A near-infrared probe for non-invasively monitoring cerebrospinal fluid flow by 18F-positron emitting tomography and fluorescence.

PURPOSE: Knowing the precise flow of cerebrospinal fluid (CSF) is important in the management of multiple neurological diseases. Technology for non-invasively quantifying CSF flow would allow for precise localization of injury and assist in evaluating the viability of certain devices placed in the central nervous system (CNS). METHODS: We describe a near-infrared fluorescent dye for accurately monitoring CSF flow by positron emission tomography (PET) and fluorescence. IR-783, a commercially available near-infrared dye, was chemically modified and radiolabeled with fluorine-18 to give [18F]-IR783-AMBF3. [18F]-IR783-AMBF3 was intrathecally injected into the rat models with normal and aberrant CSF flow and evaluated by the fluorescence and PET/MRI or PET/CT imaging modes. RESULTS: IR783-AMBF3 was clearly distributed in CSF-containing volumes by PET and fluorescence. We compared IR783-AMBF3 (fluorescent at 778/793 nm, ex/em) to a shorter-wavelength, fluorescein equivalent (fluorescent at 495/511 nm, ex/em). IR783-AMBF3 was superior for its ability to image through blood (hemorrhage) and for imaging CSF-flow, through-skin, in subdural-run lumboperitoneal shunts. IR783-AMBF3 was safe under the tested dosage both in vitro and in vivo. CONCLUSION: The superior imaging properties of IR783-AMBF3 could lead to enhanced accuracy in the treatment of patients and would assist surgeons in non-invasively diagnosing diseases of the CNS.

A lysosome specific, acidic-pH activated, near-infrared Bodipy fluorescent probe for noninvasive, long-term, in vivo tumor imaging.

Long-term, in vivo, fluorescent cell tracking probes are useful for understanding complex cellular processes including tissue regeneration, communication, development, invasion, and cancer metastasis. A near-infrared fluorescent, water-soluble probe is particularly important for studying these biological events and processes. Herein, a lysosome specific, near-infrared Bodipy probe with increased fluorescent intensity in the acidic, lysosome environment is reported. This Bodipy probe is packaged in a nanoparticle using DSPE-PEG2000. The resulting nanoparticle is intravenously delivered to a tumor xenograft, where the fluorescent Bodipy becomes useful for non-invasive, long-term, in vivo fluorescent tumor imaging for periods greater than 36 days. These long-term, in vitro and in vitro tracking data indicate that the described Bodipy nanoparticles hold great potential for monitoring biological processes.

An [18F]-Positron Emitting Fluorophore Allows Safe Evaluation of Small Molecule Distribution in the CSF, CSF Fistulas, and CNS Device Placement.

The small molecule fluorescein is commonly used to guide the repair of cerebral spinal fluid leaks (CSFLs) in the clinic. We modified fluorescein so that it is also visible by positron emission tomography (PET). This probe was used to quantitatively track the fast distribution of small molecules in the CSF of rats. We tested this probe in models relevant to the clinical diagnosis and treatment of central nervous system (CNS) diseases that affect CSF flow. In this study, fluorescein was radiolabeled with fluorine-18 to produce Fc-AMBF3. [18/19F]-Fc-AMBF3 was introduced at trace quantities (13.2 nmols, 100 µCi) intrathecally (between L5 and L6) in rats to observe the dynamic distribution and clearance of small molecules in the CSF by both [18F]-PET and fluorescence (FL) imaging. Murine models were used to demonstrate the following utilities of Fc-AMBF3: (1) utility in monitoring the spontaneous CSFL repair of a compression fracture of the cribriform plate and (2) utility in quantifying CSF flow velocity during neurosurgical lumboperitoneal shunt placement. Fc-AMBF3 clearly delineated CSF-containing volumes based on noninvasive PET imaging and in ex vivo FL histology. In vivo morbidity (n = 16 rats, <2.7 mg/kg, 77 times the PET dose) was not observed. The clearance of the contrast agent from the CNS was rapid and quantitative (t1/2 = 33.8 ± 0.6 min by FL and t1/2 = 26.0 ± 0.5 min by PET). Fc-AMBF3 was cleared from the CSF through the vasculature and/or lymphatic system that supplies the cribriform plate and the temporal bone. Fc-AMBF3 can be used to diagnose CSFLs, image CSFL repair, and determine the CSF flow velocity in the CNS or through lumboperitoneal shunts by PET/FL imaging. In conclusion, Fc-AMBF3 PET imaging has been demonstrated to safely and dynamically quantitate CSF flow, diagnose fistulas associated with the CSF space, and approximate the clearance of small molecules in the CSF.

A Fluorescent, [18F]-Positron-Emitting Agent for Imaging Prostate-Specific Membrane Antigen Allows Genetic Reporting in Adoptively Transferred, Genetically Modified Cells.

Clinical trials involving genome-edited cells are growing in popularity, where CAR-T immunotherapy and CRISPR/Cas9 editing are more recognized strategies. Genetic reporters are needed to localize the molecular events inside these cells in patients. Specifically, a nonimmunogenic genetic reporter is urgently needed as current reporters are immunogenic due to derivation from nonhuman sources. Prostate-specific membrane antigen (PSMA) is potentially nonimmunogenic due to its natural, low-level expression in select tissues (self-MHC display). PSMA overexpression on human prostate adenocarcinoma is also visible with excellent contrast. We exploit these properties in a transduced, two-component, Human-Derived, Genetic, Positron-emitting, and Fluorescent (HD-GPF) reporter system. Mechanistically analogous to the luciferase and luciferin reporter, PSMA is genetically encoded into non-PSMA expressing 8505C cells and tracked with ACUPA-Cy3-BF3, a single, systemically injected small molecule that delivers positron emitting fluoride (18F) and a fluorophore (Cy3) to report on cells expressing PSMA. PSMA-lentivirus transduced tissues become visible by Cy3 fluorescence, [18F]-positron emission tomography (PET), and γ-scintillated biodistribution. HD-GPF fluorescence is visible at subcellular resolution, while a reduced PET background is achieved in vivo, due to rapid ACUPA-Cy3-BF3 renal excretion. Co-transduction with luciferase and GFP show specific advantages over popular genetic reporters in advanced murine models including, a "mosaic" model of solid-tumor intratumoral heterogeneity and a survival model for observing postsurgical recurrence. We report an advanced genetic reporter that tracks genetically modified cells in entire animals and with subcellular resolution with PET and fluorescence, respectively. This reporter system is potentially nonimmunogenic and will therefore be useful in human studies. PSMA is a biomarker of prostate adenocarcinoma and ACUPA-Cy3-BF3 potential in radical prostatectomy is demonstrated.

An [18F]-Positron-Emitting, Fluorescent, Cerebrospinal Fluid Probe for Imaging Damage to the Brain and Spine.

Fluorescein is modified to bear 18F so that it can act as both a positron emitter, and a fluorophore, allowing detection by positron emission tomography (PET), scintillation, and fluorescent imaging (FL). [18F]-2 is injected into the intrathecal space of rats and used to observe the cerebrospinal fluid (CSF) that bathes the brain and spine. Injury in three different applications is visualized with [18F]-2: 1) detection of a 0.7 mm paranasal-sinus CSF leak (CSFL); 2) detection of 0.5 mm puncture damage to the thoracic spine (acute spinal cord injury); and 3) detection of intracerebral hemorrhage/edema because of traumatic brain injury. In all models, the location of injury is visualized with [18F]-2 at high resolution. [18F]-2 PET imaging may be a superior alternative to current clinical contrast myelography and 131I, 111In or 99mTc radionuclide cisternography. Like fluorescein, [18F]-2 may also have other uses in diagnostic or fluorescence guided medicine.

Diagnosis of vocal fold paresis: current opinion and practice.

OBJECTIVES/HYPOTHESIS: No accepted standard exists for the diagnosis of vocal fold paresis (VFP). Laryngeal specialists are surveyed to establish expert opinion on diagnostic methodology and criteria. STUDY DESIGN: Cross-sectional survey. METHODS: Questionnaires were distributed at laryngology conferences in fall 2013. Responses were collated anonymously and subjected to cross-tabulated data analysis. RESULTS: Fifty-eight responses completed by posttraining physicians whose practice focused in laryngology ≥ 75% were analyzed. One (1.7%) relied principally on laryngeal electromyography, one (1.7%) on history, 10 (17%) on laryngoscopy, and 42 (72%) on strobovideolaryngoscopy for diagnosis. Only 12 (21%) performed laryngeal electromyography on > 50% of vocal fold paresis patients. Laryngeal electromyography sensitivity was considered moderate (61 ± 3.7%, σ = 28). Laryngoscopic/stroboscopic findings considered to have the strongest positive predictive value for VFP were slow/sluggish vocal fold motion (75 ± 3.0%, σ = 23), decreased adduction (67 ± 3.5%, σ = 27), decreased abduction (65 ± 3.4%, σ = 26), and decreased vocal fold tone (61 ± 3.5%, σ = 26). Asymmetric mucosal wave amplitude (52 ± 4.2%, σ = 32), asymmetric mucosal wave phase (60 ± 4.1%, σ = 31), hemilaryngeal atrophy (60 ± 4.0%, σ = 31), and asymmetric mucosal wave frequency (49 ± 4.0%, σ = 30) generated greatest disagreement. CONCLUSIONS: Surveyed expert laryngologists diagnose vocal fold paresis predominantly on stroboscopic examination. Gross motion abnormalities had the highest positive predictive value. Laryngeal electromyography was infrequently used to assess for vocal fold paresis.

Impact of fundal extension on hearing after surgery for vestibular schwannomas.

OBJECTIVE: To compare hearing preservation after surgery for intracanalicular vestibular schwannomas with or without fundal extension. STUDY DESIGN: Retrospective chart review. PATIENTS: Patients with intracanalicular tumors (≤ 10-m maximal dimension) undergoing retrosigmoid craniotomy between 2001 and 2010. INTERVENTION: Preoperative and postoperative audiograms, preoperative magnetic resonance imaging, and operative reports were reviewed. MAIN OUTCOME MEASURES: Preoperative and postoperative hearing (American Academy of Otolaryngology-Head and Neck Surgery classification). RESULTS: Complete data for 53 patients (27 female and 24 male subjects, sex was not recorded for 2 patients) meeting selection criteria was available. Fundal involvement was identified in 39 (73.6%) of the 53 patients. The remaining 14 patients did not have tumor with fundal extension (26.4%). Average tumor size for patients with fundal extension (+FE) was 6.9 ± 2.2 mm and without fundal extension (-FE) was 8.2 ± 1.9 mm (p = 0.05, Student's t test). Average preoperative speech discrimination score for the entire study was 90.5 ± 11.8 (n = 53). After retrosigmoid approach for tumor resection, 79% of patients (42/53) had preserved hearing defined as American Academy of Otolaryngology-Head and Neck Surgery class A, B, or C. Average postoperative speech discrimination score for these patients was 89.3 ± 12.1, and average postoperative pure-tone average was 35.9 ± 9.1%. Eighty-five percent (33/39) of +FE patients had preserved hearing (class A, B, or C). In contrast, 64% (9/14) of -FE patients had hearing preserved (class A, B, or C; Fisher's exact test, p = 0.034). CONCLUSION: Hearing preservation rate after retrosigmoid craniotomy for intracanalicular vestibular schwannomas may be superior for tumors with fundal extension compared with tumors that do not extend to the fundus.

Improved facial nerve identification with novel fluorescently labeled probe.

OBJECTIVES/HYPOTHESIS: By phage display, we have developed a novel peptide (NP41) that binds selectively to nerves following systemic administration. We evaluated the pattern of facial nerve labeling with fluorescently-labeled NP41 (F-NP41). We also tested whether F-NP41 highlights facial nerves well enough to identify nerve stumps accurately several weeks after nerve transection. STUDY DESIGN: Forty-seven wild-type mice were studied prospectively. One surgeon performed the nerve transection, reanastomosis, and monitoring of functional recovery. METHODS: Fluorescent labeling: F-NP41 was administered intravenously (20 mice). Nerve labeling was studied with fluorescence microscopy. Transection and reanastomosis: the right facial nerve was transected (25 mice). Three weeks after transection, F-NP41 was administered intravenously and fluorescence microscopy was used to identify the nerve stumps and reanastomosis in one group. Nerve identification and reanastomosis was performed with white light in another group without F-NP41. The control group underwent sham surgery. Time to nerve identification was recorded. Functional recovery was monitored for at least 8 weeks. RESULTS: We found excellent labeling of intact and transected facial nerves following F-NP41 administration. Several weeks following nerve transection, F-NP41 provided accurate identification of the proximal and distal nerve stumps. Following reanastomosis, time to recovery and level of functional recovery was similar in the absence and presence of F-NP41. CONCLUSIONS: We show improved visualization of facial nerves with a novel systemically applied fluorescently labeled probe. Use of F-NP41 resulted in accurate identification of facial nerve stumps several weeks following transection. Functional recovery was similar with and without the use of F-NP41.

Vitreitis and movement disorder associated with neurosyphilis and human immunodeficiency virus (HIV) infection: case report.

In this report, we describe an unusual patient with a choreiform movement disorder, misdiagnosed as Huntington disease, who later developed dense vitreitis leading to the identification of Treponema pallidum as the underlying pathogen of both abnormalities.

Vitreitis and movement disorder associated with neurosyphilis and human immunodeficiency virus (HIV) infection: case report / Vitreíte e distúrbio motor associados à neurosífilis e infecção pelo vírus da imunodeficiência humana (HIV): relato de caso

In this report, we describe an unusual patient with a choreiform movement disorder, misdiagnosed as Huntington disease, who later developed dense vitreitis leading to the identification of Treponema pallidum as the underlying pathogen of both abnormalities.

Neste relato descrevemos um caso infreqüente de um paciente com quadro de distúrbio motor coreiforme diagnosticado equivocadamente como doença de Huntington, o qual posteriormente desenvolveu quadro de intensa vitreíte, possibilitando a identificação do Treponema pallidum como o patógeno causador de ambas anormalidades.

Detection of colonic dysplasia in vivo using a targeted heptapeptide and confocal microendoscopy.

A combination of targeted probes and new imaging technologies provides a powerful set of tools with the potential to improve the early detection of cancer. To develop a probe for detecting colon cancer, we screened phage display peptide libraries against fresh human colonic adenomas for high-affinity ligands with preferential binding to premalignant tissue. We identified a specific heptapeptide sequence, VRPMPLQ, which we synthesized, conjugated with fluorescein and tested in patients undergoing colonoscopy. We imaged topically administered peptide using a fluorescence confocal microendoscope delivered through the instrument channel of a standard colonoscope. In vivo images were acquired at 12 frames per second with 50-microm working distance and 2.5-microm (transverse) and 20-microm (axial) resolution. The fluorescein-conjugated peptide bound more strongly to dysplastic colonocytes than to adjacent normal cells with 81% sensitivity and 82% specificity. This methodology represents a promising diagnostic imaging approach for the early detection of colorectal cancer and potentially of other epithelial malignancies.

Posttraumatic anosmia secondary to central nervous system injury.

BACKGROUND: The presumed pathogenesis of posttraumatic anosmia is stretching or shearing of the olfactory nerves in a coup-contracoup head contusion. Direct injury to the brain is an alternate mechanism of injury. In this study we report a case where direct injury to the brain is the probable mechanism of injury. METHODS: A case report was performed. RESULTS: A 55-year-old man presented with loss of smell beginning 1 month after a closed head injury with loss of consciousness. The MRI showed posttraumatic scarring in the region of the olfactory bulbs. CONCLUSION: This case suggests that central nervous system injury to the olfactory bulbs and tracts may be a mechanism of posttraumatic anosmia.

Use of traditional medicine by immigrant Chinese patients.

BACKGROUND: Chinese immigrants constitute the largest group of foreign-born Asians living in the United States. Knowledge of their use of traditional Chinese medicine (TCM) is limited. A survey was conducted to determine their TCM use and to evaluate physician awareness of these practices. METHODS: Structured interviews were conducted with 198 Chinese immigrant patients, and a survey was administered to 17 physicians in two federally funded community health clinics. RESULTS: Nearly 100% of the patients had used TCM during the previous year, mostly for musculoskeletal or abdominal pain, fatigue, and health maintenance. Self-medication with herbal products was the most common (93% at least once, 43% weekly). A smaller number (23%) had used herbs prescribed by a TCM provider. Use of acupuncture was less common (14%), although higher than the national average. Most patients indicated a preference to consult Western physicians for acute infections. Only 5% reported that their physicians had ever asked about their use of TCM. By contrast, 77% of physicians reported that they "usually or sometimes" asked about TCM use. CONCLUSIONS: Results suggest that these patients used TCM, primarily self-prescribed over-the-counter herbal preparations, for many health problems. Information about use was not shared with their physicians, nor did patients perceive their doctors as soliciting sufficient information on TCM use. Physician education in this area may be warranted.