Purpose

The purpose of this study was to assess the ability of quantitative in vivo confocal microscopy (CM) to detect changes in cystine crystal volume in the cystinosisn (Ctns^−/−)mouse cornea following topical cysteamine therapy.

Methods

Fifteen Ctns^−/− mice were sequentially followed using in vivo CM from 3 to 10 months of age. In a second experiment, five mice receiving topical cysteamine eyedrops (0.55%) for 4 weeks were compared to five untreated mice. The volume of corneal cystine crystals was determined by thresholding and counting high intensity pixels in the in vivo CM scans and dividing by the stromal volume to calculate a crystal volume index (CVI).

Results

Corneal crystals progressively increased in density with age, reaching a peak density at 6–8 months and showing a 70 fold increase in CVI. Eyes treated with cysteamine drops showed significantly less crystal accumulation compared to control eyes (p<0.001) with only a 15% increase in treated eyes (p=ns) compared to 173% increase (p<0.04) for untreated eyes.

Conclusions

Measurement of CVI shows that there is a progressive increase in cystine crystal volume up to 8 months of age and that cysteamine eyedrops significantly inhibits progression in the Ctns^−/− mouse. These findings are similar to those seen clinically in patients with cystinosis, and suggest that measurement of CVI in the Ctns^−/− mouse may be used as a model to develop novel therapeutic strategies for treating corneal cystinosis.

Purpose

The purpose of this study was to assess the ability of quantitative in vivo confocal microscopy to characterize the natural history and detect changes in crystal volume in corneas from a novel animal model of cystinosis, the cystinosin (Ctns^-/-) mouse.

Methods

Two Ctns^−/− mice and one C57Bl/6 mouse were examined at each of the following time points: 2, 3, 5, 7, 10, 12, and 14 months of age. In vivo confocal microscopy scans were performed in 4 different regions of the cornea per eye. After, animals were sacrificed and cornea blocks evaluated for cell morphology using phalloidin and lymphocytic infiltration using CD45 antibodies by ex vivo confocal microscopy. Cystine crystal content in the cornea was measured by calculating the pixel intensity of the crystals divided by the stromal volume using Metamorph Image Processing Software.

Results

Corneal crystals were identified in Ctns^−/− eyes beginning at 3 months of age and increased in density until 7–12 months, at which time animals begin to succumb to the disease and corneas become scarred and neovascularized. Older Ctns^−/− mice (7 months and older) showed the presence of cell infiltrates that stained positively for CD45 associated with progressive keratocyte disruption. Finally, at 12 months of age, decreased cell density and endothelial distortion were detected.

Conclusions

Confocal microscopy identified corneal crystals starting at 3 month old Ctns^−/− eyes. Cystine crystals induce inflammatory and immune response with aging associated with loss of keratocyte and endothelial cells. These findings suggest that the Ctns^−/− mouse can be used as a model for developing and evaluating potential alternative therapies for corneal cystinosis.

Objective

Ribonucleic acids (RNA) are involved in many cellular functions. In general, RNA is made up by only four different ribonucleotides. The modifications of RNA (epitranscriptome) can greatly enhance the structural diversity of RNA, which in turn support some of the RNA functions. To determine whether the epitranscriptome of a specific probiotic is associated with its adaptation to the source of energy, Lactobacillus agilis (YZ050) was selected as a model and its epitranscriptome was profiled and compared by using mass spectrometry.

Results

The L. agilis epitranscriptome (minus rRNA modifications) consists of 17 different RNA modifications. By capturing the L. agilis cells during exponential growth, reproducible profiling was achieved. In a comparative study, the standard source of energy (glucose) in the medium was substituted by a prebiotic inulin, and a downward trend in the L. agilis epitranscriptome was detected. This marks the first report on a system-wide variation of a bacterial epitranscriptome that resulted from adapting to an alternative energy source. No correlation was found between the down-regulated RNA modifications and the expression level of corresponding writer genes. Whereas, the expression level of a specific exonuclease gene, RNase J1, was detected to be higher in cells grown on inulin.

Purpose

Blinding ocular herpetic disease in humans is due to spontaneous reactivation of herpes simplex virus type 1 (HSV-1) from latency, rather than to primary acute infection. Mice latently infected with HSV-1 undergo little or no in vivo spontaneous reactivation with accompanying virus shedding in tears. HSV-1 reactivation can be induced in latently infected mice by several in vivo procedures, with UV-B-induced reactivation being one commonly used method. In the UV-B model, corneas are scarified (lightly scratched) just prior to ocular infection to increase efficiency of the primary infection and immune serum containing HSV-1 neutralizing antibodies is injected intraperitoneally (i.p.) to increase survival and decrease acute corneal damage. Since scarification can significantly alter host gene transcription in the cornea and in the trigeminal ganglia (TG; the site of HSV-1 latency) and since injection of immune serum likely modulates innate and adaptive herpes immunity, we investigated eliminating both treatments.

Material and methods

Mice were infected with HSV-1 with or without corneal scarification and immune serum. HSV-1 reactivation and recurrent disease were induced by UV-B irradiation.

Results

When corneal scarification and immune serum were both eliminated, UV-B irradiation still induced both HSV-1 reactivation, as measured by shedding of reactivated virus in tears and herpetic eye disease, albeit at reduced levels compared to the original procedure.

Conclusion

Despite the reduced reactivation and disease, avoidance of both corneal scarification and immune serum should improve the clinical relevance of the UV-B mouse model.

Background and purpose

Neurohospitalist neurology is a fast-growing subspecialty with a variety of practice settings featuring neurohospitalist models of care. Since inception, the subspecialty has responded to new challenges in resident training, hospital reimbursement, practice, and burnout.

Methods

To characterize neurohospitalists' current practice and perspectives, we surveyed the neurohospitalists and trainees affiliated with the Neurohospitalist Society using an electronic survey distributed through the society listserv.

Results

Of 501 individuals surveyed by e-mail, 119 began the survey (23.8% response rate), with 88.2% self-identifying as neurohospitalists. Most neurohospitalists (63%) are 10 years or less out of training, devoting 70% of their professional time to inpatient clinical activities while also performing administrative or teaching activities. Only 38% are employed by an academic department. Call schedules are common, with 75% of neurohospitalists participating in a hospital or emergency call schedule, while 55% provide telemedicine services. The majority (97%) of neurohospitalists primarily care for adults, most commonly treating patients with cerebrovascular disease, seizures, and delirium/encephalopathy. The majority (87%) are overall pleased with their work, but 36% report having experienced burnout.

Conclusions

Neurohospitalists are a diverse group of neurologists primarily practicing in the inpatient setting while performing a variety of additional activities. They provide a wide array of clinical expertise for acute neurological diseases and neurological emergencies that require hospitalization, including stroke, seizure, and encephalopathy. Neurohospitalists in general are very pleased with their work, while burnout, as in neurology and other areas of medicine, remains a concern.

18F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is one of the most widely used imaging techniques to detect multiple myeloma (MM). Intracellular FDG uptake depicts in vivo metabolic activity, which can be seen in both malignant and nonmalignant cells, resulting in limited sensitivity and specificity. Our group showed preclinically that tracing MM dissemination using a CD38-directed human antibody, daratumumab, that is radioconjugated with 64Cu via the chelator DOTA (64Cu-daratumumab), led to improved sensitivity and specificity over that of FDG. Here, we report the results of a phase 1 trial designed to (1) assess the safety and feasibility of 64Cu-daratumumab PET/CT and (2) preliminarily evaluate and characterize the ability of 64Cu-daratumumab to accurately detect or exclude MM lesions. A total of 12 daratumumab-naive patients were imaged. Prior to the injection of 15 mCi/5 mg of 64Cu-daratumumab, patients were treated with 0 (n = 3), 10 (n = 3), 45 (n = 3), or 95 mg (n = 3) of unlabeled daratumumab to assess its effect on image quality. No significant adverse events were observed from either unlabeled daratumumab or 64Cu-daratumumab. Of the dose levels tested, 45 mg unlabeled daratumumab was the most optimal in terms of removing background signal without saturating target sites. 64Cu-daratumumab PET/CT provided safe whole-body imaging of MM. A trial comparing the sensitivity and specificity of 64Cu-daratumumab PET/CT with that of FDG PET/CT is planned. This trial was registered at www.clinicaltrials.gov as #NCT03311828.

Background and purpose

Therapeutic hypothermia is a potent neuroprotectant approved for cerebral protection after neonatal hypoxia-ischemia and cardiac arrest. Therapeutic hypothermia for acute ischemic stroke is safe and feasible in pilot trials. We designed a study protocol to provide safer, faster therapeutic hypothermia in stroke patients.

Methods

Safety procedures and 4°C saline infusions for faster cooling were added to the ICTuS trial (Intravascular Cooling in the Treatment of Stroke) protocol. A femoral venous intravascular cooling catheter after intravenous recombinant tissue-type plasminogen activator in eligible patients provided 24 hours cooling followed by a 12-hour rewarm. Serial safety assessments and imaging were performed. The primary end point was 3-month modified Rankin score 0,1.

Results

Of the intended 1600 subjects, 120 were enrolled before the study was stopped. Randomly, 63 were to receive hypothermia plus antishivering treatment and 57 normothermia. Compared with previous studies, cooling rates were improved with a cold saline bolus, without fluid overload. The intention-to-treat primary outcome of 90-day modified Rankin Score 0,1 occurred in 33% hypothermia and 38% normothermia subjects, odds ratio (95% confidence interval) of 0.81 (0.36-1.85). Serious adverse events occurred equally. Mortality was 15.9% hypothermia and 8.8% normothermia subjects, odds ratio (95% confidence interval) of 1.95 (0.56-7.79). Pneumonia occurred in 19% hypothermia versus 10.5% in normothermia subjects, odds ratio (95% confidence interval) of 1.99 (0.63-6.98).

Conclusions

Intravascular therapeutic hypothermia was confirmed to be safe and feasible in recombinant tissue-type plasminogen activator-treated acute ischemic stroke patients. Protocol changes designed to reduce pneumonia risk appeared to fail, although the sample is small.

Clinical trial registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01123161.