemic shunt (TIPS) was requested. The patient had a chronically occluded SVC. An alternative to classic TIPS was employed using CT guidance to traverse the left portal vein to the inferior vena cava with a small gauge needle. Fluoroscopic guidance was then used to snare a wire placed through the needle and then work from the femoral vein to create a portocaval shunt that passed through the caudate lobe. This procedure was a technical success and improved the patient's ascites.

Spectrins in developing rat hippocampal cells.

We studied the spectrins in developing hippocampal tissue in vivo and in vitro to learn how they contribute to the organization of synaptic and extrasynaptic regions of the neuronal plasma membrane. beta-Spectrin, but not beta-fodrin or alpha-fodrin, increased substantially during postnatal development in the hippocampus, where it was localized in neurons but not in astrocytes. Immunoprecipitations from neonatal and adult hippocampal extracts suggest that while both beta-spectrin and beta-fodrin form heteromers with alpha-fodrin, oligomers containing all three subunits are also present. At the subcellular level, beta-fodrin and alpha-fodrin were present in the cell bodies, dendrites, and axons of pyramidal-like neurons in culture, as well as in astrocytes. beta-Spectrin, by contrast, was absent from axons but present in cell bodies and dendrites, where it was organized in a loose, membrane-associated meshwork that lacked alpha-fodrin. A similar meshwork was also apparent in pyramidal neurons in vivo. At some dendritic spines, alpha-fodrin was present in the necks but not in the heads, whereas beta-spectrin was present at significant levels in the spine heads. The presence of significant amounts of beta-spectrin without an accompanying alpha-fodrin subunit was confirmed by immunoprecipitations from extracts of adult hippocampus. Our results suggest that the spectrins in hippocampal neurons can assemble to form different membrane-associated structures in distinct membrane domains, including those at synapses.

Prevalence of depersonalization and derealization experiences in a rural population.

BACKGROUND: Dissociative symptoms are common psychiatric symptoms whose prevalence in rural (agricultural) populations is unknown. The present study examines the prevalence of depersonalization and derealization experiences in a southern rural US population as well as socio-demographic and emotional factors associated with these experiences. METHOD: A random sample of 1008 adults in rural eastern North Carolina completed a survey by telephone, which included questions about experiences of depersonalization or derealization in the past year. Demographic information was gathered on all respondents; for those reporting these dissociative experiences, information on their frequency, duration, and whether they occurred during conditions of danger, severe stress, upsetting memories, nervousness or depression, or for no apparent reason was also elicited. RESULTS: The reported prevalence rates were 19.1% for depersonalization, 14.4% for derealization, and 23.4% for either dissociative experience. Logistic regression showed that women reported a significantly higher rate of dissociative experiences (26.5%) than men (19.5%), (Odds Ratio = 1.93, 95% CI = 1.37-2.74), particularly African-American women (29.9%). Experiencing chronic pain (OR = 2.96, 95% CI = 2.05-4.28) and irregular church attendance (OR = 1.18, 95% CI = 1.07-1.31) were also associated with increased frequency of dissociation. Increasing age (OR = 0.73, 95% CI = 0.65-0.81) and being employed (OR = 0.58, 95% CI = 0.39-0.86) were associated with reduced frequency of dissociation. Pain, gender, and age were related to both depersonalization and derealization experiences. Employment and church attendance were related to depersonalization experiences, while ethnic minorities experienced more derealization. CONCLUSIONS: A predominantly southern rural population reported a high 1-year prevalence of depersonalization and derealization experiences. The prevalence of dissociation experiences was common in this southern sample, as was found by Ross and colleagues (1990) in an urban population in Canada. Risk factors for depersonalization and derealization experiences had considerable overlap, but differed on several variables suggesting different underlying mechanisms.

Evaluation of local abciximab delivery from the surface of a polymer-coated covered stent: in vivo canine studies.

PURPOSE: To determine the in vitro feasibility of abciximab absorption and elution from a polymer-coated, silicone-covered stent, and to determine the in vivo effect of local delivery of abciximab concerning endothelialization of a polymer-coated, silicone-covered stent in a canine model. MATERIALS AND METHODS: Six polymer-coated, silicone-lined Wallstents were soaked in 2 mg/mL of concentrated solution of I131-labeled abciximab for a period as long as 48 hours. Quantification of abciximab absorption was determined by photon emission. Six maximally drug-loaded devices were then washed continuously with normal saline with use of a pustule pump apparatus. The quantity of residual abciximab was determined by photon emission for a period as long as 16 days. Eight similar devices (as described previously) were then implanted within the iliac arteries of four adult canines. Devices were identical except that four of eight were maximally loaded with abciximab. For each animal, one control implant was placed in the right iliac artery and one experimental implant (drug loaded) was placed in the left iliac artery, via right carotid cutdown. Animals were allowed to recover and no chronic medications were given. After an interval of 6 weeks, the animals were killed. Implants were isolated and perfused with 10% buffered formalin at a pressure of approximately 100 mm Hg for a period of 1 hour. Each implant was encased in methacrylate, sectioned into six equal segments, ground and polished, and stained with hematoxylin and eosin. Each slide was projected on a screen and the thickness of the neointima quantified. The mean neointima was determined for control and experimental groups, and compared for a potential significant difference with a Student t test. RESULTS: Mean absorption of abciximab was 21.53 microg +/- 2.99 per device. Devices were fully saturated at 24 hours. Forty percent was absorbed at 1 hour, and 60% and 80% were absorbed at 4 hours and 12 hours, respectively. Regarding elution, 30% of abciximab was washed out after 1 hour. There was a gradual elution of the drug to 16 days, with approximately 40% remaining at the end of the term. Mean neointimal thickness was 995 microm +/- 597 for the experimental group and 1,738 microm +/- 1,042 for the control group. The difference was significant (P <.05). CONCLUSIONS: Absorption and elution of abciximab from the surface of a covered stent is feasible. Local delivery of abciximab from the surface of this covered stent reduced the thickness of endothelial lining in the canine iliac artery compared to control.