Cross-correlation image analysis for real-time single particle tracking.

Accurately measuring the translations of objects between images is essential in many fields, including biology, medicine, chemistry, and physics. One important application is tracking one or more particles by measuring their apparent displacements in a series of images. Popular methods, such as the center of mass, often require idealized scenarios to reach the shot noise limit of particle tracking and, therefore, are not generally applicable to multiple image types. More general methods, such as maximum likelihood estimation, reliably approach the shot noise limit, but are too computationally intense for use in real-time applications. These limitations are significant, as real-time, shot-noise-limited particle tracking is of paramount importance for feedback control systems. To fill this gap, we introduce a new cross-correlation-based algorithm that approaches shot-noise-limited displacement detection and a graphics processing unit-based implementation for real-time image analysis of a single particle.

Detection of spinal muscular atrophy carriers in a sample of the Brazilian population.

BACKGROUND: Spinal muscular atrophy is a common autosomal recessive neuromuscular disorder caused by mutations in the SMN1 gene. Identification of spinal muscular atrophy carriers has important implications for individuals with a family history of the disorder and for genetic counseling. The aim of this study was to determine the frequency of carriers in a sample of the nonconsanguineous Brazilian population by denaturing high-performance liquid chromatography (DHPLC). METHODS: To validate the method, we initially determined the relative quantification of DHPLC in 28 affected patients (DHPLC values: 0.00) and 65 parents (DHPLC values: 0.49-0.69). Following quantification, we studied 150 unrelated nonconsanguineous healthy individuals from the general population. RESULTS: Four of the 150 healthy individuals tested (with no family history of a neuromuscular disorder) presented a DHPLC value in the range of heterozygous carriers (0.6-0.68). CONCLUSIONS: Based on these results, we estimated there is a carrier frequency of 2.7% in the nonconsanguineous Brazilian population, which is very similar to other areas of the world where consanguineous marriage is not common. This should be considered in the process of genetic counseling and risk calculations.

Molecular characterisation of congenital myasthenic syndromes in Southern Brazil.

OBJECTIVE: To perform genetic testing of patients with congenital myasthenic syndromes (CMS) from the Southern Brazilian state of Parana. PATIENTS AND METHODS: Twenty-five CMS patients from 18 independent families were included in the study. Known CMS genes were sequenced and restriction digest for the mutation RAPSN p.N88K was performed in all patients. RESULTS: We identified recessive mutations of CHRNE in ten families, mutations in DOK7 in three families and mutations in COLQ, CHRNA1 and CHRNB1 in one family each. The mutation CHRNE c.70insG was found in six families. We have repeatedly identified this mutation in patients from Spain and Portugal and haplotype studies indicate that CHRNE c.70insG derives from a common ancestor. CONCLUSIONS: Recessive mutations in CHRNE are the major cause of CMS in Southern Brazil with a common mutation introduced by Hispanic settlers. The second most common cause is mutations in DOK7. The minimum prevalence of CMS in Parana is 0.18/100 000.

Fungal encephalitis following bone marrow transplantation: clinical findings and prognosis.

BACKGROUND: Central nervous system fungal infections (FI) are important complications and a cause of mortality in patients who receive hematopoietic stem cell transplantation (HSCT). AIMS: To study the clinical aspects of fungal encephalitis (FE). SETTINGS AND DESIGN: The study was carried out at the HSCT Center of the Hospital de Clínicas, Federal University of Paraná, Curitiba, Brazil. MATERIALS AND METHODS: Clinical records and autopsy reports from patients submitted to HSCT with a diagnosis of FE. RESULTS: Twelve patients were diagnosed with FE presenting with lowered level of consciousness, hemiparesis and seizures. We were able to identify two subgroups regarding susceptibility to FE: (1) patients with early onset FI and severe leucopenia, and (2) patients with later onset FI with graft-versus-host disease using immunosuppressive drugs. Eleven of the patients died directly due to the neurological complication, all had post-mortem confirmation of the diagnosis of FI. CONCLUSIONS: These clinical, paraclinical and temporal patterns may provide the opportunity for earlier diagnosis and interventions.

Comparative analysis of PCR-deletion detection and immunohistochemistry in Brazilian Duchenne and Becker muscular dystrophy patients.

We studied 48 patients with dystrophinopathies (29 Duchenne muscular dystrophy (DMD), 13 Becker muscular dystrophy (BMD), four possible carriers, one female with DMD, and one intermediate form, using polymerase chain reaction (PCR) analysis of muscle tissue for 20 exons and compared them with immunohistochemistry studies for dystrophin. Of these, 42 (87.5%) showed at least one intragenic deletion. Most of them (47.45%) involved exons 2 to 20. All BMD patients presented deletions on the dystrophin gene. The 29 patients with DMD showed abnormal dystrophin in immunohistochemistry studies, some with total absence (17/29), others with residual (3/29), and the remaining with scattered positive fiber (9/29). The majority of the 13 patients with BMD had abnormal immunohistochemistry studies with diffuse reduction in the majority of muscle fibers (10/13), a few with patch discontinuation in the sarcolemma (2/13), and one normal (1/13). The immunohistochemistry exam for dystrophin is still the gold-standard method for DMD/BMD diagnosis. An ethnic difference, the analysis of several exons, the sample size, and the use of muscle tissue could explain this high frequency of deletions in the dystrophin gene found in our cases.

Central nervous system Aspergillus fumigatus infection after near drowning.

AIMS: To report the case of a 26 year old white man, who developed chronic meningitis and intracerebral granulomata 15 days after an episode of near drowning in a swamp. METHODS: Aspergillus fumigatus was isolated from cerebrospinal fluid cultures. RESULTS: The patient died 70 days after the symptoms were first noticed, and seven days after a subarachnoid haemorrhage. Aspergillus has never been reported before as a cause of intracranial infection after near drowning. CONCLUSIONS: Physicians must be aware of this possibility when confronted with such a situation, because there are now effective therapeutic options for systemic aspergillosis.

Infection of the CNS by Scedosporium apiospermum after near drowning. Report of a fatal case and analysis of its confounding factors.

This report describes a fatal case of central nervous system pseudallescheriasis. A 32 year old white man presented with headache and meningismus 15 days after nearly drowning in a swine sewage reservoir. Computerised tomography and magnetic resonance imaging of the head revealed multiple brain granulomata, which vanished when steroid and broad spectrum antimicrobial and antifungal agents, in addition to dexamethasone, were started. Cerebrospinal fluid analysis disclosed a neutrophilic meningitis. Treatment with antibiotics and amphotericin B, together with fluconazole and later itraconazole, was ineffective. Miconazole was added through an Ommaya reservoir, but was insufficient to halt the infection. Pseudallescheria boydii was finally isolated and identified in cerebrospinal fluid cultures, a few days before death, three and a half months after the symptoms began. Diagnosis was delayed because of a reduction in the lesions after partial treatment, which prevented a stereotactic biopsy. Physicians should be aware of this condition, and provide prompt stereotactic biopsy. Confirmed cases should perhaps be treated with voriconazole, probably the most effective, currently available treatment for this agent.

South American blastomycosis presenting as a posterior fossa tumor. Case report.

An unusual case of infection of the central nervous system by Paracoccidioides braziliensis, presenting as posterior fossa tumor, is discussed and the pertinent literature reviewed.

Central nervous system paracoccidioidomycosis: clinical features and laboratorial findings.

OBJECTIVE: To study prospectively the clinical features and laboratorial characteristics of 24 patients with central nervous system (CNS) involvement with paracoccidioidomycosis (PCM). PCM is an infectious disease caused by the dimorphic fungus Paracoccidioides brasiliensis, endemic in subtropical areas of Central and South America. METHODS: From 173 cases of PCM, 24 (13.9%) had CNS involvement (NPCM) and were studied prospectively from 1993 to 1997. In all the patients, the diagnosis of systemic PCM was made by the demonstration of the P. brasiliensis organisms or positive serology, DID (double immunodiffusion). In seven cases the diagnosis was made by means of a CNS biopsy. CNS clinical manifestations, neuroimaging (CT or MRI) and CSF cytochemical characteristics were reported. RESULTS: The mean age was 44 years (range 25-72 years); 23 patients were male, only one was female. Neurological symptoms began before systemic symptoms in 21%; simultaneously in 33%, and after systemic symptoms in 46%. Epilepsy was the more frequent neurological presentation (44%). Twenty-three cases had parenchymatous involvement and in two of these cases there was an association with meningitis and one case had spinal cord involvement. Lesions were more frequent in the brain hemispheres (69%), in 65% there were multiple granuloma characterized by hypodense images with annular or nodular enhancing. All cases were treated with sulphamethoxazole-trimethoprin. Four patients died, while 20 patients showed a good therapeutic response. CONCLUSION: NPCM should always be considered in the differential diagnosis of expanding lesions of the CNS and meningoencephalitis. Being alert to this diagnosis depends on knowledge of epidemiology. There was good response to sulphamethoxazole-trimethoprin treatment.

[Serum enzymes and electromyography in neuromuscular diseases: comparative study of 817 cases]. / Enzimas séricas e electromiografia em doenças neuromusculares: estudo comparativo de 817 casos.

This study reports the relationship of the serum enzymes (creatinekinase 817 cases, lactic dehydrogenase 784 cases, aldolase 718 cases, aspartate aminotransferase 767 cases and alanine aminotransferase 760 cases) and electromyography (EMG) of 588 cases (20 normal, 299 with myopathic pattern, 209 with denervation and 69 with neuromyopathic pattern) in several neuromuscular disorders. The relationships were studied using descriptive statistic and chi-square tests. It was found a statistical significance with the increased serum enzyme level with the myopathic EMG pattern and an inverse relationship with the denervation EMG. This relation was more important with the creatinekinase, following aldolase and lactic dehydrogenase. The EMG denervation pattern did not have any relation with serum enzyme levels.

[Correlation between functional disability, age, and serum enzymes in neuromuscular diseases]. / Correlação entre a incapacidade funcional, idade e enzimas séricas nas doenças neuromusculares.

We attempt to correlate the patient's disability and serum enzymes (creatinekinase, lactic dehydrogenase, aldolase, glutamic oxalacetic and glutamic piruvic transaminase) in several neuromuscular disorders using the Vignos and Archibald scale (V&A). In 806 cases we studied, serum enzyme levels and the V&A disability using a computer for Pearson's correlation and regressive analysis. A good correlation of the V&A with age suggested a progressive evolution (increased disability) in Duchenne muscular dystrophy, fascioscapulohumeral dystrophy, myotonic dystrophy, myopathies due to respiratory chain enzyme deficiency and amyotrophic lateral sclerosis. A negative correlation (decrease disability with age) was found for multicore myopathy, benign myopathy of childhood with type 1 predominance, carnitine myopathy deficiency and dermatomyositis. It was found a correlation (p < 0.05) of the V&A and the level of specific serum enzymes with Duchenne muscular dystrophy, oculocraniosomatic dystrophies, polymyositis and polyarteritis nodosa. Using regression analysis, we found a weak interrelation between serum enzymes studied simultaneously and the V&A. These weak relations suggest some limitation in the long term use of the five serum enzymes in the evaluation of neuromuscular disorders when compared with V&A; although they are very important in the diagnosis.

[Developmental Gerstmann syndrome associated with cerebellar neoplasm. Report of a case and review of the literature]. / Sindrome de Gerstmann de desenvolvimento associada a neoplasia cerebelar. Relato de um caso e revisão da literatura

A Developmental Gerstmann syndrome in a 7 years-old-boy with hyperactivity, short attention span, acalculia, agraphia, right-left confusion, finger agnosia and constructional apraxia is reported. An initial trial with methylphenidate was done with good improvement regarding hyperactivity, attention span and constructional apraxia. In the clinical course developed a cerebellar syndrome and intracranial hypertension. Surgical exploration of the cerebellum discovered a medulloblastoma. The author believes that this is the first described association of Developmental Gerstmann syndrome and cerebellar neoplasia. The clinical findings, the etiology and the topography of the Gerstmann syndrome are discussed.

[The muscular lesion in myasthenia gravis: study of 17 cases with muscular histochemistry]. / A lesão muscular na miastenia grave: estudo de 17 casos com histoquímica muscular.

A study of 17 muscle biopsies from patients with myasthenia gravis was done, using freshfrozen section and histochemistry tecnics. It was found 15 abnormal muscle biopsies. The most common abnormality were small dark angular fibers, excess of lipids droplets outside the muscle membrane, changes in fiber size and type II fiber atrophy. These findings suggested denervation in 11 biopsies, type II fiber atrophy in 7, linfocyte infiltration in 4, fiber necrosis with fagocitosis in 1 and 2 were normal. Was noted a direct correlation between the disease duration and the severity of the histological abnormality. Two patients had tymoma. Congenital myasthenia gravis, rheumatoid arthritis, intersticial hypertrophic neuritis, Hashimoto tireoiditis and concomitance of myasthenic syndrome was found once in different patients.

[Polyneuropathy caused by tuberculostatics. Study of motor nerve conduction in 29 patients]. / Polineuropathisa determinadas por tuberculostaticos. Estudo da conducão nervosa motora em 29 pacientes

The electroneurographic study in 29 patients, during treatment with isoniazid for pulmonary tuberculosis in 12 months period is reported. The patients age were between 16 and 70 years. During the study period motor nerve conduction velocity was done every two months in the median, ulnar and peroneal nerves. The statistical analysis in a 6 months period, revealed p greater than 0.05 (nonsignificant) at the median and peroneal nerves, in spite of the lowering of the motor nerve conduction in a 12 months period. The same findings were observed with the ulnar nerve, but p less than 0.01 (significant). It was impossible to establish a correlation between the motor nerve conduction velocities and the clinical findings observed in the patients. This paper, in the author's opinion, shows that the nerve motor conduction technique is worthless in the follow up of isoniazid patients.

[Peripheral nerves biopsies: analysis of 89 cases]. / Biópsias de nervos periféricos: análise de 89 casos.

Results of 89 peripheral nerve biopsies studied only by paraffin sections are analysed to determine the abnormalities incidence, and in what extent a general pathology laboratory can help in final diagnosis of patients with peripheral nerve disorders. 37% normal nerve biopsies and 63% with some histological alteration were found; only in 22% the nosological diagnosis was possible. A discussion about the low incidence of nosological diagnosis is made, and a literature revision on routine nerve biopsies. It is concluded that nerve biopsies should be done only in special cases, particularly when other diagnostic methods failed, taking into account always the limitation of the method, and preferentially studying a clinically involved nerve.

[Myasthenia gravis: clinical and surgical treatment]. / Miastenia grave. Tratamento clínico x cirúrgico.

The indication for thymectomy in myasthenia gravis still is controversial, and it is uncommon to find in the present days studies comparing conservative treatments, due to the widespread surgical treatment adopted in most centers. We studied 65 cases divided into three groups of patients: (1) 15 thymectomized patients and 50 with conservative treatment; (2) 15 thymectomized patients paired with 15 on conservative treatment; (3) 49 patients treated with corticosteroids against 16 without corticosteroids. These three groups where compared regarding age, age when the symptoms began, disease duration, clinical severity and functional scale, studying remission, stability or worsening of the symptoms and death rate after several years of treatment. It was found a reduction of the symptoms (p < 0.05) in the thymectomized patients of group 1; the remaining parameters of all three groups did not show any statistical significance. These results suggest that the type of treatment did not interfere with evolution of myasthenia gravis in this group of patients.

[Interstitial hypertrophic neuritis. Study of 3 cases]. / Neurite hipertrófica intersticial. Estudo de tres casos.

Three cases of hypertrophic interstitial neuropathy with severe decrease of motor nerve conduction velocity are reported; on sural nerve biopsy was found the typical onion bulb formation, with connective tissue proliferation. The pathogenesis of the onion bulb formation and the correlation with the decreased motor nerve conduction are discussed. The authors concluded that only one of the cases could be named Dejerin-Sottas disease, since the others probably are Charcot-Marie-Tooth disease cases.

["Central core" myopathy: report of a case]. / Miopatia do "core central": relato de um caso.

A case of a 6-years-old boy with delayed motor milestones, hypotonia since birth (floppy baby), showing a partial improvement in the latter years is reported. On physical examination was found diffuse muscle atrophy, lordosis, generalized hyporeflexia and Gowers maneuver during standing procedure. Serum enzymes were normal and electromyography had potential with increased duration and excess of polyphasic potentials. Fresh-frozen muscle biopsy processed by histochemistry showed type 1 fiber predominance, absence of oxidative enzyme activity in the center of the fibers (central cores) and slight increased of the ATPase reaction in the cores area (structured cores?). Is made a brief discussion about the pathology, pathogenesis, and the good prognosis of the disease.

[Comparative non-randomized study with midazolam versus thiopental in children with refractory status epilepticus]. / Estudo comparativo não randomizado do midazolam versus thiopental em crianças com estado de mal epiléptico refratário.

We evaluated the use of midazolam versus thiopental in 50 children with refractory status epilepticus (RSE), admitted in a pediatric intensive care unit. The study consisted of two groups of patients: Group A - Midazolam, a prospective study, and Group B - Thiopental, a historical group. These patients already had previous medication with benzodiazepin and diphenylhydantoin and other drugs. When there was no effective control of the seizures, the patients of Group A received midazolam of 200 microg/kg intravenous in bolus, being followed by continuous intravenous infusion at the rate 0. 25-15 microg/kg/min. Group B received thiopental 1 mg/kg intravenous in bolus followed by continuous intravenous infusion at the rate of 10-120 microg/kg/min. In relation to the time of seizure control and effectiveness, there was no statistical significance for the two groups. The Midazolam Group had significantly less complications during the treatment: less cyanosis (p=0.00006), and they did not need respiratory support (p<0.00001). When the therapy with midazolam was ceased, 12.5% of the patients from this group showed psychological disorders such as mental confusion, aggressive behavior, restlessness, hallucinations and agitation.