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Biomedical subjects

J Schulte

Publications and source records attributed to J Schulte.

At least 37 records · Page 2Linked to original sources
PubMed2001

Median nerve evoked responses: stimulation modalities for midlatency cortical components.

PURPOSE: Median nerve somatosensory evoked responses (MnSSER) are frequently used clinically and scientifically. However, the stimulus-response interrelationship has not been documented for the midlatency components. Therefore we investigated the spinal and cortical midlatency MnSSER, to document the effect of different stimulus intensities. METHODS: Spinal and midlatency MnSSER were recorded following percutaneous electrical stimulation of the median nerve at the wrist in 32 neurological healthy females. Three different stimulation intensities were applied: threefold sensory threshold (INT 1), motor plus sensory threshold (INT 2), individual level of tolerance (INT 3). STATISTICS: Multivariate analyses of variance (independent variable: stimulation intensity). RESULTS: Three negative and two positive midlatency components were identified after median nerve stimulation. At INT 1 the early waves N20, P25 and N35 were identified in all of the patients. In contrast, the component P45 was identifiable in 23% of the sample at the lowest intensity level and N55, respectively, in 32%. At INT 2 the spinal and the midlatency cortical amplitudes (except amplitude N35P45) were significantly increased (p < 0.014). At INT 3 the amplitudes of the primary cortical complex did not increase further, but the components > 35 ms became identifiable in the whole sample except in one subject. In contrast, there was no change in the MnSSER latencies. The intensity was comfortable for all subjects. CONCLUSION: For monitoring the midlatency MnSSER components > 35 ms the authors suggest a stimulation intensity close to individual tolerance level for optimal cortical responses.

Adult↗
PubMed2000

Developmental dynamics of peripheral glia in Drosophila melanogaster.

To study the roles of peripheral glia in nervous system development, a thorough characterization of wild type glial development must first be performed. We present a developmental profile of peripheral glia in Drosophila melanogaster that includes glial genesis, developmental morphology, the establishment of transient cellular contacts, migration patterns, and the extent of nerve wrapping in the embryonic and larval stages. In early embryonic development, immature peripheral glia that are born in the CNS seem to be intermediate targets for neurites that are migrating into the periphery. During migration to the PNS, peripheral glia follow the routes of pioneer neurons. The glia preferentially adhere to sensory axonal projections, extending cytoplasmic processes along them such that by the end of embryogenesis peripheral glial coverage of the sensory system is complete. In contrast, significant lengths of motor branch termini are unsheathed in the mature embryo. During larval stages however, peripheral glia further extend and elaborate their cytoplasmic processes until they often reach to the neuromuscular junction. Throughout the embryonic and larval developmental stages, we have also observed a number of similarities of peripheral glia to vertebrate Schwann cells and astrocytes. Peripheral glia seem to have dynamic and diverse roles and their similarities to vertebrate glia suggest that Drosophila may serve as a powerful tool for analysis of glial roles in PNS development in the future.

Animals↗
PubMed2000

Ultra Flat Gold Surfaces for Use in Chemical Force Microscopy: Scanning Probe Microscopy Studies of the Effect of Preparation Regime on Surface Morphology.

The preparation of ultra flat gold surfaces for use in chemical force microscopy (CFM) has been studied. The surfaces were studied in terms of substrate effects by comparing mica, Si (110) wafer and glass slides. The effect of different annealing regimes was also investigated. Measurements on these surfaces were made by both atomic force microscopy (AFM) (in contact and tapping mode) and by scanning tunneling microscopy (STM). The films contain different morphologies with respect to grain size and topography. Calculations of surface roughness present values less than 2.5 nm for all surfaces studied, making the choice of the "flattest" surface difficult if based on criteria of surface roughness alone. Additionally, it is shown that different acquisition parameters can produce dissimilar images that have stability and reproducibility.

Journal Article↗
PubMed2000

High prevalence of congenital toxoplasmosis in Brazil estimated in a 3-year prospective neonatal screening study.

BACKGROUND: A pilot neonatal screening programme revealed a high (approximately 1 per 4800 live births) prevalence of congenital toxoplasmosis (CT) in the State of Rio Grande do Sul, Brazil. The purpose of this paper was to estimate in a larger prospective study the prevalence of CT in the country. METHODS: At the beginning of the study, an in-house indirect enzyme immunoassay (EIA) was used, to be later replaced with a commercial capture IgM fluorometric enzyme immunoassay (FEIA). Both methods detect specific anti-Toxoplasma gondii IgM-class antibodies eluted from dried blood spots. RESULTS: Of the total of 140,914 samples received from all over the country, 47 cases were identified and confirmed as CT. This finding suggests a prevalence of 1 per 3000 live births. Of the 47 patients, only eight (17%) had clinical manifestations: two had intracranial calcifications, four had retinal scars, one had an intracranial calcification and retinal scars, and one had hepatosplenomegaly with lymphoadenopathy. The testing was paid for by the patients' families who volunteered for the study and gave their informed consent. CONCLUSION: The 3-year prospective study using sensitive detection methods, reliable confirmation, and feedback from clinicians showed that CT has an extraordinarily high prevalence in Brazil, in fact the highest ever reported in the world. Although the long-term efficacy of treatment of CT has not been well documented, in view of the availability of reliable diagnostics, confirmation and monitoring, functional logistics, and networking for screening, the insidious nature of the sequelae and the very high prevalence of the disease, neonatal screening for CT should be considered an alternative to no screening at all.

Animals↗
PubMed1999

Effects of potentization in aqueous solutions.

Over the past two decades, research into structure formation and structure conservation in water has created a significant interest among the homeopathy research community. The formation of sustained static and dynamic structures in aqueous solutions is thought to be synonymous with the possible storage of information in associated liquids. Prominent models and experiments considering this possibility are presented in this paper, and some of their subtleties, which were not given much room in the respective original publications, will be elucidated in more detail here.

Homeopathy↗
PubMed1999

Persistent tyrosinemia detected by thin-layer chromatography.

Screening for tyrosinemia is not routinely performed worldwide. Using a low expense thin-layer chromatography (TLC) for amino acids we detected a high frequency of transient tyrosinemia with secondary hyperphenylalaninemia in some newborns. Serum follow up showed the need to introduce adequate therapy in these babies.

Chromatography, Thin Layer↗
PubMed1999

A comprehensive screening program in South Brazil.

We present the experience and figures about a screening program in South Brazil carried on in Porto Alegre, capital of the Southern Brazilian State. We present the tests performed routinely in our laboratory, the prevalence of some diseases and tests for infectious diseases to be added in the most comprehensive regional program in our country.

Brazil↗
PubMed1999

Screening for congenital toxoplasmosis in Brazil.

Toxoplasmosis acquired at the end of the pregnancy can produce ocular and neurological sequelae. The detection of IgM anti-Toxoplasma gondii in dried blood spots of newborns is an important tool for early treatment and prevention. In this study we showed results of a pilot study about the prevalence of congenital toxoplasmosis in Brazil and concluded that this disease should be included in the menu of neonatal screening programs.

Animals↗
PubMed1998

Subdural haemorrhages in infants: population based study.

OBJECTIVES: To identify the incidence, clinical outcome, and associated factors of subdural haemorrhage in children under 2 years of age, and to determine how such cases were investigated and how many were due to child abuse. DESIGN: Population based case series. SETTING: South Wales and south west England. SUBJECTS: Children under 2 years of age who had a subdural haemorrhage. We excluded neonates who developed subdural haemorrhage during their stay on a neonatal unit and infants who developed a subdural haemorrhage after infection or neurosurgical intervention. MAIN OUTCOME MEASURES: Incidence and clinical outcome of subdural haemorrhage in infants, the number of cases caused by child abuse, the investigations such children received, and associated risk factors. RESULTS: Thirty three children (23 boys and 10 girls) were haemorrhage. The incidence was 12.8/100 000 children/year (95% confidence interval 5.4 to 20.2). Twenty eight cases (85%) were under 1 year of age. The incidence of subdural haemorrhage in children under 1 year of age was 21.0/100 000 children/year and was therefore higher than in the older children. The clinical outcome was poor: nine infants died and 15 had profound disability. Only 22 infants had the basic investigations of a full blood count, coagulation screen, computed tomography or magnetic resonance imaging, skeletal survey or bone scan, and ophthalmological examination. In retrospect, 27 cases (82%) were highly suggestive of abuse. CONCLUSION: Subdural haemorrhage is common in infancy and carries a poor prognosis; three quarters of such infants die or have profound disability. Most cases are due to child abuse, but in a few the cause is unknown. Some children with subdural haemorrhage do not undergo appropriate investigations. We believe the clinical investigation of such children should include a full multidisciplinary social assessment, an ophthalmic examination, a skeletal survey supplemented with a bone scan or a skeletal survey repeated at around 10 days, a coagulation screen, and computed tomography or magentic resonance imaging. Previous physical abuse in an infant is a significant risk factor for subdural haemorrhage and must be taken seriously by child protection agencies.

Child Abuse↗
PubMed1998

Sequential inversion recovery with RIDE-simultaneous suppression of two solvent signals in 17O NMR spectroscopy

Well-resolved 17O NMR spectra of D-mannopyranose in a mixture of solvents were obtained. The 17O NMR signals of DMSO and water have been successfully suppressed by incorporating two sequential inversion recovery steps, tuned to the relaxation of the two solvent signals, into the RIDE pulse sequence. The heights of the solvent signals are decreased by a factor greater than 1000. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Evaluation of transmission of Mycobacterium tuberculosis in a pediatric setting.

OBJECTIVE: To determine the extent of transmission of Mycobacterium tuberculosis to pediatric patients exposed to a pediatrician with smear- and culture-positive pulmonary tuberculosis (TB). METHODS: Clinic billing and hospital admission records were used to identify patients seen during the pediatrician's infectious period. Patients were notified of the potential exposure and were offered screening. RESULTS: A total of 1416 pediatric patients were identified as exposed. Of the 606 who completed screening, 12 (2%) had a skin test result > or = 10 mm, 2 (0.3 had a result 5 to 9 mm, and 592 (98%) had a negative test result (0 to 4 mm). No active TB cases were identified. Of the 14 children with a skin test result > or = 5 mm, 7 were U.S.-born and had no other risk for a positive skin test. The remaining seven had either been exposed to another person with infections TB or were from countries with a high prevalence of TB. CONCLUSION: We found evidence of limited transmission of Mycobacterium tuberculosis in the outpatient pediatric setting. Despite extensive resources dedication, only 43% of exposed children completed screening. In similar situations decision should balance the responsibility to protect children exposed to Mycobacterium tuberculosis with other public health priorities and available resources.

Adolescent↗
PubMed1997

Cochlear implant reimplantation.

The objective of this study was to determine whether insertion length and number of active channels remained the same after reimplantation of a cochlear implant. A retrospective case review of 170 consecutively implanted multichannedl cochlear implants was conducted. Seventeen of these devices had to be replaced. Data were analyzed for the Nucleus cochlear implant users who were reimplanted in the same ear. For most subjects, insertion length and number of channels remained unchanged, but a few subjects experienced substantial decreases. When the whole group was considered, a small but statistically significant drop was noted for both parameters. In conclusion, although reimplantation is technically possible, the first procedure provides the optimal surgical environment.

Adult↗