OBJECTIVE

Given that rabies remains endemic in the Philippines despite government interventions and the pandemicrelated restrictions have hampered its surveillance, this study aimed to estimate the effect of human population, anti-rabies vaccination efforts, and COVID-19 situation on the spread of rabies cases in the districts of Davao City, Philippines.

A retrospective study of the canine records at Davao City Veterinarians’ Office was done from January 2018 to June 2021. Monthly rabies cases were ascertained, and the effect of the human population, COVID-19 season, and vaccination ratio on rabies cases was estimated using panel regression models adjusting for confounding factors.

The reporting of rabies cases was lower during COVID-19 than during the non-COVID-19 season, with an IRR of 0.52 [95% confidence interval (CI): 0.33–0.82]. Furthermore, rabies cases increased by 2.23% (95% CI: 0.60–3.89) per 1% increase in vaccination ratio. Additionally, high-population districts recorded more rabies cases than low-population districts.

Consistency in monitoring rabies cases during the pandemic is suggested as a roadmap for future program initiatives. Vaccination efforts should be reinforced to increase rabies awareness and ensure early response to emerging diseases. Moreover, highpopulated districts should be prioritized in implementing rabies control interventions to gain optimal development.

BACKGROUND AND OBJECTIVE

Rabies continues to be a challenge in Davao City despite the efforts of the city’s local government to vaccinate primarily the non-stray dog population. Meanwhile, studies have shown that time-dependent vaccination strategy is considered a prime factor for a cost-effective rabies control strategy. Hence, this study aims to provide information that will determine the optimal vaccination strategy targeted to the stray dog population that minimizes the rabies-infected dog population and vaccination costs using optimal control theory (OCT).

OCT is used to identify the optimal level of key rabies control, i.e., vaccination. Here, OCT was applied to a modified Susceptible-Exposed-Infectious-Vaccinated (SEIV) compartmental model. The study's key parameters were derived from published articles on rabies in Davao City and similar regions, along with the city's rabies reports.

The findings revealed that while rabies remains endemic in the city, it is possible to reduce the number of cases through consistent implementation of vaccination programs to the exposed and susceptible dog populations. Nevertheless, the feasibility of these findings relies to the effective targeting of vaccine coverage for the dog population. From the simulations performed, the exposed dog population (i.e., pre-rabid dogs) was able to reach zero observation when the transmission rate (?) is 0.001 for all values of anti-rabies vaccine coverages for exposed (?) and susceptible (b) dog populations and ? = 0.01 only when ? = 0.7 and b = 0.7, ? = 0.7 and b = 0.5, and ? = 0.5 and b = 0.7. Consequently, the number of infectious dogs will thereby decrease. Moreover, a nonlinear correspondence was also observed in all scenarios between the vaccination rate and the number of rabies-exposed dogs such that the reduction in the incidence of rabies cases becomes apparent only when the vaccination rate is at least 0.9995.

In high rabies transmissibility scenarios, a time-dependent vaccination strategy demonstrated a reduction in the number of rabies-infected dogs. However, this approach involves a trade-off, limiting the period during which monthly vaccinations can be relaxed. Consequently, a robust and timely vaccination program for dogs is crucial to manage high rabies transmission rates. Lastly, the model simulation underscores the importance of initiating monthly vaccinations.

BACKGROUND

Curcumin has been investigated as a potential natural solution to prevent or even treat skeletal muscle decline. There are a number of externally sourced finished products (ie, those imported from other countries) containing curcumin, but high cost limits their usage. The emerging research and development of locally sourced curcumin is an opportunity to produce high-quality oral supplements comparable to existing imported products.

The primary purpose of this study is to determine the effects of oral administration of a local curcumin formulation on skeletal muscle using an animal model that similarly demonstrated the course of human sarcopenia.

Purpose-bred 11- to 12-week-old female Sprague Dawley (SD) rats will be used in this study. SD rats are extensively used in animal models of human diseases and conditions such as diabetes, obesity and sarcopenia. Female rats have been selected because they do not demonstrate more temperature or activity variance and have more stable behavior compared to males. To simulate sarcopenia in this animal model, the tail suspension (TS) method was utilized. The TS method involves decreased hind limb function by suspending the animal’s tail for the duration of treatment. The laboratory animals will be randomized to receive any of the four treatments: (1) low-dose curcumin + vehicle; (2) high-dose curcumin + vehicle; (3) vehicle only; and (4) control (distilled water). The interventions will be subdivided into two: 2-week treatment and 4-week treatment. The gastrocnemius muscles on both sides will be excised and weighed, and the muscle tissues subjected to rapid freezing in acetone-dry ice and sliced into 10 μm-thick sections for staining. Examination of muscle architecture and computation of atrophy factors will be performed. The presence of connective tissue, fat tissue and number of atrophic muscle cells will be determined. Accurate quantitative detection of the rat total AMP (adenosine monophosphate)-Activated Protein Kinase will be performed in the gastrocnemius muscle tissue utilizing the enzyme-linked immunosorbent assay kit.

BACKGROUND

Rabies remains to be a neglected tropical disease in the Philippines, with the country reporting a higher number of cases compared to its counterparts in Asia.

To describe the demographics, animal bite characteristics, and post-exposure prophylaxis of animal bite patients coming in for care at the Research Institute for Tropical Medicine (RITM), a large government referral center for infectious diseases, and animal bites.

Electronic patient records from January 1, 2018 to December 31, 2019 were obtained from the National Rabies Information System (NaRIS) database of the Department of Health, and summarized using applicable descriptive statistics.

A total of 14,614 patients were included over the two-year study period, and more than third of the patients were children below 15 years old, while more than half were adult males. Lower extremities were the most frequently affected area, while with children, more than a third of exposures were in the head and neck areas. Intradermal route was mostly used for the post-exposure prophylaxis, while WHO prequalified vaccines were utilized in more than 90% of the patients. Only 55.7% of patients completed the prophylaxis regimen at RITM.

These findings reflect the significant exposure of children from animal bites, and the non-compliance of patients to the prescribed post-exposure prophylaxis.

Animals, Wild ; Borneo ; Malaysia ; Biosurveillance

INTRODUCTION

Effective mosquito control is pivotal in the epidemiology of vector-borne diseases, but no successful preventive measures have been recorded for dengue vector control. Hence, possible alternatives to chemical larvicides have been explored, including plant alcoholic extracts. This study determined the larvicidal efficacy of Annona squamosa ethanolic leaf extracts against third instar larvae of Aedes aegypti.

Three replicates of varying concentrations of Annona squamosa ethanolic extract (i.e., 10%, 40%, and 70%) versus positive (Novaluron) and negative controls (tap water) were used to determine larval mortality.

Greatest larval mortality was noted using the 70% concentration (i.e., 24% versus the observed values of 20% and 8%, respectively for the 40% and 10% ethanolic concentrations). Relative to the controls, the mean differences in the mortality rates of the Aedes aegypti larvae across the leaf ethanolic concentrations were statistically significant (i.e., p-value < 0.05). There was increasing trend in larval mortality over time, but 50% lethal dose was not achieved. In conclusion, the different Annona squamosa ethanolic leaf extracts could be used as alternative botanical larvicides against Aedes species.

Retrograde adeno-associated viruses (AAVs) are capable of infecting the axons of projection neurons and serve as a powerful tool for the anatomical and functional characterization of neural networks. However, few retrograde AAV capsids have been shown to offer access to cortical projection neurons across different species and enable the manipulation of neural function in non-human primates (NHPs). Here, we report the development of a novel retrograde AAV capsid, AAV-DJ8R, which efficiently labeled cortical projection neurons after local administration into the striatum of mice and macaques. In addition, intrastriatally injected AAV-DJ8R mediated opsin expression in the mouse motor cortex and induced robust behavioral alterations. Moreover, AAV-DJ8R markedly increased motor cortical neuron firing upon optogenetic light stimulation after viral delivery into the macaque putamen. These data demonstrate the usefulness of AAV-DJ8R as an efficient retrograde tracer for cortical projection neurons in rodents and NHPs and indicate its suitability for use in conducting functional interrogations.
Animals ; Haplorhini ; Axons ; Motor Neurons ; Interneurons ; Macaca ; Dependovirus/genetics* ; Genetic Vectors

Multiple sclerosis (MS) is a neuroinflammatory demyelinating disease, mediated by pathogenic T helper 17 (Th17) cells. However, the therapeutic effect is accompanied by the fluctuation of the proportion and function of Th17 cells, which prompted us to find the key regulator of Th17 differentiation in MS. Here, we demonstrated that the triggering receptor expressed on myeloid cells 2 (TREM-2), a modulator of pattern recognition receptors on innate immune cells, was highly expressed on pathogenic CD4-positive T lymphocyte (CD4⁺ T) cells in both patients with MS and experimental autoimmune encephalomyelitis (EAE) mouse models. Conditional knockout of Trem-2 in CD4⁺ T cells significantly alleviated the disease activity and reduced Th17 cell infiltration, activation, differentiation, and inflammatory cytokine production and secretion in EAE mice. Furthermore, with Trem-2 knockout in vivo experiments and in vitro inhibitor assays, the TREM-2/zeta-chain associated protein kinase 70 (ZAP70)/signal transducer and activator of transcription 3 (STAT3) signal axis was essential for Th17 activation and differentiation in EAE progression. In conclusion, TREM-2 is a key regulator of pathogenic Th17 in EAE mice, and this sheds new light on the potential of this therapeutic target for MS.
Animals ; Humans ; Mice ; CD4-Positive T-Lymphocytes/pathology* ; Cell Differentiation ; Encephalomyelitis, Autoimmune, Experimental/metabolism* ; Mice, Inbred C57BL ; Multiple Sclerosis ; Th1 Cells/pathology*

Even though retinal images of objects change their locations following each eye movement, we perceive a stable and continuous world. One possible mechanism by which the brain achieves such visual stability is to construct a craniotopic coordinate by integrating retinal and extraretinal information. There have been several proposals on how this may be done, including eye-position modulation (gain fields) of retinotopic receptive fields (RFs) and craniotopic RFs. In the present study, we investigated coordinate systems used by RFs in the lateral intraparietal (LIP) cortex and frontal eye fields (FEF) and compared the two areas. We mapped the two-dimensional RFs of neurons in detail under two eye fixations and analyzed how the RF of a given neuron changes with eye position to determine its coordinate representation. The same recording and analysis procedures were applied to the two brain areas. We found that, in both areas, RFs were distributed from retinotopic to craniotopic representations. There was no significant difference between the distributions in the LIP and FEF. Only a small fraction of neurons was fully craniotopic, whereas most neurons were between the retinotopic and craniotopic representations. The distributions were strongly biased toward the retinotopic side but with significant craniotopic shifts. These results suggest that there is only weak evidence for craniotopic RFs in the LIP and FEF, and that transformation from retinotopic to craniotopic coordinates in these areas must rely on other factors such as gain fields.
Animals ; Macaca ; Visual Fields ; Frontal Lobe/physiology* ; Eye Movements ; Brain

Intermittent theta burst stimulation (iTBS), a time-saving and cost-effective repetitive transcranial magnetic stimulation regime, has been shown to improve cognition in patients with Alzheimer's disease (AD). However, the specific mechanism underlying iTBS-induced cognitive enhancement remains unknown. Previous studies suggested that mitochondrial functions are modulated by magnetic stimulation. Here, we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1 (ISCA1, an essential regulatory factor for mitochondrial respiration) in the brain of APP/PS1 mice. In vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function, which is required for ISCA1. Moreover, iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 mice. The present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in AD. We provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.
Humans ; Mice ; Animals ; Transcranial Magnetic Stimulation ; Alzheimer Disease/therapy* ; Cognitive Dysfunction/therapy* ; Cognition ; Sulfur ; Iron ; Iron-Sulfur Proteins ; Mitochondrial Proteins