Asynchronous and asymmetric burst-suppression in a patient with a corpus callosum lesion

INTRODUCTION

Burst suppression is seen in the electroencephalograms of patients receiving high doses of pentobarbital. In such circumstances, burst suppression is characterized by bilaterally synchronous and symmetric bursts of electrical activity followed by intervals of attenuation.

METHODS

We report on a case of asymmetric and asynchronous pentobarbital-induced burst suppression that occurred after a corpus callosum lesion sustained during trauma.

CONCLUSIONS

To our knowledge, this is the first such reported human case of asymmetric and asynchronous pentobarbital-induced burst suppression. These findings suggest that the corpus callosum may be involved in the synchronization of the burst-suppression pattern.

Biochemical and morphological analysis of non-NMDA receptor mediated excitotoxicity in chick embryo retina

Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that mediate glutamatergic neurotransmission, and when pathologically overstimulated induce excitotoxic neuronal death. Of the two families of iGluRs, the non-NMDA receptors have received less experimental attention than the NMDA receptors as mediators of neuronal death in in vitro systems. We have demonstrated that non-NMDA receptor activation is highly lethal for neurons of the chick embryo retina, and further characterize this phenomenon here. Treatment of isolated retinas with any of the non-NMDA receptor agonists glutamate, AMPA, or KA, in the presence of the NMDA receptor antagonist MK-801, led to pathomorphology and cell death. KA was the most effective toxin. All of KA-induced toxicity could be blocked by selective AMPA receptor blockers. The toxicity of both AMPA and glutamate could be greatly increased using cyclothiazide, which blocks AMPA receptor desensitization. These results indicate that KA is the most powerful toxin because it is a non-desensitizing agonist at the AMPA receptors. Glutamate exhibited a paradoxical ability to prevent KA-induced toxicity as measured by a biochemical assay of cell death. Also, histological studies indicated that glutamate selectively blocked KA-induced pathomorphological changes in bipolar cells. This protective effect of glutamate was not mimicked by AMPA, NMDA, or any of several metabotropic receptor agonists, indicating that it may be mediated by a receptor of undescribed pharmacology.

Two cases of tinea pedis caused by Scytalidium hyalinum

Two cases of tinea pedis due to Scytalidium hyalinum, the first to be described in Italy, are reported. The patients were a 41-year-old woman and a 35-year-old man who had spent periods in the Caribbean. The clinical manifestations were indistinguishable from those caused by dermatophytes. In the women they were striking with 'moccasin foot' type lesions, whereas in the man they were less evident, with minor plantar desquamation and interdigital maceration. Diagnosis was based on direct mycological microscopic examination and culture. Clinical and mycological remission were obtained with systemic itraconazole therapy. These cases are reported because infections caused by Scytalidium hyalinum are rare in Europe and their clinical and mycological diagnosis, as well as therapy, may be problematic.

Non invasive assessment of cardiac function in patients with bronchial asthma (BA) or chronic obstructive pulmonary disease (COPD)

BACKGROUND

Most respiratory diseases involve the heart and can lead to acute or chronic pulmonary heart in the most serious cases. The common pathogenetic element is pulmonary arterial hypertension which es secondary to the resistance of the pulmonary circulation together with hypertrophy and/or dilatation of the right ventricle, caused mainly by chronic hypoxia.

METHODS AND RESULTS

In order to verify the effects induced on pulmonary circulation and right heart by BA or COPD the cardiac function was assessed by mono and bidimensional Doppler echocardiography in 10 patients with BA (group A), 10 with COPD (group B) and 10 healthy control subjects (group C). At the M-mode echocardiography examination no significant difference was observed among the three study groups. By Doppler pw the peak velocity of early tricuspidal flow (VmaxE) was significantly higher in the group A when compared to the group B (p = 0.03). No subject had pulmonary hypertension. The pulmonary acceleration time (PAT) using pw Doppler technique was similar in groups A and B but it was significantly different when compared to group C (p = 0.006:A vs C; p = 0.03:B vs C).

CONCLUSIONS

Our results suggest in patients either with BA or COPD, an early involvement of the right heart even if they had a clinical stable condition and no pulmonary hypertension.

Distinct roles for sodium, chloride, and calcium in excitotoxic dendritic injury and recovery

The postsynaptic neuronal dendrite is selectively vulnerable to hypoxic-ischemic brain injury and glutamate receptor overactivation. We explored the glutamate receptor pharmacology and ionic basis of rapid, reversible alterations in dendritic shape which occur in cultured neurons exposed to glutamate. Dendrite morphology was assessed with the fluorescent membrane tracer, DiI, or immunofluorescence labeling of the somatodendritic protein, MAP2. Cortical cultures derived from 15-day-old mouse embryos underwent segmental dendritic beading when exposed to NMDA, AMPA, or kainate, but not to metabotropic glutamate receptor agonists. Varicosity formation in response to NMDA or kainate application was substantially attenuated in reduced sodium buffer (substituted with N-methyl-D-glucamine). Furthermore, veratridine-induced sodium entry mimicked excitotoxic alterations in dendrites and additionally caused varicosity formation in axons. Solutions deficient in chloride (substituted with Na methylsulfate) and antagonists of chloride-permeable GABA/glycine receptors reduced NMDA- or kainate-induced varicosity formation. An increase in dendrite volume was observed as varicosities formed, and varicosity formation was attenuated in sucrose-supplemented hypertonic media. Despite marked structural changes affecting virtually all neurons, dendrite shape returned to normal within 2 h of terminating glutamate receptor agonist application. Neurons exposed to kainate recovered more rapidly than those exposed to NMDA, and neurons exposed to NMDA in calcium-free buffer recovered more rapidly than cells treated with NMDA in normal buffer. While sodium, chloride, and water entry contribute to excitotoxic dendritic injury acutely, calcium entry through NMDA receptors results in lasting structural changes in damaged dendrites.

Skin and nail infections due to Fusarium oxysporum in Tuscany, Italy

Nine cases of skin and nail infection due to Fusarium oxysporum, diagnosed in Tuscany in the period 1985-97, are described. Two manifested as interdigital intertrigo of the feet and seven as onychomycosis. All were diagnosed on the basis of repeated mycological examination, direct microscope observation and culture, as well as histological examination of biopsy specimens in two cases of intertrigo. Fragments of the fungal colonies were examined by scanning electron microscopy (SEM) for more detailed observation of fungal morphology. All patients had normal immune status and a history of the infection extending several years. Four of the patients with onychomycosis were treated with oral itraconazole, and clinical and mycological recovery was achieved in three cases. Two others were treated with cyclopyrox nail lacquer, successfully in one case. One patient with intertrigo was treated with oral itraconazole and one with oral terbinafine; both were also treated and with topical drugs, however clinical recovery was not confirmed by the mycological results.

The intact isolated (ex vivo) retina as a model system for the study of excitotoxicity

Excitotoxicity is defined as a mode of neural cell death triggered by overactivation of receptors for the amino acid transmitter glutamate. There is considerable evidence that excitotoxicity is responsible for cell death in several neuropathological states, including some retinal diseases. The isolated retina, particularly from chick embryos, has been used extensively as an experimental system to characterize this process. This paper summarizes the use of isolated retina as a model system for studies of excitotoxicity from a theoretical and methodological point of view, and reviews results obtained from studies utilizing this system.

Onychomycosis due to Microsporum gypseum

The first four cases of onychomycosis due to Microsporum gypseum observed in Italy between 1990 and 1997 are reported. clinical manifestation was distal subungual onychomycosis in all cases. The lesions were asymptomatic in two patients. Three patients were treated with oral itraconazole (pulsed therapy) and the other with ciclopirox 8% nail lacquer. Clinical and mycological recovery was achieved in all cases. The cases are reported because of their rarity.

Clinical information technology: a new medical field?

The Economic European Society has stated that Medical Information Technology is one of the fields to be developed within the global Information Society of the future. Medical Information Technology is recognized as a speciality with formal courses in medical schools, and since it is an applicative science, medical doctors are the best analysis of clinical problems to be solved via computer. International standards are still lacking, and the successful combination of clinical content/context/technology is still a difficult task. A new profession such as the Chief Information Officer (CIO) will be more and more present within Hospitals and Health Care Organizations of the future.

Selective abolition of the NMDA component of long-term potentiation in mice lacking mGluR5

The mechanisms underlying the differential expression of long-term potentiation (LTP) by AMPA and NMDA receptors, are unknown, but could involve G-protein-linked metabotropic glutamate receptors. To investigate this hypothesis we created mutant mice that expressed no metabotropic glutamate receptor 5 (mGluR5), but showed normal development. In an earlier study of these mice we analyzed field-excitatory postsynaptic potential (fEPSPs) in CA1 region of the hippocampus and found a small decrease; possibly arising from changes in the NMDAR-mediated component of synaptic transmission. In the present study we used whole-cell patch clamp recordings of evoked excitatory postsynaptic currents (EPSCs) in CA1 pyramidal neurons to identify the AMPAR- and NMDAR-mediated components of LTP. Recordings from control mice following tetanus, or agonist application (IS, 3R-1-amino-cyclopentane 1,3-dicarboxylic acid) (ACPD), revealed equal enhancement of the AMPA and NMDA receptor-mediated components. In contrast, CA1 neurons from mGluR5-deficient mice showed a complete loss of the NMDA-receptor-mediated component of LTP (LTP(NMDA)), but normal LTP of the AMPA-receptor-mediated component (LTP(AMPA)). This selective loss of LTP(NMDA) was seen in three different genotypic backgrounds and was apparent at all holding potentials (-70 mV to +20 mV). Furthermore, the LTP(NMDA) deficit in mGluR5 mutant mice could be rescued by stimulating protein kinase C (PKC) with 4beta-phorbol-12,13-dibutyrate (PDBu). These results suggest that PKC may couple the postsynaptic mGluR5 to the NMDA-receptor potentiation during LTP, and that this signaling mechanism is distinct from LTP(AMPA). Differential enhancement of AMPAR and NMDA receptors by mGluR5 also supports a postsynaptic locus for LTP.

The hypocholesterolemic and antiatherogenic effects of Cholazol H, a chemically functionalized insoluble fiber with bile acid sequestrant properties in hamsters

Cholazol H (Alpha-Beta Technology, Worcester, MA), a chemically functionalized, insoluble dietary fiber with bile acid sequestrant properties, was studied in 30 male F1 B Golden Syrian hamsters for its effect on plasma lipid concentrations and early atherogenesis in experiment 1. In experiment 2, 30 male Golden Syrian hamsters were studied for the effects on plasma lipids and fecal excretion of bile acids. In experiment 1, three groups of 10 hamsters each were fed a chow-based hypercholesterolemic diet supplemented with 5% coconut oil and 0.1% cholesterol for 6 weeks. After 6 weeks, hamsters were continued on the diet with either 0% drug (hypercholesterolemic diet [HCD]), 0.5% cholestyramine (CSTY), or 0.5% Cholazol H for 8 weeks. Fasting plasma lipids were measured at weeks 6, 10, and 14, and early atherosclerosis (fatty streak formation) was measured at week 14. Relative to HCD, CSTY and Cholazol H significantly lowered plasma total cholesterol (TC) (-37%, P < .03, and -30%, P < .04, respectively) and plasma very-low and low-density lipoprotein-cholesterol (nonHDL-C) (-45%, P < .02, and -36%, P < .03, respectively) with no significant effects on plasma HDL-C or triglycerides (TG). Despite similar reductions in nonHDL-C, only Cholazol H significantly prevented early atherosclerosis (-38%, P < .02) relative to HCD. In experiment 2, three groups of 10 hamsters each were fed a chow-based hypercholesterolemic diet supplemented with 10% coconut oil and 0.05% cholesterol and either 0% drug HCD, 0.5% CSTY, or 0.5% Cholazol H for 4 weeks. Fasting plasma lipids were measured at weeks 2 and 4, and fecal bile acids were measured at week 4. Both Cholazol H and CSTY were equally effective in significantly lowering plasma TC (-16%, P < .003, and -13%, P < .01, respectively) and nonHDL-C (-22%, P < .004, and -18%, P < .02, respectively), with no significant effect on HDL-C and TG relative to HCD. Cholazol H and CSTY produced a significantly greater concentration of fecal total bile acids (39%, P < .001, and 28%, P < .002, respectively) relative to HCD. Also, there was a 48% (P < .002) and 65% (P < .001) greater fecal concentration of cholic acid (CA) for Cholazol H-treated hamsters compared with HCD- and CSTY-treated hamsters, respectively. Cholazol H also significantly increased fecal concentration of deoxycholic acid (DCA; 56%, P < .02) compared with HCD. In summary, Cholazol H is as effective as CSTY for prevention of diet-induced hypercholesterolemia and early atherosclerosis in hamsters.

[Nursing performance in materials management in intensive care units]

This study had as a goal to identify the nursing practice in management of material resources in a general hospital. It is a descriptive work of quanti-qualitative nature, performed in four ICU's (Intensive Care Units) among the largest general hospitals in Salvador-Bahia. It has been observed that (only) in three out of four Units, there was the presence of nurses in the commission of material purchase and selection. In addition, the participation of the nursing group in the process of material prevision and control is the lowest, there is lack of evaluation of purchased material; resulting, in turn, in the not occasional presence, of second line, useless and of low quality materials which directly or indirectly affect the provided care. It has been noticed that the nursing performance in material resources management became restrict, only for the reposition of these consumed materials, without, therefore, an effective and efficient insertion in the process of prevision, selection, purchasing and controlling.

IGF-I levels in prepubertal and pubertal children with Down syndrome

BACKGROUND

Growth retardation is a main feature of Down syndrome but it is still unclear whether an alteration of the GH/IGF-I axis is present in this condition. Concerning IGF-I levels, they have been found reduced by some authors but normal by others.

METHODS

On these bases, IGF-I levels have been assessed from prepubertal to late pubertal stages of gonadal maturation in a large group of children and adolescents with Down syndrome (DS, 68 M, 45 F, 12.5 +/- 0.6 yr; prepubertal n = 39, pubertal n = 74) with those in a group of normal children and adolescents (NS, 75 M, 87 F; 11.1 +/- 0.4 yr; prepubertal n = 94, pubertal n = 68).

RESULTS

Within each group, IGF-I levels were gender-independent while showed age-related variations with positive association with pubertal stage--peaking up in pubertal stage IV--(DS: r = 0.6, NS: r = 0.4, both p < 0.0001) and testosterone (DS: r = 0.6, NS: r = 0.5, p < 0.001) or estradiol (DS: r = 0.6, NS: r = 0.5, p < 0.001) levels. Considering whole groups, mean IGF-I levels in DS were slightly but significantly lower than those in NS (257.9 +/- 12.5 vs 310.8 +/- 12.6 micrograms/l, p < 0.02). Analyzing individual IGF-I levels in DS with respect to normal ranges per pubertal stage, more than 85% of IGF-I levels resulted within the normal limits. These results demonstrate that IGF-I levels in DS patients are generally within the normal range--though a slight reduction of mean IGF-I levels is present--and follow normal age-related variations with clear cut increase at puberty and positive association with gonadal steroid levels.

CONCLUSIONS

This evidence points toward the need to clarify the GH/IGF-I axis function and activity in DS patients.

Visual outcome at 5 years of newborn infants at risk of cerebral visual impairment

Visual development at 5 years of age was tested in a group of 39 children who had shown severe neonatal encephalopathy or perinatal brain lesions, documented by medical history, cranial ultrasound, or MRI. In all children, grating acuity was tested during the first 2 years of life. The assessment protocol at 5 years included various visual functions (grating and resolution acuity, visual field size, depth perception, optokinetic nystagmus, and ocular motility), and neurological and cognitive development. The majority of the children showed visual disorders of different type and degree, which were not due to ophthalmological abnormalities. Visual defects correlated well with the results of early visual assessment and of neuroimaging. Visual outcome could be predicted by grating acuity at 1 to 2 years in 27 of the 39 children, by neonatal cranial ultrasound in 26 of the 32 cases examined by this technique, and by later MRI in 23 out of 27. Moreover, a significant correlation was found between visual, motor, and cognitive impairment.

Ca2+-independent excitotoxic neurodegeneration in isolated retina, an intact neural net: a role for Cl- and inhibitory transmitters

Rapidly triggered excitotoxic cell death is widely thought to be due to excessive influx of extracellular Ca2+, primarily through the N-methyl-D-aspartate subtype of glutamate receptor. By devising conditions that permit the maintenance of isolated retina in the absence of Ca2+, it has become technically feasible to test the dependence of excitotoxic neurodegeneration in this intact neural system on extracellular Ca2+. Using biochemical, Ca2+ imaging, and electrophysiological techniques, we found that (1) rapidly triggered excitotoxic cell death in this system occurs independently of both extracellular Ca2+ and increases in intracellular Ca2+; (2) this cell death is highly dependent on extracellular Cl-; and (3) lethal Cl- entry occurs by multiple paths, but a significant fraction occurs through pathologically activated gamma-aminobutyric acid and glycine receptors. These results emphasize the importance of Ca2+-independent mechanisms and the role that local transmitter circuitry plays in excitotoxic cell death.

An intriguing case of LEOPARD syndrome

We report a 9-year-old boy affected by LEOPARD syndrome, who also had ichthyosis, axillary freckling, two café au lait spots, and one neurofibroma. The diagnosis of LEOPARD syndrome has been made on clinical grounds, whereas the ichthyosis and neurofibroma have been histologically confirmed. The analogies between LEOPARD syndrome and neurofibromatosis have been discussed. Finally, we maintain this case is an example of the multiple lentigines syndrome/LEOPARD syndrome spectrum.

[Primary biliary cirrhosis]

PURPOSE

To discuss exhaustively: clinical, serological and pathologic aspects of primary biliary cirrhosis (CBP); recent advantages in the knowledge of the disease's pathogenesis, therapeutical approaches that still appear less preferable than liver transplantation.

DESIGN

We reviewed the most important recent studios on CBP.

RESULTS

More than 90% of patients have antimitochondrial antibodies, so that CBP can be considered an autoimmune disease. Inciting agents could be either PDC E2-like or MHC molecules. An autoaggressive mechanism against biliary ducts could be the following: the neo-antigen on the surface of biliary tract cells could be the target for the immunological damage; anti PDC-E2 antimitochondrial antibodies could be secondary to the cellular damage and to the release of mitochondrial enzymes.

CONCLUSIONS

In primary biliary cirrhosis, several circumstances (specificity of biliary-ductal destruction, lymphocyte infiltration of portal tract, abnormal expression of HLA-DR on surface of biliary epithelium cells) suggest that the epithelial cells of intrahepatic biliary ducts are the target of a severe and isolated immune response. The identification of the E2-like PDC antigen is a significant achievement in the knowledge of the pathogenetic process. On this basis, it is now to investigate possible genetic markers of risk and to clarify the role of T cells in the immunopathogenesis of the illness. The only effective treatment for CBP is liver transplantation.

Fenamates protect neurons against ischemic and excitotoxic injury in chick embryo retina

Three fenamates (flufenamate, meclofenamate and mefenamate) were examined for their protective effect on neurons under ischemic (glucose/oxygen deprivation) or excitotoxic conditions, using the isolated retina of chick embryo as a model. Retinal damage was evaluated by histology and lactate dehydrogenase assay. Whole-cell recording was used to examine the direct effect of the fenamates on glutamate receptor-mediated currents. The fenamates protected the retina against the ischemic or excitotoxic insult. Part of the neuroprotection by the fenamates derived from inhibition of N-methyl-D-aspartate receptor-mediated currents. However, kainate receptor-mediated currents were not blocked by the fenamates, which nonetheless reduced kainate receptor-mediated retinal damage. Our results raise the possibility that fenamates may serve as lead structures in the development of novel therapeutic agents against brain ischemia.

Excitotoxic neurodegeneration induced by deprivation of oxygen and glucose in isolated retina

PURPOSE

Ischemic neurodegeneration contributes to many retinal diseases. An isolated retina model has been used to examine the neuronal cell death induced by deprivation of oxygen and glucose (simulated ischemia) as a model for ischemic disease.

METHODS

Neurodegeneration in the isolated chick embryo retina was induced by simulated ischemia and assessed using biochemical (lactate dehydrogenase release) and morphologic (light microscopy) techniques.

RESULTS

Simulated ischemia led to lactate dehydrogenase release gradually in a period of 6 to 24 hours. Light microscopic observations demonstrated morphologic cell degeneration well before lactate dehydrogenase release occurred. N-Methyl-D-aspartate (NMDA) and non-NMDA receptor blockers individually provided partial protection, and the combination was fully protective. No protection was provided if the antagonists were added after simulated ischemia. When NMDA receptors were blocked by MK-801, cyclothiazide, an inhibitor of desensitization at non-NMDA receptors, enhanced lactate dehydrogenase released after 1 or 2 hours of simulated ischemia. Low concentrations of glucose effectively prevented lactate dehydrogenase release, despite anoxic conditions.

CONCLUSIONS

The isolated retina provided a convenient system to characterize quantitatively ischemic cell death. Retinal ischemic neurodegeneration is an excitotoxic process that involves overactivation of NMDA and non-NMDA glutamate receptors. Blockade of both of these receptor subtypes was necessary for complete neuroprotection. Receptor desensitization played a protective role. If even low concentrations of glucose were delivered to an ischemic retina in vitro, substantial neuroprotection could be achieved. This may have implications for the management of acute retinal ischemic episodes.

Anti-Ro/SS-A positivity and heat shock protein antibodies in patients with normal-pressure glaucoma

PURPOSE

To describe the clinical and laboratory findings in 10 patients with normal-pressure glaucoma and anti-Ro/SS-A positivity by enzyme-linked immunosorbent assay (ELISA) and to determine whether that positivity may be related to an autoimmune mechanism for the optic neuropathy.

METHODS

In this prospective study, we evaluated ocular and systemic clinical findings of 10 patients with normal-pressure glaucoma and anti-Ro/SS-A positivity by ELISA, including sicca complex features. Oüchterlony immunodiffusion was performed to confirm the presence of antibodies for Ro/SS-A, and the presence of other serum antibodies and their possible cross-reactivities with Ro/SS-A were investigated.

RESULTS

None of the 10 patients with normal-pressure glaucoma and anti-Ro/SS-A positivity (by ELISA) had clinical or laboratory signs of Sjögren syndrome or other connective tissue diseases. Only one of 10 patients had evidence of anti-Ro/SS-A antibodies by Oüchterlony immunodiffusion. All patients demonstrated serum immunoreactivity to bacterial heat shock protein 60 (hsp60) by Western blotting. Cross-reactivity between bacterial hsp60 and Ro/SS-A was demonstrated by Western blotting. Immunoreactivity to bacterial hsp60 by ELISA was significantly elevated in the sera of patients with normal-pressure glaucoma. Furthermore, patients with either normal-pressure or primary open-angle glaucoma had increased serum immunoreactivity to human hsp60.

CONCLUSIONS

Anti-Ro/SS-A positivity by ELISA in 10 patients with normal-pressure glaucoma was associated with a high level of serum immunoreactivity to bacterial hsp60, which may indicate that their glaucomatous optic neuropathy involves an as yet unidentified autoimmune mechanism. The identification of autoantibodies that react with human hsp60 in patients with normal-pressure and primary open-angle glaucoma may signify a common finding associated with the glaucomatous optic neuropathy process in some patients and appears to be unrelated to intraocular pressure levels.