Synthesis of Antimonene on Germanium.

The lack of large-area synthesis processes on substrates compatible with industry requirements has been one of the major hurdles facing the integration of 2D materials in mainstream technologies. This is particularly the case for the recently discovered monoelemental group V 2D materials which can only be produced by exfoliation or growth on exotic substrates. Herein, to overcome this limitation, we demonstrate a scalable method to synthesize antimonene on germanium substrates using solid-source molecular beam epitaxy. This emerging 2D material has been attracting a great deal of attention due to its high environmental stability and its outstanding optical and electronic properties. In situ low energy electron microscopy allowed the real time investigation and optimization of the 2D growth. Theoretical calculations combined with atomic-scale microscopic and spectroscopic measurements demonstrated that the grown antimonene sheets are of high crystalline quality, interact weakly with germanium, exhibit semimetallic characteristics, and remain stable under ambient conditions. This achievement paves the way for the integration of antimonene in innovative nanoscale and quantum technologies compatible with the current semiconductor manufacturing.

Magnitude of change in alpha-fetoprotein in response to transarterial chemoembolization predicts survival in patients undergoing liver transplantation for hepatocellular carcinoma.

BACKGROUND: Downsizing strategies are often attempted for patients with hepatocellular carcinoma (hcc) before liver transplantation (lt). The objective of the present study was to determine clinical predictors of favourable survival outcomes after transarterial chemoembolization (tace) before lt for hcc outside the Milan criteria, so as to better select candidates for this strategy. METHODS: In this retrospective study, patients with hcc tumours either beyond Milan criteria (single lesion > 5 cm, 3 lesions with 1 or more > 3 cm) or at the upper limit of Milan criteria (single lesions between 4.1 cm and 5.0 cm), with a predicted waiting time of more than 3 months, received carboplatin-based tace treatments. Exclusion criteria for tace included Child-Pugh C cirrhosis or the presence of portal vein invasion or extrahepatic disease on imaging. Only patients without tumour progression after tace underwent lt. RESULTS: Of 160 hcc patients who received liver grafts between 1997 and 2010, 35 were treated with tace preoperatively. The median of the sum of tumour diameters was 6.7 cm (range: 4.8-8.5 cm), which decreased with tace to 5.0 cm (range: 3.3-7.0 cm) at transplantation (p < 0.0004). The percentage drop in alpha-fetoprotein (αfp) was a positive predictor (p = 0.0051) and the time from last tace treatment to transplantation was a negative predictor (p < 0.0001) for overall survival. CONCLUSIONS: The percentage drop in αfp and a shorter time from the final tace treatment to transplantation significantly predicted improved overall survival after lt for hcc downsized with tace. As a serum marker, αfp should be followed when tace is used as a strategy to stabilize or downsize hcc lesions before lt.

Re-treatment with peginterferon alfa-2a and ribavirin in patients with chronic hepatitis C who have relapsed or not responded to a first course of pegylated interferon-based therapy.

BACKGROUND: Pegylated interferon (pegIFN) and ribavirin combination therapy remains the first-line treatment for chronic hepatitis C virus (HCV) infection. In contrast to the wealth of studies in treatment-naive patients, the effectiveness of retreatment in patients who have previously failed pegIFN-based therapy is largely unreported. AIM: To assess the effectiveness of the retreatment of patients who have previously failed an initial course of pegIFN-based therapy with pegIFNalpha-2a and ribavirin. METHODS: A post-hoc analysis of a multicentre open-label study was performed. Patients received pegIFNalpha-2a and ribavirin at a dose of 800 mg/day and later 1000 mg/day to 1200 mg/day for 24 to 48 weeks at the discretion of the investigator. Outcomes at week 12 (early virological response [EVR]) and week 24 (sustained virological response [SVR]) were analyzed. RESULTS: Eighty-seven patients who had relapsed after previous pegIFN-based therapy (n=28; 78% genotype 1) or were nonresponders (n=59; 71% genotype 1) were analyzed. Of the relapsers, 86% achieved an EVR and 68% achieved an SVR. In relapsers to pegIFN monotherapy (n=15) or pegIFN plus ribavirin (n=13), 60% and 77% achieved an SVR, respectively. Fibrosis and genotype did not affect the likelihood of SVR in relapsers although this may be the result of the relatively small number of patients. In previous nonresponders, an EVR was achieved in 53% but an SVR occurred in only 17%. In nonresponders to pegIFN monotherapy (n=9) and pegIFN plus ribavirin (n=50), 33% and 14% achieved an SVR, respectively. Genotype did not affect SVR in nonresponders. Only 10% with a METAVIR score of F3 or F4 on liver biopsy achieved an SVR. CONCLUSIONS: Relapse after previous pegIFN-based therapy is associated with a strong probability of treatment success whereas retreatment of those with previous nonresponse does not.

Does a rapid decline in the hematological and biochemical parameters induced by interferon and ribavirin combination therapy for the hepatitis C virus predict a sustained viral response?

BACKGROUND AND OBJECTIVES: To analyze whether rapid myelosuppression and a decrease in alanine aminotransferase (ALT) induced by standard interferon (IFN) and ribavirin (RBV) combination therapy predict a sustained viral response (SVR) in hepatitis C virus patients. PATIENTS AND METHODS: Data from 111 patients (mean age 48.1 years) with chronic hepatitis C virus were retrospectively analyzed. All patients were treated with the same initial doses of IFN and RBV combination therapy. The following laboratory values were measured at baseline, and then at weeks 2, 4, 8, 12 and 24 of treatment: hemoglobin, white blood cells (WBCs), neutrophils, platelets and ALT. A delta value was then calculated for each interval from baseline (baseline values minus two weeks, etc). The delta value of each variable was then compared between the responders and nonresponders using Wilcoxon's signed rank test. RESULTS: Sixty patients (54%) achieved an SVR. There were no significant differences between the responder and nonresponder groups for baseline variables. The delta value of ALT was the only significant marker in the prediction of an SVR. The mean +/- SD delta values for the ALT at week 2 of treatment were 71+/-92 U/L and 44+/-85 U/L for the responders and nonresponders, respectively (P<0.0046). At week 4, the values were 101+/-96 U/L and 84+/-100 U/L for the responders and nonresponders, respectively (P<0.0154). The decline was then calculated for the ALT as a percentage decrease from baseline: at weeks 2 and 4, the decreases were 64% and 66%, respectively, for the responders, and 43% and 41%, respectively, for the nonresponders. At week 2, the delta values for WBC count were found to be significant in predicting failure to achieve an SVR, with mean +/- SD delta values of 0.85 x 10(9)/L+/-1.48 x 10(9)/L and 1.53 x 10(9)/L+/-2.16 x 10(9)/L for the responders and nonresponders, respectively (P<0.0173). The same trend emerged at two weeks for neutrophils: 0.72 x 10(9)/L+/-1.33 x 10(9)/L for the responders and 1.02 x 10(9)/L+/-1.20 x 10(9)/L for the nonresponders (P<0.0150). The delta values were insignificant for hemoglobin, lowest hemoglobin values and platelets. CONCLUSIONS: The decline rates of ALT from baseline to week 2 and 4 of IFN and RBV combination therapy are good predictors of an SVR. A significant drop in WBC and neutrophil values is a predictor of failure to achieve an SVR. The hemoglobin, platelets and lowest hemoglobin values failed to predict an SVR.

Survival after liver transplantation for hepatitis C is unchanged over two decades in Canada.

Allograft failure secondary to recurrence of hepatitis C virus (HCV) infection is the most common cause of death and retransplantation among recipients with HCV infection. It has been suggested that patients transplanted for HCV have had worse outcomes in more recent years than in previous years (the 'era effect'). A Canadian transplantation registry database was analyzed to determine the outcomes of patients transplanted over the years for HCV. The results of the present analysis of 1002 patients show that the 'era effect' was not seen in liver transplantation recipients with HCV in Canada, because no survival difference was noted based on the year of transplantation. All groups had overall two-year and five-year survival rates of 76% to 83% and 69% to 72%, respectively. The present study's national results prove continued benefit to transplantation of HCV patients.

Moderate aging does not modulate morphological responsiveness of the neuromuscular system to chronic overload in Fischer 344 rats.

The purpose of this investigation was to determine the effect of aging on neuromuscular adaptations to chronic overload. Eight young adult (8 months old) and eight aged (22 months old) Fischer 344 rats underwent unilateral synergist ablation to overload the plantaris and soleus muscles of that hindlimb and to provide control muscles from the contralateral hindlimb. Cytofluorescent staining and confocal microscopy were used to quantify pre- and post-synaptic features of neuromuscular junctions (NMJs). Histochemical staining and light microscopy were used to assess adaptations of myofibers to chronic overload. Results demonstrate that NMJs of young adult and aged muscles did not undergo morphological remodeling as a result of 4 weeks of chronic overload. In contrast, myofibers of young and aged rats displayed significant (P<0.05), but similar hypertrophy ( approximately 18%) following that 4 week intervention. In both age groups, however, this hypertrophy was detected in the plantaris, but not the soleus. These data indicate that moderate aging (the equivalent of 65 years in human lifetime) does not modify the sensitivity of the neuromuscular system to chronic overload.

Mode of transmission, rather than the hepatitis C virus, as a major determinant of poor interpersonal relationships in patients with chronic hepatitis C.

BACKGROUND: Recent studies have demonstrated that patients with the hepatitis C virus (HCV) have significant neurocognitive impairment. OBJECTIVE: To assess whether chronic HCV infection impacts on patient marital status, living arrangement and employment. METHODS: The charts of patients with chronic hepatitis C and hepatitis B were reviewed. RESULTS: The mean (+/- SD) age of the 129 patients with the hepatitis B virus (HBV) was 46+/-15 years and that of the 428 patients with HCV was 48+/-15 years. Sixty-seven per cent of HBV patients were men, compared with 68% of HCV patients. Eighty per cent of HCV patients were Caucasian, compared with 44% of patients with HBV. The main modes of transmission were intravenous drug use (37%) and transfusion of blood products (37%) for HCV, compared with country of origin (76%) for HBV. There were no differences in marital status rates between HBV- and HCV-infected patients (HBV - married (73%), single (21%) and divorced (6%); and HCV - married (66%), single (23%) and divorced (10%); P=0.20). HCV patients lived alone more often than HBV patients (HBV - 13%, HCV - 22%; P=0.03). There was no difference in overall employment rate between HCV and HBV patients (81% versus 87%; P=0.15). Though there may not have been overall differences between HCV and HBV marital status and employment status, there were differences in the HCV subgroups. These subgroup differences were discovered in the multivariate analysis; mode of transmission was identified as the only predictor of the patients' marital status and employment status. CONCLUSIONS: The most important determinant of interpersonal relationships was the mode of transmission of the viral hepatitis rather than the type of viral infection: past intravenous drug users had lower level relationships.

Moral distress in the neonatal intensive care unit: caregiver's experience.

BACKGROUND: The Neonatal Intensive Care Unit (NICU) can be ethically charged, which can create challenges for health-care workers. OBJECTIVE: To determine the frequency with which nurses and residents have experienced ethical confrontations and what factors are associated with increased frequency. DESIGN/METHODS: An anonymous questionnaire was distributed to nurses in a university center, a high-risk obstetric service, a maternity hospital NICU with 85% in-born patients and an outborn NICU, most of whose preterm admissions are those with surgical complications. Obstetric and pediatric residents in the four universities of the province also received the questionnaire, which included demographics, opinions regarding the gestational age threshold at which resuscitation of a premature infant with bradycardia was appropriate, knowledge of cerebral palsy (CP) outcomes (as an indicator of knowledge about long-term sequelae of prematurity) and questions about ethical confrontation in the NICU. RESULTS: Two hundred and seventy-nine caregivers participated (115 full time nurses and 164 residents). All the distributed questionnaires were completed. Frequent ethical confrontation was reported by 35% of the nurses and 19% of the residents. Among the nurses, moral distress differed significantly between work environments. Nurses working in an out-born NICU and obstetric nurses were more likely to overestimate CP prevalence (P<0.05). Nurses who overestimated CP rates had higher thresholds for resuscitation and were more likely to experience ethical confrontations. Of the residents, 60% were pediatric and 40% obstetric. All groups of residents frequently overestimated the prevalence of CP, and knowledge differed significantly by residency program (P<0.05). The residents who overestimated CP rates had higher thresholds for resuscitation, had more incorrect answers regarding prematurity outcomes and were less likely to have ethical confrontations. CONCLUSIONS: A large proportion of nurses and residents report frequent ethical confrontations. Many residents and nurses have limited knowledge of outcomes and high threshold for resuscitation. Ethical confrontation is more common among nurses with poor knowledge about outcomes, and less common in residents with poor knowledge about outcomes.

Increased and decreased activity elicits specific morphological adaptations of the neuromuscular junction.

The objective of this investigation was to compare the effects of decreased vs. increased activity on the neuromuscular system. Twenty-four young adult (7 weeks old) Sprague-Dawley rats were randomly assigned to three treatment groups (N=8/group). Increased activity was achieved by treadmill running for up to 1 h/day. Decreased activity was induced by muscle unloading via the hindlimb suspension model. Control animals engaged in normal weight bearing and ambulatory activity. At the end of the 10 week intervention period, animals were killed and soleus muscles were removed, quickly frozen, and examined using cytofluorescent (neuromuscular junctions) and histochemical (myofibers) procedures. Pre-synaptic morphology was quantified by measuring nerve terminal branching, and post-synaptic assessment was conducted by staining acetylcholine receptors at the endplate. Myofiber profiles of solei were compiled by determining fiber size (cross-sectional area) and fiber type composition. Results show that exercise training significantly (P

Treating chronic hepatitis C with pegylated interferon alfa-2a (40 KD) and ribavirin in clinical practice.

BACKGROUND: Pegylated interferon alfa-2a (40 KD) plus ribavirin therapy induces sustained virological response rates up to 63% in randomized-controlled trials. AIM: To conduct a prospective open-label programme to examine the efficacy and safety of this therapy in routine clinical practice. METHODS: Treatment-naive patients with chronic hepatitis C received, at the discretion of the investigator, pegylated interferon alfa-2a 180 microg/week + ribavirin 800 mg/day for 24 or 48 weeks. In total, 508 patients were enrolled [334 non-cirrhotic; 174 cirrhotic (defined as stage F3 and F4)]. RESULTS: In genotype 1 patients treated for 48 weeks, sustained virological response rates were 41% in non-cirrhotics and 34% in cirrhotics. Sustained virological response rates in genotype 2 or 3 non-cirrhotics were 79% (24 weeks) and 72% (48 weeks). Corresponding values for cirrhotic genotype 2/3 were 66% and 44%. The negative predictive value of an early virological response at week 12 was 94%. Predictive factors for sustained virological response on multivariate analysis were genotype (2/3 vs. 1), low viral load and degree of fibrosis. Rates of serious adverse events (

Elderly patients are at greater risk of cytopenia during antiviral therapy for hepatitis C.

UNLABELLED: The results of antiviral therapy for hepatitis C virus (HCV) have improved recently with the use of pegylated interferon (PEG-IFN)/ribavirin (RBV) combination therapy. At this point, most patients with chronic HCV remain untreated. Thus, it is anticipated that therapy will be more appealing and prescribed more broadly than in the past, including in patients considered marginal. AIM: To examine the effects of PEG-IFN-based antiviral therapy in elderly patients with chronic HCV. METHODS: The charts of patients treated with chronic HCV were reviewed. Patients were defined as elderly if they were 60 years of age or older. The control group consisted of patients younger than 60 years of age who were matched to the treated elderly patients based on sex, treating physician, prescribed treatment and intended prescribed treatment duration. The data recorded included end of treatment response, sustained virological response (SVR), adverse events, dose modification and withdrawal of therapy. RESULTS: Thirty of 147 (20.4%) elderly patients attending a hepatitis C clinic were treated. The average age of the elderly patients was 65+/-4 years. Forty-three per cent were men and 57% were women. Ten per cent received IFN monotherapy, 70% received a combination of IFN/RBV therapy and 20% received a combination of PEG-IFN/RBV therapy. The overall response rates in the elderly patients compared with the younger patients was 46.7% versus 65.8% (P=0.11) for end of treatment response and 33.3% versus 51.2% (P=0.13) for SVR. The rate of dose modification was 50% in the elderly patients compared with 29% in the control group (P=0.08). Therapy was discontinued in 53% of the elderly compared with 34% of younger patients (P=0.17). The younger patients reported more side effects than elderly patients; although, there were more laboratory abnormalities (anemia, thrombocytopenia and neutropenia) in the elderly patients during therapy than in the younger group (0.93 per patient versus 0.49 per patient, P=0.01). CONCLUSION: Elderly patients with chronic HCV can be treated successfully. However, they are more at risk to develop cytopenias while on treatment. In such patients, the close monitoring of blood counts is necessary. Larger studies are needed to confirm these findings and to determine whether SVR differs in this population.

Effects of exercise training on neuromuscular junction morphology and pre- to post-synaptic coupling in young and aged rats.

The objective of this study was to determine whether pre- to post-synaptic coupling of the neuromuscular junction (NMJ) could be maintained in the face of significant morphological remodeling brought about by exercise training, and whether aging altered this capacity. Eighteen young adult (8 mo) and eighteen aged (24 mo) Fischer 344 rats were randomly assigned to either endurance trained (treadmill running) or untrained control conditions resulting in four groups (N=9/group). After the 10-week intervention rats were euthanized and hindlimb muscles were surgically removed, quickly frozen at approximate resting length and stored at -85°C. The plantaris and EDL muscles were selected for study as they have different functions (ankle extensor and ankle flexor, respectively) but both are similarly and overwhelmingly comprised of fast-twitch myofibers. NMJs were stained with immunofluorescent procedures and images were collected with confocal microscopy. Each variable of interest was analyzed with a 2-way ANOVA with main effects of age and endurance training; in all cases significance was set at P⩽0.05. Results showed that no main effects of aging were detected in NMJs of either the plantaris or the EDL. Similarly, endurance training failed to alter any synaptic parameters of EDL muscles. The same exercise stimulus in the plantaris however, resulted in significant pre- and post-synaptic remodeling, but without altering pre- to post-synaptic coupling of the NMJs. Myofiber profiles of the same plantaris and EDL muscles were also analyzed. Unlike NMJs, myofibers displayed significant age-related atrophy in both the plantaris and EDL muscles. Overall, these results confirm that despite significant training-induced reconfiguration of NMJs, pre- to post-synaptic coupling remains intact underscoring the importance of maintaining proper apposition of neurotransmitter release and binding sites so that effective nerve to muscle communication is assured.

Single- and multi-whisker channels in the ascending projections from the principal trigeminal nucleus in the rat.

This study investigated the relationship between axonal projections and receptive field properties of whisker-sensitive cells in the principal trigeminal sensory nucleus of the rat. The labeling of small groups of trigeminothalamic axons with biotinylated dextran amine disclosed two broad classes of axons; a majority of fibers (68%; n = 107) project to a single barreloid of the ventral posteromedial nucleus, and the remaining group includes axons that innervate both the posterior group of the thalamus and the tectum. Additional terminal sites for axons of this latter group may include the pretectum, the zona incerta, the medial part of the medial geniculate nucleus, and the ventral posteromedial nucleus. Corresponding to these two classes of fibers, 67% of the cells in the principal trigeminal nucleus (n = 313) have single-whisker receptive fields, whereas the rest of the population have receptive fields composed of multiple whiskers. The tonic or phasic properties of the responses apparently bear no relation to the axonal projection patterns. Solid retrograde labeling of cells that project to the ventral posteromedial nucleus and intracellular staining revealed that single-whisker cells have small somata and narrow, barrelette-bounded dendritic trees. In contrast, multi-whisker neurons have large multipolar somata, expansive dendritic trees, and many respond antidromically to stimulation of the superior colliculus. Together, these results provide evidence for two main channels of vibrissal information: a single-whisker channel that links trigeminal barrelettes to their corresponding barreloids, and a multi-whisker channel that distributes principally in the posterior group and tectum.

Parallel streams for the relay of vibrissal information through thalamic barreloids.

This study investigated the organization of a vibrissal pathway that arises from the interpolar division of the spinal trigeminal complex (SP5i), transits through the ventral posterior medial nucleus (VPM), and innervates the somatosensory cortical areas in the rat. Using Fluoro-Gold and biotinylated dextran amine, respectively, as retrograde and anterograde tracers, the following organization plan was disclosed. The SP5i projection arises from a population of small-sized neurons that selectively innervate the ventral lateral part of VPM. In cytochrome oxidase-stained material, this region does not display any barreloid arrangement, but Fluoro-Gold injections in single barrel columns labeled rods of cells that extend caudally into the ventral lateral division of VPM. Thus, on the basis of retrograde labeling, barreloids were divided into core and tail compartments, which correspond to the rod segments running across the dorsal and ventral lateral parts of VPM, respectively. Double-labeling experiments revealed that SP5i afferents innervate the tail of barreloids. The anterograde labeling of thalamocortical axons show that most "core cells" project to a single barrel column, whereas some "tail cells" give rise to branching axons that innervate the second somatosensory area and the dysgranular zone of the barrel field. Injections that straddled the transition zone between the core and tail regions disclosed cells projecting to a single barrel column and to the surrounding dysgranular zone. These results suggest that the projection of "barreloids cells" to the granular and/or dysgranular zones relates to the class of prethalamic input(s) they receive.

Projection and innervation patterns of individual thalamic reticular axons in the thalamus of the adult rat: a three-dimensional, graphic, and morphometric analysis.

The gamma-aminobutyric acid-ergic thalamic reticular nucleus (Rt), which carries matching topographical maps of both the thalamus and cortex and in which constituent cells can synaptically communicate between each other, is the major extrinsic source of thalamic inhibitions and disinhibitions. Whether all the Rt axonal projections into the thalamus are similarly organized and have common projection and innervation patterns are questions of great interest to further our knowledge of the functioning of the Rt. The present study provides architectural and morphometric data of individual, anterogradely labeled axonal arbors that arose from distinct parts of the Rt. One hundred twenty-seven Rt neurons from all regions of Rt were marked juxtacellularly with biocytin or Neurobiotin in urethane-anesthetized adult rats. Eighteen two-dimensional and 14 three-dimensional reconstructions of single tracer-filled Rt neurons were made from serial, frontal, horizontal, or sagittal sections. Both the somatodendritic and axonal fields of tracer-filled Rt cells were mapped in three dimensions and illustrated to provide a complementary stereotaxic reference for future studies. Most marked units projected to a single nucleus of the anterior, dorsal, intralaminar, posterior, or ventral thalamus. Axons emerging from cells in distinct sectors of the Rt projected to distinct nuclei. Within a sector, neurons with separate dendritic fields innervated separate regions either in a single nucleus or into different but functionally related thalamic nuclei. Neurons with an overlap of their dendritic fields gave rise either to overlapping axonal arborizations or, more rarely, to distinct axonal arbors within two different thalamic nuclei implicated in the same function. In rare instances, an Rt axon could project within these two nuclei. Thalamic reticular axons commonly displayed a single well-circumscribed arbor containing a total of about 4,000 +/- 1,000 boutons. Every arbor was composed of a dense central core, which encompassed a thalamic volume of 5-63 x 10(6) microm3 and was made up of patches of maximal innervation density (10 +/- 4 boutons/tissue cube of 25 microm each side), surrounded by a sparse component. The metric relationships between the Rt axonal arbors and the dendrites of their target thalamocortical neurons were determined. Both the size and maximal innervation density of the axonal patches were found to fit in with the somatodendritic architecture of the target cells. The Rt axonal projections of adult rats are thus characterized by their (1) well-focused terminal field with a patchy distribution of boutons and (2) parallel organization with a certain degree of divergence. The role of the Rt-mediated thalamic inhibition and disinhibition may be to contrast significant with nonrelevant ongoing thalamocortical information.

Intracortical arborizations and receptive fields of identified ventrobasal thalamocortical afferents to the primary somatic sensory cortex in the cat.

The intracortical arborizations of neurons from the ventroposterolateral thalamic nucleus (VPL) in the cat were studied by intraaxonal injections of horseradish peroxidase (HRP) following identification of their receptive fields. In the primary somatic sensory cortex (SI) VPL cells terminated in different cytoarchitectonic areas according to their receptive field modality. Fibers excited by deep tissue or joint rotation arborized preferentially in area 3a. Those responding tonically to cutaneous stimuli were located in the anterior part of area 3b; hairdriven cells terminated in area 3b and in the rostral pole of area 1. All fibers had a similar laminar distribution within SI. Axons terminated mostly in layers VI, iV, and the lower part of layer III. None terminated in layers I and II. Most terminal arbors were oriented along the mediolateral axis of the brain. The main arborization of a single VPL cell formed a bush of about 500 micrometers in diameter. some fibers generated two such bushes with an uninvaded region of about 300 micrometer between them. It is proposed that this patchy organization underlies in part the columnar organization of areas SI. Many VPL cells had secondary projection sites in SI. These were issued from smaller-sized collaterals and were located in a different cytoarchitectonic area than that of the main terminal plexuses. A significant number of these collaterals projected to area 4, Insufficient filling of the collaterals by HRP prevented a more complete characterization of the secondary arbors.

Corticothalamic projections from layer 5 of the vibrissal barrel cortex in the rat.

This study bears on the projections of layer 5 cells of the vibrissal sensory cortex to the somatosensory thalamus in rats. Small groups of cells were labeled with biotinylated dextran amine (BDA), and their axonal arborizations were individually reconstructed from horizontal sections counterstained for cytochrome oxidase. Results show that the vast majority ( approximately 95%) of layer 5 axons that innervate the somatosensory thalamus are collaterals of corticofugal fibers that project to the brainstem. The anterior pretectal nucleus, the deep layers of the superior colliculus, and the pontine nuclei are among the structures most often coinnervated. In the thalamus, layer 5 axons terminate exclusively in the dorsal part of the posterior group (Po), where they form clusters of large terminations. Because dorsal Po projects to multiple cortical areas, we sought to determine whether all recipient areas return a layer 5 projection to this part of the thalamus. Additional experiments using fluoro-gold and BDA injections provided evidence that the primary somatosensory area is the sole source of layer 5 projections to dorsal Po but that this thalamic region receives convergent layer 6 projections from the primary and second somatosensory areas and from the motor and insular cortices. These results show that layer 5 projections do not overlap in associative thalamic nuclei, thus defining area-related subdivisions. Furthermore, the coinnervation of brainstem nuclei by layer 5 CT axons suggests that this pathway conveys to the thalamus a copy of the cortical output aimed at brainstem structures.

Thalamic projections from the whisker-sensitive regions of the spinal trigeminal complex in the rat.

This study investigated the axonal projections of whisker-sensitive cells of the spinal trigeminal subnuclei (SP5) in rat oral, interpolar, and caudal divisions (SP5o, SP5i, and SP5c, respectively). The labeling of small groups of trigeminothalamic axons with biotinylated dextran amine disclosed the following classes of axons. 1) Few SP5o cells project to the thalamus: They innervate the caudal part of the posterior group (Po) and the region intercalated between the anterior pretectal and the medial geniculate nuclei. These fibers also branch profusely in the tectum. 2) Two types of ascending fibers arise from SP5i: Type I fibers are thick and distribute to the Po and to other regions of the midbrain, i.e., the prerubral field, the deep layers of the superior colliculus, the anterior pretectal nucleus, and the ventral part of the zona incerta. Type II fibers are thin; branch sparsely in the tectum; and form small-sized, bushy arbors in the ventral posterior medial nucleus (VPM). Accordingly, a statistical analysis of the distribution of antidromic invasion latencies of 96 SP5i cells to thalamic stimulation disclosed two populations of neurons: fast-conducting cells, which invaded at a mean latency of 1.23 +/- 0. 62 msec, and slow-conducting cells, which invaded at a mean latency of 2.97 +/- 0.62 msec. 3) The rostral part of SP5c contains cells with thalamic projections similar to that of type II SP5i neurons, whereas the caudal part did not label thalamic fibers in this study. A comparison of SP5i projections and PR5 projections in the VPM revealed that the former are restricted to ventral-lateral tier of the nucleus, whereas the latter terminate principally in the upper two tiers of the VPM. These results suggest a functional compartmentation of thalamic barreloids that is defined by the topographic distribution of PR5 and type II SP5i afferents.

Early allograft dysfunction after liver transplantation: a definition and predictors of outcome. National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database.

BACKGROUND: Poor graft function early after liver transplantation is an important cause of morbidity and mortality. We defined early allograft dysfunction (EAD) using readily available indices of function and identified donor, graft, and pretransplant recipient factors associated with this outcome. METHODS: This study examined 710 adult recipients of a first, single-organ liver transplantation for non-fulminant liver disease at three United States centers. EAD was defined by the presence of at least one of the following between 2 and 7 days after liver transplantation: serum bilirubin >10 mg/dl, prothrombin time (PT) > or =17 sec, and hepatic encephalopathy. RESULTS: EAD incidence was 23%. Median intensive care unit (ICU) and hospital stays were longer for recipients with EAD than those without (4 days vs. 3 days, P = 0.0001; 24 vs. 15 days, P = 0.0001, respectively). Three-year recipient and graft survival were worse in those with EAD than in those without (68% vs. 83%, P = .0001; 61% vs. 79%, P = 0.0001). A logistic regression model combining donor, graft, and recipient factors predicted EAD better than models examining these factors in isolation. Pretransplant recipient elevations in PT and bilirubin, awaiting a graft in hospital or ICU, donor age > or =50 years, donor hospital stay >3 days, preprocurement acidosis, and cold ischemia time > or =15 hr were independently associated with EAD. CONCLUSION: Recipients who develop EAD have longer ICU and hospital stays and greater mortality than those without. Donor, graft, and recipient risk factors all contribute to the development of EAD. Results of these analyses identify factors that, if modified, may alter the risk of EAD.

Efficacy of mycophenolate mofetil combined with very low-dose cyclosporine microemulsion in long-term liver-transplant patients with renal dysfunction.

BACKGROUND: Cyclosporine (CsA)-induced renal dysfunction is common after liver transplantation. We evaluated the efficacy of tapering CsA to a very low dose and introducing mycophenolate mofetil (MMF) in long-term liver-transplant recipients with renal dysfunction. In addition, we assessed the impact of this strategy on calcineurin inhibition and on transforming growth factor (TGF)-beta levels. METHODS: We prospectively enrolled 19 adult, long-term (>1 year) liver-transplant recipients with a decreased creatinine clearance greater than 25% compared with the first month posttransplant. MMF was introduced, and CsA was tapered to 25 mg twice daily. Calcineurin inhibition and TGF-beta were measured at baseline and 3 months thereafter. RESULTS: The CsA dose was tapered over 13+/-3 weeks. At 1-year follow-up, serum creatinine decreased from 141+/-24 to 105+/-22 micromol/L (P=0.002), creatinine clearance increased from 53+/-9 to 71+/-19 ml/min (P=0.02), and glomerular filtration rate increased from 40+/-13 to 64+/-18 mL/min (P=0.002). The incidence of acute rejection was 29%. Antihypertensive medications were discontinued in 71% of the patients. Although CsA levels decreased significantly, serum TGF-beta did not differ from normal controls, and calcineurin inhibition remained stable. The incidence of gastrointestinal side-effects and leukopenia was 18% and 24%, respectively. CONCLUSION: In long-term liver-transplant recipients with renal dysfunction, the introduction of MMF followed by tapering of CsA to a very low dose resulted in a significant improvement in renal function. However, this strategy maybe associated with a risk of acute rejection. The clinical pertinence of measuring serum TGF-beta levels and calcineurin inhibition remains to be determined.