Associations between total MRI-visible small vessel disease burden and domain-specific cognitive abilities in a community-dwelling older-age cohort.

Cerebral small vessel disease (SVD) is a leading cause of vascular cognitive impairment, however the precise nature of SVD-related cognitive deficits, and their associations with structural brain changes, remain unclear. We combined computational volumes and visually-rated MRI markers of SVD to quantify total SVD burden, using data from the Lothian Birth Cohort 1936 (n = 540; age: 72.6 ± 0.7 years). We found negative associations between total SVD burden and general cognitive ability (standardized ß: -0.363; 95%CI: [-0.49, -0.23]; p(FDR) < 0.001), processing speed (-0.371 [-0.50, -0.24]; p(FDR) < 0.001), verbal memory (-0.265; [-0.42, -0.11]; p(FDR) = 0.002), and visuospatial ability (-0.170; [-0.32, -0.02]; p(FDR) = 0.029). Only the association between SVD burden and processing speed remained after accounting for covariance with general cognitive ability (-0.325; [-0.61, -0.04]; p(FDR) = 0.029). This suggests that SVD's association with poorer processing speed is not driven by, but is independent of its association with poorer general cognitive ability. Tests of processing speed may be particularly sensitive to the cognitive impact of SVD, but all major cognitive domains should be tested to determine the full range of SVD-related cognitive characteristics.

Cerebral small vessel disease burden and longitudinal cognitive decline from age 73 to 82: the Lothian Birth Cohort 1936.

Slowed processing speed is considered a hallmark feature of cognitive decline in cerebral small vessel disease (SVD); however, it is unclear whether SVD's association with slowed processing might be due to its association with overall declining general cognitive ability. We quantified the total MRI-visible SVD burden of 540 members of the Lothian Birth Cohort 1936 (age: 72.6 ± 0.7 years; 47% female). Using latent growth curve modelling, we tested associations between total SVD burden at mean age 73 and changes in general cognitive ability, processing speed, verbal memory and visuospatial ability, measured at age 73, 76, 79 and 82. Covariates included age, sex, vascular risk and childhood cognitive ability. In the fully adjusted models, greater SVD burden was associated with greater declines in general cognitive ability (standardised ß: -0.201; 95% CI: [-0.36, -0.04]; pFDR = 0.022) and processing speed (-0.222; [-0.40, -0.04]; pFDR = 0.022). SVD burden accounted for between 4 and 5% of variance in declines of general cognitive ability and processing speed. After accounting for the covariance between tests of processing speed and general cognitive ability, only SVD's association with greater decline in general cognitive ability remained significant, prior to FDR correction (-0.222; [-0.39, -0.06]; p = 0.008; pFDR = 0.085). Our findings do not support the notion that SVD has a specific association with declining processing speed, independent of decline in general cognitive ability (which captures the variance shared across domains of cognitive ability). The association between SVD burden and declining general cognitive ability supports the notion of SVD as a diffuse, whole-brain disease and suggests that trials monitoring SVD-related cognitive changes should consider domain-specific changes in the context of overall, general cognitive decline.

[The role of podocyte damage in the pathogenesis of glomerulosclerosis and possible repair mechanisms]. / Ruolo del danno podocitario nella patogenesi della glomerulosclerosi e possibili meccanismi di riparazione.

Converging evidence suggests that damage to podocytes plays a key role in progression towards glomerulosclerosis, in particular as the primary cause of all forms of focal segmental glomerulosclerosis (FSGS), the most common glomerular disease leading to end-stage renal disease. Any damage occurring to the complex architecture of specialized proteins that constitute the podocyte foot processes, essential to the highly specialized functions of podocytes, leads inevitably to loss of function in the glomerular filtration barrier, and ultimately to proteinuria. Recent studies have also highlighted that a reduction of the podocyte number in a damaged glomerulus is a critical factor for the development of proteinuria and glomerulosclerosis. As long as the podocyte loss is limited, restitution or repair is possible, which shows that the glomerular architecture can be remodeled. However, mature podocytes have limited capacity to divide and display all the phenotypic and functional features of highly specialized, terminally differentiated cells. A potential mechanism for podocyte replacement might be stem-cell-based regeneration, since it has been established that the developmental source of podocytes are resident renal progenitors. Podocyte damage could then be potentially repaired by a stem cell population resident in the kidney.

Glutamate uptake from the synaptic cleft does not shape the decay of the non-NMDA component of the synaptic current.

To study the role of glutamate uptake at central glutamatergic synapses, we used the uptake blocker L-transpyrrolidine-2,4-dicarboxylate (PDC). The effects of PDC on the glutamate uptake current in salamander retinal glia indicated that PDC competes with glutamate for transport on the uptake carrier and that 300 microM PDC should significantly reduce the uptake of glutamate during the synaptic current. In isolated rat hippocampal neurons, 300 microM PDC did not affect non-N-methyl-D-aspartate (NMDA) receptor currents, but reduced NMDA receptor currents by 30%. In hippocampal and cerebellar slices, whereas 300 microM PDC reduced the NMDA component of excitatory synaptic currents by 50%, it reduced the non-NMDA component only slightly with no change in its decay time constant. Thus, the decay rate of the non-NMDA component is not set by the rate of glutamate uptake from the synaptic cleft into the presynaptic terminal.

[The role of endothelial progenitor cells in renal disease]. / Ruolo dei progenitori endoteliali nelle malattie renali.

Recent evidence suggests that injury to the renal vasculature may play an important role in the pathogenesis of both chronic and acute ischemic kidney injury. Early alterations in peritubular capillary blood flow during reperfusion have been documented and associated with loss of normal endothelial cell function. In addition, ischemia induces alterations in endothelial cells that may promote inflammation and procoagulant activity, thus contributing to vascular congestion. Reduction of the microvasculature density increases hypoxia-mediated fibrosis and alters proper hemodynamics, which may lead to hypertension. This may play a critical role in the progression of chronic kidney disease following initial recovery from ischemia/reperfusion-induced acute kidney injury. The turnover and replacement of endothelial cells is therefore an important mechanism in the maintenance of vascular integrity also in the kidney. It is becoming clear that impaired vascular repair mechanisms as a result of a reduced number and/or impaired function of endothelial progenitor cells may contribute to renal disease. Moreover, investigators have begun to identify potential mechanisms responsible for the loss of function of endothelial progenitors in renal disease. In allografts, persistent injury results in excessive turnover of graft vascular endothelial cells. Moreover, chronic damage elicits a response that is associated with the recruitment of both leukocytes and endothelial progenitors, facilitating an overlapping process of inflammation and angiogenesis. In conclusion, angiogenesis and endothelial cell turnover play a pivotal role in renal disease and allograft rejection. Manipulation of these processes might have important implications for the development of novel therapeutic strategies in the near future.

Bridging pro-inflammatory signals, synaptic transmission and protection in spinal explants in vitro.

Multiple sclerosis is characterized by tissue atrophy involving the brain and the spinal cord, where reactive inflammation contributes to the neurodegenerative processes. Recently, the presence of synapse alterations induced by the inflammatory responses was suggested by experimental and clinical observations, in experimental autoimmune encephalomyelitis mouse model and in patients, respectively. Further knowledge on the interplay between pro-inflammatory agents, neuroglia and synaptic dysfunction is crucial to the design of unconventional protective molecules. Here we report the effects, on spinal cord circuits, of a cytokine cocktail that partly mimics the signature of T lymphocytes sub population Th1. In embryonic mouse spinal organ-cultures, containing neuronal cells and neuroglia, cytokines induced inflammatory responses accompanied by a significant increase in spontaneous synaptic activity. We suggest that cytokines specifically altered signal integration in spinal networks by speeding the decay of GABAA responses. This hypothesis is supported by the finding that synapse protection by a non-peptidic NGF mimetic molecule prevented both the changes in the time course of GABA events and in network activity that were left unchanged by the cytokine production from astrocytes and microglia present in the cultured tissue. In conclusion, we developed an important tool for the study of synaptic alterations induced by inflammation, that takes into account the role of neuronal and not neuronal resident cells.

The -374T/A variant of the rage gene promoter is associated with clinical restenosis after coronary stent placement.

Upregulation of the receptor for advanced glycation end products (RAGE) may play a crucial role in neointimal formation upon vessel injury. The -374T/A variant of the RAGE gene promoter, which has been associated with an altered expression of the cell-surface receptor, could exert a protective effect toward the development of vascular disease. The aim of this study is to determine the impact of this common genetic variant in the occurrence of clinical in-stent restenosis after coronary stent implantation. The -374T/A polymorphism of the RAGE gene promoter was evaluated by PCR-RFLPs in 267 patients with coronary artery disease who underwent coronary stent implantation and a subsequent coronary angiography 6-9 months later for suspected restenosis. In-stent restenosis was assessed by means of quantitative angiography. Carriers of the -374AA genotype showed a significantly reduced risk of developing restenosis after percutaneous transluminal intervention than non-carriers. To determine whether the protective effect of the homozygous AA genotype toward clinical restenosis was independent of potential confounders, we performed multivariable logistic regression analysis. After allowance for clinical and biochemical risk factors and stent length, the AA genotype remained significantly associated with a reduced prevalence of in-stent restenosis. No relation was evident between the RAGE genotype and established cardiovascular risk factors. In conclusion, the -374AA genotype of the RAGE gene promoter could be associated with a reduced risk of in-stent restenosis after coronary stent implantation.

Early signs of motoneuron vulnerability in a disease model system: Characterization of transverse slice cultures of spinal cord isolated from embryonic ALS mice.

Mutations in the SOD1 gene are associated with familial amyotrophic lateral sclerosis. The mechanisms by which these mutations lead to cell loss within the spinal cord ventral horns are unknown. In the present report we used the G93A transgenic mouse model of amyotrophic lateral sclerosis to develop and characterize an in vitro tool for the investigation of subtle alterations of spinal tissue prior to frank neuronal degeneration. To this aim, we developed organotypic slice cultures from wild type and G93A embryonic spinal cords. We combined immunocytochemistry and electron microscopy techniques to compare wild type and G93A spinal cord tissues after 14 days of growth under standard in vitro conditions. By SMI32 and choline acetyl transferase immunostaining, the distribution and morphology of motoneurons were compared in the two culture groups. Wild type and mutant cultures displayed no differences in the analyzed parameters as well as in the number of motoneurons. Similar results were observed when glial fibrillary acidic protein and myelin basic protein-positive cells were examined. Cell types within the G93A slice underwent maturation and slices could be maintained in culture for at least 3 weeks when prepared from embryos. Electron microscopy investigation confirmed the absence of early signs of mitochondria vacuolization or protein aggregate formation in G93A ventral horns. However, a significantly different ratio between inhibitory and excitatory synapses was present in G93A cultures, when compared with wild type ones, suggesting the expression of subtle synaptic dysfunction in G93A cultured tissue. When compared with controls, G93A motoneurons exhibited increased vulnerability to AMPA glutamate receptor-mediated excitotoxic stress prior to clear disease appearance. This in vitro disease model may thus represent a valuable tool to test early mechanisms contributing to motoneuron degeneration and potential therapeutic molecular interventions.

Nosogogy: when the learner is a patient with chronic renal failure.

Patient education approaches are currently derived from a biomedical 'acute' model characterized by the sequence of health, disease, and recovery resulting from our professional intervention. Unfortunately, this model proves to be totally inadequate when applied to a chronic disease such as kidney failure. Our patients never fully regain their health and may continue to worsen under our care, even after many state-of-the-art treatments. The solution is represented in acquiring a new professional identity, shifting from the 'biomedical' acute model to a 'bio-psycho-social-educational model'. Within this model, a Therapeutic Education approach in predialysis has been proven to provide both short- and long-term positive results for renal patients. There is a tremendous difference between the learning processes in children and adults and two different sciences have already been described. 'Pedagogy' deals with child learning and 'Andragogy' with adult learning. Nevertheless, when the learner is a patient with a chronic disease, we believe that new considerations must be taken into account. We propose to create a novel science and to call it 'Nosogogy', derived from the ancient Greek word (see text), meaning 'disease'. Nosogogy could be defined as the science of teaching adults affected by chronic disease. The new educator is someone deeply involved in renal care who knows and understands the characteristic conflicts and dynamics that arise in the renal patient, and possesses adequate communication skills to deal with him. In our experience, we prefer to have educational sessions run by nephrologists and nurses who have great experience in the field.

Patient re-training in peritoneal dialysis: why and when it is needed.

The aim of this multicenter, quantitative, observational study was to analyze compliance and re-training needs of patients on peritoneal dialysis (PD) through the assessment of patient knowledge (with a Patient Questionnaire; phase 1) and patient behavior (home visit with a Score Card; phase 2). A total of 353 patients from 11 Italian centers participated in the first phase and 191 patients from nine centers in the second phase. Overall, 66% of questions on the Patient Questionnaire were answered correctly. Correct answers were more frequent in females than males, in patients under 55 years of age, and in those with higher education. The lowest rate of correct answers involved questions related to diet and physical activity (67% and 51%, respectively). Data collected during the home visit showed that 25% of patients were partially compliant with their drug therapy. Twenty-three percent of patients were non-compliant with the exchange protocol procedures, with a significant association between compliance and the incidence of peritonitis, and 11% were non-compliant with the exit-site protocol procedures without a statistically significant correlation to peritonitis. By combining the two evaluations, we found that approximately one-third (29%) of patients needed reinforcement of knowledge and ability to correctly perform PD as related to infection control and 27% for the correct use of drugs. Looking at the combined evaluation of infection control and drug use, results showed that 47% of patients needed re-training. This need for re-training was greater for younger patients (less than 55 years old), patients with lower education degree and patients in the early or late phase of PD therapy (less than 18 months or more than 36 months). Gender and degree of autonomy had no effect on the need for re-training.

Microcirculation as a novel marker of membrane biocompatibility.

BACKGROUND: It is possible to consider microcirculation as a kind of OwitnessO of the complex biological reactions triggered by the dialytic treatment. The reactivity of microcirculation to the dialytic stress may represent a measure of the overall biocompatibility of the membrane. In this study we tested the hypothesis that different synthetic membranes may have different biological effects, particularly related to microcirculation. SUBJECTS AND METHODS: In this crossover study, we observed 16 chronically hemodialyzed patients. All patients were treated with the EVAL membrane; we recorded the TcPO2 during the second treatment of the week. All patients were then switched to the hf-PS membrane. During the study observation we did not change the dialytic prescription or the pharmacologic treatment. RESULTS: From the beginning of the session until 90O, the behavior of TcPO2 is similar for both the membranes. From 120O to the end of the treatment in sessions with the EVAL membrane, the TcPO2 values come back to the starting level, whereas in the treatments with hf-PS the TcPO2, the values remain at a lower level; there was a significant difference between EVAL and hf-PS in the values recorded. Arterial blood gas values of paO2 and paCO2 are quite similar in the treatments with both the membranes, without any significant difference. CONCLUSIONS: The analysis of microcirculation by means of TcPO2 measurement is a useful tool to obtain a OclinicalO measure of biocompatibility of the dialytic treatment and different membranes may have different impacts on TcPO2.

Mammary tumors induced in rats by adriamycin and daunomycin.

The two anthracycline antitumor antibiotics, Adriamycin and daunomycin (DM), induced a high incidence of mammary tumors, both fibroadenomas and adenocarcinomas, in female rats that received a single i.v. dose, thus confirming previous results. The incidence of DM-induced adenocarcinomas increased with the dose of the drug, whereas the incidence of Adriamycin-induced adenocarcinomas showed a plateau at 5 mg/kg and above. Adriamycin- and DM-induced fibroadenomas showed a peak at lower doses (about 5 to 6 mg/kg). With the highest DM dose (12.5 mg/kg) used, there was a slight prevalence of adenocarcinomas over fibroadenomas.

Minimally invasive or interventional repair of atrial septal defects in children: experience in 171 cases and comparison with conventional strategies.

OBJECTIVES: The goal of this study was to evaluate percutaneous interventional and minimally invasive surgical closure of secundum atrial septal defect (ASD) in children. BACKGROUND: Concern has surrounded abandoning conventional midline sternotomy in favor of the less invasive approaches pursuing a better cosmetic result and a more rational resource utilization. METHODS: A retrospective analysis was performed on the patients treated from June 1996 to December 1998. RESULTS: One hundred seventy-one children (median age 5.8 years, median weight 22.1 kg) underwent 52 device implants, 72 minimally invasive surgical operations and 50 conventional sternotomy operations. There were no deaths and no residual left to right shunt in any of the groups. The overall complication rate causing delayed discharge was 12.6% for minimally invasive surgery, 12.0% for midline sternotomy and 3.8% for transcatheter device closure (p < 0.01). The mean hospital stay was 2.8 +/- 1.0 days, 6.5 +/- 2.1 days and 2.1 +/- 0.5 days (p < 0.01); the skin-to-skin time was 196 +/- 43 min, 163 +/- 46 min and 118 +/- 58 min, respectively (p < 0.001). Extracorporeal circulation time was 49.9 +/- 10.1 min in the minithoracotomy group versus 37.2 +/- 13.8 min in the sternotomy group (p < 0.01) but without differences in aortic cross-clamping time. Sternotomy was the most expensive procedure (15,000 EUR +/- 1,050 EUR vs. 12,250 EUR +/- 472 EUR for minithoracotomy and 13,000 EUR +/- 300 EUR for percutaneous devices). CONCLUSIONS: While equally effective compared with sternotomy, the cosmetic and financial appeal of the percutaneous and minimally invasive approaches must be weighed against their greater exposure to technical pitfalls. Adequate training is needed if a strategy of surgical or percutaneous minimally invasive closure of ASD in children is planned in place of conventional surgery.

Interneurons transiently express the ERG K+ channels during development of mouse spinal networks in vitro.

During spinal cord maturation neuronal excitability gradually differentiates to meet different functional demands. Spontaneous activity, appearing early during spinal development, is regulated by the expression pattern of ion channels in individual neurons. While emerging excitability of embryonic motoneurons has been widely investigated, little is known about that of spinal interneurons. Voltage-dependent K+ channels are a heterogeneous class of ion channels that accomplish several functions. Recently voltage-dependent K+ channels encoded by erg subfamily genes (ERG channels) were shown to modulate excitability in immature neurons of mouse and quail. We investigated the expression of ERG channels in immature spinal interneurons, using organotypic embryonic cultures of mouse spinal cord after 1 and 2 weeks of development in vitro. We report here that all the genes of the erg family known so far (erg1a, erg1b, erg2, erg3) are expressed in embryonic spinal cultures. We demonstrate for the first time that three ERG proteins (ERG1A, ERG2 and ERG3) are co-expressed in the same neuronal population, and display a spatio-temporal distribution in the spinal slices. ERG immuno-positive cells, representing mainly GABAergic interneurons, were present in large numbers at early stages of development, while declining later, with a ventral to dorsal gradient. Patch clamp recordings confirmed these data, showing that ventral interneurons expressed functional ERG currents only transiently. Similar expression of the erg genes was observed at comparable ages in vivo. The role of ERG currents in regulating neuronal excitability during the earliest phases of spinal circuitry development will be examined in future studies.

Antagonism by (1,2,5,6-tetrahydropyridine-4-yl) methylphosphinic acid of synaptic transmission in the neonatal rat spinal cord in vitro: an electrophysiological study.

The effect of the novel GABAc receptor antagonist (1,2,5,6-tetrahydropyridine-4-yl)methyl-phosphinic acid (TPMPA) on synaptic transmission and GABA-mediated responses was investigated with electrophysiological recordings from the in vitro spinal cord preparation of the neonatal rat. Bath-applied TPMPA (10 microM) had no effect on spinal reflexes evoked by dorsal root stimulation, on ventral root polarization level or amplitude of ventral root depolarizations induced by exogenously applied GABA (0.5 mM). TPMPA significantly attenuated the depressant action of GABA on spinal reflexes without changing responses induced by the GABA(A) receptor agonist isoguvacine (50 microM) or the GABA(B) receptor agonist baclofen (0.5-2 microM). Following block of GABA(A) receptors by bicuculline (20 microM) and of glycine receptors by strychnine (1 microM), regular bursting activity recorded from ventral roots developed spontaneously and persisted unchanged for many hours. This bursting pattern, which is generated at the level of the interneuronal network, was significantly slowed down by TPMPA, which also increased the duration of individual bursts and the number of intraburst oscillations. These results suggest that in the neonatal rat spinal cord some functional GABAc receptors exist: their role was clearly unmasked following pharmacological block of GABA(A) (and glycine) receptors. Under these conditions GABAc receptors appeared to contribute to the excitation of spinal interneurons supporting rhythmic bursting activity.

EPSP-spike potentiation during primed burst-induced long-term potentiation in the CA1 region of rat hippocampal slices.

Long-term potentiation induced by high-frequency stimulation in the CA1 region of the hippocampus exhibits EPSP-spike potentiation. This consists of an increase in population spike amplitude exceeding that predicted by EPSP potentiation alone. This phenomenon is apparently due to an increase in pyramidal cell excitability. Patterns of afferent stimuli which activate pyramidal cells to reproduce the theta rhythm observed in the hippocampus under physiological conditions, have been shown to induce LTP-like enhancement of synaptic responses in vitro. The aim of this study was to investigate the presence of EPSP-spike potentiation and/or changes in pyramidal cell excitability during the long-term potentiation induced in the CA1 region of rat hippocampal slices by theta-like patterns of stimuli: the primed burst and the patterned stimulation. Using extracellular recording, a significant leftward shift in the EPSP-spike relationship was found 30 min after primed burst or patterned stimulation. The magnitude of EPSP-spike potentiation induced by patterned stimulation was similar to that produced by high-frequency stimulation. Both were significantly greater than that induced by a primed burst, indicating that only a subset of pyramidal cells were potentiated by this kind of afferent activation. Modifications in synaptic efficacy and cell excitability brought about by a primed burst were investigated in 25 intracellularly recorded pyramidal cells. Consistent with extracellular results, it was found that only 11 out of 25 neurons receiving a primed burst were potentiated. In these cells the increase in probability of firing action potentials elicited by synaptic activation with test shocks was accompanied by enhanced cell excitability, but not by an increase in EPSP slope. High-frequency stimulation delivered 40 min after a primed burst invariably increased the EPSP slope, the probability of firing upon synaptic stimulation, and the excitability of cells. The presence of EPSP-spike potentiation and of increased excitability of potentiated cells during the primed burst-induced long-term potentiation strengthen the suggestion that theta pattern-induced synaptic potentiation can be considered similar to high-frequency stimulation and long-term potentiation and supports the notion that the EPSP-spike potentiation is a constitutive characteristic of long-term potentiation.

Serotonin blocks the long-term potentiation induced by primed burst stimulation in the CA1 region of rat hippocampal slices.

The effect of 5-hydroxytryptamine on the induction of long-term potentiation by a train of high frequency pulses (100 Hz; 1 s) or by a stimulation consisting of one burst of five pulses at 100 Hz delivered 170 ms after a single pulse (primed burst) was investigated in the CA1 region of the rat hippocampal slice in vitro with extracellular recordings. Superfusion with 5-hydroxytryptamine (3-30 microM) produced a concentration-dependent decrease in amplitude of the population spikes evoked by test stimuli. The presence of 5-hydroxytryptamine (30 microM) did not affect the magnitude of long-term potentiation produced by the high-frequency stimulation but it prevented the long-term potentiation induced by a primed burst. The action of 5-hydroxytryptamine was mimicked by the 5-hydroxytryptamine1A agonist 5-carboxamidotryptamine (0.3 microM) and blocked by the 5-hydroxytryptamine2/5-hydroxytryptamine1A antagonist spiperone (3 microM) or by the 5-hydroxytryptamine1/5-hydroxytryptamine2 antagonist methiothepin (1-10 microM). The selective 5-hydroxytryptamine2 antagonist ritanserin (1 microM) did not antagonize the block of long-term potentiation produced by 5-hydroxytryptamine. The selective 5-hydroxytryptamine3 antagonists (3-tropanyl)-1H-indole-3-carboxylic acid ester (ICS 205-930; 1 nM) and ondansetron (GR-38032; 30 nM) did not affect the reduction in the population spike produced by application of 5-hydroxytryptamine. In contrast, a primed burst delivered at the fifth minute of 5-hydroxytryptamine application in the presence of a 5-hydroxytryptamine3 antagonist induced a long-term potentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Spinal circuits formation: a study of developmentally regulated markers in organotypic cultures of embryonic mouse spinal cord.

In this study, we have addressed the issue of neural circuit formation using the mouse spinal cord as a model system. Our primary objective was to assess the suitability of organotypic cultures from embryonic mouse spinal cord to investigate, during critical periods of spinal network formation, the role of the local spinal cellular environment in promoting circuit development and refinement. These cultures offer the great advantage over other in vitro systems, of preserving the basic cytoarchitecture and the dorsal-ventral orientation of the spinal segment from which they are derived [Eur J Neurosci 14 (2001) 903; Eur J Neurosci 16 (2002) 2123]. Long-term embryonic spinal cultures were developed and analyzed at sequential times in vitro, namely after 1, 2, and 3 weeks. Spatial and temporal regulation of neuronal and non-neuronal markers was investigated by immunocytochemical and Western blotting analysis using antibodies against: a) the non-phosphorylated epitope of neurofilament H (SMI32 antibody); b) the enzyme choline acetyltransferase, to localize motoneurons and cholinergic interneurons; c) the enzyme glutamic acid decarboxylase 67, to identify GABAergic interneurons; d) human eag-related gene (HERG) K(+) channels, which appear to be involved in early stages of neuronal and muscle development; e) glial fibrillary acidic protein, to identify mature astrocytes; f) myelin basic protein, to identify the onset of myelination by oligodendrocytes. To examine the development of muscle acetylcholine receptors clusters in vitro, we incubated live cultures with tetramethylrhodamine isothiocyanate-labeled alpha-bungarotoxin, and we subsequently immunostained them with SMI32 or with anti-myosin antibodies. Our results indicate that the developmental pattern of expression of these markers in organotypic cultures shows close similarities to the one observed in vivo. Therefore, spinal organotypic cultures provide a useful in vitro model system to study several aspects of neurogenesis, gliogenesis, muscle innervation, and synaptogenesis.

Patent ductus arteriosus occlusion using detachable coils.

Occlusion of patent ductus arteriosus was performed using detachable coils in 193 cases, with 181 successful implants and a low embolization rate. This technique is safe and effective for occlusion of ductuses of various sizes, and is low cost.

Comparison of three different atrial septal defect occlusion devices.

Three different devices were used to close secundum-type atrial septal defects in 28 patients. The "Amplatzer" is associated with an easier and shorter procedure than are the "Sideris Buttoned Device" and the Microvena "Angel Wings" devices.