bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vestibular Evoked Myogenic Potentials and Glycerol Testing
Authors: Magliulo Giuseppe , Cuiuli Giuseppe , Gagliardi Mario , Ciniglio‐Appiani Giuseppe , D'Amico Raffaello 
Published: January 2004

AbstractObjectives/Hypothesis: The objective was to evaluate dizziness as the first symptom of endolymphatic hydrops, which could provide valuable information on the initial stages of endolymphatic hydrops development.Study Design: The present investigation was specifically designed to establish whether a combination of the traditional glycerol test and the vestibular evoked myogenic potential (VEMP) glycerol test is capable of diagnosing endolymphatic hydrops early and to identify potential Meniere's disease. The study was limited to patients who complained of dizziness as their only vestibular symptom.Methods: Thirty‐eight consecutive patients with dizziness who had received no treatment were investigated. Each patient underwent glycerol testing measured with both conventional pure‐tone audiometry and vestibular evoked myogenic potential testing. For the vestibular evoked myogenic potential glycerol test, an increase of more than 20% in both latency and amplitude after glycerol intake was considered an improvement.Results: In one patient, the reappearance of the vestibular evoked myogenic potentials was observed. In another six patients, there was an increase in the vestibular evoked myogenic potential amplitudes, unilaterally in four cases and bilaterally in two. One patient showed a bilateral improvement in amplitude and an unilateral amelioration in latency.Conclusion: The assumption of saccular dilation as a sign of early Meniere's disease was not supported by the literature, which considered saccular hydrops as the final progression of the dilation of the endolymphatic compartments into the cochlea. These data seem to indicate that in our patients a saccular dysfunction rather than an early saccular hydrops has been documented, confirming vestibular evoked myogenic potential testing as an intriguing diagnostic option for a lesion of this structure. The vestibular evoked myogenic potential glycerol test proved capable of identifying dysfunctions of the saccule that were not otherwise detectable by the routine methods. Therefore, the vestibular evoked myogenic potential glycerol test should be considered as an additional method of diagnosis in patients with vertigo or dizziness.
Audiovestibular Findings in Patients with Mitochondrial A1555G Mutation
Authors: Noguchi Yoshihiro , Yashima Takatoshi , Ito Taku , Sumi Takuro , Tsuzuku Toshihiro , Kitamura Ken 
Published: January 2004

AbstractObjective: The aims of this study were to explore the prevalence of the A1555G mutation among a group of Japanese patients and to assess the pathophysiology of the hearing impairment associated with the mutation.Study Design: Genetic study and retrospective chart review.Methods: We screened for the mitochondrial DNA A1555G mutation in 138 unrelated Japanese deaf patients, including 63 sporadic cases and 75 familial cases with different patterns of inheritance. When available, patients carrying the mutation received audiovestibular examinations, including speech audiometry, distortion‐product otoacoustic emission (DPOAE) testing, electrocochleography (ECochG), and electronystagmography.Results: One of 63 sporadic cases (1.6%) and 6 of 75 familial cases (8.0%) carried the A1555G mutation. Patients with the mutation and a familial history included two with autosomal recessive inheritance and four with maternal inheritance. In addition, two of six patients (33.3%) presenting with aminoglycoside‐induced sensorineural hearing loss (SNHL) were associated with the A1555G mutation. All but one of the patients carrying the mutation showed high‐frequency SNHL. Distortion‐product levels of DPOAE were reduced to the noise levels, suggesting the A1555G mutation caused cochlear deafness. Cochlear microphonics in ECochG showed elevation of the detection thresholds and corresponding audiometric thresholds. The ECochG data implied that patients with high‐frequency SNHL had impairment of the cochlear hair cells that was most severe toward the basal turn. The electronystagmographic findings indicated no apparent vestibular dysfunction.Conclusions: Screening for the A1555G mutation, even in patients with idiopathic bilateral SNHL, likely would be useful for preventing further development and/or acceleration of the deafness.
Microbiology of Stents in Laryngotracheal Reconstruction
Authors: Simoni Payman , Wiatrak Brian J. 
Published: January 2004

AbstractObjectives: Granulation tissue often forms around a laryngotracheal stent, tracheostomy tube, or other airway prosthesis, especially if infection occurs. We studied the types and frequency of organisms colonizing stents used in pediatric laryngotracheal reconstruction.Study Design: This prospective study included 21 patients undergoing 23 consecutive laryngotracheal reconstructions with stents between 1991 and 1999.Methods: After endoscopic removal, each laryngotracheal stent was placed immediately in a sterile container and transported to the laboratory. Specimens for culture were obtained from biofilms on the stents and plated on agars for growth of aerobic, anaerobic, and fungal organisms. Culture results were analyzed with regard to patient age, duration of stenting, and graft type.Results: All stents were colonized with more than one pathogen (range 2–7). The most frequent aerobic isolates were Streptococcus viridians, Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenza, and Neisseria species. Anaerobic organisms were isolated in 26% of cases. Candida species were isolated in 57% of the cases; patients whose stents were colonized with Candida were significantly (P = .007) older (mean 77.5 months) than those not colonized with this organism (mean 26.1 months)Conclusions: The antibiotic agents currently used for children undergoing laryngotracheal reconstruction target mainly aerobic organisms. Despite prophylactic measures, the incidence of granulation tissue formation is clinically significant, and the prevalence of anaerobic, including fungal, pathogens is high. Antibiotic therapy directed toward controlling anaerobic and fungal organisms could help in controlling local inflammation and thus granulation tissue formation.
Inspiratory Activation of the Vocal Cord Adductor, Part I: Human Study in Patients With Restricted Abduction of the Vocal Cords
Authors: Shiba Keisuke , Isono Shiroh , Sekita Yasuko , Tanaka Atsuko 
Published: January 2004

AbstractObjectives/Hypothesis: In patients with restricted abduction of the vocal cords, it has generally been accepted that glottis narrowing with laryngeal stridor during inspiration is attributed to static and passive obstruction of the glottis. However, active glottis narrowing can also be contributory. We tested the hypothesis that the vocal cord adductor is activated during inspiration in patients with restricted abduction of the vocal cords.Study Design: Electromyographic evaluation of vocal cord adductor activity in patients with restricted abduction of the vocal cords.Methods: Five patients with restricted abduction of the vocal cords who had stridor with mild to severe dyspnea during wakefulness were anesthetized with propofol. We recorded the adductor muscle electromyogram during breathing through a laryngeal mask airway while observing the vocal cord movement endoscopically. In three patients who had undergone tracheostomy, we also recorded adductor firing patterns not only while closing but also while opening the tracheostoma.Results: The adductor was activated during inspiration, and the glottis was narrowed in accordance with inspiratory stridor. This adductor inspiratory activity was abolished by opening the tracheostoma in the tracheostomized patients.Conclusion: Not only static or passive glottis narrowing but also active narrowing may contribute to inspiratory flow limitation in patients with restricted abduction of the vocal cords. This active glottis narrowing is probably induced by an airway reflex.
Vascular Endothelial Growth Factor Induces Abnormal Microvasculature in the Endoglin Heterozygous Mouse Brain
Authors: Xu Bin , Wu Yong Qin , Huey Madeleine , Arthur Helen M. , Marchuk Douglas A. , Hashimoto Tomoki , Young William L. , Yang Guo-Yuan 
Published: January 2004

Hereditary hemorrhagic telangiectasia (HHT), associated with brain arteriovenous malformations, is caused by a loss of function mutation in either the endoglin (HHT1) or activin receptor-like kinase 1 gene (ALK-1, HHT2). Endoglin heterozygous ( Eng+/−)mice have been proposed as a disease model. To better understand the role of endoglin in vascular malformation development, we examined the effect of vascular endothelial growth factor (VEGF) hyperstimulation on microvessels in adult endoglin heterozygous ( Eng+/−) mice using an adenoviral vector to deliver recombinant human VEGF165 cDNA (Ad hVEGF) into basal ganglia. VEGF expression was increased in Ad hVEGF mice compared with the Ad lacZ and saline group ( P < 0.05) and localized to multiple cell types (neurons, astrocytes, endothelial cells, and smooth muscle cells) by double-labeled immunostaining. VEGF overexpression increased microvessel count for up to 4 weeks in both the Eng+/+ and Eng+/+ groups ( Eng+/+ 185 ± 14 vs. Eng+/− 201 ± 10 microvessels/mm2). Confocal microscopic examination revealed grossly abnormal microvessels in eight of nine Eng+/− mouse brains compared with zero of nine in Eng+/+ mice ( P < 0.05). Abnormal microvessels featured enlargement, clustering, twist, or spirals. VEGF receptor Flk-1 and TGF-β receptor 1 (TβR1) expression were reduced in the Eng+/− mouse brain compared with control. Excessive VEGF stimulation may play a pivotal role in the initiation and development of brain vessel malformations in states of relative endoglin insufficiency in adulthood. These observations are relevant to our general understanding of the maintenance of vascular integrity.
Amlodipine‐induced immune thrombocytopenia
Authors: Garbe E. , Meyer O. , Andersohn F. , Aslan T. , Kiesewetter H. , Salama A. 
Published: January 2004

Background and Objectives  Drug‐induced thrombocytopenia is a serious, but rare, side‐effect of treatment with a number of drugs. In this report, we investigate the suspicion that amlodipine, a calcium‐channel blocker, was responsible for immune thrombocytopenia in a 79‐year‐old patient.Patient and Methods  Our patient experienced two attacks of thrombocytopenic purpura after 10 years of treatment with amlodipine. Antibodies to platelets were tested by standard methods.Results  Initially, the platelet count increased owing to treatment with prednisolone and intravenous immunoglobulin G, but decreased shortly after discontinuation of this treatment. The patient's serum was found to contain amlodipine‐dependent antibodies to platelets, and he recovered after stopping the drug.Conclusions  Amlodipine can induce immune thrombocytopenia, which may strongly resemble autoimmune thrombocytopenia.
Platelet function abnormalities in qualified whole‐blood donors: effects of medication and recent food intake
Authors: Paglieroni T. G. , Janatpour K. , Gosselin R. , Crocker V. , Dwyre D. M. , MacKenzie M. R. , Holland P. V. , Larkin E. C. 
Published: January 2004

Background and Objectives  Platelet function abnormalities have been reported in blood donors who have not consumed aspirin. Our objective was to identify factors other than aspirin that may contribute to impaired platelet function in qualified volunteer blood donors.Materials and Methods  Blood samples were obtained from 24 donors following routine blood donation. Donors completed a study questionnaire that included questions about recent food consumption, medication and medical history. Platelet activation was measured using monoclonal antibodies and flow cytometry. CD62P expression and PAC‐1 binding on platelets were used as indicators of platelet activation. Platelet function was measured on a platelet function analyser (PFA‐100®) using both collagen/epinephrine (cEPI) and collagen/ADP (cADP) cartridges.Results  Fifty‐four per cent of donors (13 of 24) had normal platelet function. Thirty‐eight per cent (nine of 24) had prolonged cEPI closure times, of whom four (17%) had no cEPI closure (> 300 seconds). No closure was associated with aspirin use (two donors) or chocolate consumption (two donors) before donation. Two donors (8%) had either a shortened cEPI or cADP closure time.Conclusions  Platelet dysfunction in qualified blood donors is underestimated. Platelet function screening can identify donors with diet‐related platelet dysfunction or with poor recollection of aspirin use.
Continuous cytomegalovirus seroconversion in a large group of healthy blood donors
Authors: Hecker M. , Qiu D. , Marquardt K. , Bein G. , Hackstein H. 
Published: January 2004

Background and Objectives  Transmission of cytomegalovirus (CMV) to seronegative, immunocompromised recipients can cause serious and fatal complications. Although the seroprevalence of CMV is high, the risk of primary CMV infection among healthy blood donors has not yet been analysed in a large population.Materials and Methods  We developed an algorithm to determine the rate of CMV seroconversion in an overall cohort of 24 260 subjects who donated 176 474 blood units during an 11‐year observation period.Results  We detected CMV seroconversion in all relevant age groups (18–60 years) with an overall seroconversion rate of 0·55% per year. Both CMV seroconversion and seroprevalence occurred more frequently in female donors (P = 0·02 and P < 0·001, respectively). We identified 30–35‐year‐old blood donors as the group with the highest rate of CMV seroconversion per year (1·33% vs. 0·46%; P < 0·0001).Conclusions  We conclude that the risk of primary CMV infection is a continuous lifelong event and correlates with age and female gender.
CD117, CK20, TTF‐1, and DNA topoisomerase II‐α antigen expression in small cell tumors
Authors: Yang David T. , Holden Joseph A. , Florell Scott R. 
Published: January 2004

Background:  Distinguishing merkel cell carcinoma (MCC), small cell lung carcinoma (SCLC) metastatic to the skin, and atypical basal cell carcinoma (BCC) can be problematic in some cases. Significant differences in the biology of these tumors necessitate that they need to be distinguished from one another.Methods:  We evaluated the immunophenotypic characteristics of 22 MCCs, nine SCLCs, and 19 BCCs using antibodies to cytokeratin 20 (CK20), thyroid transcription factor‐1 (TTF‐1), CD117, and DNA topoisomerase II‐α (topo II).Results:  Nineteen of 22 MCCs stained with the antibody to CK20, none stained with anti‐TTF‐1, and 13 stained with anti‐CD117. No SCLC stained with anti‐CK20, all stained with anti‐TTF‐1, and eight stained with anti‐CD117. No BCC stained with any of the three markers. The proliferative index (PI), determined by the expression of topo II, was similar for SLCLs (mean 58.5 ± 9.0%) and MCCs (mean 45.2 ± 12.4%) and was lowest in BCCs (mean 25.0 ± 8.7%).Conclusions:  CK20 and TTF‐1 appear to be reliable in distinguishing MCC from SCLC. CD117 is expressed in both MCC and SCLC, limiting its diagnostic utility. CK20, TTF‐1, and CD117 are not expressed in BCC. The high PI seen in MCCs suggests a role for topoisomerase II inhibitors in their treatment.
The T1796A mutation of the BRAF gene is absent in Spitz nevi
Authors: Palmedo Gabriele , Hantschke Markus , Rütten Arno , Mentzel Thomas , Hügel Heino , Flaig Michael J. , Yazdi Amir S. , Sander Christian A. , Kutzner Heinz 
Published: January 2004

Background:  BRAF, a serine/threonine kinase, is a component of the retrovirus‐associated sequence (RAS)–RAF–extracellular‐regulated protein kinase (ERK)–MAP kinase signal transduction pathway mediating signals from RAS to ERK.The T1796A single point mutation in exon 15 of the BRAF gene has recently been reported in a high percentage of malignant melanomas and benign melanocytic lesions such as congenital nevi, compound nevi, intradermal nevi and dysplastic nevi. The T1796A mutation has been shown to promote cell proliferation.Methods:  We screened 21 Spitz nevi and six spitzoid malignant melanomas for the presence of the T1796A BRAF mutation.Results:  The T1796A BRAF mutation could not be detected in any of the 21 Spitz nevi but was present in two of the six spitzoid malignant melanomas.Conclusions:  Our results, in conjunction with data from a previous investigation, suggest that the melanocytic proliferation of Spitz nevi might be induced by components of the RAS–RAF–ERK–MAP kinase pathway different from BRAF, possibly combined with other genetic aberrations. The lack of the T1796A BRAF mutation might be of practical importance in distinguishing Spitz nevi from other melanocytic lesions simulating Spitz nevi as a part of a future complex diagnostic assay.
Calciphylaxis and metastatic calcification associated with nephrogenic fibrosing dermopathy
Authors: Edsall Lisa C. , English Joseph C. , Patterson James W. 
Published: January 2004

Background:  Calciphylaxis and metastatic calcification are known complications of chronic renal failure. Recently, a sclerosing condition of the skin termed nephrogenic fibrosing dermopathy (NFD) has been described in patients with renal disease, many of whom have undergone hemodialysis and/or renal transplantation. To our knowledge, the simultaneous occurrence of both conditions in the same patient, in the same lesion, has not been previously reported.Case report:  We report the clinical, microscopic, and immunohistochemical features of two patients with chronic renal failure whose lesional skin biopsies showed both subcutaneous calcification and NFD. We consider the possible mechanisms that might explain the coexistence of these two disorders.Results:  Both patients presented with erythematous, indurated skin over the lower extremities. Purpuric, reticulated patches, necrosis, or ulceration were not observed. Microscopic examination showed the characteristic changes of NFD involving dermis and subcutaneous septa. In addition, biopsies of both individuals showed subcutaneous calcification, one in a diffuse distribution and the other involving the walls of subcutaneous vessels, as seen in calciphylaxis. Calcification was not suspected clinically in either case.Conclusions:  Metastatic calcification or calciphylaxis and NFD can occur simultaneously in patients with chronic renal failure and may be found together in the same lesion. Because subcutaneous calcification may not be suspected clinically in these cases, and in view of the adverse outcomes frequently associated with calciphylaxis, we recommend deep incisional biopsy of patients presenting with the clinical features of NFD. Both the fibrosis and the calcification of chronic renal failure may be related to the activity of transforming growth factor‐β/Smad signaling cascades.
HMB‐45 (gp103) and MART‐1 expression within giant cells in an atypical fibroxanthoma: a case report
Authors: Smith‐Zagone Megan J. , Prieto Victor G. , Hayes Ruth A. , Timperman Walter W. , Diwan A. Hafeez 
Published: January 2004

Background:  Atypical fibroxanthoma (AFX) is a cutaneous tumor that primarily occurs in the sun‐damaged skin of the head and neck of adults. It is often a rapidly growing, solitary lesion that may clinically resemble squamous cell carcinoma, malignant melanoma, or lobular hemangioma. The histologic differential diagnosis primarily includes spindle cell squamous carcinoma and spindle cell melanoma, and immunohistochemical studies are often needed to establish the diagnosis.Case report:  We report an unusual case of an AFX with aberrant HMB‐45 and MART‐1 (melanoma antigen recognized by T cells‐1) immunohistochemical expression. Clinical information was obtained. Histologic examination and immunohistochemical studies were performed.Results:  A 54‐year‐old woman presented with a 1.5 cm posterior scalp lesion, which was excised. Microscopic examination revealed a dermal tumor composed of pleomorphic and spindled cells with numerous giant cells. The tumor cells expressed CD68 but did not express either keratin or S‐100. In addition, there was focal gp100 (with HMB‐45) and MART‐1 expression limited to the large, multinucleated cells with vacuolated cytoplasm. A diagnosis of AFX was subsequently made.Conclusions:  This is the first reported case of an AFX with HMB‐45 and MART‐1 reactivity.
Single‐neuron evidence for a contribution of the dorsal pontine nuclei to both types of target‐directed eye movements, saccades and smooth‐pursuit
Authors: Dicke Peter W. , Barash Shabtai , Ilg Uwe J. , Thier Peter 
Published: January 2004

AbstractThe primate dorsolateral pontine nucleus (DLPN) is a key link in a cerebro‐cerebellar pathway for smooth pursuit eye movements, a pathway assumed to be anatomically segregated from tegmental circuits subserving saccades. However, the existence of afferents from several cerebrocortical and subcortical centres for saccades suggests that the DLPN and neighbouring parts of the dorsal pontine nuclei (DPN) might contribute to saccades as well. In order to test this hypothesis, we recorded from the DPN of two monkeys trained to perform smooth pursuit eye movements as well as visually and memory‐guided saccades. Out of 281 neurons isolated from the DPN, 138 were responsive in oculomotor tasks. Forty‐five were exclusively activated in saccade paradigms, 68 exclusively by smooth pursuit and 25 neurons showed responses in both. Pursuit‐related responses reflected sensitivity to eye position, velocity or combinations of velocity and position with minor contributions of acceleration in many cases. When tested in the memory‐guided saccades paradigm, 65 out of 70 neurons activated in saccade paradigms showed significant saccade‐related bursts and 20 significant activity in the memory period. Our finding of saccade‐related activity in the DPN in conjunction with the existence of strong anatomical input from saccade‐related cerebrocortical areas suggests that the DPN serves as a precerebellar relay for both pursuit and saccade‐related information originating from cerebral cortex, in addition to the classical tecto‐tegmental circuitry for saccades.
Cognitive generation of affect in bipolar depression: an fMRI study
Authors: Malhi Gin S. , Lagopoulos Jim , Ward Philip B. , Kumari Veena , Mitchell Philip B. , Parker Gordon B. , Ivanovski Belinda , Sachdev Perminder 
Published: January 2004

AbstractIndividuals with bipolar disorder manifest the full spectrum of emotions ranging from depression to mania. In attempting to understand the functional substrates of mood we attempted to identify brain regions associated with the cognitive generation of affect in bipolar depressed patients. We therefore examined ten depressed female subjects with bipolar affective disorder, and ten age‐matched and sex‐matched healthy comparison subjects using functional magnetic resonance imaging (fMRI) while viewing alternating blocks of captioned pictures designed to evoke negative, positive or no affective change. The activation paradigm involved the presentation of the same visual materials over three experiments alternating (experiment 1) negative and reference; (experiment 2) positive and reference and (experiment 3) positive and negative captioned pictures. The stimuli produced activation in both patients and comparison subjects in brain regions previously implicated in the generation and modulation of affect, in particular the prefrontal and anterior cingulate cortices. The activation in patients, when compared with healthy subjects, involved additional subcortical regions, in particular the amygdala, thalamus, hypothalamus and medial globus pallidus. Patients and comparison subjects displayed differential sensitivity to affective change with negative (experiment 1) and positive (experiment 2) affect induction producing converse patterns of activation. We conclude that bipolar depressed patients perhaps recruit additional subcortical limbic systems for emotional evaluation and this may reflect state‐related or trait‐related dysfunction. The differential patterns of activation inform us about bipolar depression and have potential diagnostic and therapeutic significance.