Increased task-relevant fMRI responsiveness in comatose cardiac arrest patients is associated with improved neurologic outcomes

Early prediction of the recovery of consciousness in comatose cardiac arrest patients remains challenging. We prospectively studied task-relevant fMRI responses in 19 comatose cardiac arrest patients and five healthy controls to assess the fMRI's utility for neuroprognostication. Tasks involved instrumental music listening, forward and backward language listening, and motor imagery. Task-specific reference images were created from group-level fMRI responses from the healthy controls. Dice scores measured the overlap of individual subject-level fMRI responses with the reference images. Task-relevant responsiveness index (Rindex) was calculated as the maximum Dice score across the four tasks. Correlation analyses showed that increased Dice scores were significantly associated with arousal recovery (P < 0.05) and emergence from the minimally conscious state (EMCS) by one year (P < 0.001) for all tasks except motor imagery. Greater Rindex was significantly correlated with improved arousal recovery (P = 0.002) and consciousness (P = 0.001). For patients who survived to discharge (n = 6), the Rindex's sensitivity was 75% for predicting EMCS (n = 4). Task-based fMRI holds promise for detecting covert consciousness in comatose cardiac arrest patients, but further studies are needed to confirm these findings. Caution is necessary when interpreting the absence of task-relevant fMRI responses as a surrogate for inevitable poor neurological prognosis.

Awareness and Knowledge of Glaucoma and their Associated Factors among Staffs in a Tertiary-level Hospital in Central Nepal

Background Since glaucoma-related blindness may only be prevented with early identification and treatment, finding asymptomatic individuals in the target population is critical. It is thus important to determine the awareness and knowledge on glaucoma. Objective To determine the knowledge and awareness on glaucoma among the staff of a tertiary level hospital in central Nepal. Method This was a cross sectional study among the staffs of Dhulikhel Hospital who participated voluntarily in the study. The data was collected through the administration of semi-structured questionnaires. R version 4.0.3 (2020-10-10) was used for the data analysis. Categorical variables are presented as frequency (percentages) and the numerical ones are presented as mean (standard deviation). Adjusted odds ratio (AOR) with 95% confidence interval were estimated through logistic regression analysis for determining factors associated with awareness and knowledge of glaucoma. Result A total of 107 (89.2%) participants had heard about glaucoma of which 93 (86.9%) had good knowledge and 14(13.1%) had poor knowledge on glaucoma. The mean score of knowledge was 64.1±16.9. Only 47.7% of the participants said that glaucoma also has an asymptomatic course. We could not find an association of awareness and knowledge of glaucoma with any of the selected sociodemographic variables. Conclusion Although there was a fairly good glaucoma related awareness and knowledge among hospital staff, we found lack of understanding on some critical issues on glaucoma, mainly related to its asymptomatic nature. There is thus room for improvement in educating about glaucoma even in healthcare settings. Given the necessity of expanding glaucoma awareness in the public, hospital staff might potentially serve as messengers to the communities.

Ocular Survey in Kathmandu University Medical Students

Background Medical students spend long time in academic activities that increases the risk of developing refractive errors and dry eyes that can affect their learning and social abilities. Only a few studies are available regarding ocular problems and its contribution to visual impairment among medical students in Nepal. Objective To evaluate the ocular problems among the medical students in a University hospital. Method An observational, descriptive, cross-sectional study was conducted among five batches undergraduate medical students until 2022 of Kathmandu University School of Medical Sciences, Dhulikhel, Kavre. A self-administered questionnaire was used to obtain demographic data and information on visual problems followed by a detailed ocular examination that included refraction, color vision and Schirmer test. Result Total of 284 medical students (with 568 eyes) with mean age of 22.8 years, 179 males and 105 females were enrolled. Among them, 270 (47.5%) eyes were emmetropic. Simple Myopia was the commonest followed by Compound Myopic Astigmatism. The mean spherical equivalent in right and left eye were -0.914 ± 1.54 and -0.886 ± 1.53 respectively. Approximately 18% students had some form of dry eye. Nineteen students (6.7%) had color vision deficiency and 13 (4.6%) had deuteranomalia, 3(1.1%) had deuteranopia and 3(1.1%) had protanomalia. Conclusion Eye defects, like refractive errors, dry eyes and color blindness, are common among medical students. They need to be advised for frequent eye check up in order to diagnose eye defects timely and arrest visual impairment at early stage.

Awareness and Knowledge of Glaucoma and their Associated Factors among People Visiting a Tertiary Level Hospital in Central Nepal

Background Glaucoma is one of the major causes of irreversible blindness globally. Almost 60 million people globally are affected by glaucoma making it the second leading cause of blindness worldwide. Diagnosis of glaucoma early on is vital for timely management and prevention of blindness. However, it is challenging to diagnose it early because it is asymptomatic in the initial stage, and there is also the dearth of appropriate screening tools. Awareness, knowledge, and beliefs are believed to influence the treatment-seeking behavior of people as well as their uptake of services. Objective To assess the awareness and knowledge about glaucoma among general patients and patient attendants visiting Dhulikhel Hospital. Method We conducted a cross sectional quantitative study among general patients visiting Dhulikhel Hospital. We collected data using face-to-face interviews with semistructured questionnaires. We analyzed data in R version 4.0.3 (2020-10-10). We presented numerical variables as mean and standard deviation whereas categorical variables as frequency and percentage. We determined factors associated with awareness and knowledge of glaucoma using logistic regression analysis and estimated adjusted odds ratio (AOR) with 95% confidence interval. Result Of 379 participants, a total of 214 (56.5%) participants had heard about glaucoma. Out of the participants who heard about glaucoma, the mean knowledge score was 48.3±21.7 and 53.3% had good knowledge on glaucoma. The odds of having heard about glaucoma were two percent lower (AOR=0.98; 95%CI: 0.97-0.99; p-value 0.036) in the older participants compared to one year younger participant, 1.98 (95%CI:1.01-3.86; p-value 0.046) times higher among literates and 2.79 (95%CI: 1.76- 4.41; p-value < 0.001) times among participants with previous ocular examination. The odds of having good knowledge was 1.94 (95%CI: 1.10-3.42; p value 0.021) times among participants with previous ocular examinations. Conclusion The knowledge and awareness regarding glaucoma in a hospital-visiting population in central Nepal was low. Half of the participants were unaware of the disease glaucoma and half of the participants who heard of the glaucoma had poor knowledge on glaucoma.

Prevalence of Refractive Error and Ocular Pathologies among School Children: Finding from the School Eye Program of Dhulikhel Hospital

Background Childhood blindness and visual impairments could lead to the onset of blindness among children and adolescents. New cases appear particularly between the ages of 6-15 years and if uncorrected, runs a risk of developing Amblyopia, strabismus. There exists a mounting need to strengthen and modify established school eye health programs in Nepal as per the local needs and conditions. Objective To determine the prevalence of refractive error and ocular pathologies among school children in rural Nepal. Method This cross-sectional study was conducted in nine schools of Kavrepalanchowk and Bhaktapur district with 953 students screened from December 2018 to February 2020. The team of optometrist, ophthalmic assistants and ophthalmologist applied a standard protocol for screening of refractive error as a part of the school eye program of Dhulikhel Hospital. Other standard eye examinations were performed to note the ocular pathologies. The association of socio-demographic factors of students having refractive errors with that in emmetropes was identified using logistic regression analysis. Result A total of 953 students were screened in nine study sites, age ranged from 5-19 years. There were 183 students (19.2%) with refractive errors. Blurred vision was the common complaint reported by 2.5% of students. Multivariate logistic regression analysis showed higher age group children (aOR=2.93; 95% CI: 1.62-5.29; P=0.01) and urban area children (aOR=4.37; 95% CI: 0.87-21.98; P=0.07) to have higher odds of refractive error. Conclusion Refractive error is the major eye problem among school children. Despite its high prevalence, there is still a major gap in timely diagnosis and treatment. Regular vision screening and timely treatment is required for better addressing refractive error among school-going children.

Enhanced White Matter Fiber Tracts in Advanced Jazz Improvisers

Human cognition and behavior arise from neuronal interactions over brain structural networks. These neuronal interactions cause changes in structural networks over time. How a creative activity such as musical improvisation performance changes the brain structure is largely unknown. In this diffusion magnetic resonance imaging study, we examined the brain’s white matter fiber properties in previously identified functional networks and compared the findings between advanced jazz improvisers and non-musicians. We found that, for advanced improvisers compared with non-musicians, the normalized quantitative anisotropy (NQA) is elevated in the lateral prefrontal areas and supplementary motor area, and the underlying white matter fiber tracts connecting these areas. This enhancement of the diffusion anisotropy along the fiber pathway connecting the lateral prefrontal and supplementary motor is consistent with the functional networks during musical improvisation tasks performed by expert jazz improvisers. These findings together suggest that experts’ creative skill is associated with the task-relevant, long-timescale brain structural network changes, in support of related cognitive underpinnings.

Persistent behavior deficits, neuroinflammation, and oxidative stress in a rat model of acute organophosphate intoxication

Current medical countermeasures for organophosphate (OP)-induced status epilepticus (SE) are not effective in preventing long-term morbidity and there is an urgent need for improved therapies. Rat models of acute intoxication with the OP, diisopropylfluorophosphate (DFP), are increasingly being used to evaluate therapeutic candidates for efficacy in mitigating the long-term neurologic effects associated with OP-induced SE. Many of these therapeutic candidates target neuroinflammation and oxidative stress because of their implication in the pathogenesis of persistent neurologic deficits associated with OP-induced SE. Critical to these efforts is the rigorous characterization of the rat DFP model with respect to outcomes associated with acute OP intoxication in humans, which include long-term electroencephalographic, neurobehavioral, and neuropathologic effects, and their temporal relationship to neuroinflammation and oxidative stress. To address these needs, we examined a range of outcomes at later times post-exposure than have previously been reported for this model. Adult male Sprague-Dawley rats were given pyridostigmine bromide (0.1 mg/kg, im) 30 min prior to administration of DFP (4 mg/kg, sc), which was immediately followed by atropine sulfate (2 mg/kg, im) and pralidoxime (25 mg/kg, im). This exposure paradigm triggered robust electroencephalographic and behavioral seizures that rapidly progressed to SE lasting several hours in 90% of exposed animals. Animals that survived DFP-induced SE (~70%) exhibited spontaneous recurrent seizures and hyperreactive responses to tactile stimuli over the first 2 months post-exposure. Performance in the elevated plus maze, open field, and Pavlovian fear conditioning tests indicated that acute DFP intoxication reduced anxiety-like behavior and impaired learning and memory at 1 and 2 months post-exposure in the absence of effects on general locomotor behavior. Immunohistochemical analyses revealed significantly increased expression of biomarkers of reactive astrogliosis, microglial activation and oxidative stress in multiple brain regions at 1 and 2 months post-DFP, although there was significant spatiotemporal heterogeneity across these endpoints. Collectively, these data largely support the relevance of the rat model of acute DFP intoxication as a model for acute OP intoxication in the human, and support the hypothesis that neuroinflammation and/or oxidative stress represent potential therapeutic targets for mitigating the long-term neurologic sequelae of acute OP intoxication.

Sources and toxicities of phenolic polychlorinated biphenyls (OH-PCBs)

Polychlorinated biphenyls (PCBs), a group of 209 congeners that differ in the number and position of chlorines on the biphenyl ring, are anthropogenic chemicals that belong to the persistent organic pollutants (POPs). For many years, PCBs have been a topic of interest because of their biomagnification in the food chain and their environmental persistence. PCBs with fewer chlorine atoms, however, are less persistent and more susceptible to metabolic attack, giving rise to chemicals characterized by the addition of one or more hydroxyl groups to the chlorinated biphenyl skeleton, collectively known as hydroxylated PCBs (OH-PCBs). In animals and plants, this biotransformation of PCBs to OH-PCBs is primarily carried out by cytochrome P-450-dependent monooxygenases. One of the reasons for infrequent detection of lower chlorinated PCBs in serum and other biological matrices is their shorter half-lives, and their metabolic transformation, resulting in OH-PCBs or their conjugates, such as sulfates and glucuronides, or macromolecule adducts. Recent biomonitoring studies have reported the presence of OH-PCBs in human serum. The occurrence of OH-PCBs, the size of this group (there are 837 mono-hydroxyl PCBs alone), and their wide spectra of physical characteristics (pKa's and log P's ranging over 5 to 6 orders of magnitude) give rise to a multiplicity of biological effects. Among those are bioactivation to electrophilic metabolites that can form covalent adducts with DNA and other macromolecules, interference with hormonal signaling, inhibition of enzymes that regulate cellular concentrations of active hormones, and interference with the transport of hormones. This new information creates an urgent need for a new perspective on these often overlooked metabolites.

Introducing leprosy post-exposure prophylaxis into the health systems of India, Nepal and Indonesia: a case study

Background

Leprosy has a wide range of clinical and socio-economic consequences. India, Indonesia and Nepal contribute significantly to the global leprosy burden. After integration, the health systems are pivotal in leprosy service delivery. The Leprosy Post Exposure Prophylaxis (LPEP) program is ongoing to investigate the feasibility of providing single dose rifampicin (SDR) as post-exposure prophylaxis (PEP) to the contacts of leprosy cases in various health systems. We aim to compare national leprosy control programs, and adapted LPEP strategies in India, Nepal and Indonesia. The purpose is to establish a baseline of the health system’s situation and document the subsequent adjustment of LPEP, which will provide the context for interpreting the LPEP results in future.

Methods

The study followed the multiple-case study design with single units of analysis. The data collection methods were direct observation, in-depth interviews and desk review. The study was divided into two phases, i.e. review of national leprosy programs and description of the LPEP program. The comparative analysis was performed using the WHO health system frameworks (2007).

Results

In all countries leprosy services including contact tracing is integrated into the health systems. The LPEP program is fully integrated into the established national leprosy programs, with SDR and increased documentation, which need major additions to standard procedures. PEP administration was widely perceived as well manageable, but the additional LPEP data collection was reported to increase workload in the first year.

Conclusions

The findings of our study led to the recommendation that field-based leprosy research programs should keep health systems in focus. The national leprosy programs are diverse in terms of organizational hierarchy, human resource quantity and capacity. We conclude that PEP can be integrated into different health systems without major structural and personal changes, but provisions are necessary for the additional monitoring requirements.

Electronic supplementary material

The online version of this article (10.1186/s12913-017-2611-7) contains supplementary material, which is available to authorized users.

Disposition of phenolic and sulfated metabolites after inhalation exposure to 4-chlorobiphenyl (PCB3) in female rats

PCBs, such as PCB3, are air contaminants in buildings and outdoors. Metabolites of PCB3 are potential endocrine disrupting chemicals and genotoxic agents. We studied the disposition of phenolic and sulfated metabolites after acute nose-only inhalation exposure to airborne PCB3 for 2 h in female rats. Inhalation exposure was carried out in three groups. In the first group, rats exposed to an estimated dose of 26 μg/rat were euthanized at 0, 1, 2, and 4 h after exposure. Highest concentrations of phenols and sulfates were observed at 0 h, and the values were 7 ± 1 and 560 ± 60 ng/mL in serum, 213 ± 120 and 842 ± 80 ng/g in liver, 31 ± 27 and 22 ± 7 ng/g in lung, and 27 ± 6 and 3 ± 0 ng/g in brain, respectively. First-order serum clearance half-lives of 0.5 h for phenols and 1 h for sulfates were estimated. In the second group, rats exposed to an estimated dose of 35 μg/rat were transferred to metabolism cages immediately after exposure for the collection of urine and feces over 24 h. Approximately 45 ± 5% of the dose was recovered from urine and consisted mostly of sulfates; the 18 ± 5% of the dose recovered from feces was exclusively phenols. Unchanged PCB3 was detected in both urine and feces but accounted for only 5 ± 3% of the dose. Peak excretion of metabolites in both urine and feces occurred within 18 h postexposure. In the third group, three bile-cannulated rats exposed to an estimated dose of 277 μg/rat were used for bile collection. Bile was collected for 4 h immediately after 2 h exposure. Biliary metabolites consisted mostly of sulfates, some glucuronides, and lower amounts of the free phenols. Control rats in each group were exposed to clean air. Clinical serum chemistry values, serum T4 level, and urinary 8-hydroxy-2'-deoxyguanosine were similar in treated and control rats. These data show that PCB3 is rapidly metabolized to phenols and conjugated to sulfates after inhalation and that both of these metabolites are distributed to liver, lungs, and brain. The sulfates elaborated into bile are either reabsorbed or hydrolyzed in the intestine and excreted in the feces as phenols.

Sulfate conjugates are urinary markers of inhalation exposure to 4-chlorobiphenyl (PCB3)

PCBs are contaminants in the air of older buildings and cities, which raises the concern of inhalation exposure. No reliable biomarker of such exposure is available. We exposed rats to air containing 2 mg/m(3) PCB3 via nose-only inhalation for 2 h, collected urine, and analyzed it by LC/MS. Each rat inhaled an estimated dose of 35 μg PCB3, and excreted 27 ± 2% of it as sulfates within 24 h. Peak excretion occurred within 6 h. PCB sulfates were stable in urine for at least three days at room temperature without chemical preservatives. These data support the use of PCB sulfate conjugates as suitable urinary biomarkers of PCB3 and other airborne PCBs.

Fiber-optic two-photon optogenetic stimulation

Optogenetic stimulation of genetically targeted cells is proving to be a powerful tool in the study of cellular systems, both in vitro and in vivo. However, most opsins are activated in the visible spectrum, where significant absorption and scattering of stimulating light occurs, leading to low penetration depth and less precise stimulation. Since we first (to the best of our knowledge) demonstrated two-photon optogenetic stimulation (TPOS), it has gained considerable interest in the probing of cellular circuitry by precise spatial modulation. However, all existing methods use microscope objectives and complex scanning beam geometries. Here, we report a nonscanning method based on multimode fiber to accomplish fiber-optic TPOS of cells.

Identification of sulfated metabolites of 4-chlorobiphenyl (PCB3) in the serum and urine of male rats

Polychlorinated biphenyls (PCBs) are legacy pollutants that exert toxicities through various mechanisms. In recent years exposure to PCBs via inhalation has been recognized as a hazard. Those PCBs with lower numbers of chlorine atoms (LC-PCBs) are semivolatile and have been reported in urban air, as well as in the indoor air of older buildings. LC-PCBs are bioactivated to phenols and further to quinone electrophiles with genotoxic/carcinogenic potential. We hypothesized that phenolic LC-PCBs are subject to conjugation and excretion in the urine. PCB3, often present in high concentrations in air, is a prototypical congener for the study of the metabolism and toxicity of LC-PCBs. Our objective was to identify metabolites of PCB3 in urine that could be potentially employed in the estimation of exposure to LC-PCBs. Male Sprague-Dawley rats (150-175 g) were housed in metabolism cages and received a single intraperitoneal injection of 600 μmol/kg body weight of PCB3. Urine was collected every 4 h; rats were euthanized at 36 h; and serum was collected. LC/MS analysis of urine before and after incubation with β-glucuronidase and sulfatase showed that sulfate conjugates were in higher concentrations than glucuronide conjugates and free phenolic forms. At least two major metabolites and two minor metabolites were identified in urine that could be attributed to mercapturic acid metabolites of PCB3. Quantitation by authentic standards confirmed that approximately 3% of the dose was excreted in the urine as sulfates over 36 h, with peak excretion occurring at 10-20 h after exposure. The major metabolites were 4'PCB3sulfate, 3'PCB3 sulfate, 2'PCB3 sulfate, and presumably a catechol sulfate. The serum concentration of 4'PCB3 sulfate was 6.18 ± 2.16 μg/mL. This is the first report that sulfated metabolites of PCBs are formed in vivo. These findings suggest a prospective approach for exposure assessment of LC-PCBs by analysis of phase II metabolites in urine.

Calf birth weight, gestation length, calving ease, and neonatal calf mortality in Holstein, Jersey, and crossbred cows in a pasture system

Holstein (HH), Jersey (JJ), and crosses of these breeds were mated to HH or JJ bulls to form purebreds, reciprocal crosses, backcrosses, and other crosses in a rotational mating system. The herd was located at the Center for Environmental Farming Systems in Goldsboro, North Carolina. Data for calf birth weight (CBW), calving ease (0 for unassisted, n=1,135, and 1 for assisted, n=96), and neonatal calf mortality (0 for alive, n=1,150, and 1 for abortions recorded after mid-gestation, stillborn, and dead within 48 h, n=81) of calves (n=1,231) were recorded over 9 calving seasons from 2003 through 2011. Gestation length (GL) was calculated as the number of days from last insemination to calving. Linear mixed models for CBW and GL included fixed effects of sex, parity (first vs. later parities), twin status, and 6 genetic groups: HH, JJ, reciprocal F(1) crosses (HJ, JH), crosses >50% Holsteins (HX) and crosses >50% Jerseys (JX), where sire breed is listed first. The CBW model also included GL as a covariate. Logistic regression for calving ease and neonatal calf mortality included fixed effects of sex, parity, and genetic group. Genetic groups were replaced by linear regression using percentage of HH genes as coefficients on the above models and included as covariates to determine various genetic effects. Year and dam were included as random effects in all models. Female calves (27.57±0.54 kg), twins (26.39±1.0 kg), and calves born to first-parity cows (27.67±0.56 kg) had lower CBW than respective male calves (29.53±0.53 kg), single births (30.71±0.19 kg), or calves born to multiparous cows (29.43±0.52 kg). Differences in genetic groups were observed for CBW and GL. Increased HH percentage in the calf increased CBW (+9.3±0.57 kg for HH vs. JJ calves), and increased HH percentage in the dams increased CBW (+1.71±0.53 kg for calves from HH dams vs. JJ dams); JH calves weighed 1.33 kg more than reciprocal HJ calves. Shorter GL was observed for twin births (272.6±1.1 d), female calves (273.9±0.6 d), and for first-parity dams (273.8±0.6 d). Direct genetic effects of HH alleles shortened GL (-3.5±0.7 d), whereas maternal HH alleles increased GL (2.7±0.6 d). Female calves had lower odds ratio (0.32, confidence interval=0.10-0.99) for neonatal calf mortality in second and later parities than did male calves. Maternal heterosis in crossbred primiparous dams was associated with reduced calf mortality.