Inhibition of C5aR1 as a promising approach to treat taxane-induced neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of several antitumor agents resulting in progressive and often irreversible damage of peripheral nerves. In addition to their known anticancer effects, taxanes, including paclitaxel, can also induce peripheral neuropathy by activating microglia and astrocytes, which release pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1β), and chemokine (C-C motif) ligand 2 (CCL-2). All these events contribute to the maintenance of neuropathic or inflammatory response. Complement component 5a (C5a)/C5a receptor 1 (C5aR1) signaling was very recently shown to play a crucial role in paclitaxel-induced peripheral neuropathy. Our recent findings highlighted that taxanes have the previously unreported property of binding and activating C5aR1, and that C5aR1 inhibition by DF3966A is effective in preventing paclitaxel-induced peripheral neuropathy (PIPN) in animal models. Here, we investigated if C5aR1 inhibition maintains efficacy in reducing PIPN in a therapeutic setting. Furthermore, we characterized the role of C5aR1 activation by paclitaxel and the CIPN-associated activation of nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome. Our results clearly show that administration of the C5aR1 inhibitor strongly reduced cold and mechanical allodynia in mice when given both during the onset of PIPN and when neuropathy is well established. C5aR1 activation by paclitaxel was found to be a key event in the induction of inflammatory factors in spinal cord, such as TNF-α, ionized calcium-binding adapter molecule 1 (Iba-1), and glial fibrillary acidic protein (GFAP). In addition, C5aR1 inhibition significantly mitigated paclitaxel-induced inflammation and inflammasome activation by reducing IL-1β and NLRP3 expression at both sciatic and dorsal root ganglia level, confirming the involvement of inflammasome in PIPN. Moreover, paclitaxel-induced upregulation of C5aR1 was significantly reduced by DF3966A treatment in central nervous system. Lastly, the antinociceptive effect of C5aR1 inhibition was confirmed in an in vitro model of sensory neurons in which we focused on receptor channels usually activated upon neuropathy. In conclusion, C5aR1 inhibition is proposed as a therapeutic option with the potential to exert long-term protective effect on PIPN-associated neuropathic pain and inflammation.

Characteristics of 1573 healthcare workers who underwent nasopharyngeal swab testing for SARS-CoV-2 in Milan, Lombardy, Italy

OBJECTIVES

The management of healthcare workers (HCWs) exposed to confirmed cases of coronavirus disease 2019 (COVID-19) is still a matter of debate. We aimed to assess in this group the attack rate of asymptomatic carriers and the symptoms most frequently associated with infection.

METHODS

Occupational and clinical characteristics of HCWs who underwent nasopharyngeal swab testing for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a university hospital from 24 February 2020 to 31 March 2020 were collected. For those who tested positive and for those who tested positive but who were asymptomatic, we checked the laboratory and clinical data as of 22 May to calculate the time necessary for HCWs to then test negative and to verify whether symptoms developed thereafter. Frequencies of positive tests were compared according to selected variables using multivariable logistic regression models.

RESULTS

There were 139 positive tests (8.8%) among 1573 HCWs (95% confidence interval, 7.5-10.3), with a marked difference between symptomatic (122/503, 24.2%) and asymptomatic (17/1070, 1.6%) workers (p < 0.001). Physicians were the group with the highest frequency of positive tests (61/582, 10.5%), whereas clerical workers and technicians had the lowest frequency (5/137, 3.6%). The likelihood of testing positive for COVID-19 increased with the number of reported symptoms; the strongest predictors of test positivity were taste and smell alterations (odds ratio = 76.9) and fever (odds ratio = 9.12). The median time from first positive test to a negative test was 27 days (95% confidence interval, 24-30).

CONCLUSIONS

HCWs can be infected with SARS-CoV-2 without displaying any symptoms. Among symptomatic HCWs, the key symptoms to guide diagnosis are taste and smell alterations and fever. A median of almost 4 weeks is necessary before nasopharyngeal swab test results are negative.

Comprehensive genomic analysis of the dromedary T cell receptor gamma (TRG) locus and identification of a functional TRGC5 cassette

The emergent availability in public databases of more complete genome assemblies allows us to improve genomic data obtained by classical molecular cloning. The main goal of this study was to refine the genomic map of the dromedary TRG locus by integrating our previous genomic data with the analysis of recent genomic assemblies. We identified an additional TRGC cassette, defined as a V-J-C recombination unit, located at the 5' of the locus and made up of five TRGV genes followed by three TRGJ genes and one TRGC gene. Hence, the complete dromedary TRG locus spans about 105 Kb and consists of three in tandem TRGC cassettes delimited by AMPH and STARD3NL genes at the 5' and 3' end, respectively. An expression assay carried out on peripheral blood showed the functional competency for the dromedary TRGC5 cassette and confirmed the presence of the somatic hypermutation mechanism able to enlarge the repertoire diversity of the dromedary γδ T cells.

YAP/TAZ mechano-transduction as the underlying mechanism of neuronal differentiation induced by reduced graphene oxide

AIM

The aim of this work is the dissection of the molecular pathways underlying the differentiation effect of reduced graphene oxide (GO) materials in the absence of differentiation agents.

MATERIALS & METHODS

Reduced GO is obtained either by drop casting method and heat-treated or biological reduction by the interaction between GO and wtPrxI. Cells were grown on both materials and the differentiation process studied by immunological and morphological detection.

RESULTS & CONCLUSION

The results obtained indicate that both reduction methods of GO can determine the modulation of pathway involved in mechano-transduction and differentiation, by affecting YAP/TAZ localization outside the nuclei and increasing neuronal differentiation markers. This suggests that the mechano-transduction pathways are responsible for the differentiation process.

PPARs in Neurodegenerative and Neuroinflammatory Pathways

Background:

PPARs are lipid sensors activated by dietary lipids or their metabolites, mainly fatty acids and eicosanoids, that play critical roles in CNS biology, since brain has a very high lipid content and has the higher energetic metabolism in the body.

Methods:

In neurodegenerative diseases in addition to metabolic impairment, also neuroinflammation is observed and PPARs are also closely linked to inflammatory processes. Several studies have revealed a complicated relationship between the innate immune response and tissue metabolism.

Results:

In the brain, during pathological conditions, an alteration in metabolic status occurs, particularly involving glucose utilization and production, a condition which is generally related to metabolic changes.

Conclusion:

Taking into account the high expression of PPARs in the brain, this review will focus on the role of these transcription factors in CNS diseases.

PDE10A and PDE10A-dependent cAMP catabolism are dysregulated oppositely in striatum and nucleus accumbens after lesion of midbrain dopamine neurons in rat: a key step in parkinsonism physiopathology

Loss of dopamine neurons in experimental parkinsonism results in altered cyclic nucleotide cAMP and cGMP levels throughout the basal ganglia. Our objective was to examine whether expression of phosphodiesterase 10A (PDE10A), an isozyme presenting a unique distribution in basal ganglia, is altered after unilateral injection of 6-hydroxydopamine in the medial forebrain bundle, eliminating all midbrain dopaminergic neurons, such that cyclic nucleotide catabolism and steady state could be affected. Our study demonstrates that PDE10A mRNA levels were decreased in striatal neurons 10 weeks after 6-hydroxydopamine midbrain lesion. Such changes occurred in the striatum ipsilateral to lesion and were paralleled by decreased PDE10A protein levels and activity in striatal neurons and in striato-pallidal and striato-nigral projections. However, PDE10A protein and activity were increased while PDE10A mRNA was unchanged in the nucleus accumbens ipsilateral to the 6-hydroxydopamine midbrain lesion. Accordingly, cAMP levels were down-regulated in the nucleus accumbens, and up-regulated in the striatum ipsilateral to the lesion, but they were not significantly changed in substantia nigra and globus pallidus. Unlike cAMP, cGMP levels were decreased in all dopamine-deafferented regions. The opposite variations of cAMP steady state in striatum and nucleus accumbens are concordant and likely dependent, at least in part, on the down-regulation of PDE10A expression and activity in the former and its up-regulation in the latter. On the other hand, the down-regulation of cGMP steady state in the striato-nigral and striato-pallidal complex is not consistent with and is likely independent from the concomitant down-regulation of PDE10A. Therefore, dopamine loss inversely regulates PDE10A gene expression in the striatum and PDE10A post-transcription in the nucleus accumbens, therein differentially modulating PDE10A-dependent cAMP catabolism.

[Cat scratch pneumonia: a case report]

Pasteurella multocida infections can be caused by scratches or bites of many animals including pets. An unrecognized infection can lead to severe complications such as arthritis, osteomyelitis, respiratory infections and even meningitis or endocarditis. We present the case of a woman affected by soft tissue infection caused by Pasteurella multocida complicated by bacteremia and pneumonia.

Response of bovine endothelial cells to FGF-2 and VEGF is dependent on their site of origin: Relevance to the regulation of angiogenesis

Angiogenesis, the formation of new capillary blood vessels, occurs almost exclusively in the microcirculation. This process is controlled by the interaction between factors with positive and negative regulatory activity. In this study, we have compared the effect of two well described positive regulators, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF-2) on bovine adrenal cortex-derived microvascular endothelial (BME) and bovine aortic endothelial (BAE) cells. The parameters we assessed included (a) cellular reorganization and lumen formation following exposure of the apical cell surface to a three-dimensional collagen gel; (b) organization of the actin cytoskeleton; (c) expression of thrombospondin-1 (TSP-1), an endogenous negative regulator of angiogenesis; and (d) extracellular proteolytic activity mediated by the plasminogen activator (PA)/plasmin system. We found that (a) collagen gel overlay induces rapid reorganization and lumen formation in BME but not BAE cells; (b) FGF-2 but not VEGF induced dramatic reorganization of actin microfilaments in BME cells, with neither cytokine affecting BAE cells; (c) FGF-2 decreased TSP-1 protein and mRNA expression in BME cells, an effect which was specific for FGF-2 and BME cells, since TSP-1 protein levels were unaffected by VEGF in BME cells, or by FGF-2 or VEGF in BAE cells; (d) FGF-2 induced urokinase-type PA (uPA) in BME and BAE cells, while VEGF induced uPA and tissue-type PA in BME cells with no effect on BAE cells. Taken together, these findings reveal endothelial cell-type specific responses to FGF-2 and VEGF, and point to the greater specificity of these cytokines for endothelial cells of the microvasculature than for large vessel (aortic) endothelial cells. Furthermore, when viewed in the context of our previous observation on the synergistic interaction between VEGF and FGF-2, our present findings provide evidence for complementary mechanisms which, when acting in concert, might account for the synergistic effect.

Phenotypic alterations in senescent large-vessel and microvascular endothelial cells

Endothelial cell senescence likely plays a key role in age-associated vascular diseases. A close relationship between in vitro and in vivo senescence of endothelial cells has been established. Therefore, elucidating the structural and functional changes occurring during long-term cultures of endothelial cells would contribute to clarifying the pathogenesis of vascular disorders in the elderly. We investigated the effects of replicative senescence on the architecture of bovine aortic vs microvascular endothelial cells. A marked increase in cell area was observed in both cell types, whereas dramatic morphological alterations were detected in microvascular endothelial cells only. The latter also showed age-associated reorganization of the actin cytoskeleton. Finally, both aortic and microvascular endothelial cells lost their migratory response to basic fibroblast growth factor with age. Our results highlight dramatic structural and functional alterations in senescent endothelial cells. Such rearrangements might account for in vivo endothelial cell alterations involved in age-associated vascular dysfunction.

Characterization of novel clonal murine endothelial cell lines with an extended life span

A murine endothelial cell line was recently established from microvessels that had invaded a subcutaneous sponge implant (Dong, Q. G.; Bernasconi, S.; Lostaglio, S., et al. Arterioscl. Thromb. Vasc. Biol. 17:1599-1604; 1997). From these sponge-induced endothelial (SIE) cells, we have isolated two subpopulations endowed with different phenotypic properties. Clone SIE-F consists of large, highly spread cells that have a relatively slow growth rate, form contact-inhibited monolayers, do not grow under anchorage-independent conditions, express elevated levels of thrombospondin-1 (TSP-1) and are not tumorigenic in vivo. In contrast, clone SIE-S2 consists of small, spindle-shaped cells that have a high proliferation rate, do not show contact-inhibition, grow under anchorage-independent conditions, express very low levels of TSP-1 and are tumorigenic in vivo. Both clones express the endothelial markers vascular endothelial-cadherin and vascular intercellular adhesion molecule-1, but do not express CD31 and E-selectin. In addition, SIE-S2 cells, but not SIE-F cells, express the alpha-smooth muscle actin isoform. SIE-S2 cells, but not SIE-F cells, are able to form branching tubes in fibrin gels. The SIE-F and SIE-S2 clones, which have properties of nontransformed and transformed cells, respectively, should provide useful tools to investigate physiological and pathological processes involving vascular endothelium.

Occurrence of papillary carcinoma in a hyperfunctioning thyroid nodule: report of a case and diagnostic considerations

Papillary carcinoma of the thyroid occurring within a hyperfunctioning nodule is an extremely rare disorder. A case in a woman is reported. We believe that diagnostic and therapeutic procedures to be used in the case of a hot thyroid nodule must take this possible occurrence into account.

[Hypothyroidism and simple goiter in pregnancy]

The incidence of hypothyroidism during pregnancy is 2.5%. Failure to diagnose the problem causes serious complications both to the mater and to the fetus. This pathological condition is verified on the basis of clinical analysis and above all in the laboratory. Autoimmunity is frequently the cause of hypothyroidism whereas this condition is rarely provoked as a result of surgery and therapy with I131. Pregnancy causes a definite deterioration of a pre-existing euthyroid goiter, so as it requires a careful monitoring of woman at risk. If the goiter is found to be neoplastic, its histotype and size must be studied carefully in order to provide for surgery. Therapy with L-thyroxine is essential to avoid damage to both mater and fetus and to monitor the glandular growth in the euthyroid goiter.

[Hyperthyroidism during pregnancy]

The authors review the current knowledge of fetus and woman thyroid physiology during pregnancy. They analyze the abnormalities related to hyperthyroidism, and clinical and therapeutic aspects of thyrotoxicosis; in detail possible fetal complications. They suggest the practical management of thyrotoxicosis during pregnancy.

[Echocardiographic changes in primary autoimmune hypothyroidism]

Echocardiographic features in patients with autoimmune hypothyroidism have been described. Plasma levels of T3, T4 and TSH have been compared with the severity of the echocardiographic alterations. Echocardiography demonstrated abnormalities more frequently in patients with severe hypothyroidism. No pericardial effusion has been detected. We discuss the possible etiopathogenic mechanisms.

Treatment of solitary bone cysts with intramedullary nailing

The article describes the treatment of solitary bone cysts of the upper and lower limbs by means of elastic intramedullary nailing. In the 11 cases treated, bone rehabilitation was complete, probably due to the defluction of the intracystic fluid by means of the drainage caused by the nails.

Digital angiography in evaluation of orthopedic tumors

Preoperative evaluation of orthopedic tumors using digital subtraction angiography (DSA) proved useful to ascertain the nature of the lesion, its extension to soft tissues and joints, and the presence of arteriovenous (AV) shunts. We report that overall accuracy varied from 89% to 92%, depending on the feature evaluated. The importance of angiographic examination of this entity is discussed as well as the advantages of DSA over conventional angiography.

High Speed Cylindrical Rolling Element Bearing Analysis “CYBEAN”—Analytic Formulation

This paper documents the analytic foundation and software architecture for the computerized mathematical simulation of high speed cylindrical rolling element bearing behavior. The software, CYBEAN (CYlindrical BEaring ANalysis), considers a flexible, variable geometry outer ring, EHD films, roller centrifugal and quasidynamic loads, roller tilt and skew, mounting fits, cage and flange interactions. The representation includes both steady state and time transient simulation of thermal interactions internal to and coupled with the surroundings of the bearing. A sample problem illustrating program use is presented.

A Theoretical Investigation of Compliant Surface Journal Bearings

The problem of the compliant surface journal bearing is investigated. The mathematical problem is divided into two parts, the elasticity problem and the fluid problem. The equations of linear elasticity, which represent the elasticity problem, are solved; (a) by expansion of the solution in eigenfunctions (b) by the Raleigh Ritz method, and (c) by a collocation method. Reynolds’ equation, which represents the fluid problem, is then coupled with the solution to the elasticity problem. The corresponding finite difference representation of Reynolds’ equation, which is a set of fourth-order nonlinear algebraic equations, is inverted by Newton iteration. Finally, numerical results are presented.

Performance Characteristics of Spiral-Groove and Shrouded Rayleigh Step Profiles for High-Speed Noncontacting Gas Seals

Current methods in gas lubrication have been used in this paper to analyze the gas-film characteristics in a high-speed, face-type gas seal. Detailed analyses are presented for two different surface geometries, the spiral-groove-orifice seal and the shrouded Rayleigh step seal. Results are presented in three parts. The first part shows the performance of a spiral-groove seal without the orifices, and also the difference in performance when the grooves are located at the high pressure, low pressure, or both sides. The second part gives typical performance of a nonparallel film profile for the spiral-groove-orifice seal as well as for the shrouded Rayleigh step seal. In the last part, a comparison is made between the two seal geometries on their tolerance to coning or dishing under a constant seal load.

On the Analytical and Experimental Investigation of a Hydrostatic, Axisymmetric Compliant-Surface Thrust Bearing

The paper presents experimental and theoretical data on the axisymmetric hydrostatic thrust bearing with one bonded compliant surface. The theoretical results are exact and are based on linear elasticity theory. The effects of compliance on the behavior of the thrust bearing are discussed and illustrated.