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Biomedical subjects

E Mohr

Publications and source records attributed to E Mohr.

At least 19 recordsLinked to original sources

[Neck dissection for stage N0 oral cavity carcinoma].

OBJECTIVES: The management of N0 neck remains controversial. The purpose of this study was to evaluate the efficacy of selective neck dissection (SND) in managing N0 neck of oral cavity carcinomas. MATERIAL AND METHODS: A retrospective chart review of 77 previously untreated patients with squamous cell carcinomas of the oral cavity with N0 neck from 1988 to 2001 was performed. Cervical treatments were "wait and see" policy in 7 cases, neck dissection in 56 cases, radiotherapy alone in 14 cases. 77 neck dissections were performed in which 62 were selective and 15 were radical modified. RESULTS: On pathologic examination, the average number of lymph nodes was 10.7 per neck. Occult disease (cN0pN+) was detected in 32.5%, and occult extracapsular spread (cN0pN+R+) was detected in 7.8%. The median follow-up was 43 months. The overall neck recurrence rate in patients with controlled primary disease was 2.4%. Recurrent disease developed in 2.9% of the cNOpN0 neck. Regional control rate of the dissected neck was 94%. No cervical recurrence occurred in 11 patients treated with SND alone. There was no survival or recurrence rate difference in T1T2pN0 patients with or without post-operative radiotherapy. Post-operative radiotherapy could be avoided in 27% of the dissected neck. One, 3 and 5 years overall survival rate were 89.3%, 77.7% and 63.2%. CONCLUSIONS: SND is an effective procedure for staging and treating the clinically negative neck of oral cavity cancer.

Adult↗

[Vestibular neurotomy versus chemical labyrinthectomy for disabling Menière disease].

OBJECTIVE: To evaluate the efficiency on the vertigos and the impact on the audition of the vestibular neurotomy (VN) and the chemical labyrinthectomy (CL) in patients with severe Menière's disease, in order to determine the precise place for each technique in treatment algorithm. METHOD: Retrospective study of 71 VN (performed between 1986 and 2003) and 35 CL (performed between 1997 and 2003). These two treatments both aim at obtaining a vestibular deafferentation in order to free definitely the patient of vertigo manifestations. Vestibular results have been assessed by caloric tests performed before and 6 months after treatment. Subjective success was evaluated by searching for recurrent attacks of vertigo and by the AAO-HNS (American Academy of Otolaryngology-Head and Neck Society) scale of subjective evaluation of vertigos (follow-up of 6.4 years after VN and 2.4 years after CL). Pure tone audiometry before treatment and then 6 months later was performed. Complications of two types of treatment were recorded and evaluated. RESULTS: In 90% of the cases after VN and 86% of the cases after CL, caloric tests indicated a strong vestibular hyporeflexy (hypovalence > 90%). Attacks of vertigo reoccurred in 5.6% of the cases when the hyporeflexy was strong and 85.7% of the cases when it was weak. The quality of the vestibular results on vertigo depends on the degree of hypovalence after treatment. An improvement of the AAO-HNS scale have been obtained in 93% of the cases in the NV group and in 81% of the cases in the LC group. Attacks of vertigo were recurrent in 7% of the patients operated on by VN and 11.4% of the patients treated by CL. Mean pure tone auditory thresholds changed from 50.24 dB HL to 55.64 dB HL (p=0.003) in the VN group and from 69.11 dB HL to 74.51 dB HL (p=0.41) in the CL group. Comparison of the variations of the mean pure tone auditory thresholds before treatment and 6 months after the end of the treatment doesn't show any significant difference between the 2 groups (p > 0.05). Impairment of the audition superior to 20 dB HL was observed in 8.5% of the patients of each group. The auditive results are similar in the 2 groups. CONCLUSION: These two methods of treatment can not be strictly compared due to several bias in this study. Indeed more patients were treated by VN with a longer follow-up and only the patients with a class C or D audition according to the criteria of the AAO-HNS could be treated by CL. The VN provides a better control of the vertigos than the CL which is an efficient method of treatment in invalidating Meniere's disease. In all the cases, the quality of the results on vertigos depends on the degree of hypovalence after treatment. The auditive results are similar. Since the results of the two treatments are similar, the simplicity of CL encourages us to broaden the indications and to modify the place of the VN in the therapeutic algorithm of Menière's disease.

Adult↗

Subcellular vasopressin mRNA trafficking and local translation in dendrites.

Vasopressin mRNA is delivered to axons and dendrites of rat hypothalamic magnocellular neurones. Subcellular localization of mRNAs requires sequences (cis-acting elements) within the RNA and proteins (trans-acting factors), which together mediate nucleic acid transport along the cytoskeleton to specific cytoplasmic destinations. In cultured neurones, vasopressin mRNA transcribed from a microinjected eukaryotic expression vector is sorted to dendrites. Detailed analyses revealed the presence of a complex cis-acting element, called dendritic localizer sequence (DLS), within part of the coding- and the 3'-untranslated region of vasopressin mRNA. Biochemical investigations have shown a specific interaction of poly(A)-binding protein (PABP) with the DLS. PABP is implicated in translation, translational control, RNA stability and RNA transport. Hence, PABP could be a component of a probably multifactor complex regulating transport and local translation of vasopressin mRNA. Dendrites are capable of translation. Local synthesis of the vasopressin precursor in dendrites of in vitro cultured neurones was demonstrated by microinjecting a vector encoding a mutant vasopressin polyprotein that is unable to leave the rough endoplasmic reticulum. Expression of this construct revealed that the nondiffusable protein is only detectable in dendrites harbouring vasopressin mRNA whereas dendrites devoid of this transcript lack the mutant vasopressin precursor.

Animals↗

[Fecal occult blood testing for colorectal cancer ].

Screening with Fecal Occult Blood Test (FOBT) fails to adequately select patients who could have colorectal tumors and should be sent to colonoscopy. The latter investigation should be considered as the first intention examination in every person aged more than 50 years old (or, 40 years if there is a family history of elevated cancer risk). Colonoscopy will allow to identify the numerous patients who, in spite of significant disease, would have a negative FOBT.

Colonoscopy↗

[Forestier disease presenting as dysphagia].

INTRODUCTION: Forestier's disease is characterized by hyperostosis of the anterolateral margin of the vertebral bodies. Cervical spine involvement rarely leads to dysphagia. OBSERVATION: A 76 year-old man suffered from progressive dysphagia, feeling of suffocation and left cervical pain. Clinical examination was unremarkable but cervical spine radiographies revealed large anterior osteophytes creating pharyngeal encroachment. Computed tomography showed a "double vertebral body" aspect notably in C2 and C3, compressing ahead structures. Surgical procedure consisted in resection of the anterior osteophytes. Postoperative course was uneventful and all the symptoms resolved within a few weeks. DISCUSSION: Anterior cervical spine hyperostosis in Forestier's disease can lead to dysphagia by direct pharyngeal or esophageal compression and, later on, by muscular fibrosis of the pharyngoesophageal wall in severe cases. Surgery must take the place of medical treatment in severe dysphagias with a good radioclinical correlation, to improve functional prognosis.

Aged↗

Acute nicotine effects on auditory sensory memory in tacrine-treated and nontreated patients with Alzheimer's disease: an event-related potential study.

The auditory mismatch negativity (MMN) event-related brain potential (ERP) reflects the storage of information in acoustic sensory memory. Thirteen patients with Alzheimer's disease (AD), 6 receiving treatment with the cholinesterase inhibitor, tacrine [tetrahydroaminoacridine (THA)], and 7 receiving no treatment, were administered 2 mg of nicotine polacrilex and placebo. MMNs were recorded with 1- and 3-s interstimulus intervals (ISIs) during pre- and post-placebo/nicotine administration. Amplitudes decreased from pre- to post-placebo recordings in nontreated patients but remained stable in THA-treated patients. Comparison of pre- and post-nicotine MMNs found amplitude increases with nicotine in nontreated but not in THA-treated patients. MMN latencies were shortened by nicotine in both treatment groups. These exploratory findings suggest that nicotine-improved strength of acoustic sensory memory traces and speed of acoustic sensory discrimination in AD are differentially affected by chronic tacrine treatment.

Acoustic Stimulation↗

Effects of aqua-treadmill exercise on selected blood parameters and on heart-rate variability of horses.

The objectives of the present study were to investigate the effects of Aquatraining of horses (aqua-treadmill exercise; treadmill manufactured by Equitech - L.u.S. Equipment, Warendorf, Germany) on selected blood parameters [lactic acid concentration (mmol/l), haemoglobin content (g/l)] and on heart-rate variability (HRV) [heart rate (beats per min; b.p.m.), standard deviation of all NN-intervals (SDNN; ms), normalized power of the low and high frequency band (LFnorm, Hfnorm; au), % recurrence, % determinism and ratio(corr)]. Seven horses performed six exercise tests with different work loads (walking (x = 1.56 +/- 0.08 m/s) and trotting (x = 2.9 +/- 0.13 m/s): dry, water above the carpus and water above the elbow). The standardized test-protocol was: 5 min warm-up at walk while the water was pumped in, followed by the 20-min exercise period at walk or trot, followed by a 5-min walk while pumping out the water. Blood samples were taken prior to each test at rest in the stable, as well as exactly 5 min after the end of the 20-min exercise period. Electrocardiograms were recorded during rest and the 20-min exercise period. Compared to rest, neither the chosen velocities, the two water levels, nor the dry tests led to a significant increase of the lactic acid concentration in any horse. The haemoglobin content showed a significant increase as a result of exercise. Significant differences could be found between the heart rates at rest and the six exercise tests and between the mean of the levels 'walking' and the mean of the levels 'trotting'. An exercise-induced change of HRV was characterized by a decreasing SDNN, a significantly higher LFnorm (sympathetic influence) combined with a significantly lower HF(norm) power (parasympathetic activity) and a rising degree of order (significantly higher % determinism and nearly unchanged % recurrence) and stability (significantly rising ratio(corr)) of the recurrence plot. In conclusion, the used training-protocol for aqua-treadmill exercises only represents a medium-sized aerobic work load for horses, but the different levels of burden were indicated especially by changes in HRV.

Animals↗

Effects of acute nicotine administration on cognitive event-related potentials in tacrine-treated and non-treated patients with Alzheimer's disease.

Earlier studies of cognitive event-related brain potentials (ERPs) reporting diminished amplitudes and delayed latencies of the P300 potential in dementia of the Alzheimer type (DAT), together with independent findings of the P300- and performance-enhancing properties of nicotine in normal adults, stimulated this study to explore the single-dose effects of nicotine on auditory and visual P300s in DAT. Thirteen patients, 6 currently receiving treatment with the cholinesterase inhibitor tacrine (tetrahydroaminoacridine; THA) and the remaining being medication free, were administered 2 mg of nicotine polacrilex under double-blind, randomized, placebo-controlled conditions. Prior to nicotine administration, THA-treated patients exhibited shorter auditory P300 latencies than non-treated patients. Acutely administered nicotine failed to alter auditory P300, but increased the amplitudes of visual P300s in both DAT patient groups. Neither THA treatment nor single-dose nicotine altered behavioural performance in the visual and auditory task paradigms. The results are discussed in relation to nicotinic cholinergic, attentional and cognitive processes in DAT.

Administration, Oral↗

Nicotine and sensory memory in Alzheimer's disease: an event-related potential study.

The auditory mismatch negativity (MMN) event-related brain potential (ERP) reflects the storage of information in acoustic sensory memory. Thirteen patients with probable Alzheimer's disease (AD), 6 receiving treatment with the cholinesterase inhibitor (ChEI) tacrine (tetrahydroaminoacridine, THA) and 7 receiving no treatment, were administered 2 mg of nicotine polacrilex and placebo. MMNs were recorded with 1- and 3-s interstimulus intervals pre- and postplacebo/nicotine administration. In nontreated patients, amplitudes were decreased from pre- to postplacebo recordings but remained stable in THA-treated patients. Comparison of pre- and postnicotine MMNs found amplitude increases with nicotine in nontreated but not THA-treated patients. MMN latencies were shortened by nicotine in both treatment groups. These exploratory findings suggest that nicotine-improved strength of acoustic sensory memory traces and speed of acoustic sensory discrimination in AD are differentially affected by chronic ChEI treatment.

Acoustic Stimulation↗

Vasopressin mRNA localization in nerve cells: characterization of cis-acting elements and trans-acting factors.

mRNA localization is a complex pathway. Besides mRNA sorting per se, this process includes aspects of regulated translation. It requires protein factors that interact with defined sequences (or sequence motifs) of the transcript, and the protein/RNA complexes are finally guided along the cytoskeleton to their ultimate destinations. The mRNA encoding the vasopressin (VP) precursor protein is localized to the nerve cell processes in vivo and in primary cultured nerve cells. Sorting of VP transcripts to dendrites is mediated by the last 395 nucleotides of the mRNA, the dendritic localizer sequence, and it depends on intact microtubules. In vitro interaction studies with cytosolic extracts demonstrated specific binding of a protein, enriched in nerve cell tissues, to the radiolabeled dendritic localizer sequence probe. Biochemical purification revealed that this protein is the multifunctional poly(A)-binding protein (PABP). It is well known for its ability to bind with high affinity to poly(A) tails of mRNAs, prerequisite for mRNA stabilization and stimulation of translational initiation, respectively. With lower affinities, PABP can also associate with non-poly(A) sequences. The physiological consequences of these PABP/RNA interactions are far from clear but may include functions such as translational silencing. Presumably, the translational state of mRNAs subject to dendritic sorting is influenced by external stimuli. PABP thus could be a component required to regulate local synthesis of the VP precursor and possibly of other proteins.

Amino Acid Sequence↗

Location analysis of DNA-bound proteins at the whole-genome level: untangling transcriptional regulatory networks.

In this post-sequencing era, geneticists can focus on functional genomics on a much larger scale than ever before. One goal is the discovery and elucidation of the intricate genetic networks that co-ordinate transcriptional activation in different regulatory circuitries. High-throughput gene expression measurement using DNA arrays has thus become routine strategy. This approach, however, does not directly identify gene loci that belong to the same regulatory group; e.g., those that are bound by a common (set of) transcription factor(s). Working in yeast, two groups have recently published an elegant method that could circumvent this problem, by combining chromatin immunoprecipitation and DNA microarrays.(1,2) The method is likely to provide a powerful tool for the dissection of global regulatory networks in eukaryotic cells.

DNA↗

Messenger RNA on the move: implications for cell polarity.

RNA sorting is an evolutionarily conserved mechanism for establishing asymmetries within a given cell concerning the macromolecular equipment of defined domains. mRNAs as well as non-coding transcripts are delivered to specific subcellular compartments in diverse organisms including developmental systems of Drosophila, Xenopus, ascidiens, zebrafish and echinoderms and in differentiated cells from yeast to mammals. The composition of the RNA localization machinery is complex. Both sequence- or structural motifs within RNA molecules to be transported (cis-acting elements) and various proteins (trans-acting factors) contribute to the localization procedure. Most often these macromolecular ribonucleoprotein complexes exhibit a granular appearance, and granule localization depends on intact microfilaments or microtubules. When delivered to their ultimate destinations mRNAs are anchored to await translational activation at the appropriate timepoint. Beyond doubt, RNA localization plays a pivotal role in embryonic development, where mRNA mislocations cause severe body pattern defects. In terminally differentiated vertebrate cells RNA transport and local on-site translation presumably have an impact on various cellular functions such as cell motility, myelinization of nerve cell axons and nerve cell communications in the central and peripheral nervous system.

Animals↗

VP-RBP, a protein enriched in brain tissue, specifically interacts with the dendritic localizer sequence of rat vasopressin mRNA.

The concept of mRNA localization suggests that this process is mediated by sequences residing in the transcript to which proteins specifically bind and ultimately deliver the mRNA along cytoskeletal elements to specific intracellular destinations. The mRNA encoding the vasopressin (VP) precursor protein is localized to the nerve cell processes both in hypothalamic magnocellular neurons and in primary cultured neurons derived from embryonic rat superior cervical ganglia microinjected with a corresponding eukaryotic expression vector. The last 395 nucleotides of the VP mRNA encompassing part of the coding region, as well as the complete 3'-untranslated region, are sufficient to confer dendritic targeting to a normally nonlocalized reporter transcript. Here we report that, by employing in vitro crosslinking analyses with rat brain proteins and radiolabelled VP transcripts, an RNA-binding protein specifically interacts with the dendritic localizer sequence of the VP mRNA. This protein is enriched in nerve cell tissues. Peripheral tissues and various cell lines contain only low amounts of the binding activity. It therefore represents a candidate protein that may be involved in any aspect related to subcellular VP mRNA sorting in nerve cells, including transport and anchoring of the mRNA and possibly its translational control.

Animals↗

Quantitative electroencephalography in Alzheimer's disease: comparison with a control group, population norms and mental status.

OBJECTIVE: Given that quantitative electroencephalography (EEG) has repeatedly shown excessive slow wave activity in dementia of the Alzheimer type (DAT) that increases with disease progression, we assessed the clinical utility of this tool by comparing various approaches used to assess slowing. DESIGN: Cross-sectional study comparing quantitative EEG data from patients with DAT with normative data from an elderly control group and from EEG norms derived from a large population. PARTICIPANTS: 35 subjects diagnosed with probable DAT and 30 elderly controls. OUTCOME MEASURE: EEG recorded from 21 scalp sites of each patient and elderly control during vigilance-controlled, eyes-closed, resting conditions was spectrally analyzed to yield measures of absolute and relative power in delta, theta, alpha and beta bands and indices of mean alpha band and total band frequency. RESULTS: Group comparisons of raw or age-regressed z-score population normative values yielded different profiles with respect to direction of frequency band changes, regional topography and clinical rating correlations, but both procedures evidenced overall patterns of EEG slowing in DAT. However, both methodologies yielded only modest (75%) classification rates. CONCLUSION: Quantitative EEG remains a valuable research tool but, as yet, an unproven diagnostic tool, for DAT.

Aged↗

[Bicycle helmet].

Explore the source record for details and available documents.

Bicycling↗

Risperidone in the treatment of dopamine-induced psychosis in Parkinson's disease: an open pilot trial.

PURPOSE: To evaluate the safety and efficacy of risperidone in patients with Parkinson's disease (PD) who are experiencing significant dopamine-induced psychosis. PATIENTS AND METHODS: Seventeen patients (median age, 72 yrs) participated in this 12-week, open pilot study receiving 0.5 to 3 mg oral risperidone per day. Maintenance antiparkinsonian medication was continued throughout, although psychotropic medication was discontinued. EFFICACY RESULTS: Risperidone produced a substantial improvement in psychotic symptoms, shown on the mean total positive subscale score on the Positive and Negative Syndrome Scale (PANSS) by a 30% improvement (-3.1 decrease) after 1 week and a 66% improvement (-6.8 decrease) at end point. This improvement was most evident in the items delusions, hallucinatory behavior, and suspiciousness/persecution. Risperidone also achieved significant improvement from baseline in Clinical Global Impression (CGI)-severity and CGI-improvement (p < 0.001, Page test). Risperidone treatment did not adversely affect symptoms specific to Parkinson's disease, as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). SAFETY RESULTS: Sixteen patients reported at least one adverse event, but only two patients withdrew as a result of adverse events. No significant changes or clinically relevant abnormalities were observed in laboratory parameters or vital signs. CONCLUSION: Short-term use of risperidone (mean dosage, 1.1 mg per day) improves the psychopathology of patients with PD who have dopamine-induced psychosis without adversely affecting the symptoms of PD. Higher doses and long-term use were not addressed in this study and may be precluded by extrapyramidal side effects.

Adult↗