Search PubMed⌕ Search

Biomedical subjects

E Martin

Publications and source records attributed to E Martin.

At least 847 records · Page 47Linked to original sources
PubMedDate not supplied

Endogenous inhibition of antimycobacterial immunity by IL-10 varies between mycobacterial species.

Interleukin (IL)-10 is an immunoregulatory cytokine that inhibits both Th1-like T cell responses and macrophage activation. Deficiency of IL-10 has been associated with increased Th1-like CD4+ T-cell responses and increased clearance of some intracellular pathogens, however, its role in mycobacterial infections is controversial. In order to examine the effects of mycobacterial virulence on the outcome of infection we compared infection with Mycobacterium avium and virulent Mycobacterium tuberculosis in C57Bl/6 IL-10-/- mice. M. avium infection in IL-10-/- mice resulted in sustained increases in interferon (IFN)-gamma-secreting T-cell responses and was associated with the increased clearance of M. avium from the liver and lung. By contrast, M. tuberculosis infection in IL-10-/- mice led to a transient increase in IFN-gamma T-cell responses at 4 weeks postinfection, with reduced bacterial burden in the lungs. This was not sustained so that by 8 weeks there was no difference to wild-type (WT) mice. In vitro infection of IL-10-/- macrophages with M. avium, but not M. tuberculosis, led to an increased IL-12 production. Therefore, endogenous IL-10 exerts a significant inhibition on specific IFN-gamma T-cell responses to M. avium infection, however, this effect is short lived during the M. tuberculosis infection, and fails to influence the long-term course of infection.

Animals↗
PubMedDate not supplied

Ultrasound imaging of the thoracic epidural space.

BACKGROUND AND OBJECTIVES: In thoracic epidural anesthesia, the "loss of resistance" technique is the standard technique for the identification of the epidural space (EDS), the feedback to the operator is often solely tactile. Our aim was to establish ultrasonography for the prepuncture demonstration of the anatomic structures surrounding the thoracic EDS and to evaluate its precision and imaging quality. METHODS: We examined 20 volunteers. In each participant, the extradural space and the neighboring anatomic landmarks in the intervertebral space Th 5-6 were identified using 2 imaging techniques: magnetic resonance imaging (MRI) and ultrasonography. We compared corresponding images regarding distance measurements and the visibility of anatomic landmarks. RESULTS: The capacity of ultrasound imaging (US) to depict the thoracic EDS was limited. Due to the better overview, MR images were easier to interpret. However, US proved to be of better value than MRI in the depiction of the dura mater. All important landmarks for the puncture of the thoracic EDS could be identified with both techniques. The overall correlation was satisfactory. US depicted the different structures of the thoracic EDS with an acceptable precision (confidence interval, 4.6 to 8.7 mm). CONCLUSIONS: US showed good correlation with MRI, which is a standard imaging technique for the depiction of the spine. We anticipate that prepuncture ultrasonography may facilitate thoracic epidural anesthesia by needle placement.

Adult↗
PubMedDate not supplied

[Autologous transfusion in scoliosis operations: preoperative autologous blood donations and intraoperative mechanical autotransfusion].

Autologous transfusion was used to reduce the high demand for blood accompanied with scoliosis surgery. Half of the blood loss could be saved by intraoperative autotransfusion (35 patients). This resulted in a corresponding reduction in homologous transfusion. An elimination of the need for homologous blood could be achieved only by the combination of preoperative blood donation and intraoperative autotransfusion (37 patients). With freezing the predeposit blood was independent of storage time and autologous plasma was available. Thus, the risks of transfusion can be avoided.

Adolescent↗
PubMedDate not supplied

Improved enantiospecific RP-HPLC assays for propranolol in plasma and urine with pronethalol as internal standard.

For the enantiospecific assay of propranolol in biological material, formation of diastereomeric derivatives is one possible approach. The aim of the present study was the development and optimization of three analytical methods based on different chiral reagents: phenylethylisocyanate and the acyl chloride as well as the isocyanate that are derived from the fluorescent S-flunoxaprofen. Pronethalol is used as internal standard in all three procedures and improves the coefficients of variation significantly. After extraction from human plasma or urine, propranolol is reacted with one of these compounds in anhydrous organic solvents with addition of triethylamine. The diastereomeric derivatives are then resolved on an octadecylsilane column using mixtures of water and methanol with or without addition of glacial acetic acid. Good resolutions of the diastereomeric derivatives are found under these conditions. Conjugates are cleaved prior to analysis using beta-glucuronidase-arylsulfatase and assayed as parent propranolol enantiomers. All three procedures were suitable for analysis of propranolol enantiomers in biological samples in the lower nanogram range (1-2 ng/mL). A preliminary clinical study confirmed the known enantiospecificity in the pharmacokinetics of propranolol and showed high concentrations of conjugates with R/S ratios that were similar to those of the parent enantiomers.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Improved enantiospecific RP-HPLC assays for propranolol in plasma and urine with pronethalol as internal standard.

For the enantiospecific assay of propranolol in biological material, formation of diastereomeric derivatives is one possible approach. The aim of the present study was the development and optimization of three analytical methods based on different chiral reagents: phenylethylisocyanate and the acyl chloride as well as the isocyanate that are derived from the fluorescent S-flunoxaprofen. Pronethalol is used as internal standard in all three procedures and improves the coefficients of variation significantly. After extraction from human plasma or urine, propanolol is reacted with one of these compounds in anhydrous organic solvents with addition of triethylamine. The diastereomeric derivatives are then resolved on an octadecylsilane column using mixtures of water and methanol with or without addition of glacial acetic acid. Good resolutions of the diastereomeric derivatives are found under these conditions. Conjugates are cleaved prior to analysis using beta-glucuronidase-arylsulfatase and assayed as parent propranolol enantiomers. All three procedures were suitable for analysis of propranolol enantiomers in biological samples in the lower nanogram range (1-2 ng/mL). A preliminary clinical study confirmed the known enantiospecificity in the pharmacokinetics of propranolol and showed high concentrations of conjugates with R/S ratios that were similar to those of the parent enantiomers.

Benzoxazoles↗
PubMedDate not supplied

Developmental stages of human brain: an MR study.

The differentiation of the telencephalon (TC) gyri and the myelination of TC and diencephalon were analyzed quantitatively in 50 children, 32-240 weeks' postconceptional age (PCA). For this purpose, a four-stage grading system was developed by correlating magnetic resonance images from age-matched postmortem brains with subsequently prepared myelin-stained macroslices. Gyration and myelination progressed in a occipito-rostral direction. Stages 3 and 4 myelination were recognized earlier on T1-weighted images [spin echo (SE) 500/30] than on T2-weighted images (SE 3,000/120). However, long repetition time/echo time sequences yielded better contrast and allowed finer differentiation between myelinated and nonmyelinated structures. At term, the posterior limb of the internal capsule was generally myelinated (stage 2), whereas in 50% of the children, myelin appeared in the TC between 55 and 65 weeks' PCA, e.g., between 3 and 6 months postnatally. The morphological differentiation of the brain surface preceded the biochemical maturation (myelination) by an average of 12 months. Applying such a grading system to a larger population will help establish normal standards for brain maturation and a "brain age" scale during the first 4 years of life.

Brain↗
PubMedDate not supplied

MR imaging of brain maturation in normal and developmentally handicapped children.

White matter myelination was assessed in the frontal, temporal, and occipital lobes and in the internal capsule in 91 neurodevelopmentally handicapped infants on T2-weighted images (spin echo 3,000/120 ms) and compared with myelination scores from 53 normal control subjects. Clinical diagnosis was birth asphyxia (34), seizures with delays of various causes (33), congenital infections (15), and intracerebral hemorrhages (9). Myelination in the total group of patients was generally delayed. However, we found distinct differences in myelin deposition between groups. Myelination of handicapped children with seizures or with intrauterine infections was retarded most severely at all ages. Children with intracerebral hemorrhages were almost never significantly different from normals in any part of the brain, whereas children with birth asphyxia had myelination scores in between. We conclude that magnetic resonance staging of developmental processes, such as myelination, in the infants' brain helps to recognize delays at an early age.

Asphyxia Neonatorum↗
PubMedDate not supplied

Unusual presentations of neuroborreliosis (Lyme disease) in childhood.

Two children with atypical neuroborreliosis (cranial polyneuritis and acute transverse myelitis) are presented. The diagnosis was confirmed by the determination of specific antibodies against Borrelia burgdorferi in both serum and CSF. Neuroimaging findings were nonspecific, indicating, however, that neuroborreliosis should be included in the differential diagnosis of cases with cranial polyneuritis and acute transverse myelitis in childhood.

Antibodies, Bacterial↗
PubMedDate not supplied

Heterogeneity of steroid 21-hydroxylase genes in classical congenital adrenal hyperplasia.

Careful genotyping of three families, each having a member with classical salt-losing steroid 21-hydroxylase deficiency, has allowed identification of carrier haplotypes. Digestion with TaqI or EcoRI and probing with a cDNA probe for the 21-hydroxylase genes (pC21/3c) revealed that all six affected haplotypes are abnormal with at least EcoRI. The data suggest that there is extreme polymorphism of the 21-hydroxylase genes and that dysfunction may result from several different abnormalities.

Adrenal Hyperplasia, Congenital↗
PubMedDate not supplied

Long-term registration of cutaneous microcirculation during general anesthesia.

The temporal dynamics of the systemic arterial pressure can be monitored noninvasively from the skin of the earlobe or forehead by photoplethysmography under the provision that the active control of the microcirculatory perfusion is eliminated. Using this approach, we have been able to detect a highly stable blood pressure rhythm in the range of 0.15 Hz during psychophysical relaxation or sleep. The aim of the present study was to investigate the occurrence and behavior of blood pressure rhythms below 0.2 Hz during general anesthesia. In 30 patients (ASA groups I-II) undergoing basic surgical procedures, photoplethysmographic recordings from the earlobe were made during the whole time of anesthesia. The recorded signals were divided into segments of 200 s of duration, the temporal structure of which was analyzed by fast Fourier transform. Different characteristic patterns of rhythmical behavior were detected: (1) absence of activity below 0.2 Hz ('low-frequency range'); (2) slow sinusoidal rhythmicity below 0.05 Hz; (3) 'chaotic' behavior, i.e. multiple incoherent fluctuations without stationary periods or amplitudes; (4) short-term rhythmical activity at about 0.15 Hz, and (5) long-term rhythmical activity at about 0.15 Hz. In patients sufficiently sedated to eliminate low-frequency activity, rhythmicity could sometimes be triggered by certain surgical stimuli, the response to which was suppressed by injection of opioids. The data presented strongly suggest that rhythmical perfusion patterns of the cutaneous microcirculation could serve as an indicator for the depth of anesthesia.

Adolescent↗
PubMedDate not supplied

Experiences with the Nucleus multichannel cochlear implant in three young children.

Clinical trials for the Nucleus multichannel cochlear implant in children 2 through 9 years of age have been ongoing for approximately 1 year. We describe three children who have used the device for at least 8 months. Based on these three cases, we discuss some factors that might affect the outcome of the Nucleus implant in young children: age at implantation, age at onset of deafness, and duration of profound deafness before implantation. Surgical and rehabilitation issues, including educational settings, are reviewed.

Auditory Threshold↗
PubMedDate not supplied

Switched on.

Explore the source record for details and available documents.

Depressive Disorder↗