Challenges and Benefits of Repurposing Products for Use during a Radiation Public Health Emergency: Lessons Learned from Biological Threats and other Disease Treatments.

The risk of a radiological or nuclear public health emergency is a major growing concern of the U.S. government. To address a potential incident and ensure that the government is prepared to respond to any subsequent civilian or military casualties, the U.S. Department of Health and Human Services and the Department of Defense have been charged with the development of medical countermeasures (MCMs) to treat the acute and delayed injuries that can result from radiation exposure. Because of the limited budgets in research and development and the high costs associated with bring promising approaches from the bench through advanced product development activities, and ultimately, to regulatory approval, the U.S. government places a priority on repurposing products for which there already exists relevant safety and other important information concerning their use in humans. Generating human data can be a costly and time-consuming process; therefore, the U.S. government has interest in drugs for which such relevant information has been established (e.g., products for another indication), and in determining if they could be repurposed for use as MCMs to treat radiation injuries as well as chemical and biological insults. To explore these possibilities, the National Institute of Allergy and Infectious Diseases (NIAID) convened a workshop including U.S. government, industry and academic subject matter experts, to discuss the challenges and benefits of repurposing products for a radiation indication. Topics covered included a discussion of U.S. government efforts (e.g. funding, stockpiling and making products available for study), as well unique regulatory and other challenges faced when repurposing patent protected or generic drugs. Other discussions involved lessons learned from industry on repurposing pre-license, pipeline products within drug development portfolios. This report reviews the information presented, as well as an overview of discussions from the meeting.

Spontaneous cerebrospinal fluid rhinorrhea: a clinical and anatomical study.

OBJECTIVES/HYPOTHESIS: Spontaneous nasal cerebrospinal fluid (CSF) fistula represents a rare clinical entity. The possible etiology and the localization of the rhinorrhea remain an ongoing clinical challenge. The purpose of this study was to evaluate the localization of spontaneous CSF fistula and to correlate it with anatomical studies. STUDY DESIGN: Retrospective clinical study, prospective anatomical study. METHODS: Twenty-nine patients with spontaneous CSF rhinorrhea were retrospectively studied, 10 males and 19 females. Ages ranged from 10 to 92 years (mean, 50 years). In addition, 48 human skulls from newborns to adults were examined for the postnatal development of the anterior and middle cranial fossa. RESULTS: In our study isolated cribriform plate defects were found in four patients. The lateral lamina of the ethmoid bone showed defects in three patients. In nine patients the bony defect could be found in the region of the fovea ethmoidalis. The bony defect between the extra- and intracranial space was found in the lateral recess of the sphenoid sinus in eight patients. Five patients had special sites (e.g., supraorbital recess and frontal recess). CONCLUSIONS: This study supports the theory that bony dehiscence in the lateral lamina of the ethmoid bone can be congenital and can also be spontaneously acquired later. The bony dehiscence in the lateral wall of the sphenoid sinus can only develop during pneumatization.

Correlation of the Epworth Sleepiness Scale with respiratory sleep parameters in patients with sleep-related breathing disorders and upper airway pathology.

The aim of the study was to test whether a correlation between the Epworth Sleepiness Scale (ESS) and respiratory sleep parameters recorded by polysomnography (PSG) in patients with sleep-related breathing disorders and upper airway pathology exists. The PSG records of 130 patients (average age 52.6 +/- 10.7 years) with upper airway pathology suspected of having obstructive sleep apnea (OSA) have been retrospectively evaluated. Upper airway pathology included deviation of the nasal septum, inferior nasal turbinate hypertrophy, soft palate webbing, elongated uvula, tonsillar hypertrophy, macroglossia, hypertrophy of the tongue base, unfavorable palate position relative to the tongue base. To test for a possible correlation in this patient population between ESS score and arithmetic values of AHI, SPO(2), ODI and Arousal Index, the Spearman's correlation coefficient was calculated. No correlation between ESS and AHI, minimal SpO(2) and ODI was proven and only a weak positive correlation between Arousal Index and ESS was found in this particular patient population. We concluded that in patients with upper airway pathology, it is not possible to predict solely on the basis of the ESS score the existence of OSA or of other disturbances in Arousal Index, minimal SpO(2) and ODI. Nevertheless, historical data evaluated by questionnaires, such as the ESS provide for additional information combined with the clinical findings to select patients who are candidates for further detailed sleep studies.

First-night-effect on polysomnographic respiratory sleep parameters in patients with sleep-disordered breathing and upper airway pathology.

The objective of this study is to test whether there is a difference between the polysomnographic (PSG) values of Apnea-hypopnea index (AHI), minimal oxygen saturation (SpO(2)), oxygen desaturation index (ODI) and arousal index recorded on two consecutive nights (so-called "first night effect") in patients with sleep-disordered breathing (SDB) and concomitant upper airway pathology. Retrospective case-control study of polysomnographical recordings of 130 patients (112 males, 18 females, age range 23-80 years) with SDB and upper airway pathology who were tested on two consecutive nights in a hospital sleep laboratory was conducted. Only patients with upper airway pathology without other medical conditions causing SDB were included. AHI, minimal SpO(2), ODI and arousal index values of the first night were compared to those of the second night using Wilcoxon's test. There were no significant statistical differences between AHI, SpO(2), ODI and arousal index values (P = 0.130, P = 0.640, P = 0.052, and P = 0.692, respectively) between the two nights. However, 15% of the patients showed significant variability in the AHI between the two recordings and in 6% of the patients, a diagnosis of severe OSA (AHI > 10/h) would have been missed if only one night of sleep study had been performed. In general, one night of sleep study is sufficient to lead to a clear diagnosis of severe OSA in patients with sleep-disordered breathing and upper airway pathology but may still not diagnose 6% of the patients with severe OSA. Additionally, 15% of the patients showed a significant variability in the AHI between the two nights.

Noise exposure alters cyclooxygenase 1 (COX-1) and 5-lipoxygenase (5-LO) expression in the guinea pig cochlea.

CONCLUSION: Changes in the metabolism of arachidonic acid (AA) might be part of a noise-induced compensatory mechanism with regional specificity. OBJECTIVES: The released imbalance of prostaglandins and leukotrienes, both AA metabolites, might result in altered blood flow regulation in the inner ear and probably contributes to noise-induced hearing loss. The aim of this study was to gain further information about noise-dependent changes in AA metabolism in the mammalian cochlea. METHODS: In this prospective animal study, 10 male guinea pigs were exposed to tone bursts for 1 h at 70 dB sound pressure level (SPL) (n = 5) or 90 dB SPL (n = 5). Five animals were used as controls. Alterations in cyclooxygenase 1 (COX-1) and 5-lipoxygenase (5-LO) expression were determined by quantitative immunohistochemical analysis in 11 cochlear regions. RESULTS: COX-1 expression was decreased after both 70 dB SPL and 90 dB SPL exposure in most cell types of the organ of Corti and increased in the nerve fibers of the osseous spiral lamina. 5-LO was lowered after 90 dB SPL exposure, preferentially in the third cochlear turn in the organ of Corti, in the first and second turn in spiral ganglion cells, and in all turns in the stria vascularis.

Polysomnography and ApneaGraph in patients with sleep-related breathing disorders.

PURPOSE: To evaluate whether ApneaGraph (AG) and polysomnography (PSG) deliver comparable results in patients with sleep-related breathing disorders. PROCEDURES: A prospective study was performed, which included 14 patients with obstructive sleep apnea syndrome. Apnea-hypopnea index (AHI), hypopnea index (HI), apnea index (AI), obstructive, central and mixed apnea, oxygen saturation (SaO2), pulse and body position were simultaneously assessed by PSG and AG in each individual. RESULTS: There was a good correlation between measurements of AG and PSG for AHI, pulse, SaO2, body position and central apnea. However, our study showed differences between PSG and AG for AI (p = 0.002), HI (p = 0.013), mixed apnea (p = 0.003) and obstructive apnea (p = 0.013). AG indicated that 2/14 patients had a pure upper airway obstruction, 6/14 patients had a predominance of lower obstruction and 6/14 patients had a predominance of upper obstruction. CONCLUSION: AG provides comparable results for AHI, pulse, SaO2, body position and central apnea when compared to PSG, but not for the rest of the measurements. Using AG, the distribution of sites of obstructive events could be identified in this study in all of the patients.

Cochlear implantation after surgery for bilateral jugular foramen paragangliomas: a case report.

This paper describes a case of cochlear implantation for deafness due to bilateral glomus jugulare tumors (paragangliomas) as well as an unusual complication after cochlear implantation in a 31-year-old male. A 31-year-old male with profound sensorineural hearing loss on the right side and deafness on the left side, caused by bilateral jugular foramen paragangliomas, was implanted with a multi-channel cochlear implant (Combi 40+, Med-El) on the right side during subtotal petrosectomy for removal of the right-sided glomus jugulare tumor. No postoperative medical complications were observed. The patient responded to acoustic stimuli. Postoperative computed tomography (CT) did not show any misplacement of the electrode. Three years after implantation, an acute, rapidly progressive hearing impairment with pain to acoustic stimuli was observed. A CT scan at that time showed cochlear bone resorption. No radiologic evidence of paraganglioma recurrence was observed. The implant was removed and a biopsy of the cochlea was performed which on histologic examination showed fibrosis without any sign of any tumor recurrence. Cochlear implantation can restore hearing in deafness due to bilateral glomus jugulare tumors. Cochlear resorption may occur as a late complication in the implanted side in the patients.

Akt and c-Jun N-terminal kinase are regulated in response to moderate noise exposure in the cochlea of guinea pigs.

The molecular mechanisms induced in the inner ear after noise exposure are not well understood. Akt and c-Jun N-terminal kinase (JNK) are key factors of signaling pathways balancing cellular survival and apoptosis. Therefore, we analyzed the spatial distribution of Akt, JNK, their respective activated (i.e. phosphorylated) forms, p-Akt and p-JNK, as well as NF kappa B by immunohistochemistry after 70- and 90-dB noise exposure in an animal model. Alterations of the expression patterns compared to unexposed animals were quantified by a computer-based image analysis method. In unexposed specimens, Akt, p-Akt, JNK, p-JNK were found to be commonly expressed in different regions of the cochlea, whereas NF kappa B was exclusively restricted to the lateral wall. After noise stimulation, the expression of the different molecules was downregulated with the exception of JNK. JNK remained largely unchanged or increased JNK levels were identified in ganglion cells and Schwann cells after 70 dB as well as in the unstained nerve fibers. The stable or increasing levels of JNK might be indicative of a preapoptotic state. The downregulation of Akt in the cochlea might support these activities. p-Akt was not reduced in the spiral ganglion cells after 90-dB exposure and was upregulated in the unstained nerve fibers, probably indicating a counteracting prosurvival cellular reaction in these tissues. In conclusion, we suggest that the observed alterations in both the Akt and JNK pathways are part of a noise distress-induced response indicating pro- and antiapoptotic activities in the different tissues of the cochlea.

Fast alterations of vascular endothelial growth factor (VEGF) expression and that of its receptors (Flt-1, Flk-1 and Neuropilin) in the cochlea of guinea pigs after moderate noise exposure.

Vascular endothelial growth factor (VEGF) is a vascular permeability regulating, proangiogenic factor with neuroprotective properties. Its expression in the inner ear has been demonstrated, but little is known concerning its subcellular distribution or potential involvement in sound perception and adaptation to noise. Therefore, we determined the expression patterns and levels of VEGF and the three VEGF-receptors FLK, FLT and Neuropilin in the cochlea of guinea pigs, and examined the alterations occurring after noise exposure. After 70 dB exposure, VEGF expression was found to be reduced in all cell types of the organ of Corti, in the stria vascularis and in spiral ganglion cells. Additional down-regulation was observed in the spiral ligament and in interdental cells after 90 dB. In contrast, VEGF showed an in tendency increased level after both intensities in nerve fibers of the osseous spiral lamina. Expression of FLT was affected similarly, showing down-regulation after 70 and 90 dB on spiral ganglion cells, the nerve fibers of the osseous spiral lamina and on Deiters cells. Additionally, down-regulation was observed in the remaining cell types of the organ of Corti, the stria vascularis, the spiral ligament and the interdental cells. The Neuropilin levels remained unchanged by our experiments; apart from the blood vessel endothelium, there was no detectable expression in any of the cell types investigated. The FLK expression pattern was likewise unaffected by exposure to 70 or 90 dB, with the notable exception of an increased level occurring in Schwann cells after 90 dB. We postulate that modulation of VEGF and its receptors may be part of a neuroprotective mechanism in response to noise.

Endothelial nitric oxide synthase upregulation in the cochlea of the guinea pig after intratympanic gentamicin injection.

Single-shot transtympanic gentamicin therapy has become a popular treatment modality for Meniere's disease despite the known possible ototoxic properties of this drug. It was shown recently that NO production and iNOS were upregulated after gentamicin application, which was interpreted as a possible effect of ototoxicity. In this study we analyzed the expression of eNOS after gentamicin application to determine a possible correlation of this enzyme with gentamicin-induced ototoxicity. We compared eNOS expression in gentamicin-treated and non-treated guinea pigs in the second turn of the cochlea, an area corresponding to speech perception in humans. Gentamicin (4 mg) was injected intratympanically into the middle ear of guinea pigs ( n =3) and the reduction of the hearing threshold level was determined by recording acoustic-evoked potentials (AEP) before and 5 days after gentamicin application. Morphological alterations in the organ of Corti were analyzed by light and electron microscopy. Gold-labeled anti-eNOS antibodies were counted in eight different cell areas for quantification of eNOS expression. Seven animals were analyzed as controls. After gentamicin application, a deterioration of hearing level was observed varying from 10 to 30 dB. A high degree of vacuolization was identified in the third row of outer hair cells. At the subcellular level, the subsurface cisterns in outer hair cells were dissociated from the basolateral cell membrane, and the mitochondrial membranes were frequently damaged. Statistically significant upregulation of eNOS was observed in all cell types analyzed. Depending on the various cell types the amount of gold-labeled eNOS antibodies was 2.5 to 5.7 times higher after gentamicin application. We observed significant eNOS upregulation after gentamicin application in the cochlea, in conjunction with cellular damages and decreased hearing.

COX-2 expression in the guinea pig cochlea is partly altered by moderate sound exposure.

The cyclooxygenase-2 isoform (COX-2) was found recently to be constitutively expressed in the guinea pig inner ear. To gain knowledge about its role in sound perception, alterations in the COX-2 level of moderate noise-stimulated cochleae were determined. Staining intensities were quantified in different regions using an immunohistochemical staining procedure and computer-assisted system. After 70 dB and 90 dB noise exposure for 1 h at 8000 Hz, COX-2 downregulation was observed in the organ of Corti, which was most prominent in Deiters' cells near Hensen cells and outer hair cells. In pillar cells, COX-2 levels were only slightly reduced after 70 dB but strongly diminished after 90 dB exposure. In Hensen cells, COX-2 was downregulated after 70 dB stimulation, revealing a decreasing COX-2 content from the third to the first turn of the cochlea and a homogeneously reduced enzyme expression in all three turns after 90 dB. The COX-2 content in inner hair cells was nearly identical to unexposed cochleae after 70 dB exposure but significantly reduced after 90 dB stimulation. In spiral ganglion cells, stria vascularis, spiral ligament and limbus, COX-2 expression was unchanged after 70 dB and 90 dB. We suggest that alterations in COX-2 expression might contribute to diminished sensitivity at the cochlea after noise exposure to reduce subsequent noise distress, termed sound conditioning.

Endothelial nitric oxide synthase upregulation in the guinea pig organ of Corti after acute noise trauma.

Endothelial nitric oxide synthase (eNOS) upregulation was identified 60 h after acute noise trauma in morphologically intact cells of the reticular lamina in the organ of Corti of the guinea pig in the second turn of the cochlea. Using gold-coupled anti-eNOS antibodies and electron microscopy, it was shown that eNOS expression was upregulated in all cell areas and cell types except inner hair cells. Furthermore, eNOS was found in the organelle-free cytoplasm and in mitochondria of various cell types. The density of eNOS in mitochondria was considerably higher compared with the surrounding cytoplasm. Since eNOS activity is regulated by calcium, the eNOS detection was combined with calcium precipitation, a method for visualizing intracellular Ca2+ distribution. After acute noise trauma, intracellular Ca2+ was increased in all cell types and cell areas except in outer hair cells. Comparing the distribution patterns of eNOS and calcium, significantly elevated levels (P < 0.0001) of eNOS were detected within a 100 nm radius near calcium precipitates in all cuticular structures as well as microtubule-rich regions and Deiters' cells near Hensen cells. The observed colocalization lends support to the postulated mechanism of eNOS activation by Ca2+. eNOS upregulation after acute noise trauma might therefore be part of an induced stress response. The eNOS upregulation in cell areas with numerous microtubule- and actin-rich structures is discussed with respect to possible cytoskeleton-dependent processes in eNOS regulation.