Estimating phonation threshold pressure

Phonation threshold pressure (PTP) is the minimum subglottal pressure required to initiate vocal fold oscillation. Although potentially useful clinically, PTP is difficult to estimate noninvasively because of limitations to vocal motor control near the threshold of soft phonation. Previous investigators observed, for example, that trained subjects were unable to produce flat, consistent oral pressure peaks during/pae/syllable strings when they attempted to phonate as softly as possible (Verdolini-Marston, Titze, & Druker, 1990). The present study aimed to determine if nasal airflow or vowel context affected phonation threshold pressure as estimated from oral pressure (Smitheran & Hixon, 1981) in 5 untrained female speakers with normal velopharyngeal and voice function. Nasal airflow during /p/occlusion was observed for 3 of 5 participants when they attempted to phonate near threshold pressure. When the nose was occluded, nasal airflow was reduced or eliminated during /p/;however, individuals then evidenced compensatory changes in glottal adduction and/or respiratory effort that may be expected to alter PTP estimates. Results demonstrate the importance of monitoring nasal flow (or the flow zero point in undivided masks) when obtaining PTP measurements noninvasively. Results also highlight the need to pursue improved methods for noninvasive estimation of PTP.     

Diagnosis of systemic causes of uveitis; a matter of ophthalmologist and internist

OBJECTIVE: To assess how often the aetiology is established in patients with uveitis, what systemic disease are found and what is the contribution of the internist to the diagnostic process. DESIGN: Retrospective study. SETTING: University Hospital Leiden, the Netherlands. METHOD: From January 1987 to April 1992, 342 patients presented with uveitis. All patients underwent a standard ophthalmological examination. Referral to an internist and individualised laboratory screening followed in patients with recurrent, chronic, bilateral or panuveitis. Recorded were: ophthalmological data, results of laboratory screening, results of analysis by the internist, final diagnosis and presence of systemic disease. RESULTS: 149 (44%) patients were examined by the internist, 18 (5.2%) were seen by another specialist. In 169 (49%) patients a specific diagnosis was made. 74 (22%) had a systemic disease, 74 a primary ocular disease. In 28 (8%) a systemic disease was presumed (5% were HLA-B27 positive, 3% had abnormal laboratory results); 5 (1%) patients had endophthalmitis as a complication of a septic process. CONCLUSION: In approximately 1/3 of the patients with uveitis a systemic disease was found. Examination by the internist tailored to the individual patient is essential in the evaluation of uveitis patients.     

Model-driven systems development and integration environment

Telecommunications operators are undergoing massive transformations in order to metamorphose themselves into the ICT world and compete with agile, lean IT organisations. The main challenges facing telecommunications operators, such as BT, are to reduce costs and increase agility in deploying software systems for provisioning ICT services. Despite using reusable capabilities and COTS packages, the major source of increased cost lies in the heavy integration tax we incur for integrating diverse systems implemented on diverse platforms and middleware, with heterogeneous data and process models. This paper looks at cost implications of lengthy and often manual migration to-and-from systems and platforms, and shows the clear business benefits of model-driven development (MDD) as defined by the Object Management Group (OMG). It is clearly demonstrated that model-driven development has matured into a practical, industrialised, scalable and evolvable technology, culminating from decades of R&D on specification and design languages, executable formalisms and domainspecific languages and language transformations.     

Stochastic model for a wavelike exothermal reaction in condensed heterogeneous systems

The labile protons of two 32-base-pair, four-arm models of immobile Holliday junctions have been studied by two-dimensional 1H nuclear magnetic resonance (NMR) spectroscopy. Overlap of resonances in the imino-imino region of two-dimensional nuclear Overhauser enhancement (NOE) spectra necessitates the use of a multi-pathway approach for obtaining sequence-specific assignments wherein all possible NOE connectivities to the labile protons are utilized, including those from the 2H of adenine, 5CH3 of thymine, and 5H of cytosine. Resonance assignments are obtained for all slowly exchanging imino and cytosine amino protons. Base-pairing up to and including the junction point is found in all four arms of both Holliday junctions. Several cross-arm NOE connectivities are identified and can be used to infer the geometry of the helical stacking domains. The two Holliday junctions studied, which differ only by the exchange of two base pairs at the branch point, appear to have opposite arm stacking geometries. These assignments form an important part of the critical background for detailed NMR analysis of Holliday junction structure and dynamics.     

Peripheral nerve stimulation in a whole-body echo-planar imaging system

Echo-planar techniques in MRI use a rapidly oscillating frequency-encoding gradient with the potential to produce peripheral nerve stimulation. To evaluate the incidence, type, and location of stimulation in a commercial whole-body scanner, we studied two groups: (a) 173 consecutive individuals scanned by echo-planar imaging for other purposes and (b) seven subjects who were scanned with an extensive set of 36 echo-planar sequences (with prompting after each scan to report any peripheral nerve stimulation) to test the effects of various parameters. Although only 5% of group A reported symptoms of peripheral nerve stimulation, all in group B experienced some type of stimulation, dependent primarily on direction of the oscillating gradient and location of the body within the gradient coil. Maximum stimulation typically occurred 30 to 40 cm from isocenter in the region of maximum dB/dt. Generally, y gradients produced truncal stimulation, and x gradients produced stimulation in the head. When hands were clasped over the abdomen, a tingling in the hands occasionally was felt. Patients should be instructed to keep their hands apart.     

Oncological outcomes of operative treatment of subcutaneous soft-tissue sarcomas of the extremities

We reviewed the cases of sixty-two patients who had had a subcutaneous sarcoma to determine the effect of tumor and treatment-related variables on the rates of survival and local recurrence. Fifty-nine (95 per cent) of the patients had had an operation at another hospital before being referred to us. Twenty-nine (47 per cent) of the sixty-two tumors were high-grade, forty-two (68 per cent) were small (five centimeters or less), and thirty (48 per cent) were malignant fibrous histiocytomas. We followed a treatment strategy that consisted of repeat excision with the goal of obtaining wide margins. Excluding thirteen patients who had had a palpable local recurrence at the time of presentation, twenty (49 per cent) of forty-one patients who had had a marginal excision at another hospital had microscopic residual tumor on repeat excision. At a median of fifty-six months after the repeat excision, fifty (81 per cent) of the sixty-two patients had been continuously disease-free, one had no evidence of disease, eight had died of the disease, and three had died of other causes. The five-year rate of disease-free survival was 85 per cent (fifty-three of sixty-two patients). There were three local recurrences, all in patients who had had a marginal resection. No recurrences were noted in patients who had had a wide local excision of the tumor or of the previous operative field. Multivariate analysis revealed that a large tumor (greater than five centimeters), a marginal excision, and adjuvant radiation therapy were associated with a worse prognosis. Excellent rates of survival for patients who have a subcutaneous sarcoma, including those who have a large or high-grade tumor and those who have residual tumor following a previous operation, can be obtained with carefully planned operative treatment alone. We recommend operative excision or repeat excision with wide margins because of the high prevalence of residual tumor. Size is the most important tumor-related factor, and the operative margin is the most important treatment-related factor. The additional value of adjuvant radiation therapy remains unproved.     

Expression of functional MHC class II molecules by a mouse pro-B cell clone

OBJECTIVE: Pooled bronchoalveolar lavage fluid (BALF), the return of lavage, contains both bronchial and alveolar material which differ from each other. Artifacts may be created by filtering, centrifuging and washing cells before cytopreparation. This study presents reference values of healthy volunteers for the alveolar sample, ALF, cytopreparation being performed without filtration or centrifugation. METHODS: Eighteen healthy, non-smoking volunteers underwent a standard bronchoalveolar lavage using 10 aliquots of 20 ml of saline. Excluding the return of the first and second aliquots, the rest were pooled and examined cytologically, immunocytochemically and biochemically. The mean, standard deviation, and 95% confidence limits were calculated for the following variables: amount of return, estimated content of epithelial lining fluid (ELF), total and differential cell counts on filter and cytocentrifuge (CCF) preparations, computed cell counts per unit volume of ALF, distribution of lymphocyte subgroups CD3+CD2, CD4, CD8, CD19, CD25 and CD57, and the ratio of CD4 to CD8, the amounts of lymphocytes in the same subgroups per volume of ALF, and the concentrations of total protein, albumin, immunoglobulins A, G and M, hyaluronic acid, eosinophilic cationic protein (ECP), procollagen III aminoterminal propeptide (PCP) and beta 2-microglobulin in ALF and in ELF, as well as the ratios of the concentrations of the solutes in ALF to the same in serum. RESULTS: The 95% confidence limits of means for the most important variables were as follows: estimated ELF content 0.42-0.74%; total cells in ALF 76.6-143.0 x 10(6) l-1; distribution of inflammatory cells on filter and CCF slides: macrophages 74.9-83.6 and 81.4-90.1%, lymphocytes 13.1-22.5 and 8.1-16.4%, and neutrophils 1.0-4.1 and 0.7-2.7%, respectively; distribution of lymphocyte subsets: CD3+CD2 85.6-90.6%, CD4 44.3-53.1%, CD8 26.9-35.8%; concentration of solutes in ALF: total protein 44.8-61.3 mg l-1, albumin 15.4-22.2 mg l-1, IgA 1.8-3.4 mg l-1, IgG 3.1-6.1 mg l-1, IgM 0.05-0.26 mg l-1, hyaluronic acid 8.8-11.1 micrograms l-1, ECP 0.19-0.77 micrograms l-1, PCP 0.005-0.58 micrograms l-1, beta 2-microglobulin 62.2-81.5 micrograms l-1. CONCLUSIONS: Our results show that excluding the bronchial sample from ALF of volunteer subjects and omitting filtering and washing before cytopreparation produces cytologic, immunocytochemical and biochemical reference values with reasonable 95% confidence limits to be used in clinical settings.     

Effects of gemfibrozil (Lopid) on hyperlipidemia in acitretin-treated patients. Results of a double-blind cross-over study

Retrospectively 78 patients with uni- or bilateral acute acoustic trauma (AAT) were evaluated to assess the therapeutic effect of hyperbaric oxygenation (HBO). All subjects received saline or dextran (Rheomacodrex) infusions with Ginkgo extracts (Tebonin) and prednisone. Thirty six patients underwent additional hyperbaric oxygenation at a pressure of 2 atmospheres absolute for 60 minutes once daily. Both treatment groups were comparable as far as age, gender, initial hearing loss and prednisone dose are concerned. The delay of therapy onset was 15 hours in both groups and treatment was started within 72 hours in all cases. Control audiometry was performed after 6.5 days, when the HBO group had had 5 exposures to hyperbaric oxygenation. The average hearing gain in the group without HBO was 74.3 dB and in the group treated additionally with HBO 121.3 dB (P < 0.004). It is concluded, that hyperbaric oxygenation significantly improves hearing recovery after AAT. Therefore acute acoustic trauma with significant hearing threshold depression remains an otological emergency. Minimal therapy involving waiting for spontaneous recovery, which is mostly incomplete leaving a residual C5 or C6 and handicapping tinnitus, is not the treatment of choice. Randomized prospective clinical trials with a larger patient series are needed and further experimental studies are required to understand the physiological mechanisms of HBO responsible for the clinical success in AAT.