31 research outputs found

    Nitrofurantoin-induced pulmonary fibrosis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Nitrofurantoin is a commonly used drug in the treatment and prevention of urinary tract infections. Many adverse effects of nitrofurantoin have been documented, including aplastic anemia, polyneuritis, and liver and pulmonary toxicity.</p> <p>Case presentation</p> <p>We describe the clinical history and the autopsy findings in a 51-year-old woman with lung fibrosis of unknown etiology. She had a history of recurrent urinary tract infections, treated with nitrofurantoin for many years. She was referred to our hospital for screening for lung transplantation because of severe pulmonary restriction and dyspnea. Unfortunately, she died as a result of progressive respiratory insufficiency. At autopsy bilateral patchy, sharply circumscribed fibrotic areas in the upper and lower lobes of the lungs were seen with honeycombing. Microscopically, end-stage interstitial fibrosis with diffuse alveolar damage was observed. Due to the atypical distribution of the fibrosis involving both the lower and upper lobes of the lung, the microscopic pattern of the fibrosis and the history of long-term nitrofurantoin use, we concluded that this drug induced the lung fibrosis. The recurrent urinary tract infections were probably caused by a diverticulum of the urinary bladder, which was discovered at autopsy.</p> <p>Conclusion</p> <p>This case shows that the use of nitrofurantoin may cause severe pulmonary disease. Patients with long-term use of nitrofurantoin should be monitored regularly for adverse pulmonary effects.</p

    On the stability of a class of shoreline planform models

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    AbstractThe evolution of beaches in response to the incident wave conditions has long attracted the attention of researchers and engineers. A popular mathematical model describing the change in the position of a single height contour on the coastline assumes that the beach profile is stable and the plan shape evolves due to wave-driven long-shore transport. Extensions of this model include more contours and allow for beach profile alteration through cross-shore transport of sediment. Despite this advantage, models with multiple contours remain relatively underused. In this paper we examine the stability of this class of model for the cases of one to three contours. Unstable modes may exist when there is more than one contour. These include short waves whose growth rate is strongly dependent upon wavenumber. For the case of three contours an additional long wave instability is possible. A necessary, but not sufficient, condition for instability is found. It requires a reversal of transport direction amongst the contours. The existence of these instabilities provides a possible explanation for the difficulties found in implementing computational multi-line models, particularly where structures alter the natural longshore transport rates so they satisfy, locally, the condition for instability

    High-angle wave instability and emergent shoreline shapes : 1. Modeling of sand waves, flying spits, and capes

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    Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): F04011, doi:10.1029/2005JF000422.Contrary to traditional findings, the deepwater angle of wave approach strongly affects plan view coastal evolution, giving rise to an antidiffusional “high wave angle” instability for sufficiently oblique deepwater waves (with angles between wave crests and the shoreline trend larger than the value that maximizes alongshore sediment transport, ∼45°). A one-contour-line numerical model shows that a predominance of high-angle waves can cause a shoreline to self-organize into regular, quasiperiodic shapes similar to those found along many natural coasts at scales ranging from kilometers to hundreds of kilometers. The numerical model has been updated from a previous version to include a formulation for the widening of an overly thin barrier by the process of barrier overwash, which is assumed to maintain a minimum barrier width. Systematic analysis shows that the wave climate determines the form of coastal response. For nearly symmetric wave climates (small net alongshore sediment transport), cuspate coasts develop that exhibit increasing relative cross-shore amplitude and pointier tips as the proportion of high-angle waves is increased. For asymmetrical wave climates, shoreline features migrate in the downdrift direction, either as subtle alongshore sand waves or as offshore-extending “flying spits,” depending on the proportion of high-angle waves. Numerical analyses further show that the rate that the alongshore scale of model features increases through merging follows a diffusional temporal scale over several orders of magnitude, a rate that is insensitive to the proportion of high-angle waves. The proportion of high-angle waves determines the offshore versus alongshore aspect ratio of self-organized shoreline undulations.This research was funded by the Andrew W. Mellon Foundation and NSF grants DEB-05-07987 and EAR-04-44792

    Cholesterol nucleation-influencing activity in T-tube bile

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    Nucleation-influencing activity was determined in T-tube bile samples derived from patients with obstructive jaundice. Since native T-tube bile samples do not nucleate, nucleation-influencing activity was determined by measuring the influence of T-tube bile on the nucleation time of model bile. In the assay, T-tube bile was mixed with model bile, and the nucleation time of this mixture was compared with the nucleation time of a model bile supplemented with the same amount of lipid as present in the bile sample. The results were expressed as ratio of the nucleation time of the mixture and the nucleation time of the control (NTm/NTc). There was a significant difference (p less than 0.01) between bile samples from patients with cholesterol gallstones and samples from patients with biliary obstruction due to other causes. More than 80% of the 33 samples from eight patients with stones were nucleation-promoting (NTm/NTc less than or equal to 0.6). Of the 40 bile samples from patients without stones, 7 were nucleation-promoting, 25 had no effect (NTm/NTc = 0.8 to 1.2) and 8 bile samples were nucleation-inhibiting (NTm/NTc greater than or equal to 1.4). There was no correlation between the lipid or protein content of a T-tube bile sample and its nucleation-influencing activity. The presence of both nucleation-promoting and nucleation-inhibiting activity in the same T-tube bile was demonstrated by chromatography on concanavalin A-Sepharose. More than 75% of the biliary protein did not bind to the column. This fraction showed nucleation-inhibiting activity.(ABSTRACT TRUNCATED AT 250 WORDS

    Imaging Pulmonary Inflammation

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    Simultaneous passive and active immunization against hepatitis B: noninterference of hepatitis B immune globulin with the anti-HBs response to reduced doses of heat-inactivated hepatitis B vaccine

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    The effect of simultaneous administration of hepatitis B immune globulin on the antibody response to a low dose of heat-inactivated hepatitis B vaccine was investigated in 175 health care workers. Subjects were divided into four groups: Groups I and II received 3 monthly injections of a reduced dose (0.6 microgram) of a heat-inactivated hepatitis B vaccine (the usual dose being 3 micrograms) along with 500 IU of hepatitis B immune globulin simultaneously with the first injection of vaccine; Groups III and IV received the vaccine only. In addition, Groups I and III received a final booster injection with 0.6 microgram of the vaccine 8 months after the initial injection. Anti-HBs passively acquired from hepatitis B immune globulin did not interfere with the development of an active antibody response to the vaccine: the anti-HBs conversion rates were similar in persons treated with the combined regimen (89%) as in those who received the vaccine only (91%). At 3 and 5 months after the first injection, however, anti-HBs titers in the recipients of vaccine alone were slightly but statistically significantly higher than those of persons who received both hepatitis B immune globulin and vaccine; but at 8 months, this difference was no longer statistically significant. After a booster inoculation at 8 months, the geometric mean titer of anti-HBs increased 7- to 8-fold in antibody-positive vaccinees, regardless of whether hepatitis B immune globulin had been given earlier. Moreover, 6 of 13 nonresponders to the initial three vaccine injections developed anti-HBs after the booster inoculation.(ABSTRACT TRUNCATED AT 250 WORDS
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