The empirical use of aminoglycosides in Ludwig's angina based on bacterial analysis of 63 cases.

PURPOSES: To determine if the empirical use of aminoglycosides is justified in Ludwig's angina based on microscopy, culture and sensitivity results. METHODS: A retrospective analysis was done on patients that presented with Ludwig's angina to the Maxillofacial and Oral surgery department at the University of Pretoria. Demographical data was extracted from patient files. Pus specimens that were submitted as part of the initial surgical intervention were analysed. RESULTS: Sixty-three patients were included in the study with the majority, 76.19% (n=48/63), comprising males. The mean patient age was 38.6 years (range 6 months to 78 years). The majority of infections (87.3%) had an odontogenic aetiology (n=55/63). Forty-four percent of the patients had immunosuppressive co-morbidities (n=28/63). Streptococci contributed 71.26% (n=62/87) of the cultured bacteria. Similar bacteria were cultured in the immunocompromised and the immunocompetent patients (p=0.672). Ninety-two percent (n=57/62) of the streptococci cultured were sensitive to penicillin. The addition of aminoglycosides to the study sample would not have made a statistically significant difference (p=0.1556). CONCLUSION: Based on the findings of this study, the empirical use of aminoglycosides is not warranted in either immunocompromised or immunocompetent patients with Ludwig's angina.

A Change in the Use of Regulatory Criteria for Assessing Potential Impacts of Sound on Fishes.

The National Marine Fisheries Service (NMFS) currently uses interim criteria developed on the US West Coast to assess the potential onset of peak and cumulative effects of noise on fishes. Analyses performed for this project provided adequate support for the NMFS to use the peak criterion (i.e., area ensonified by 206 dB re 1 µPa peak sound pressure level [SPL(peak)]) for estimating the incidental take of Hudson River sturgeon. Application of the peak criterion (rather than the cumulative criterion) could have implications for future construction projects because estimates of take using SPL(peak) will generally be considerably lower than estimates of take based on the cumulative sound exposure level.

Avoidance of Pile-Driving Noise by Hudson River Sturgeon During Construction of the New NY Bridge at Tappan Zee.

Sturgeon movements were monitored during a pile-driving operation. Fewer sturgeon were detected during pile driving and remained for a shorter time than during silent control periods. Moreover, the short time spent by sturgeon near pile driving suggests that they were unlikely to have reached the criterion of 187 dB re 1 µPa(2)·s cumulative sound exposure level. These results suggest that sturgeon are likely to avoid impact pile driving and not remain long enough to experience physiological effects, thus providing empirical evidence that the 206 dB re 1 µPa peak sound pressure level is the appropriate criterion for assessing the impacts of pile-driving noise on sturgeon.

Methods for Predicting Potential Impacts of Pile-Driving Noise on Endangered Sturgeon During Bridge Construction.

The potential impacts of pile-driving noise on Hudson River sturgeon during construction of the New NY Bridge were predicted. Abundance data for shortnose and Atlantic sturgeon derived from fisheries sampling were combined with data about the spatial extent of pile-driving noise. This approach was used to calculate the number of sturgeon that could occur within sound level isopleths exceeding peak and cumulative noise criteria used by the National Marine Fisheries Service to determine the incidental take of sturgeon. The number of sturgeon subject to the potential onset of physiological effects during pile driving was predicted to be 35-41 fish for each species.

Pile Driving at the New Bridge at Tappan Zee: Potential Environmental Impacts.

A new bridge will be constructed to replace the aging Tappan Zee Bridge over the Hudson River in New York. Construction will potentially result in hydroacoustic impacts to the local fish fauna. As a consequence, a substantial environmental impact analysis had to be conducted to obtain construction permits. This paper describes the process of environmental analysis and some of the results of the studies that led up to the final permitting. The process included modeling of pile-driving acoustics, analysis of river ambient noise, analysis of test piling, and observations on fish behavior during these tests.

Retrospective analysis of etiology and comorbid diseases associated with Ludwig's Angina.

INTRODUCTION: Ludwig's angina (LA) still presents regularly at our tertiary academic hospital. Various etiologies and comorbid diseases are documented worldwide, but the South African population has not been studied. AIM: To establish whether LA cases presenting to the department are different from international reports regarding etiology and comorbidities. SETTINGS AND DESIGN: Retrospective analysis of patients presenting with LA to a tertiary hospital. MATERIALS AND METHODS: 93 patients were included over a 5-year period. Archived files were analyzed for data including age, gender, comorbid diseases, etiology, airway management, and season on admission. STATISTICAL ANALYSIS: Descriptive statistics with the inclusion of frequency distributions. RESULTS: 93 patients were included; 65 (69.9%) male and 28 (30.1%) female; age - minimum 20 years, maximum 75 years, mean 40.366. ETIOLOGY: 68 (73.1%) odontogenic, 13 (14%) nonodontogenic, and 12 (12.9%) unknown cause. Comorbid diseases: 21 (22.6%) diabetes mellitus (DM), 19 (20.4%) hypertension, and 18 (19.4%) human immunodeficiency virus (HIV). Airway management: 61 (65.6%) tracheostomy and 32 (34.4%) nonsurgical. COMPLICATIONS: 11 (11.8%) deaths, 8 (8.60%) descending mediastinitis, and 7 (7.53%) necrotizing fasciitis. Seasonal occurrence: 30 (32.3%) spring, 24 (25.8%) winter, 22 (23.7%) summer, and 17 (18.3%) autumn. CONCLUSION: A 2.32:1 ratio male: female presentation mirrors previous statistics. DM patients had increased risks of complications, which resulted in multiple deaths. HIV patients showed increased risks for complications with more intense, longer hospital stays, but lower percentages of deaths compared to patients with DM and complications who died. There was no statistically significant finding regarding seasonal tendency.

[Relevance of nuclear medicine in the diagnosis and treatment of malignant paraganglioma]. / Relevancia de la medicina nuclear en el diagnóstico y tratamiento del paraganglioma maligno.

BACKGROUND: Paragangliomas are neoplasms of the chromaffin tissue characterized by the synthesis and/or secretion of catecholamines. Their treatment depends on the extension and functional characteristics of the tumor. In this pathology, the anatomic and functional diagnostic evaluations provided by nuclear medicine imaging studies have significant usefulness. CLINICAL CASE: A 34-year-old male was diagnosed with a paraganglioma at the level of the aortic bifurcation by means of laboratory tests, imaging studies and nuclear medicine studies. Nuclear medicine was carried out with a scintigraphy with a norepinephrine analog, radioactive meta-iodo-benzyl-guanidine (131I-MIBG), which demonstrates functionally and specifically the presence of neoplastic adrenergic tissue and extratumoral extension. In addition, a positron emission tomography coupled with computed tomography with a radioactive analog of glucose locates the extratumoral activity at bone level. Nuclear medicine studies allow the diagnosis of a malignant paraganglioma with presence of bone metastasis. The therapy includes surgical removal of the tumor and ablation of residual malignant tissue and metastatic lesions by radiotherapy with 131I-MIBG. Radiotherapeutic treatment was possible due to the capacity of the tumor to uptake and to concentrate the radioactive hormonal analog. CONCLUSIONS: In cases of paraganglioma, in addition to the localization of the tumor and the evaluation of biochemical alterations, it is indispensable to obtain anatomic and functional evaluation provided by nuclear medicine studies in order to achieve appropriate diagnoses and treatment.

Relevancia de la medicina nuclear en el diagnóstico y tratamiento del paraganglioma maligno / Relevance of nuclear medicine in the diagnosis and treatment of malignant paraganglioma

Introducción: Los paragangliomas son tumores del tejido cromafín caracterizados por la síntesis o secreción de catecolaminas, en los que el tratamiento depende de su extensión y características funcionales. Dentro de la evaluación diagnóstica anatómica y funcional de este padecimiento, los métodos de imagen de medicina nuclear sobresalen por su utilidad. Caso clínico: Paciente con paraganglioma a nivel de la bifurcación de la aorta en quien el diagnóstico se realizó por estudios de laboratorio, imagenología y medicina nuclear. Se llevó a cabo centelleografía con un análogo de norepinefrina, la metayodobencilguanidina marcada radiactivamente (131I-MIBG), que demostró funcional y específicamente la presencia de tejido adrenérgico neoplásico y su extensión extratumoral. Complementariamente se efectuó tomografía por emisión de positrones fusionada con tomografía computarizada, utilizando un análogo radiactivo de la glucosa que localizó la actividad extratumoral a nivel óseo. Los estudios de medicina nuclear permitieron concluir que se trataba de un paraganglioma maligno con metástasis óseas. El tratamiento incluyó resección quirúrgica del tumor y ablación del tejido tumoral residual y de los focos metastásicos con radioterapia interna mediante 131I-MIBG. El tratamiento radioterapéutico fue posible dada la capacidad del tumor y las metástasis de concentrar el análogo hormonal radiactivo. Conclusiones: Ante casos de paragangliomas, además de la localización del tumor y la evaluación de las alteraciones bioquímicas, es indispensable la evaluación funcional que brinda la medicina nuclear para la realización de un diagnóstico y tratamiento adecuados.

BACKGROUND: Paragangliomas are neoplasms of the chromaffin tissue characterized by the synthesis and/or secretion of catecholamines. Their treatment depends on the extension and functional characteristics of the tumor. In this pathology, the anatomic and functional diagnostic evaluations provided by nuclear medicine imaging studies have significant usefulness. CLINICAL CASE: A 34-year-old male was diagnosed with a paraganglioma at the level of the aortic bifurcation by means of laboratory tests, imaging studies and nuclear medicine studies. Nuclear medicine was carried out with a scintigraphy with a norepinephrine analog, radioactive meta-iodo-benzyl-guanidine (131I-MIBG), which demonstrates functionally and specifically the presence of neoplastic adrenergic tissue and extratumoral extension. In addition, a positron emission tomography coupled with computed tomography with a radioactive analog of glucose locates the extratumoral activity at bone level. Nuclear medicine studies allow the diagnosis of a malignant paraganglioma with presence of bone metastasis. The therapy includes surgical removal of the tumor and ablation of residual malignant tissue and metastatic lesions by radiotherapy with 131I-MIBG. Radiotherapeutic treatment was possible due to the capacity of the tumor to uptake and to concentrate the radioactive hormonal analog. CONCLUSIONS: In cases of paraganglioma, in addition to the localization of the tumor and the evaluation of biochemical alterations, it is indispensable to obtain anatomic and functional evaluation provided by nuclear medicine studies in order to achieve appropriate diagnoses and treatment.

Differential expression of the Ebola virus GP(1,2) protein and its fragments in E. coli.

Bacterial expression platforms are frequently used for the expression and production of different recombinant proteins. The full length Ebola virus (EBOV) GP(1,2) gene and subfragments of the GP(1) gene were cloned in a bacterial expression vector as a C-terminal His(6) fusion protein. Surprisingly, the full length EBOV GP(1,2) gene could not be expressed in Escherichia coli. The subfragments of GP(1) were only expressed in small amounts with the exception of one small fragment (subfragment D) which was expressed at very high levels as inclusion bodies. This was seen even in the in vitro translation system with no expression of full length GP(1,2), GP(1) subfragments A and C and low level expression of subfragment B. Only the subfragment D showed high level of expression. In E. coli (Top10), the recombinant GP(1) subfragment D protein was expressed exclusively as an insoluble approximately 25 kDa His(6) fusion protein, which is the expected size for a non-glycosylated recombinant protein. The IMAC purified and refolded non-glycosylated protein was used to immunize mice for the development of monoclonal anti-EBOV antibodies which successfully yielded several monoclonal antibodies with different specificities. The monoclonal and polyclonal antiserum derived from the animals immunized with this recombinant GP(1) subfragment D protein was found to specifically recognize the full length glycosylated EBOV GP(1,2) protein expressed in mammalian 293T cells, thus, demonstrating the immunogenicity of the recombinant subfragment.

Mucin 1-specific immunotherapy in a mouse model of spontaneous breast cancer.

Human mucin 1 (MUC1) is an epithelial mucin glycoprotein that is overexpressed in 90% of all adenocarcinomas including breast, lung, pancreas, prostate, stomach, colon, and ovary. MUC1 is a target for immune intervention, because, in patients with solid adenocarcinomas, low-level cellular and humoral immune responses to MUC1 have been observed, which are not sufficiently strong to eradicate the growing tumor. The hypothesis for this study is that enhancing MUC1-specific immunity will result in antitumor immunity. To test this, the authors have developed a clinically relevant breast cancer model that demonstrates peripheral and central tolerance to MUC1 and develops spontaneous tumors of the mammary gland. In these mice, the authors tested a vaccine formulation comprised of liposomal-MUC1 lipopeptide and human recombinant interleukin-2. Results indicate that when compared with untreated mice, immunized mice develop T cells that express intracellular IFN-gamma, are reactive with MHC class I H-2Db/MUC1 tetramer, and are cytotoxic against MUC1-expressing tumor cells in vitro. The presence of MUC1-specific CTL did not translate into a clinical response as measured by time of tumor onset, tumor burden, and survival. The authors demonstrate that some of the immune-evasion mechanisms used by the tumor cells include downregulation of MHC-class I molecule, expression of TGF-beta2, and decrease in IFN-gamma -expressing effector T cells as tumors progress. Finally, utilizing an injectable breast cancer model, the authors show that targeting a single tumor antigen may not be an effective antitumor treatment, but that immunization with dendritic cells fed with whole tumor lysate is effective in breaking tolerance and protecting mice from subsequent tumor challenge. A physiologically relevant spontaneous breast cancer model has been developed to test improved immunotherapeutic approaches.

Evaluation of quantitative cardiac biomarker point-of-care testing in the emergency department.

This study was undertaken to evaluate the diagnostic accuracy and practicality of Emergency Department (ED) testing for cardiac biomarkers in the diagnosis of acute coronary syndromes. All patients presenting with chest pain to the ED of a community-based tertiary care facility over a 16-day period (N = 205) had blood drawn and tested for cardiac troponin I, myoglobin, and CK-MB by a quantitative, point-of-care instrument system (Stratus CS). Point-of-care cardiac testing expedited diagnosis by decreasing the turn-around time by 55% compared to the central laboratory. The extreme sensitivity of the cardiac troponin I assay integral to this system was responsible for the high diagnostic accuracy (100% sensitivity; virtually 100% specificity, compared with the final assigned diagnosis). The assay also identified a clinically significant "high-risk" zone for near-future cardiac events: 17 patients were identified and four of these progressed to further cardiac events in the next 9 months. Further studies to explore the clinical implications of this high-risk zone are warranted.