Dynamic PET Reveals Compartmentalized Brain and Lung Tissue Antibiotic Exposures

Tuberculosis (TB) remains a leading cause of death, but antibiotic treatments for tuberculous meningitis, the deadliest form of TB, are based on those developed for pulmonary TB and not optimized for brain penetration. Here, we performed first-in-human dynamic 18F-pretomanid positron emission tomography (PET) studies in eight human subjects for three-dimensional, multi-compartmental in situ visualization of antibiotic concentration-time exposures (area under the curve - AUC), demonstrating preferential brain (AUCtissue/plasma 2.25) versus lung (AUCtissue/plasma 0.97) tissue partitioning. Preferential, antibiotic-specific partitioning into brain or lung tissues of antibiotics active against MDR strains were confirmed in experimentally-infected mice and rabbits, using dynamic PET with chemically identical antibiotic radioanalogs, and postmortem mass spectrometry measurements. PET-facilitated pharmacokinetic modeling predicted human dosing necessary to attain therapeutic brain exposures in human subjects. These data were used to design optimized, pretomanid-based regimens which were evaluated at human equipotent dosing in a mouse model of TB meningitis, demonstrating excellent bactericidal activity without an increase in intracerebral inflammation or brain injury. Importantly, several antibiotic regimens demonstrated discordant activities in brain and lung tissues in the same animal, correlating with the compartmentalized tissue exposures of the component antibiotics. These data provide a mechanistic basis for the compartmentalized activities of antibiotic regimens, with important implications for the development of antimicrobial regimens for meningitis and other infections in compartments with unique antibiotic penetration.

Who are the most vulnerable populations for primary care? Avoidable hospitalizations across individuals with different types of disabilities in South Korea

BACKGROUND

Individuals with disabilities have limited access to primary care, the quality of care must be examined.

OBJECTIVE

To examine avoidable hospitalizations among individuals with disabilities and determine the most vulnerable populations across types of disabilities.

METHODS

Using the Korean National Health Insurance Claims Database, we compared hypertension- and diabetes-related avoidable hospitalizations (HRAH and DRAH, respectively) across disability status and disability type based on age-sex standardized rates from 2011 to 2020 and logistic regression.

RESULTS

The gap between those with and without disabilities in age-sex standardized HRAH and DRAH increased over 10 years. Odds ratios for HRAH were higher for those with disabilities, with individuals with mental disabilities having the highest odds ratio, followed by those with intellectual/developmental disabilities, then those with physical disabilities; for DRAH, the three highest odds ratios belonged to individuals with mental, intellectual/developmental, and visual disabilities. Among those with disabilities, HRAH was higher for those with mental, intellectual/developmental, and severe physical disabilities, whereas DRAH was higher for those with mental, severe visual, and intellectual/developmental disabilities compared to those with mild physical disabilities.

CONCLUSION

This study reveals high avoidable hospitalization rates among individuals with disabilities and calls for policies supporting quality primary care and comprehensively addressing disparities.

0785 Associations Between Circadian Preference And Sleep-related Thoughts: Data From The 2015 Sleep In America Poll

Introduction

Evening types of sleep tend to have poorer sleep quality and sleep habits than morning types. Maladaptive beliefs or thoughts about sleep can affect one’s sleep and may differ between evening and morning types. We examined the association between the circadian preference and sleep-related thoughts in U.S adults.

Methods

A secondary analysis used survey data from the 2015 National Sleep Foundation’s Sleep in America Poll. Questions included normal bedtime and wake-up time for week/work days and weekend/non-work days. Circadian preference was determined by midpoint of sleep calculated as midpoint of sleep on weekends corrected for average nightly sleep duration. Participants were excluded if their sleep midpoint was from noon to midnight. Midpoint of sleep was divided into two groups using median split (“earlier” vs. “later”). Sleep-related thoughts were “worry about getting a good sleep”, “overwhelming thoughts about getting enough sleep”, “motivation to get sleep”, and “concern about serious physical consequences due to poor sleep”; responded often/always or extremely to somewhat for these items were coded as maladaptive. Logistic regression analysis controlling for socio-demographics, sleep duration, and sleep disturbance (PROMIS Scale; higher scores = greater sleep disturbance) was conducted to examine the relationships between midpoint of sleep and sleep-related thoughts.

Results

The sample (N = 1011) was primarily White (73.6%), male (50.9%), college educated (62.2%), married/partnered (67.6%) with a mean age of 51.65 ± 17.05 years. Mean midpoint of sleep in “earlier” type was 2:33AM and 5:29AM in “later” type. “Later” type had shorter sleep duration on weekdays and longer sleep duration on weekends than “earlier” type (p < .01), but average sleep duration was similar between two types. “Later” type had more “worry” and “overwhelming thoughts” (p < .05) about sleep. In logistic models, midpoint of sleep was significant only for “concern” (p = .02).

Conclusion

In this study, late chronotype was associated with increased sleep disturbances and greater variability in sleep duration. The relationship between the timing of sleep and thoughts about the impact of impaired sleep remains unclear and an area for further study with objective measures.

Support

 

0829 Sleep, Chronic Pain, and Global Health in Adults Ages 65 or Older

Introduction

Understanding the association of sleep and pain in older adults can help improve their global health. The purpose of the study was to describe the associations between sleep, chronic pain, and global health in adults ages 65 or older.

Methods

This study was a secondary analysis of data from adults over 65 years in the 2015 Sleep in America Poll - Sleep and Pain by the National Sleep Foundation (NSF). The survey included demographics (age, race, marital status, education), sleep (duration, quality, insomnia symptoms), and pain (type [none, chronic, fleeting], intensity, location). Global health derived from general health, physical health, mental health, and quality of life with a potential range of 4-20; higher score=better health. The survey also queried fatigue and stress.

Results

The sample (N=248) was 65-91 years (mean age=72.8±5.9), male (53.6%), White (82.7%), married (65.7%), and with post-highschool education (54.4%). Average sleep duration was 425±74 minutes. “No pain” was reported by 38.7% of the sample (n=96), “fleeting pain” by 32.7% (n= 81), and “chronic pain” by 28.6% (n=71). The most common locations for chronic pain were shoulder or neck (63.2%) and back (69.4%). Average global health score was 9.8±2.9. There was no significant difference in time in bed, sleep duration, bedtime, or wake-up time between groups. Persons with chronic pain had higher average pain intensity, worst pain intensity, and current pain; they reported significantly lower sleep quality with significantly more restlessness, trouble staying asleep, and worry about getting a good night sleep (all p-values<.02), there was no significant difference in difficulty falling asleep compared to persons with no pain. Persons with chronic pain had significantly worse general health, physical health, mental health, global health, fatigue, and stress (all p-values<.02); but no significant difference in quality of life compared to persons with no pain.

Conclusion

We conclude that chronic pain has a significant negative impact on sleep and global health in the sample of adults ages 65 or older from the 2015 Sleep in America Poll - Sleep and Pain by the NSF.

Support

Undergraduate Research Mentoring Program, University of Pittsburgh School of Nursing.

Protection of spermatogenesis against gamma ray-induced damage by granulocyte colony-stimulating factor in mice

The radioprotective effects of granulocyte colony-stimulating factor (GCSF) were further investigated with respect to the testicular system. Recombinant human GCSF (100 μg kg(-1) body weight/day) was administrated to male C3H/HeN mice by subcutaneous injection for three consecutive days before pelvic irradiation (5 Gy) and histopathological parameters were assessed at 12 h and 21 days post-irradiation (pi). The GCSF protected the germ cells from radiation induced- apoptosis (P < 0.01 vs. irradiated group at 12 h pi). GCSF remarkably attenuated radiation-induced reduction in testis weight, seminiferous tubular diameter, seminiferous epithelial depth and sperm head count in the testes (P < 0.05 versus irradiated group at 21 days pi). Repopulation index and stem cell survival index of the seminiferous tubules were increased in the GCSF-treated group when compared with the radiation group (P < 0.01). The frequency of abnormal sperm in the GCSF group was lower than that in the irradiated group at 21 days pi (P < 0.01). The decrease in the sperm count and in sperm liability in the epididymis caused by irradiation was counteracted by GCSF. The present study suggests that GCSF protects from radiation-induced testicular dysfunction via an anti-apoptotic effect and recovery of spermatogenesis.

Combustion characteristics of simulated gas fuel in a 30 kg/h scale pyrolysis-melting incinerator

Combustion characteristics of gas fuel in a pyrolysis-melting incinerator having a 30 kg/h capacity were investigated. Pyrolyzed gas from waste was simulated by propane that was injected in the combustion chamber, and burnt through multi-staged combustion by distributing the combustion air to primary, secondary, and tertiary air nozzles. Temperatures and the concentrations of gas components in the combustion chamber were measured. Combustion performance was evaluated with respect to the temperature distribution and combustion gas concentrations of O2, CO and NOx. Using secondary air and/or tertiary air, the combustion performance was improved, and, in particular, NOx concentration decreased significantly following the tertiary air injection.

Energy relaxation rates in dense hydrogen plasmas

A comprehensive study is made of the energy relaxation rates between ions and electrons in a dense hydrogen plasma. Results of classical molecular dynamics (MD) simulations are compared with quantal calculations using the Fermi golden rule and using dimensional continuation. The rates from the molecular dynamics simulations employing a screened potential are found to be in reasonable agreement with the Landau-Spitzer relaxation rates, and are around 30% higher than the Fermi golden rule rates. By inverting the classical MD relaxation rate vs the quantal result, a semiclassical value for the screening length is suggested. We present energy relaxation rates relevant for radiation-hydrodynamic simulations of inertial confinement fusion devices.

Dopamine transporter density is decreased in parkinsonian patients with a history of manganese exposure: what does it mean?

Manganese (Mn) exposure can cause parkinsonism. Pathological changes occur mostly in the pallidum and striatum. Two patients with a long history of occupational Mn exposure presented with Mn-induced parkinsonism. In one patient, magnetic resonance imaging (MRI) showed findings consistent with Mn exposure, and Mn concentration was increased in the blood and urine. However, this patient's clinical features were typical of idiopathic Parkinson disease (PD). Previous pathological and positron emission tomography studies indicate that striatal dopamine transporter density is normal in Mn-induced parkinsonism, whereas it is decreased in PD. Therefore, we performed [(123)I]-(1r)-2 beta-carboxymethoxy-3beta-(4-iodophenyl)tropane ([(123)I]-beta-CIT) single-photon emission computed tomography. Severe reduction of striatal beta-CIT binding was indicated, which is consistent with PD. We propose three interpretations: (1) the patients have PD, and Mn exposure is incidental; (2) Mn induces selective degeneration of presynaptic dopaminergic nerve terminals, thereby causing parkinsonism; or (3) Mn exposure acts as a risk of PD in these patients. Our results and careful review of previous studies indicate that the axiom that Mn causes parkinsonism by pallidal lesion may be over-simplified; Mn exposure and parkinsonism may be more complex than previously thought. Further studies are required to elucidate the relationship between Mn and various forms of parkinsonism.

High level expression of Thermococcus litoralis 4-alpha-glucanotransferase in a soluble form in Escherichia coli with a novel expression system involving minor arginine tRNAs and GroELS

The Thermococcus litoralis 4-alpha-glucanotransferase (GTase) gene has a high content of AGA and AGG codons for arginine, which are extremely rare in Escherichia coli. Expression of the GTase gene in E. coli resulted in low protein production and the accumulation of inclusion bodies. However, simultaneous expression of GTase with tRNA(AGA), tRNA(AGG) and GroELS affected both the production and solubility of GTase, and production of soluble GTase increasing about 5-fold. This new E. coli expression system should be applicable to the expression of not only archaeal but also eukaryotic genes, which usually contain a large number of AGA and AGG codons.

Dopamine transporter imaging with [123I]-beta-CIT demonstrates presynaptic nigrostriatal dopaminergic damage in Wilson's disease

OBJECTIVES

The most common neurological manifestations in Wilson's disease are parkinsonism and dystonia. These are assumed to be due to striatal injury, which has been repeatedly demonstrated by pathology and CT or MRI. The substantia nigra has not been shown to be damaged in pathological studies. However, there have been clinical and imaging studies suggesting presynaptic nigrostriatal injury. (1r)-2Beta-carbomethoxy-3beta-(4-iodophenyl)tropane (beta-CIT) is a specific ligand that binds to the dopamine transporter (DAT), and can examine the integrity of dopaminergic nerve terminals. Evidence for presynaptic nigrostriatal dopaminergic damage in Wilson's disease was searched for using [123I]-beta-CIT SPECT.

METHODS

Six patients with Wilson's disease were studied, together with 15 healthy normal controls, and six patients with Parkinson's disease. After injection of [123I]-beta-CIT, SPECT studies were done at 18 hours. Specific striatal/occipital binding ratio (S/O ratio) was calculated as (striatal binding-occipital binding)/occipital binding.

RESULTS

The specific S/O ratios were 6.22 (1.32) (mean (SD)) in normal volunteers, 3.78 (0.65) in Parkinson's disease, and 3.60 (0.49) in Wilson's disease.

CONCLUSION

There was severe loss of the DAT in the striatum suggesting significant damage in presynaptic nigrostriatal dopaminergic nerve terminals. Therefore, a presynaptic lesion may contribute to neurological manifestations in Wilson's disease.