Dissolvable Immunomodulatory Microneedles for Treatment of Skin Wounds

Sustained inflammation can halt or delay wound healing, and macrophages play a central role in wound healing. Inflammatory macrophages are responsible for the removal of pathogens, debris, and neutrophils, while anti-inflammatory macrophages stimulate various regenerative processes. Recombinant human Proteoglycan 4 (rhPRG4) is shown to modulate macrophage polarization and to prevent fibrosis and scarring in ear wound healing. Here, dissolvable microneedle arrays (MNAs) carrying rhPRG4 are engineered for the treatment of skin wounds. The in vitro experiments suggest that rhPRG4 modulates the inflammatory function of bone marrow-derived macrophages. Degradable and detachable microneedles are developed from gelatin methacryloyl (GelMA) attach to a dissolvable gelatin backing. The developed MNAs are able to deliver a high dose of rhPRG4 through the dissolution of the gelatin backing post-injury, while the GelMA microneedles sustain rhPRG4 bioavailability over the course of treatment. In vivo results in a murine model of full-thickness wounds with impaired healing confirm a decrease in inflammatory biomarkers such as TNF-α and IL-6, and an increase in angiogenesis and collagen deposition. Collectively, these results demonstrate rhPRG4-incorporating MNA is a promising platform in skin wound healing applications.

Astrocyte Heterogeneity in Multiple Sclerosis: Current Understanding and Technical Challenges

The emergence of single cell technologies provides the opportunity to characterize complex immune/central nervous system cell assemblies in multiple sclerosis (MS) and to study their cell population structures, network activation and dynamics at unprecedented depths. In this review, we summarize the current knowledge of astrocyte subpopulations in MS tissue and discuss the challenges associated with resolving astrocyte heterogeneity with single-nucleus RNA-sequencing (snRNA-seq). We further discuss multiplexed imaging techniques as tools for defining population clusters within a spatial context. Finally, we will provide an outlook on how these technologies may aid in answering unresolved questions in MS, such as the glial phenotypes that drive MS progression and/or neuropathological differences between different clinical MS subtypes.

QSM is an imaging biomarker for chronic glial activation in multiple sclerosis lesions

BACKGROUND

Inflammation in chronic active lesions occurs behind a closed blood-brain barrier and cannot be detected with MRI. Activated microglia are highly enriched for iron and can be visualized with quantitative susceptibility mapping (QSM), an MRI technique used to delineate iron.

OBJECTIVE

To characterize the histopathological correlates of different QSM hyperintensity patterns in MS lesions.

METHODS

MS brain slabs were imaged with MRI and QSM, and processed for histology. Immunolabeled cells were quantified in the lesion rim, center, and adjacent normal-appearing white matter (NAWM). Iron⁺ myeloid cell densities at the rims were correlated with susceptibilities. Human-induced pluripotent stem cell (iPSC)-derived microglia were used to determine the effect of iron on the production of reactive oxygen species (ROS) and pro-inflammatory cytokines.

RESULTS

QSM hyperintensity at the lesion perimeter correlated with activated iron⁺ myeloid cells in the rim and NAWM. Lesions with high punctate or homogenous QSM signal contained no or minimally activated iron^- myeloid cells. In vitro, iron accumulation was highest in M1-polarized human iPSC-derived microglia, but it did not enhance ROS or cytokine production.

CONCLUSION

A high QSM signal outlining the lesion rim but not punctate signal in the center is a biomarker for chronic inflammation in white matter lesions.

Abnormal calcium signalling and the caffeine-halothane contracture test

Background

The variable clinical presentation of malignant hyperthermia (MH), a disorder of calcium signalling, hinders its diagnosis and management. Diagnosis relies on the caffeine–halothane contracture test, measuring contraction forces upon exposure of muscle to caffeine or halothane (F_C and F_H, respectively). Patients with above-threshold F_C or F_H are diagnosed as MH susceptible. Many patients test positive to halothane only (termed ‘HH’). Our objective was to determine the characteristics of these HH patients, including their clinical symptoms and features of cytosolic Ca²⁺ signalling related to excitation–contraction coupling in myotubes.

Methods

After institutional ethics committee approval, recruited patients undergoing contracture testing at Toronto's MH centre were assigned to three groups: HH, doubly positive (HS), and negative patients (HN). A clinical index was assembled from musculoskeletal symptoms and signs. An analogous calcium index summarised four measures in cultured myotubes: resting [Ca²⁺]_cytosol, frequency of spontaneous cytosolic Ca²⁺ events, Ca²⁺ waves, and cell-wide Ca²⁺ spikes after electrical stimulation.

Results

The highest values of both indexes were found in the HH group; the differences in calcium index between HH and the other groups were statistically significant. The principal component analysis confirmed the unique cell-level features of the HH group, and identified elevated resting [Ca²⁺]_cytosol and spontaneous event frequency as the defining HH characteristics.

Conclusions

These findings suggest that HH pathogenesis stems from excess Ca²⁺ leak through sarcoplasmic reticulum channels. This identifies HH as a separate diagnostic group and opens their condition to treatment based on understanding of pathophysiological mechanisms.

A scientist's guide for submitting data to ZFIN

The Zebrafish Model Organism Database (ZFIN; zfin.org) serves as the central repository for genetic and genomic data produced using zebrafish (Danio rerio). Data in ZFIN are either manually curated from peer-reviewed publications or submitted directly to ZFIN from various data repositories. Data types currently supported include mutants, transgenic lines, DNA constructs, gene expression, phenotypes, antibodies, morpholinos, TALENs, CRISPRs, disease models, movies, and images. The rapidly changing methods of genomic science have increased the production of data that cannot readily be represented in standard journal publications. These large data sets require web-based presentation. As the central repository for zebrafish research data, it has become increasingly important for ZFIN to provide the zebrafish research community with support for their data sets and guidance on what is required to submit these data to ZFIN. Regardless of their volume, all data that are submitted for inclusion in ZFIN must include a minimum set of information that describes the data. The aim of this chapter is to identify data types that fit into the current ZFIN database and explain how to provide those data in the optimal format for integration. We identify the required and optional data elements, define jargon, and present tools and templates that can help with the acquisition and organization of data as they are being prepared for submission to ZFIN. This information will also appear in the ZFIN wiki, where it will be updated as our services evolve over time.

Air pollution and cardiovascular admissions association in Spain: results within the EMECAS project

OBJECTIVE

To evaluate the short term effect of air pollution on cardiovascular admissions in 14 Spanish cities

METHODS

The period under study was from 1995 to 1999. Daily emergency admissions for all cardiovascular diseases (CVD) and heart diseases (HD) were obtained from hospital records, and the corresponding daily levels of particulates, SO2, NO2, CO, and ozone were recorded. The magnitude of association was estimated using Poisson generalised additive models controlling for confounding and overdispersion. For each cause, lagged effects, up to three days, of each pollutant were examined and combined estimates were obtained. For ozone the analyses were restricted to the warm period. One and two pollutant models were performed.

RESULTS

Associations were more consistent in lag 0 (concurrent day) and 1 (lag 0-1), except in the case of ozone where there was a more delayed relation (lag 2-3). For combined estimates an increase of 10 microg/m3 in the PM10 levels in lag 0-1 was associated with an increase of 0.9% (95% CI: 0.4 to 1.5%) in the number of hospital admissions for CVD, and 1.6% (0.8 to 2.3%) for HD. For ozone the corresponding estimates for lag 2-3 were 0.7% (0.3 to 1.0) for CVD, and 0.7% (0.1 to 1.2) for HD. An increase of 1 mg/m3 in CO levels was associated with an increase of 2.1% (0.7 to 3.5%) in CVD admissions, and 4.2% (1.3 to 7.1%) in HD admissions. SO2 and NO2 estimates were more sensitive in two pollutant models

CONCLUSIONS

A short term association between increases in daily levels of air pollutants and the number of daily admissions for cardiovascular diseases, with specificity for heart diseases, has been described in Spanish cities.

The molecular epidemiology of tuberculosis in Caracas, Venezuela, with IS6110 DNA fingerprinting

In this retrospective study we asses the molecular epidemiological situation of Tuberculosis of the city of Caracas, Venezuela in the year 1994, applying IS6110 DNA Fingerprinting of clinical isolates. Fingerprinting of Mycobacterium tuberculosis strains of sixty-four patients TB patients from all the 5 districts of the city revealed fifty-one distinct IS6110 patterns. Isolates from 20 patients (30%) had fingerprints that were shared with at least one other patient. Based on this sampling we conclude that at least a third of the tuberculosis cases in Caracas in the year 1994 were the result of recent and ongoing transmission, indicating micro-epidemics in the town.

GABAergic presynaptic inhibition of rat neostriatal afferents is mediated by Q-type Ca(2+) channels

Population spikes associated with the paired pulse facilitation paradigm have been successfully used to measure presynaptic inhibition in several systems. In the present work, this paradigm was used to evaluate the action of baclofen on neostriatal glutamatergic transmission. Baclofen enhanced synaptic facilitation with an EC(50)=0.57 microM and a maximal effect of 457%. Selective antagonists for N-, P- and Q-type Ca(2+)-channels enhanced paired pulse facilitation; suggesting that these channel types participate in the release of transmitter. Nevertheless, neither 1 microM omega-conotoxin GVIA, nor 20 nM omega-agatoxinTK occluded the action of baclofen. Baclofen's action was occluded only by 400 nM omega-agatoxinTK. These data suggest that Q-type Ca(2+)-channels mediate gamma-aminobutyric acid(B) presynaptic inhibition of neostriatal afferents.

[A clone of Neisseria meningitidis serogroup C was responsible in 1994 of an unusual high rate of strains with a moderate resistance to penicillin in Caracas (Venezuela)]

BACKGROUND

The aim of the study was to analyse meningococcal strains isolated from patients in Caracas (Venezuela) with epidemiological markers and to determine their susceptibility to antimicrobial agents.

METHODS

We analyzed 29 meningococcal clinical strains isolated during 1994 in Caracas by serogrouping, serotyping and subserotyping, multilocus enzyme analysis (MEE), ribotyping and pulse field electrophoresis (PFGE) profile. We also determined the Minimal Inhibitory Concentration (MIC) to 5 antimicrobial agents.

RESULTS

Twenty four (82.7%) were group C meningococcal strains. All group C meningococci were characterized as C: 2b: P1.5, belonging to the same electrophoretic type (ET) by MEE and showing the same profile by PFGE by using Bg/II endonuclease restriction enzyme. These group C meningococci showed two different patterns by ribotyping, with only one band difference. All Group C and one group B N. meningitidis isolates were moderately resistant to penicillin (MIC > or = 0.12 mg/l).

CONCLUSIONS

During 1994 an unusual high incidence of meningococcal strains moderately resistant to penicillin (PenMR) was detected in Caracas (Venezuela). A clone of C: 2b: P1.5 meningococci seem to be responsable for this high incidence of PenMR isolates.

An update on the discovery, pathophysiological actions, clinical manifestations and possible physiology of parathyroid related peptide

PTHrP has had an unidentified role in medicine since 1930, when Albright described a patient with renal cortical cell carcinoma with hypercalcemia. Since then hypercalcemia has been recognized as the most common paraneoplastic syndrome. At that time the concept of "ectopic PTH syndrome" was introduced, and remained in literature until the true etiology was finally described. In the early 1970's Roof and Benson presented evidence that PTH in humoral hypercalcemia differed from "authentic" PTH. This marked the starting point for researchers to try identifying the molecule that mimicked PTH action and structure. This molecule, named parathyroid-related peptide, has been associated to hypercalcemia seen with solid tumors, such as squamous cell carcinoma of the lung and renal cortical cell carcinoma. PTHrP has been demonstrated to have similar actions to PTH but to differ in decreasing osteoblastic activity while increasing osteoclastic activity. The more fascinating finding was the presence of the PTHrP genes throughout the body, mostly the lactating breast as well as the heart, lungs and skin among others. Despite its identification, finding its physiological roles on normal tissue still remains to be clarified.

[The incidence of Trypanosoma cruzi antibodies in patients with dilated myocardiopathy at the Instituto Nacional de Cardiología Ignacio Chávez]

Our objective was to measure the incidence of humoral immune response against Trypanosoma cruzi among patients with a definitive diagnosis of dilated cardiomyopathy at the Instituto Nacional de Cardiología "I. Chávez" over a year. Thirty seven patients were collected, 15 of them (40%) had antibodies against T. cruzi in two different tests, indirect immunofluorescence and ELISA, the presence of IgG antibody was confirmed through Western blot. There was not differences in clinical picture of cardiomyopathy nor on paraclinical studies. However, there was a significant difference in regard socio economical indexes between the group with positive anti T. cruzi antibodies. They had a predominant rural origin, poor housing and were aware of the vector bug. Also they recalled primary infection in their childhood--American trypanosomiasis could be on important etiologic factor for dilated cardiomyopathy in our country.