Biomedical subjects

Carlos Gilberto Carlotti

Publications and source records attributed to Carlos Gilberto Carlotti.

14 recordsLinked to original sources

PubMed2006

Neurogenic thoracic outlet syndromes: a comparison of true and nonspecific syndromes after surgical treatment.

BACKGROUND: Neurogenic thoracic outlet syndrome (NTOS) is attributed to compression of the brachial plexus at the scalene hiatus. Patients with true NTOS (TNTOS) have typical clinical and electrophysiological changes and are considered to respond well to surgical treatment, but patients with nonspecific NTOS (NNTOS) have predominantly sensory signs, not well-defined electrophysiological changes, and are thought not to respond favorably to surgical treatment. The postsurgical outcome of patients with cervicobrachialgia diagnosed as TNTOS and as NNTOS is analyzed. METHODS: Seven patients with typical electrophysiological features of TNTOS and 11 with nonspecific signs (NNTOS--extraspinal compression of C5-T1) were treated from 1986 to 2001. Age, duration of symptoms, and follow-up were similar in both groups. All patients underwent unilateral (14) or bilateral (4) supraclavicular decompression of the brachial plexus, for a total of 22 procedures. Clinical outcome was evaluated based on sensory and motor signs and on functional capacity. The Mann-Whitney U test and Fisher exact test were used to compare demographic data and proportions, respectively. RESULTS: Improvement of pain/paresthesias, sensory loss, atrophy, and muscular weakness after surgery was similar in the two groups. Regarding functional capacity, 57.1% of patients with TNTOS and 63.6% of patients with NNTOS became normal or reacquired their previous condition with slight limitation. Surgery-related complications were paresthesias and paresis in the arm, sympathetic dystrophy, pneumothorax, and lymphatic collections, all in patients with NNTOS. CONCLUSIONS: Patients with NNTOS with electrophysiological signs of extraspinal radicular impairment had the same chances of improvement after surgical treatment as patients with TNTOS.

Activities of Daily Living↗

PubMed2006

Parasagittal meningiomas: follow-up review.

BACKGROUND: Parasagittal meningioma is one that fills the parasagittal angle, with no brain tissue between the tumor and the SSS. Invasion of the SSS is a challenge for complete removal and, consequently, for recurrence of these tumors. The objective of this study was to analyze the factors that influenced the clinical outcome of patients with parasagittal tumors surgically treated. METHODS: Review of data on 53 patients with diagnosis of parasagittal meningiomas surgically treated from 1984 to 2004. Thirty-four (64.2%) were female and 19 (35.8%) were male; age ranged from 18 to 81 years old (mean, 54.98 +/- 5.80). Follow-up ranged from 2 to 261 months (mean, 93.71 +/- 68.45). The patients were operated on using microsurgical techniques. Tumors in the anterior third (9) or occluding the SSS (5) were removed with the sinus; tumors touching/pouching the SSS (20) were removed and its dural attachment coagulated; tumors invading one sinus wall (10) were removed with partial excision and reconstruction of the sinus wall, and tumors invading more than one sinus wall in the posterior two thirds of the SSS (7) had a subtotal removal. No attempt at sinus resection and reconstruction was performed for tumors placed in the posterior two thirds of the SSS. Analysis of the patient outcome was done using survival and RFS Kaplan-Meier curves. The chi(2), Fisher exact, log-rank, Mann-Whitney, and Kruskall-Wallis ANOVA tests were used for comparing demographic data, survival curves, proportions, and medians, respectively. RESULTS: Total and subtotal resection were achieved in 85% and 13.1%, respectively. Males had better survival than females (P = .0252). Total RF rates were 10%, 25%, and 100% at 5 years and 100%, 50%, and 100% at 10 years for patients with meningiomas WHO grades I, II, and III, respectively. The RF survival curve was better for patients with grade I meningioma (grades I vs II vs III, P = .0001). There was no difference between the RF survival curves according to age, histopathologic WHO grade, location along or invasion of the SSS, and extent of resection. Males (P = .0401), WHO grade I (P < .0001), total resection (P = .0139), and less sinus invasion (P = .0308) had better RFS curves. Operative, surgery-related, and overall mortality were 1.9%, 5.4%, and 26.4%, respectively. CONCLUSIONS: Recurrence of parasagittal meningiomas predominated in males, in grades II/III tumors, after subtotal resection, and with more invasion of the SSS. Subtotal or total resections without sinus resection were considered adequate for treating these patients.

Adolescent↗

PubMed2005

Impaired exercise capacity, but unaltered mitochondrial respiration in skeletal or cardiac muscle of mice lacking cellular prion protein.

The studies of physiological roles for cellular prion protein (PrP(c)) have focused on possible functions of this protein in the CNS, where it is largely expressed. However, the observation that PrP(c) is expressed also in muscle tissue suggests that the physiological role of PrP(c) might not be limited to the central nervous system. In the present study, we investigated possible functions of PrP(c) in muscle using PrP(c) gene (Prnp) null mice (Prnp(0/0)). For this purpose, we submitted Prnp(0/0) animals to different protocols of exercise, and compared their performance to that of their respective wild-type controls. Prnp(0/0) mice showed an exercise-dependent impairment of locomotor activity. In searching for possible mechanisms associated with the impairment observed, we evaluated mitochondrial respiration (MR) in skeletal or cardiac muscle from these mice during resting or after different intensities of exercise. Baseline MR (states 3 and 4), respiratory control ratio (RCR) and mitochondrial membrane potential (DeltaPsi) were evaluated and were not different in skeletal or cardiac muscle tissue of Prnp(0/0) mice when compared with wild-type animals. We concluded that Prnp(0/0) mice show impairment of swimming capacity, perhaps reflecting impairment of muscular activity under more extreme exercise conditions. In spite of the mitochondrial abnormalities reported in Prnp(0/0) mice, our observation seems not to be related to MR. Our results indicate that further investigations should be conducted in order to improve our knowledge about the function of PrP(c) in muscle physiology and its possible role in several different neuromuscular pathologies.

Animals↗

PubMed2005

Central nervous system paracoccidioidomycosis: diagnosis and treatment.

BACKGROUND: Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides brasiliensis. The involvement of the central nervous system (CNS) in paracoccidioidomycosis is higher than previously thought and 2 clinical presentations have been reported, meningitis and pseudotumoral. METHODS: Twenty medical records of patients with CNS paracoccidioidomycosis treated from 1986 to 2003 were analyzed. The follow-up ranged from 1 to 18 years (mean = 8.9 +/- 4.2). RESULTS: Besides CNS paracoccidioidomycosis, all patients but one had the chronic systemic form and the pseudotumoral clinical presentation was the most frequent. Based on computed tomography scan findings, 4 image patterns were identified: low-density lesion with ring enhancement, lesion with calcification and ring enhancement, multiloculated low-density lesion with ring enhancement, and diffuse subarachnoid enhancement. The magnetic resonance imaging was performed in 3 patients and showed subarachnoid enhancement in 1 patient and heterogeneous lesion with ring enhancement in 2 patients. Eleven patients were submitted to medical treatment and 9 needed neurosurgical treatment; ventriculoperitoneal shunts in 4 patients, brain lesions resection in 3 patients, and partial resection of spinal cord lesions in 2 patients. Eleven patients had excellent outcome, 4 patients died, 3 are in good clinical condition with residual pulmonary dysfunction, and 1 patient was lost to follow-up. CONCLUSIONS: The diagnosis of paracoccidioidomycosis with involvement of the CNS is difficult and clinical suspicion is a key point to achieve the correct diagnosis. Patients with early diagnosis have a favorable outcome with clinical or surgical treatment.

Adult↗

PubMed2005

Plasticity, synaptic strength, and epilepsy: what can we learn from ultrastructural data?

Central nervous system synapses have an intrinsic plastic capacity to adapt to new conditions with rapid changes in their structure. Such activity-dependent refinement occurs during development and learning, and shares features with diseases such as epilepsy. Quantitative ultrastructural studies based on serial sectioning and reconstructions have shown various structural changes associated with synaptic strength involving both dendritic spines and postsynaptic densities (PSDs) during long-term potentiation (LTP). In this review, we focus on experimental studies that have analyzed at the ultrastructural level the consequences of LTP in rodents, and plastic changes in the hippocampus of experimental models of epilepsy and human tissue obtained during surgeries for intractable temporal lobe epilepsy (TLE). Modifications in spine morphology, increases in the proportion of synapses with perforated PSDs, and formation of multiple spine boutons arising from the same dendrite are the possible sequence of events that accompany hippocampal LTP. Structural remodeling of mossy fiber synapses and formation of aberrant synaptic contacts in the dentate gyrus are common features in experimental models of epilepsy and in human TLE. Combined electrophysiological and ultrastructural studies in kindled rats and chronic epileptic animals have indicated the occurrence of seizure- and neuron loss-induced changes in the hippocampal network. In these experiments, the synaptic contacts on granule cells are similar to those described for LTP. Such changes could be associated with enhancement of synaptic efficiency and may be important in epileptogenesis.

Animals↗

PubMed2004

Normal brain mitochondrial respiration in adult mice lacking cellular prion protein.

Cellular prion protein (PrP(c)) gene (Prnp) null mice (Prnp0/0) show higher sensitivity to seizures, enhanced brain oxidative stress, and their neurons exhibit higher excitability "in vitro". Mitochondrial respiration is a useful parameter for the determination of cellular metabolic rate and it is a major source of reactive oxygen species (ROS). In the present study, we investigated the mitochondrial function of different brain areas of Prnp0/0 adult mice and then compared this to normal control animals. Baseline mitochondrial respiration (stages 3 and 4), respiratory control ratio (RCR) and membrane potential were evaluated in the neocortex, entorhinal cortex, hippocampus, and cerebellum. No differences in these parameters were detected between Prnp0/0 and wild-type mice. Thus, we concluded that baseline mitochondrial respiration might not be directly related with the higher oxidative stress previously observed in brains from Prnp0/0 mice.

Animals↗

PubMed2004

Surgical management of axis' traumatic spondylolisthesis (Hangman's fracture).

OBJECTIVE: To evaluate the results of surgical treatment using pedicle screws going through C2 pedicles for fixating the spondylolisthesis of the axis in patients who presented pseudoarthrosis after clinical treatment, or who have no condition for fixation with "halo vest", due to serious head trauma. METHOD: Ten patients have been operated from June 1998 to April 2002, nine suffering from traumatic spondylolisthesis of the axis caused by car accident and one horse fall. Four of those patients have undergone clinical treatment and presented signs of pseudoarthrosis, suffering intense pain at the movement of the cervical spine. Two of them presented moderate head trauma with multiple fractures of the skull. Another one was submitted to a surgical treatment for an acute extradural hematoma. Three patients presented a serious dislocation of C2 over C3. The patients were submitted to arthrodesis of the fractures with two screws, placed on the C2 pedicles, which allowed a better approximation of the fractures with the alignment of C2-C3. Two other patients required additional fixation with a plate on the lateral masses of C3. RESULTS: Nine patients had a good post surgery evolution with satisfactory consolidation of the fractures and disappearance of the symptoms. One patient had a good evolution but still has cervical pain resulting from strain. CONCLUSION: The fixation of the traumatic spondylolisthesis of the axis using screws in C2 pedicles and through fractures traces is a good option for treating patients who present pseudoarthrosis after clinical treatment or who present contraindication to the "halo vest", such as skull fracture or great lacerations in the scalp.

Adult↗

PubMed2004

Enhancement of blood-tumor barrier permeability by Sar-[D-Phe8]des-Arg9BK, a metabolically resistant bradykinin B1 agonist, in a rat C6 glioma model.

BACKGROUND: While it is well known that bradykinin B2 agonists increase plasma protein extravasation (PPE) in brain tumors, the bradykinin B1 agonists tested thus far are unable to produce this effect. Here we examine the effect of the selective B1 agonist bradykinin (BK) Sar-[D-Phe8]des-Arg9BK (SAR), a compound resistant to enzymatic degradation with prolonged activity on PPE in the blood circulation in the C6 rat glioma model. RESULTS: SAR administration significantly enhanced PPE in C6 rat brain glioma compared to saline or BK (p < 0.01). Pre-administration of the bradykinin B1 antagonist [Leu8]-des-Arg (100 nmol/Kg) blocked the SAR-induced PPE in the tumor area. CONCLUSIONS: Our data suggest that the B1 receptor modulates PPE in the blood tumor barrier of C6 glioma. A possible role for the use of SAR in the chemotherapy of gliomas deserves further study.

Animals↗

PubMed2004

Surgical treatment for mesial temporal lobe epilepsy in the presence of massive calcified neurocysticercosis.

BACKGROUND: Neurocysticercosis (NCC) is the most common parasitic disease of the human central nervous system and a major health problem for most developing countries. The most common clinical manifestations of NCC are epileptic seizures. Whenever epilepsy and NCC coexist in the same patient, an uncertainty may rise about a causal relationship between them. OBSERVATION: We described a female patient with disseminated calcified NCC lesions and intractable epilepsy. Her medical history included cysticercotic meningoencephalitis and status epilepticus caused by active NCC. Fundoscopy showed the ocular presence of parasite; computed tomography of the brain showed evidence of cystic lesions with the scolex and calcified lesions; enzyme-linked immunosorbent assay of the cerebrospinal fluid was positive for cysticercosis. Epileptic seizures started after an 8-year silent period. Magnetic resonance imaging showed left hippocampal sclerosis. Plain x-ray film showed calcifications in muscles and subcutaneous tissue. Video-electroencephalography and ictal and interictal single-photon emission computed tomography disclosed left mesial temporal lobe epilepsy. The patient underwent left temporal lobectomy and has been seizure free since surgery, for a follow-up of 4 years. CONCLUSION: This case report highlights and supports surgical therapy in patients with epileptic seizures and calcified NCC, even when there are several calcifications, provided that clear localization of epilepsy has been determined by means of a presurgical workup.

Adult↗

PubMed2004

Ictal chronology and interictal spikes predict perfusion patterns in temporal lobe epilepsy: a multivariate study.

Typical (TPP) and atypical (APP) perfusion patterns (PP) may be seen in ictal SPECT of patients with temporal lobe epilepsy (TLE). APP may pose problem in the lateralization of the epileptogenic zone (EZ). We aimed to investigate predictive variables for the occurrence of TPP and APP. Fifty-one TLE patients were submitted to successful anterior-mesial temporal lobectomy. Univariate (UVA) and multivariate (MVA) analysis were performed upon clinical data, distribution of interictal spikes, and ictal chronology of seizures. From MVA, a final predictive model (FPM) was determined to better predict TPP and APP. Forty patients showed TPP (78.5%) and 11 patients APP (21.5%). Accuracy of ictal SPECT was higher in the unilateral (UIS) than in the bilateral (BIS) interictal spikes group (P = 0.05). FPM showed that patients exhibiting BIS, with shorter proportion of the electrographic seizure occurring after completion of tracer injection, and longer clinical than EEG seizure duration had more APP (P = 0.003). Generalized tonic-clonic seizures did not result in more APP. We concluded that analysis of ictal SPECT in TLE requires the knowledge of TPP and APP, the distribution of interictal spikes on temporal lobes and the ictal chronology of seizures. BIS showed that beyond a more complex epileptogenicity and seizure propagation, they may also lead to APP.

Adolescent↗

PubMed2004

Experimental microaneurysms in rats: I. Model for induction.

BACKGROUND: Small aneurysms (lesser than 2 mm) in humans called sessile, baby aneurysms, or microaneurysms, generally are not able to be clipped or to be coil-packed through endovascular route. Among the modalities of treatment that have been used for treating microaneurysms, bipolar coagulation and wrapping of the lesion are outstanding. Nevertheless, demonstration of the efficacy of these treatments is difficult because most reported experimental models for inducting aneurysms are complex and difficult to be reproduced. This study aimed to develop a simple and reproducible model for inducing microaneurysms. METHODS: Microaneurysms were induced using a mechanical lesion of the bifurcation of the aorta in 72 rats. Three groups of 10 animals were sacrificed 7, 14, and 21 days after the lesion and 2 groups (35 and 7 animals) after 30 days. The aortic bifurcation was macro/microscopically analyzed in the first 4 groups and a resistance test was applied in the fifth group. RESULTS: Microaneurysms occurred in 77.8% of cases. Microscopically, degenerative changes were observed in the intima, media, and adventitia and in the internal elastic lamina. The bursting pressure ranged from 368 to 1,472 mm Hg during the resistance test in the fifth group. CONCLUSIONS: The presented model of experimental microaneurysm induction is simple, reproducible and gives a high rate of positivity.

Aneurysm, Ruptured↗

PubMed2004

Experimental microaneurysms in rats: II. Comparison between cotton wrapping and microbipolar coagulation.

BACKGROUND: Microsurgical aneurysm clipping is considered the best treatment for intracranial aneurysms, but often it cannot be used for microaneurysms. These aneurysms may require different type of treatment like bipolar coagulation or wrapping to reinforce the aneurysm wall, but these treatments have no experimentally proven efficacy. In this study the authors analyze the efficacy of 2 methods of treatment to prevent rupture of experimentally induced microaneurysms. METHODS: Microaneurysms were induced using mechanical compression of the wall of the aortic bifurcation in 60 rats. The animals were divided in three groups according to aneurysm treatment: Group 1-aneurysms treated using microbipolar coagulation; Group 2-aneurysms wrapped with cotton, and Group 3-no treatment. Four weeks after the treatment, the resistance of the microaneurysm was tested applying intraluminal hyperpressure (up to 2,427 mm Hg). After that, the vessels were microscopically analyzed. RESULTS: No rupture of the aneurysms was observed in Group 2 and all aneurysms ruptured in Groups 1 and 3 during the resistance test. Comparison between the mean bursting pressure of Groups 1 and 3 showed no significant difference (Student's t test, p > 0.05). The probability of rupture of the microaneurysms was significantly different between Groups 1 and 2, favoring Group 2 (Fisher exact test, p < 0.001). CONCLUSIONS: Wrapping of experimental microaneurysms with cotton was effective to protect aneurysm rupture under hyperpressure; and there was no protection using microbipolar coagulation.

Aneurysm, Ruptured↗

PubMed2004

Galectin-3 as an immunohistochemical tool to distinguish pilocytic astrocytomas from diffuse astrocytomas, and glioblastomas from anaplastic oligodendrogliomas.

The distinction of astrocytomas and oligodendrogliomas, mainly pilocytic astrocytomas (PILOs) from infiltrating astrocytomas and oligodendrogliomas (ODs), and high-grade oligodendrogliomas from glioblastomas (GBMs), poses a serious clinical problem. There is no useful immunohistochemical (IHC) marker to differentiate these gliomas, and sometimes the differential diagnosis between them is arbitrary. We identified galectin-3 (Gal-3) as a possible tool to differentiate them based on gene expression profiles of GBMs. We confirmed the differential expression in 45 surgical samples (thirteen GBMs; seven PILOs; 5 grade II ODs; 5 anaplastic oligodendrogliomas [AODs], including 2 Oligo-astrocytomas; 8 diffuse astrocytomas [ASTs], and 7 non-neoplastic samples) by quantification of Gal-3 gene expression by real-time quantitative PCR (rt-PCR). Higher expression of Gal-3 was observed in GBMs and PILOs than in OD, AODs and ASTs. The IHC expression of Gal-3 was evaluated in 90 specimens (fifteen PlLOs, fourteen ASTs, 10 anaplastic astrocytomas, fifteen GBMs, eleven ODs, fifteen AODs, and 10 dysembryoplastic neuroepithelial tumors). The mean labeling score for Gal-3 determined according to the percentage of labeled cells in the tumor bulk was significantly different in GBMs versus AODs and in PILOs versus ASTs. Hence, Gal-3 is differentially expressed in central nervous system tumors, making IHC detection of Gal-3 a useful tool in distinguishing between these gliomas.

Adolescent↗

PubMed2002

Spinal cord cysticercosis: neurosurgical aspects.

OBJECT: The authors report their experience in the treatment of 12 symptomatic patients with intradural spinal neurocysticercosis. METHODS: The mean age of the 12 patients was 33 years. There were eight female and four male patients. Cysticercosis was present in association with hydrocephalus in nine cases. In nine of 12 patients the spinal lesion was confined to the thoracic or lumbar spinal cord, and in three the cysticerci occupied the cervical region. In all patients with hydrocephalus nerve root symptoms developed seven to 48 months later (mean 27.6 +/- 15.5 months). In one patient hydrocephalus was absent, but he presented with cysticercal meningitis 24 months before spinal cord compression developed. Presenting symptoms suggesting spinal cysticercosis included muscular weakness (67%), pain (67%), and sphincter disturbance (25%). Neurological examination demonstrated a motor deficit in nine patients, sensory deficit in four, and radicular pain in three. The prognosis was worse in patients with moderate-to-severe arachnoiditis and spinal cord compression compared with those with isolated nerve roots involvement in whom outcome was favorable. Ten patients underwent laminectomy, after which neurological status improved in 44%, remained unchanged in 33%, or worsened in 22.2%. CONCLUSIONS: The authors discuss their findings in these cases. Additionally they briefly review the literature, pathophysiology, and therapeutic and/or surgical strategies involved in this disease.

Adolescent↗