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Biomedical subjects

I Bruck

Publications and source records attributed to I Bruck.

At least 19 recordsLinked to original sources
PubMed2006

[Neurocysticercosis in children: clinical study and follow-up of 112 patients].

INTRODUCTION: Neurocysticercosis (NC) is the infection of the central nervous system caused by the Taenia solium larva. It is related to a wide variety of clinical symptoms and pathological findings. AIM: Clinical study, diagnosis, treatment and evolution of 112 patients with NC. PATIENTS AND METHODS: 112 patients with NC, between 1 and 14 years of age, were evaluated and followed from 18 months up to 13 years. RESULTS: The most common clinical symptoms were epileptic seizures and signs of intracranial hypertension. The disease progressed as follows: active forms were seen in around 39% of the cases (viable cysts in 3% and transitional/granulomatous form in 36%), encephalitic form in 22% and inactive form (calcifications) in 39%. In the great majority of the cases, a treatment with anti-helmitic was not used. The control of the crises was positive in 86% of the cases -94% in the transitional forms, 93% in the inactive forms and 68% in the encephalitic form-. Recurrence of crises happened after suspension of the medication in 12,5% of the granulomatous form and in 11,2% of the inactive form. Neurological sequelae occurred only in the encephalitic form (12/25 patients). CONCLUSIONS: Clinical findings and clinical evolution of neurocysticercosis in children is related to the evolutive form of the disease. The clinical evolution, including control of the crises and radiological control, is benign in the inactive and active forms, except in the encephalitic forms. The extraparenquimatous form is quite rare in the pediatric group.

Adolescent↗
PubMed2001

The ring-type polymerase sliding clamp family.

Ring-type polymerases consist of a DNA polymerase, a ring-shaped sliding clamp protein and a clamp-loading complex. Sliding clamp proteins are found in all organisms and are called proliferating cell nuclear antigen (PCNA) in eukaryotes and the beta clamp in prokaryotes. Both PCNA and beta form a ring around DNA, which is made up of two subunits of three domains each in beta but three subunits of two domains each in PCNA. Despite this difference and a lack of detectable sequence homology, the structures of the two rings are very similar. The sliding clamp slides along DNA and tethers the polymerase to the DNA, enabling rapid and processive DNA replication.

Animals↗
PubMed2001

Epilepsy in children with cerebral palsy.

OBJECTIVE: To describe the prevalence and characteristics of epilepsy in patients with cerebral palsy in a tertiary center. METHODS: a total of 100 consecutive patients with cerebral palsy were retrospectively studied. Criteria for inclusion were follow-up period for at least 2 years. Types and incidence of epilepsy were correlated with the different forms of cerebral palsy. Other factors associated with epilepsy such as age of first seizure, neonatal seizures and family history of epilepsy were also analysed. RESULTS: follow-up ranged between 24 and 151 months (mean 57 months). The overall prevalence of epilepsy was 62%. Incidence of epilepsy was predominant in patients with hemiplegic and tetraplegic palsies: 70.6% and 66.1%, respectively. First seizure occurred during the first year of life in 74.2% of patients with epilepsy. Generalized and partial were the predominant types of epilepsy (61.3% and 27.4%, respectively). Thirty-three (53.2%) of 62 patients were seizure free for at least 1 year. Neonatal seizures and family history of epilepsy were associated with a higher incidence of epilepsy. CONCLUSIONS: epilepsy in cerebral palsy can be predicted if seizures occur in the first year of life, in neonatal period and if there is family history of epilepsy.

Adolescent↗
PubMed2001

Sudden unexpected, unexplained death in epilepsy autopsied patients.

Sudden unexpected, unexplained death in epilepsy (SUDEP) has been reported to be responsible for 2 to 17% of all deaths in patients with epilepsy. This study was conducted to determine the circumstances of SUDEP and the autopsy findings in these patients. Fifty-three individuals whose cause of death was related to epilepsy were identified and in 30 cases relatives or friends were interviewed about the circumstances of death and other information which allowed to classify the patients as SUDEP or not. The death certificates were also reviewed. We found 20 cases of SUDEP. Most of them were found dead lying on the bed with no evidence of seizure event, and most of them had pulmonary and/or cerebral edema as the cause of death. The incidence and the risk of SUDEP can only be fully ascertained if all sudden deaths had postmortem examination. Consensus in certifying SUDEP cases would allow better accuracy in national mortality rate.

Adolescent↗
PubMed2001

Learning disabilities: analysis of 69 children.

With this article we intend to demonstrate the importance of evaluation and follow up of children with learning disabilities, through a multidisciplinary team. As well as to establish the need of intervention. We evaluate 69 children, from Aline Picheth Public School, in Curitiba, attending first or second grade of elementary school, through general and evolutionary neurological examination, pediatric checklist symptoms, and social, linguistic and psychological (WISC-III, Bender Infantile and WPPSI-figures) evaluation. The incidence was higher in boys (84,1%), familiar history of learning disabilities was found in 42%, and writing abnormalities in 56,5%. The most frequent diagnosis was attention deficit and hyperactivity disorder, in 39,1%. With this program, we aimed to reduce the retention taxes and stress the importance of this evaluation, and, if necessary, multidisciplinary intervention in the cases of learning disabilities.

Attention Deficit Disorder with Hyperactivity↗
PubMed2001

Developmental milestones of vertically HIV infected and seroreverters children: follow up of 83 children.

The aim of the study was to detect neurological abnormalities in human immunodeficiency virus (HIV) infected children. This was achieved by a prospective evaluation, from November/1995 to April/2000, of 43 HIV infected children (group I) and 40 HIV seroreverters children (group II) through neurological exam and neurodevelopmental tests: Denver Developmental Screening Test (DDST) and Clinical Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS). A control group (III), of 67 children, were evaluated by CAT/CLAMS. Hyperactivity, irritability and hypotonia were the findings on neurological examination, without statistical differences between group I and II. On CAT/CLAMS, the group I developmental quotient (DQ) was significantly lower than the other groups. The same occurred in DDST, with group I presenting significantly more failures than group II. Nineteen HIV children of group I had brain computed tomographic scan, with abnormalities in three of them (basal ganglia calcification, white matter hypodensity and asymmetry of lateral ventricles). We conclude that in HIV infected children a neurodevelopment delay occur early in the disease, and it can be detected by screening tests.

Child↗
PubMed2001

[Schizencephaly: report of eleven cases].

A retrospective study comparing clinical and computerized tomography (CT) in 11 patients diagnosed as having schizencephaly was conducted. Seven of these patients were girls and four boys. Six of them had tetraparesis, three hemiparesis and one no motor deficits. Six had epilepsy and ten developmental delay. On CT examinations, 7 patients were found as having bilateral clefts and four unilateral defect. Eight had opened lip clefts and four had a closed lip defect. The commonest associated anomaly was an absent septum pellucidum (n=9), followed by subependymal nodules (n=4), hydrocephalus (n=2) and microcephaly (n=1). Despite magnetic resonance image is the gold-standard to diagnose neuronal migration anomalies, CT can be useful in showing typical aspects of schizencephaly.

Adolescent↗
PubMed2001

[Rett syndrome: retrospective and prospective study of 28 patients].

From November 1982 to May 1999, 28 children with Rett syndrome were followed-up for a medium period of 6 years and 2 months. Regression of developmental milestones started at the age between 5 and 20 months. Nineteen cases of typical Rett syndrome had uneventful pre and perinatal periods, loss of previously acquired purposeful hand skills, mental and motor regression and developed hand stereotypies; sixteen had head growth deceleration and 12 gait apraxia. Nine patients were atypical cases, 2 formes frustres, 2 congenital, 3 with early seizure onset, 1 preserved speech and 1 male. Epilepsy was present in 21 patients, predominantly partial seizures and the drug of choice was carbamazepine (15 patients). In the initial evaluation most patients were distributed on Stages II and III and on follow-up on Stages III and IV. Three children died.

Adolescent↗
PubMed2001

[Cerebral arterial aneurysm in a child with acquired immunodeficiency syndrome: case report].

Cerebral aneurysmal arteriopathy of the circle of Willis is an uncommon manifestation of acquired human immunodeficiency virus (HIV) infection and up to now only 15 cases have been published in the literature. For this reason we add our experience of this rare case, and review the most important aspects related to this entity. The patient is a 6 year old male with perinatal transmitted AIDS, tetraparethic, developed symptoms characterized by episodes of dystonic postures. The computed tomography of the brain showed aneurismal arteriopathy of the circle of Willis. He had a previous normal examination. The review of the literature shows the pathological abnormalities of the affected vessels are mainly medial fibrosis, with destruction of the internal elastic lamina and intimal hyperplasia. The etiology for the vasculitis is unknown. Varicela zoster virus, as well as HIV by itself, can be related to the physiopathology of the vasculitis. On conclusion, it can be said that although uncommon, such complications are of great importance by the fact that the patients with vascular aneurismal arteriopathy are in high risk for vascular accidents, and once a diagnosis was made, death occurs in less than 6 months, according to the literature.

Acquired Immunodeficiency Syndrome↗
PubMed2000

The DNA replication machine of a gram-positive organism.

This report outlines the protein requirements and subunit organization of the DNA replication apparatus of Streptococcus pyogenes, a Gram-positive organism. Five proteins coordinate their actions to achieve rapid and processive DNA synthesis. These proteins are: the PolC DNA polymerase, tau, delta, delta', and beta. S. pyogenes dnaX encodes only the full-length tau, unlike the Escherichia coli system in which dnaX encodes two proteins, tau and gamma. The S. pyogenes tau binds PolC, but the interaction is not as firm as the corresponding interaction in E. coli, underlying the inability to purify a PolC holoenzyme from Gram-positive cells. The tau also binds the delta and delta' subunits to form a taudeltadelta' "clamp loader." PolC can assemble with taudeltadelta' to form a PolC.taudeltadelta' complex. After PolC.taudeltadelta' clamps beta to a primed site, it extends DNA 700 nucleotides/second in a highly processive fashion. Gram-positive cells contain a second DNA polymerase, encoded by dnaE, that has homology to the E. coli alpha subunit of E. coli DNA polymerase III. We show here that the S. pyogenes DnaE polymerase also functions with the beta clamp.

Amino Acid Sequence↗
PubMed2000

Visualization of two binding sites for the Escherichia coli UmuD'(2)C complex (DNA pol V) on RecA-ssDNA filaments.

The heterotrimeric UmuD'(2)C complex of Escherichia coli has recently been shown to possess intrinsic DNA polymerase activity (DNA pol V) that facilitates error-prone translesion DNA synthesis (SOS mutagenesis). When overexpressed in vivo, UmuD'(2)C also inhibits homologous recombination. In both activities, UmuD'(2)C interacts with RecA nucleoprotein filaments. To examine the biochemical and structural basis of these reactions, we have analyzed the ability of the UmuD'(2)C complex to bind to RecA-ssDNA filaments in vitro. As estimated by a gel retardation assay, binding saturates at a stoichiometry of approximately one complex per two RecA monomers. Visualized by cryo-electron microscopy under these conditions, UmuD'(2)C is seen to bind uniformly along the filaments, such that the complexes are completely submerged in the deep helical groove. This mode of binding would impede access to DNA in a RecA filament, thus explaining the ability of UmuD'(2)C to inhibit homologous recombination. At sub-saturating binding, the distribution of UmuD'(2)C complexes along RecA-ssDNA filaments was characterized by immuno-gold labelling with anti-UmuC antibodies. These data revealed preferential binding at filament ends (most likely, at one end). End-specific binding is consistent with genetic models whereby such binding positions the UmuD'(2)C complex (pol V) appropriately for its role in SOS mutagenesis.

Binding Sites↗
PubMed2000

[Hypertensive encephalopathy associated to repetitive seizures: case report].

Five years old, female, who started with tonic-clonic seizures on the right side of the body, with vomits and unconsciousness. The patient had been hospitalized for eight times in the last sixty days because of seizures. At physical exam, she had a severe arterial hypertension (270/140 mmHg). The computerized tomographic scan and magnetic resonance imaging revealed hypodense areas, mainly on the right parietal-temporal region, suggesting presence of edema. The angiography showed stenosis of the right renal artery, that was the cause of arterial hypertension. After the control of arterial hypertension by nephrectomy, the patient had a complete remission of the symptoms, as well as the images anomalies.

Angiography↗
PubMed2000

[West syndrome: clinical and electroencephalographic follow up of 70 patients and response to its treatment with adrenocorticotropic hormone, prednisone, vigabatrin, nitrazepam and valproate].

In a retrospective study we assessed the outcome of the criptogenic and symptomatic forms of West syndrome and evaluated the efficacy of adrenocorticotropic hormone, vigabatrin, prednisone, valproate and nitrazepam in the spasms control. Seventy patients were follwed up by 2 years. Twelve (17%) were criptogenics and 58 (83%) symptomatics. In criptogenic group significantly more patients were in regular school classes and with normal motor development, better control of seizure, less tendency to evoluate to Lennox Gastaut syndrome and 83. 3% had control of spasms (72.4% of patients from symptomatic group had control of spasms). Adrenocorticotropic hormone and vigabatrin were the most efective drugs, with 68.75% and 60% of spasms control, respectivelly, when used as first line of therapy and 75% and 50%, respectivelly, as second line of therapy.

Adolescent↗
PubMed2000

Cerebellar vermis hypoplasia - non progressive congenital ataxia: clinical and radiological findings in a pair of siblings.

We describe the clinical and radiological findings of a pair of siblings with cerebellar vermis hypoplasia and compare them with the literature. Both of them present pregnancies and deliveries uneventful and both presented some grade of hypotonia, ataxia, ocular motor abnormalities and mild motor delay and slurred speech. These siblings meet many of the criteria described in non-progressive congenital ataxia in which can occur familial cases with cerebellar atrophy, including vermis hypoplasia. As differential diagnosis we compare them with related syndromes and with Joubert's syndrome which main radiological finding on MRI is vermis hypoplasia associated with "molar tooth" appearance. The correct answer for these cases will only be possible by molecular genetics.

Cerebellar Ataxia↗
PubMed2000

[Intravenous immunoglobulin in children with Guillain-Barré syndrome].

We report our experience with intravenous immunoglobulin (IVIG), plasmapheresis and supportive care in 13 patients with the Guillain-Barré syndrome. Seven of 13 patients received IVIG, 2 plasmapheresis and 4 supportive care. At 15th day after IVIG administration, all patients in this group had improved at least one disability grade. In the plasmapheresis group, 1 improved at 5th day after the procedure. Two of the 4 patients that received supportive care improved at 20th day of evaluation. In the IVIG group, the final scores were lower and had no relapses. These results suggest faster clinical improvement with IVIG when compared with supportive measures.

Child↗
PubMed1998

Modulation of RecA nucleoprotein function by the mutagenic UmuD'C protein complex.

The RecA, UmuC, and UmuD' proteins are essential for error-prone, replicative bypass of DNA lesions. Normally, RecA protein mediates homologous pairing of DNA. We show that purified Umu(D')2C blocks this recombination function. Biosensor measurements establish that the mutagenic complex binds to the RecA nucleoprotein filament with a stoichiometry of one Umu(D')2C complex for every two RecA monomers. Furthermore, Umu(D')2C competitively inhibits LexA repressor cleavage but not ATPase activity, implying that Umu(D')2C binds in or proximal to the helical groove of the RecA nucleoprotein filament. This binding reduces joint molecule formation and even more severely impedes DNA heteroduplex formation by RecA protein, ultimately blocking all DNA pairing activity and thereby abridging participation in recombination function. Thus, Umu(D')2C restricts the activities of the RecA nucleoprotein filament and presumably, in this manner, recruits it for mutagenic repair function. This modulation by Umu(D')2C is envisioned as a key event in the transition from a normal mode of genomic maintenance by "error-free" recombinational repair, to one of "error-prone" DNA replication.

Bacterial Proteins↗
PubMed1998

Biochemical basis of SOS-induced mutagenesis in Escherichia coli: reconstitution of in vitro lesion bypass dependent on the UmuD'2C mutagenic complex and RecA protein.

Damage-induced SOS mutagenesis requiring the UmuD'C proteins occurs as part of the cells' global response to DNA damage. In vitro studies on the biochemical basis of SOS mutagenesis have been hampered by difficulties in obtaining biologically active UmuC protein, which, when overproduced, is insoluble in aqueous solution. We have circumvented this problem by purifying the UmuD'2C complex in soluble form and have used it to reconstitute an SOS lesion bypass system in vitro. Stimulated bypass of a site-directed model abasic lesion occurs in the presence of UmuD'2C, activated RecA protein (RecA*), beta-sliding clamp, gamma-clamp loading complex, single-stranded binding protein (SSB), and either DNA polymerases III or II. Synthesis in the presence of UmuD'2C is nonprocessive on damaged and undamaged DNA. No lesion bypass is observed when wild-type RecA is replaced with RecA1730, a mutant that is specifically defective for Umu-dependent mutagenesis. Perhaps the most noteworthy property of UmuD'2C resides in its ability to stimulate both nucleotide misincorporation and mismatch extension at aberrant and normal template sites. These observations provide a biochemical basis for the role of the Umu complex in SOS-targeted and SOS-untargeted mutagenesis.

Bacterial Proteins↗