The health hazards of mobile phones.
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Environmental Exposure↗
Biomedical subjects
M Maier
Publications and source records attributed to M Maier.
[Endoscopically controlled surgery with the micro-drill and intubation of the lacrimal ducts].
PURPOSE: Operative procedures to manage lacrimal outflow obstruction were made traditionally without endoscopic assistance. For dacryoendoscopy we previously used a 0.5-mm endoscope with a special wash cannula. We now use the microendoscope Vitroptic T for dacryoendoscopy and for endoscopically controlled surgery with a microdrill. METHODS: In an attempt to perform microinvasive lacrimal surgery we use a 1.1-mm endoscope (Vitroptik T) with a wash cannula, a channel for the microoptic and a channel for a microdrill. We report on our initial experiences and on the results of eight patients with stenosis of the lacrimal outflow system who were treated with an endoscopic microdrill and silicone tubing. One patient had lacrimal stenosis after external dacryocystorhinostomy (DCR), and seven patients showed punctual stenosis in the nasolacrimal duct. RESULTS: Using the dacryoendoscope (Vitroptic T) we were able to visualize pathologic changes of the lacrimal outflow system. Intraoperative situations during dacryoendoscopy are demonstrated. The Vitroptic T allows dacryoendoscopy and endoscopically controlled surgery of the lacrimal drainage system. Three months after surgery in six patients (75%) the lacrimal outflow system was patent with the silicone tube in place, and these patients had no epiphora. The patient with re-stenosis after external DCR showed patency. CONCLUSIONS: Dacryoendoscopy and endoscopic controlled surgery of the lacrimal drainage system enables atraumatic and minimally invasive surgery. The Vitroptik T with the microdrill allows endoscopically controlled microsurgery. Possible indications for the microdrill are punctual stenosis and re-stenosis after external DCR.
Dacryocystorhinostomy↗
Shockwave application in calcifying tendinitis of the shoulder--prediction of outcome by imaging.
This prospective study examined 62 patients (65 shoulders) with chronic courses of calcifying tendinitis of the shoulder before and after low-energy extracorporeal shockwave application (ESWA) in order to identify variables associated with the outcome of this treatment. Before ESWA, radiographs and contrast-enhanced magnetic resonance imaging (MRI) of the affected shoulders were obtained in order to document the size and morphology of the calcifications and the contrast media reactions in areas of interest (deposit, synovia, bursae), respectively. In addition, a clinical evaluation was performed. After ESWA (mean follow-up 18.2 months), clinical evaluations of all 65 shoulders revealed an increase in the Constant score from 44% to 78% (p < 0.0001). While size (p = 0.61) and morphology (p = 0.7) of the deposits before ESWA were not associated with the clinical outcome, negative contrast reactions around the deposits (p) = 0.0001), synovia (p = 0.0049) and bursae (p < 0.01) were associated with improved clinical outcomes. After the total study group was divided into two groups, one with Constant scores > or = 75% (n = 43) and the other with scores < 75% (n = 22), the positive predictive value (ppv), specificity (sp) and sensitivity (se) were determined for the negative reaction around the deposit (ppv: 0.94; sp: 0.95; se: 0.38), synovia (ppv: 0.84; sp: 0.82; se: 0.49) and bursae (ppv: 0.86; sp: 0.86; se: 0.44). In 5 cases (7.7%), surgery of the affected shoulder during the follow-up period was performed. No major side-effects were seen in the study group. In conclusion, our results suggest that in patients with chronic calcifying tendinitis, the absence of contrast enhancement, especially around the deposit, is a strong predictive parameter of a positive clinical outcome of ESWA.
Adult↗
Schizophrenia, temporal lobe epilepsy and psychosis: an in vivo magnetic resonance spectroscopy and imaging study of the hippocampus/amygdala complex.
BACKGROUND: We have used proton magnetic resonance imaging and spectroscopy to measure hippocampus/amygdala volumes and anterior hippocampal metabolite concentrations (N-acetyl aspartate (NAA), creatine/phosphocreatine and choline) in subjects with temporal lobe epilepsy (TLE), schizophrenia and in normal controls. METHOD: Four groups of right-handed patients were selected: 12 with TLE and psychosis (EP), 12 with TLE and no psychosis (ENP), 26 with schizophrenia, and 38 normal controls. Imaging and spectroscopy were performed with a 1.5T Signa GE scanner. RESULTS: The schizophrenia group showed a significant left-sided reduction in all metabolites. In the epilepsy groups NAA was reduced bilaterally. The NAA reduction in the EP group was greater than in the ENP group, especially on the left, although the result did not reach significance. Total hippocampus/amygdala volumes showed no significant differences in any of the groups when compared with normal controls. When compared with controls significant, specific regional volume reductions were present bilaterally in the EP group and in the left hippocampus/amygdala in schizophrenia. The regional volume reduction found in schizophrenia was also present in EP but not in ENP. CONCLUSION: Spectroscopic abnormalities were more pronounced in the epilepsy groups and were bilateral, and abnormalities in schizophrenia were left sided. Specific regional hippocampus/amygdala volume reductions were more marked in the EP group and were bilateral. Left-sided regional volume reduction identified in the dominant hemisphere of schizophrenics was also present in EP patients, but not in ENP, suggesting that this region in the left temporal lobe may be significant in the aetiology of psychosis. This is further supported by the predominantly left-sided NAA reduction in schizophrenia. High resolution morphometric studies may identify specific regions of the brain associated with the development of psychosis.
Adult↗
Distribution of mislocalizations of tactile stimuli on the fingers of the human hand.
Sensitivity of the fingers of the two hands to faint tactile stimuli were tested in eight healthy subjects with a von Frey hair in a forced choice point localization test. Frequencies of correct responses were higher on the left than on the right hand, consistent with a right hemispheric advantage for spatial processing. Within the hands, stimulations of the ring fingers resulted in the highest percentage of correct localizations and stimulations of the thumbs in the fewest correct responses. This superiority of the ring fingers is probably related to a higher point pressure sensitivity and does not reflect the relative size of the representational area of the different fingers in the somatosensory cortex. Mislocalizations, i.e., stimuli that were not correctly attributed to the stimulation site, were located in the vicinity of the stimulation site within the finger as well as across fingers. The distribution of mislocalization across fingers deviates from a distribution expected by chance, showing a higher frequency of mislocalizations to the neighboring fingers than to more distant fingers. This observation in humans matches well with electrophysiological evidence from animal studies that some primary somatosensory cortex neurons have receptive fields that are not restricted to a single digit, but rather cover neighboring digits.
Adult↗
Cloning and characterization of sialidases with 2-6' and 2-3' sialyl lactose specificity from Pasteurella multocida.
Pasteurella multocida is a mucosal pathogen that colonizes the respiratory system of susceptible hosts. Most isolates of P. multocida produce sialidase activity, which may contribute to colonization of the respiratory tract or the production of lesions in an active infection. We have cloned and sequenced a sialidase gene, nanH, from a fowl cholera isolate of P. multocida. Sequence analysis of NanH revealed that it exhibited significant amino acid sequence homology with many microbial sialidases. Insertional inactivation of nanH resulted in a mutant strain that was not deficient in sialidase production. However, this mutant exhibited reduced enzyme activity and growth rate on 2-3' sialyl lactose compared to the wild type. Subsequently, we demonstrated the presence of two sialidases by cloning another sialidase gene that differed from nanH in DNA sequence and substrate specificity. NanB demonstrated activity on both 2-3' and 2-6' sialyl lactose, while NanH demonstrated activity only on 2-3' sialyl lactose. Neither enzyme liberated sialic acid from colominic acid (2-8' sialyl lactose). Recombinant E. coli containing the sialidase genes were able to utilize several sialoconjugants when they were provided as sole carbon sources in minimal medium. These data suggest that sialidases have a nutritional function and may contribute to the ability of P. multocida to colonize and persist on vertebrate mucosal surfaces.
Amino Acid Sequence↗
In vivo investigation of white matter pathology in schizophrenia with magnetisation transfer imaging.
OBJECTIVES: This study is the first to use magnetisation transfer imaging (MTI), a technique sensitive to myelin and axonal abnormalities, to investigate the white matter in vivo in patients with schizophrenia. METHODS: MTI was performed in 25 schizophrenic patients and 30 healthy controls. A region of interest (ROI) approach was used to obtain magnetisation transfer ratios (MTRs) in several regions of cerebral white matter. RESULTS: MTR values were significantly reduced in the right and left temporal regions in schizophrenic patients compared with controls (p<0.001). Clinical variables such as age, duration of symptoms, schizophrenic symptomatology, and soft neurological signs did not predict this reduction in MTR. There were no MTR abnormalities in the other regions sampled. However, the correlation between the left and right frontal MTR values was marginally significantly different in schizophrenic patients compared with controls suggesting that subtle differences in interhemispheric connections may be present. CONCLUSIONS: Subtle white matter pathology, most likely related to myelin and axonal abnormalities, can be detected in the temporal lobes in schizophrenic patients. MTI may be a useful tool in investigating the white matter in schizophrenia.
Adult↗
Neuropathological abnormalities of the corpus callosum in schizophrenia: a diffusion tensor imaging study.
OBJECTIVES: Diffusion tensor imaging (DTI), a technique capable of examining water diffusion in different tissues and the organisation of white matter tracts, was used to investigate the neuropathology of the corpus callosum in vivo in patients with schizophrenia. METHODS: Diffusion tensor imaging was performed in 20 schizophrenic patients and 25 healthy controls. Two complementary measures, mean diffusivity and fractional anisotropy, which are considered to be sensitive indices of axonal integrity, were obtained from regions of interest in the genu (anterior) and splenium (posterior) of the corpus callosum. RESULTS: Mean diffusivity was significantly increased and fractional anisotropy significantly reduced in the splenium but not the genu of the corpus callosum in the schizophrenic group compared with controls. There were no significant sex differences in the DTI measures for either the schizophrenic or control group. Clinical variables such as age, duration of illness, dose of antipsychotic medication, and schizophrenic symptoms did not predict the DTI changes in the schizophrenic patients. CONCLUSIONS: The presence of DTI changes in the splenium but not the genu of the corpus callosum suggests that there may be a focal disruption of commisural connectivity in schizophrenia. However, these findings do not exclude the possibility of abnormalities in other areas of the corpus callosum or other regions of white matter and further research using different methods of analysis may enable us to clarify this. Diffusion tensor imaging is a valuable tool in investigating the structure of white matter in schizophrenia.
Adult↗
Extracorporeal shock wave application for chronic plantar fasciitis associated with heel spurs: prediction of outcome by magnetic resonance imaging.
OBJECTIVE: To clarify morphologic features associated with the clinical outcome of extracorporeal shock wave application (ESWA) in chronic plantar fasciitis. METHODS: In this prospective study 43 patients (48 heels) with chronic courses of plantar fasciitis were clinically examined before and after repetitive low energy ESWA. Standard radiographs of the affected heels were obtained before ESWA to document the existence of a calcaneal heel spur. Magnetic resonance imaging (MRI) was performed before ESWA to evaluate abnormalities of the plantar fascia, the surrounding soft tissue structures, and bone marrow edema of the calcaneus. RESULTS: After ESWA (mean followup 19.3 mo), clinical evaluation of all 48 heels revealed a statistically significant decrease in the mean visual analog scale score from 74.5 to 25.4. Using the Roles and Maudsley score (RM), an established scoring system for categorizing results of treatment following ESWA for patients with plantar fasciitis, patients could be divided into 2 groups, i.e., satisfactory clinical outcome of ESWA (grades 1 and 2 by RM scale; n = 36 heels) and unsatisfactory outcome (grades 3 and 4 by RM scale; n = 12 heels). While thickness of plantar aponeurosis, soft tissue signal intensity changes, and soft tissue contrast medium uptake did not correlate with clinical outcome, the presence of a calcaneal bone marrow edema was highly predictive for satisfactory clinical outcome (positive predictive value 0.94, sensitivity 0.89, specificity 0.8). CONCLUSION: This study indicates that in patients with chronic plantar fasciitis, the presence of calcaneal bone marrow edema on pretherapeutic MRI is a good predictive variable for a satisfactory clinical outcome of ESWA.
Adult↗
Interaction of chemically modified antisense oligonucleotides with sense DNA: a label-free interaction study with reflectometric interference spectroscopy.
Antisense oligonucleotides (ON) are regarded as potential therapeutic agents for controlling gene expression at the mRNA level. The strength of the interaction with the target sequence is one critical factor for the therapeutic efficiency of an ON. Herein, the results of studies on antisense 15mer and 20mer ONs against mdr1b-mRNA are described. The mdr1b is a member of the group that encodes the P-glycoprotein (Pgp), responsible for the phenomenon of multidrug resistance. The effects of backbone modification (DNA, phosphorothioate (PTO)), terminal modifications (hexadecyl, cholesteryl, tocopherol, polyethylenglycol, 2'-O-methyl-modified RNA) and base sequence misalignments (1 to 3 bases) on interaction kinetics and binding strength were investigated. The interaction of an immobilized sense strand with the dissolved antisense ON was monitored with a label-free optical transducer based on thin film interference (RIfS). Association kinetics were detected at a low density of immobilized ON. Thermodynamics were investigated by homogeneous phase titration of sense and antisense ON and subsequent quantification of equilibrium concentrations of unbound ON at a transducer highly loaded with sense ON. Association rate constants varied from 3.1 (+/- 0.2) x 10(4) M-1 s-1 (poly(ethylene glycol)-modified DNA strand) to 4.3 (+/- 0.1) x 10(4) M-1 s-1 (hexadecyl-modified strand). Binding constants varied from 1.9 (+/- 0.1) x 10(8) M-1 (cholesteryl modification) to 5 (+/- 0.4) x 10(7) M-1 (tocopherol modification). Phosphorothioate ON showed a reduction in binding strength of more than 1 order of magnitude. The data presented give valuable information for the efficiency of modified antisense oligonucleotides.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Castor oil decreases pain during extracorporeal shock wave application.
In a prospective single-blind study the contact media ultrasound gel, vaseline and castor oil were examined for their effect on surface pain caused by extracorporeal shock waves used for tendinosis calcarea (n = 25), radiohumeral epicondylitis (n = 23) and plantar heel spur (n = 12). A total of 60 patients was divided into six groups. Using a Compact S shockwave source (Dornier MedTech), an energy flux density up to 0.12 mJ/mm2 was applied three times within 3 weeks. Independent of the diagnosis, there was a statistically significant influence of the contact medium on the intensity of application pain. In this comparison castor oil was best. For the diagnosis of tendinosis calcarea and plantar heel spur, castor oil was significantly better than the other two contact media, while for epicondylitis there was no significant difference. Castor oil was found to have an advantage over ultrasound jelly and vaseline in all indications used with regard to application pain. The positive effect of castor oil can be explained by its cavitation-free quality.
Castor Oil↗
Phenol as an adjuvant for local control in the treatment of giant cell tumour of the bone.
AIMS: Intralesional treatment of giant cell tumour (GCT) of the bone may result in a high rate of local recurrence. The introduction of local adjuvant therapy, such as cementation or phenolization, has lead to a significant reduction in recurrence rates. Due to the combined use of phenol and cementation in most studies, the effect of phenol alone is described in this study. METHODS: Twenty primary and nine recurrent surgical procedures in 26 patients with GCT of the bone with a median follow-up of 61 months were reviewed retrospectively. The mean age was 33.5 years (range 13.5-76.5 years). Eighteen curettages and 11 resections were performed. For the curettages, a large bone window was cut followed by high speed burring and bone graft reconstruction. In 11 of 18 curettages and three of 12 resections, phenol was additionally applied. RESULTS: Four patients showed pulmonary metastasis. Three of these four cases also experienced local recurrences. Three patients died due to metastatic disease. In total, five patients developed local recurrence (17.2%); three in the first 2 years and one after 4 years. Four of 18 curettages recurred (22.2%), compared to one of 11 resections (9.1%). Only one of 11 patients (9.1%) treated with curettage and adjuvant phenol recurred, whereas three of seven patients (42.9%) treated with curettage alone recurred. CONCLUSION: Phenolization is an effective and safe local adjuvant therapy for GCT. We did not observe any significant differences in recurrence rates for curettage, phenolization and bone grafting compared to most published results using cryosurgery or cementation alone. We recommend adjuvant phenolization in the treatment of GCT of the bone after careful curettage in applicable cases, regardless of whether additional cementation is used.
Adolescent↗
[MRI of plantar fasciitis].
PURPOSE: The purpose of this study was to determine the type and frequency of characteristic bone and soft tissue changes on MRI of patients with a clinical diagnosis of plantar fasciitis. MATERIALS AND METHODS: 28 patients with a clinical diagnosis of plantar fasciitis underwent MR imaging. Besides T1- and T2-weighted sequences, short-tau-inversion-recovery sequences were used routinely. In 27 patients T1-weighted images after intravenous contrast injection were acquired additionally. As a control group the images of 15 patients without clinical signs for plantar fasciitis were evaluated. RESULTS: In 25 of 28 cases (89%) the clinical diagnosis of plantar fasciitis was established by MR imaging. The most common finding was a peritendinous edema at the calcaneal insertion site which was found in all 25 patients. In 19 of 25 cases (76%) a bone marrow edema of the calcaneus was present. In 14 of 25 cases (56%) an intratendinous signal intensity increase of the plantar fascia could be observed which showed contrast enhancement in 12 cases. Compared to the control group (mean thickness 3.3 mm) the plantar fascia showed significant thickening in the 25 MR positive patients (mean thickness 6.72 mm). DISCUSSION: Besides thickening of the plantar fascia and intratendinous signal intensity increase with contrast enhancement to some extent, bone marrow edema of the calcaneus and peritendinous edema close to the plantar fascia are characteristic signs of plantar fasciitis on MRI. Both signs can reliably be seen on STIR sequences only.
Adult↗
Surgical treatment of osseous metastases in patients with renal cell carcinoma.
Forty-five patients who underwent surgical treatment for osseous metastases secondary to renal cell carcinoma between 1980 and 1998 were reviewed. The diagnosis was confirmed histologically in all patients. The mean age of the 34 men was 61.5 +/- 9 years and of the 11 women 55.2 +/- 17.6 years. The most common locations of the metastases were the spine (15 patients), the pelvis (eight patients), and the femur (11 patients). In 21 patients, the renal cell carcinoma was diagnosed when the osseous metastasis was detected. The time from diagnosis of the primary tumor to metastasis in the remaining patients ranged from 0 to 23 years (mean, 3 +/- 5 years). At presentation, 19 patients had a singular lesion. Nine patients had multiple osseous metastases and 17 patients had additional visceral involvement. In seven patients, a wide or radical resection was done; in 35 patients, a palliative procedure was done; and in three patients, only a diagnostic procedure was done. For the whole group, the survival was 49% after 1 year, 39% after 2 years, and 15% after 5 years. Only the extent of the disease and the latency period between primary tumor diagnosis and first detection of osseous metastasis could be identified as independent factors of survival. Nine patients with solitary metastasis to the bone more than 12 months after resection of the primary tumor showed a 5-year survival of 54%.
Adult↗
Quantitative analysis of modified antisense oligonucleotides in biological fluids using cationic nanoparticles for solid-phase extraction.
Based on a novel method for solid-phase extraction using cationic polystyrene nanoparticles, the suitability of the extraction procedure for quantitation of terminally and backbone-modified antisense oligonucleotides was investigated. Extractions were carried out from both human plasma and urine. Quantitative analysis of the extracted samples was performed with capillary gel electrophoresis. In accordance with previous results obtained with phosphorothioate oligonucleotides in human plasma, high linearity and accuracy of the assay was demonstrated for an oligodeoxyribonucleotide-palmityl conjugate as well as for a modified oligoribonucleotide. Optimized extraction conditions allow the isolation of oligonucleotides in high yields and purity even for concentrations in the low nanomolar range, down to 5 nM. Comparing the results obtained from human plasma and urine, no significant differences in the absolute recovery rates which reach values up to 95% were observed. However, when the loading capacity of the nanoparticles was exceeded, selective recovery was observed for the coisolation of phosphodiester and phosphorothioate oligonucleotides. This effect can be explained by differences in the attractive forces between PO- and PS-oligonucleotides and the particle surface and appears to be valuable for a modification-dependent enrichment of oligonucleotides out of complex mixtures.
Calibration↗
Quantitation of phosphorothioate oligonucleotides in human blood plasma using a nanoparticle-based method for solid-phase extraction.
Based on the application of cationic polystyrene nanoparticles, a novel method for solid-phase extraction of phosphorothioate oligonucleotides from human plasma has been developed. A high binding affinity, which is required for an effective isolation out of complex mixtures, is mediated by hydrophobic and multiple electrostatic interactions between the oligonucleotides and the nanoparticles. The principle of the method is based on a pH-controlled adsorption/desorption mechanism. Analysis of the extracted samples was performed by capillary gel electrophoresis. Extraction conditions were optimized, providing the isolation of oligonucleotides (> or = 10 nucleotide units) in high yields and purity even at concentrations in the low-nanomolar range (down to 5 nM). The low salt contamination of the samples allows their direct analysis by electrospray mass spectrometry. The combined linearity and accuracy of the assay together with absolute recovery rates in the range of 60-90% indicate that the developed solid-phase extraction method is generally applicable to quantitation of oligonucleotides in human plasma. Further improvement was achieved with an optimized carrier system of 2-fold enlarged particles which reduces the time consumption of the extraction procedure to approximately 30 min.
Humans↗
Growth inhibition of pancreatic tumor cells by modified antisense oligodeoxynucleotides.
INTRODUCTION: Pancreatic adenocarcinomas are largely resistant to apoptosis. More than 50% of pancreatic tumors reveal mutations in the p53 tumor suppressor gene. METHODS: We investigated the growth of pancreatic tumor cells after downregulation of p53 protein expression by antisense oligodeoxynucleotides. RESULTS: Proliferation and p53 expression of PancTu-I cells overexpressing mutant p53 protein were inhibited by antisense oligodeoxynucleotide treatment. When analyzed, two of three other pancreatic tumor cell lines with mutated p53 were also inhibited in their growth. Two of two wild-type (wt) p53 pancreatic tumor cells were not significantly influenced by p53 expression and were, only to a lesser extent, affected in their proliferation. K562 cells (lacking p53 mRNA) and normal human skin fibroblasts used as a target mismatch control showed no changes in proliferation rates with treatment. The different biological effects in the various cells were not caused by differences in the uptake of the oligodeoxynucleotides as monitored by confocal laser-scanning microscopy. CONCLUSIONS: Truncation and 5'- and 3'-lipophilic modifications of the oligodeoxynucleotides drastically enhanced the growth inhibition of PancTu-I cells, which were resistant to apoptosis-inducing agents. Furthermore, a higher sequence-specificity of the observed effects was achieved with these compounds.
Adenocarcinoma↗
Splenic sympathetic response to endotoxin is blunted in the fetal alcohol-exposed rat: role of nitric oxide.
This study was designed to test the hypothesis that nitric oxide (NO) mediates the blunted splenic sympathetic response to lipopolysaccharide (endotoxin) that occurs in young rats exposed to alcohol in utero (FAE). The subjects, 26-29-day-old rats, were progeny of pregnant dams fed an alcohol diet (35% of the calories were derived from ethanol) or their control and pair-fed (PFC) cohorts. We examined the effects of lipopolysaccharide (LPS) (0.5 mg/kg, i.p.) on splenic norepinephrine (NE) turnover, an index of sympathetic neural activity, splenic inducible NO synthase (iNOS) protein immunoreactivity, and NO metabolites nitrite/nitrate concentrations in plasma. In response to LPS, splenic NE turnover was increased by more than twofold in the PFC groups, but the increase did not occur in their FAE cohorts. The blockade of NOS with L-NAME (30 mg/kg, i.p.) reversed this difference. In both the PFC and FAE rats, basal levels of splenic iNOS protein immunoreactivity were equally barely detected and plasma NO metabolite levels were relatively low (25 microM in both groups). In response to LPS, however, iNOS protein displayed a marked increase in the PFC group and an even greater increase (by close to threefold) in the FAE rats. LPS also substantially increased plasma NO metabolite levels by close to eightfold in the control groups, but by 15-fold in their FAE cohorts compared to the basal levels. These findings support the hypothesis that in the FAE rat, an augmented NO formation accounts for the blunted sympathetic response to endotoxin.
Animals↗