Accuracy and safety of 3D printed surgical guides combined with monitored guidewires for placement of cervicothoracic pedicle screws: Technical note

Subaxial cervical pedicle screws provide rigid fixation, but their placement poses an important neurovascular injury risk. 3D printed guides have successfully been used to place pedicle screws, but experience in the subaxial cervical spine is limited. We present a case of cervicothoracic dissociation after a pathological fracture due to tumour involvement of the upper thoracic spine, causing paraparesis and intense pain. The cervicothoracic junction is of difficult visualization on fluoroscopy and the patients' severe instability made navigation unreliable. 3D printed individualized guidewire guides were used to help place canulated pedicle screws from C4 to T6. We successfully report the use of impedance guidewire monitoring to prevent pedicle violation and improve procedure safety.

Ex vivo UV-vis and FTIR photoacoustic spectroscopy of natural nanoemulsions from cellulose nanocrystals and saponins topically applied into the skin: Diffusion rates and physicochemical evaluation

Nanoemulsions are increasingly gaining importance in the development of topically applied medicine and cosmetic products because their small droplets favor the penetration rates of active compounds into the body. In this scenario, the measurements of their diffusion rates as well as eventual physicochemical changes in the target tissues are of utmost importance. It is also recognized that the use of natural surfactants can avoid allergic reactions as frequently observed for synthetic products. The natural saponins extracted from Sapindus Saponaria have the property of forming foam and are exploited as biocompatible and biodegradable, while cellulose nanocrystals are known to increase the stability of a formulation avoiding the coalescence of drops at the interface. Therefore, nanoemulsions combining natural saponins and cellulose nanocrystals are promising systems that may facilitate greater diffusion rates of molecules into the skin, being candidates to substitute synthetic formulations. This study applied the Photoacoustic Spectroscopy technique to measure the diffusion rates and the physicochemical properties of nanoemulsified formulations containing saponins and cellulose nanocrystals topically applied to the skin. The ex vivo study combined the first-time photoacoustic measurements performed in both ultraviolet-visible and mid-infrared spectral regions. The toxicity of these formulations in L929 cells was also evaluated. The results showed that the formulations were able to propagate throughout the skin to a depth of approximately 756 μm, reaching the dermal side. The non-observation of absorbing band shifting or new bands in the FTIR spectra suggests that there were no structural changes in the skin as well as in the formulations after the nanoemulsions administration. The cytotoxicity results showed that the increase of cellulose nanocrystals concentration decreased cellular toxicity. In conclusion, the results demonstrated the advantage of combining photoacoustic methods in the ultraviolet-visible and mid-infrared spectral regions to analyze drug diffusion and interaction with the skin tissues. Both methods complement each other, allowing the confirmation of the nanoemulsion diffusion through the skin and also suggesting there were no detectable physicochemical changes in the tissues. Formulations stabilized with saponins and cellulose nanocrystals showed great potential for the development of topically administered cosmetics and drugs.

Furoxan derivatives demonstrated in vivo efficacy by reducing Mycobacterium tuberculosis to undetectable levels in a mouse model of infection

OBJECTIVES

The most recent survey conducted by the World Health Organization described Tuberculosis (TB) as one of the top 10 causes of death and the leading cause of death from a single infectious agent. The increasing number of TB-resistant cases has contributed to this scenario. In light of this, new strategies to control and treat the disease are necessary. Our research group has previously described furoxan derivatives as promising scaffolds to be explored as new antitubercular drugs.

RESULTS

Two of these furoxan derivatives, (14b) and (14c), demonstrated a high selectivity against Mycobacterium tuberculosis. The compounds (14b) and (14c) were also active against a latent M. tuberculosis strain, with MIC₉₀ values of 6.67 μM and 9.84 μM, respectively; they were also active against monoresistant strains (MIC₉₀ values ranging from 0.61 to 20.42 μM) and clinical MDR strains (MIC₉₀ values ranging from 3.09 to 42.95 μM). Time-kill experiments with compound (14c) showed early bactericidal effects that were superior to those of the first- and second-line anti-tuberculosis drugs currently used in therapy. The safety of compounds (14b) and (14c) was demonstrated by the Ames test because these molecules were not mutagenic under the tested conditions. Finally, we confirmed the safety, and high efficacy of compounds (14b) and (14c), which reduced M. tuberculosis to undetectable levels in a mouse aerosol model of infection.

CONCLUSION

Altogether, we have identified two advanced lead compounds, (14b) and (14c), as novel promising candidates for the treatment of TB infection.

IL-1β dominates the promucin secretory cytokine profile in cystic fibrosis

Cystic fibrosis (CF) lung disease is characterized by early and persistent mucus accumulation and neutrophilic inflammation in the distal airways. Identification of the factors in CF mucopurulent secretions that perpetuate CF mucoinflammation may provide strategies for novel CF pharmacotherapies. We show that IL-1β, with IL-1α, dominated the mucin prosecretory activities of supernatants of airway mucopurulent secretions (SAMS). Like SAMS, IL-1β alone induced MUC5B and MUC5AC protein secretion and mucus hyperconcentration in CF human bronchial epithelial (HBE) cells. Mechanistically, IL-1β induced the sterile α motif-pointed domain containing ETS transcription factor (SPDEF) and downstream endoplasmic reticulum to nucleus signaling 2 (ERN2) to upregulate mucin gene expression. Increased mRNA levels of IL1B, SPDEF, and ERN2 were associated with increased MUC5B and MUC5AC expression in the distal airways of excised CF lungs. Administration of an IL-1 receptor antagonist (IL-1Ra) blocked SAMS-induced expression of mucins and proinflammatory mediators in CF HBE cells. In conclusion, IL-1α and IL-1β are upstream components of a signaling pathway, including IL-1R1 and downstream SPDEF and ERN2, that generate a positive feedback cycle capable of producing persistent mucus hyperconcentration and IL-1α and/or IL-1β-mediated neutrophilic inflammation in the absence of infection in CF airways. Targeting this pathway therapeutically may ameliorate mucus obstruction and inflammation-induced structural damage in young CF children.

In search of new paradigms for epididymal health and disease: innate immunity, inflammatory mediators, and steroid hormones

The primary job of the epididymis is to mature and protect the luminally transiting spermatozoa. Mounting evidence is showing that innate immune components [including Toll-like receptors (TLRs) and antimicrobial proteins, among which are β-defensins] and inflammatory mediators, under the primary influence of androgens, participate in the cellular and molecular processes that define this tissue. Here, we present an overview of the contributions of these signaling pathway components during epididymal homeostasis and discuss the hypotheses as to their involvement in epididymitis, the most common urological inflammatory condition in men, frequently impairing their fertility. Drawing primarily from rodent models, we also focus on how the distribution and functional expression of innate immune components are differentially regulated in the prenatal developing epididymis, providing new insights into the disruption of these signaling pathways throughout the lifespan. Male infertility is caused by a variety of conditions, such as congenital malformations, genetic and endocrine disorders, exposure to environmental toxicants, and inflammatory/infectious conditions. More than one-third of infertile men with an idiopathic condition cannot currently be adequately diagnosed. Thinking about the innate immunity and inflammation context of the epididymis may provide new insights and directions as to how these systems contribute to male fertility, as well as also uncover urological and andrological outcomes that may aid clinicians in diagnosing and preventing epididymal pathologies.

M2 macrophages coexist with a Th1-driven profile in periapical cysts

AIM

To evaluate the participation of both Th1 and Th2 responses in periapical cysts by assessing the presence of M2 macrophages, as well as acute IL-1 β, TNF-α and IL-6 cytokines.

METHODOLOGY

Twenty-four cases of periapical cysts were selected. Immuno-expressions of IL-1 β, IL-6, TNF-α and CD163 were analysed in the cystic capsules in both superficial and deeper regions. Data were analysed with paired Wilcoxon test and Spearman correlation coefficient (P ≤ 0.05).

RESULTS

There was a higher expression of IL-1β, IL-6, TNF-α and M2 macrophages in the superficial region (P < 0.001) of cystic capsules. All acute cytokines had significant positive correlations amongst them regardless of the cystic capsule region. Regarding CD163, positive correlations occurred only with TNF-α (P = 0.007; r = 0.537) and IL-6 (P = 0.018; r = 0.478) in the superficial regions of the cystic capsule.

CONCLUSIONS

M2 macrophages participated actively in the inflammatory response of periapical cysts and correlated with the expression of certain acute Th1-related cytokines. This illustrates the coexistence of an acute and chronic Th2-driven immune response in these lesions. Although M2 macrophages favour the healing process, their presence is not sufficient for periapical cyst regression, once an acute active response has occurred due to an infectious stimuli.

alpha(1)-adrenergic receptors mediate LH-releasing hormone secretion through phospholipases C and A(2) in immortalized hypothalamic neurons

Norepinephrine has long been known to stimulate the pulsatile and preovulatory release of LH-releasing hormone (LHRH). In vivo and in vitro studies indicate that these effects are mediated primarily through alpha(1)-adrenergic receptors (alpha(1)-ARs). With the immortalized hypothalamic LHRH neurons, we have found that alpha(1)-adrenergic agents directly stimulate the secretion of LHRH in a dose-dependent manner. Ligand binding and RNA studies demonstrate that the GT1 cells contain both alpha(1A)- and alpha(1B)-ARs. Competition binding experiments show that approximately 75% of the binding is due to alpha(1B)-ARs; the remainder is made up of alpha(1A)-ARs. Receptor activation leads to stimulation of PLC. PLC beta 1 and PLC beta 3 are expressed in GT1 neurons, and these PLCs are probably responsible for the release of diacylglycerol and IP as well as the increase in intracellular calcium. The mobilization of cytoplasmic calcium is sufficient to stimulate cytosolic PLA(2) (cPLA(2)) and release arachidonic acid. A dissection of the contributions of the phospholipases to LHRH secretion suggests that cPLA(2) acts downstream of PLC and that it significantly augments the PLC-stimulated LHRH secretory response. Inasmuch as the alpha(1)-ARs are known to play a critical role in LHRH physiology, we propose that both PLC and cPLA(2) are critical in regulating and amplifying LHRH release.

Cloning and functional characterization of two murine uridine nucleotide receptors reveal a potential target for correcting ion transport deficiency in cystic fibrosis gallbladder

Extracellular nucleotides regulate transepithelial ion secretion via multiple receptors. The P2Y(2) receptor is the predominant transducer of chloride transport responses to nucleotides in the airways, but the P2 receptors that control ion transport in gastrointestinal epithelia have not been identified. UTP and UDP promote chloride secretion in mouse jejuna and gallbladder epithelia, respectively, and these responses were unaffected by P2Y(2) receptor gene disruption. Pharmacological data suggested the involvement of P2Y(4) and P2Y(6) receptors in gastrointestinal responses. To identify the P2Y receptors responsible for the gastrointestinal actions of UTP and UDP, we have cloned the murine P2Y(4) and P2Y(6) receptors and have stably expressed each in a null cell line to examine the nucleotide-promoted inositol phosphate formation and intracellular Ca(2+) mobilization. The (m)P2Y(4) receptor was potently, but not selectively, activated by UTP (UTP > or = ATP >ITP > GTP > CTP), and it was not activated by UDP or ADP. The (m)P2Y(6) receptor was highly selective for UDP (UDP >> ADP = GDP). The nucleotide selectivities observed with the recombinant (m)P2Y(4) and (m)P2Y(6) receptors resemble those for nucleotide-promoted chloride transport in murine P2Y(2)(-/-) jejuna and gallbladder epithelial cells, respectively. Ion transport responses to nucleotide additions were examined in freshly excised tissues from cystic fibrosis transmembrane regulator-deficient mice. Although the effect of UTP on jejunal short-circuit current (I(sc)) was impaired in the CF mouse, UDP-promoted I(sc) changes were not affected in CF gallbladder epithelium, suggesting that the P2Y(6) receptor is a target for treatment of CF gallbladder disease.

Polarized signaling via purinoceptors in normal and cystic fibrosis airway epithelia

Airway epithelia are confronted with distinct signals emanating from the luminal and/or serosal environments. This study tested whether airway epithelia exhibit polarized intracellular free calcium (Ca(2+)(i)) and anion secretory responses to 5' triphosphate nucleotides (ATP/UTP), which may be released across both barriers of these epithelia. In both normal and cystic fibrosis (CF) airway epithelia, mucosal exposure to ATP/UTP increased Ca(2+)(i) and anion secretion, but both responses were greater in magnitude for CF epithelia. In CF epithelia, the mucosal nucleotide-induced response was mediated exclusively via Ca(2+)(i) interacting with a Ca(2+)-activated Cl(-) channel (CaCC). In normal airway epithelia (but not CF), nucleotides stimulated a component of anion secretion via a chelerythrine-sensitive, Ca(2+)-independent PKC activation of cystic fibrosis transmembrane conductance regulator. In normal and CF airway epithelia, serosally applied ATP or UTP were equally effective in mobilizing Ca(2+)(i). However, serosally applied nucleotides failed to induce anion transport in CF epithelia, whereas a PKC-regulated anion secretory response was detected in normal airway epithelia. We conclude that (1) in normal nasal epithelium, apical/basolateral purinergic receptor activation by ATP/UTP regulates separate Ca(2+)-sensitive and Ca(2+)-insensitive (PKC-mediated) anion conductances; (2) in CF airway epithelia, the mucosal ATP/UTP-dependent anion secretory response is mediated exclusively via Ca(2+)(i); and (3) Ca(2+)(i) regulation of the Ca(2+)-sensitive anion conductance (via CaCC) is compartmentalized in both CF and normal airway epithelia, with basolaterally released Ca(2+)(i) failing to activate CaCC in both epithelia.

Signaling pathways between the plasma membrane and endoplasmic reticulum calcium stores

This review discusses multiple ways in which the endoplasmic reticulum participates in and is influenced by signal transduction pathways. The endoplasmic reticulum provides a Ca2+ store that can be mobilized either by calcium-induced calcium release or by the diffusible messenger inositol 1,4,5-trisphosphate. Depletion of endoplasmic reticulum Ca2+ stores provides a signal that activates surface membrane Ca2+ channels, a process known as capacitative calcium entry. Depletion of endoplasmic reticulum stores can also signal long-term cellular responses such as gene expression and programmed cell death or apoptosis. In addition to serving as a source of cellular signals, the endoplasmic reticulum is also functionally and structurally modified by the Ca2+ and protein kinase C pathways. Elevated cytoplasmic Ca2+ causes a rearrangement and fragmentation of endoplasmic reticulum membranes. Protein kinase C activation reduces the storage capacity of the endoplasmic reticulum Ca2+ pool. In some cell types, protein kinase C inhibits capacitative calcium entry. Protein kinase C activation also protects the endoplasmic reticulum from the structural effects of high cytoplasmic Ca2+. The emerging view is one of a complex network of pathways through which the endoplasmic reticulum and the Ca2+ and protein kinase C signaling pathways interact at various levels regulating cellular structure and function.

Effects of elevated cytoplasmic calcium and protein kinase C on endoplasmic reticulum structure and function in HEK293 cells

In human embryonic kidney (HEK) cells stably transfected with green fluorescent protein targeted to the endoplasmic reticulum (ER), elevation of intracellular Ca2+ ([Ca2+]i) altered ER morphology, making it appear punctate. Electron microscopy revealed that these punctate structures represented circular and branched rearrangements of the endoplasmic reticulum, but did not involve obvious swelling or pathological fragmentation. Activation of protein kinase C with phorbol 12-myristate 13-acetate (PMA), prevented the effects of ionomycin on ER structure without affecting the elevation of [Ca2+]i. These results suggest that protein kinase C activation alters cytoplasmic or ER components underlying the effects of high [Ca2+]i on ER structure. Treatment of HEK cells with PMA also reduced the size of the thapsigargin-sensitive Ca2+ pool and inhibited Ca2+ entry in response to thapsigargin. Thus, protein kinase C activation has multiple actions on the calcium storage and signalling function of the endoplasmic reticulum in HEK cells: (1) reduced intracellular Ca2+ storage capacity, (2) inhibition of capacitative Ca2+ entry, and (3) protection of the endoplasmic reticulum against the effects of high [Ca2+]i.

Calcium signalling in exocrine glands

In exocrine gland cells, stimulation of a variety of surface receptors initiates a Ca2+ signalling system through activation of a polyphosphoinositide-specific phospholipase C. One product of phospholipase C activity, inositol 1,4,5-trisphosphate ((1,4,5)IP3), signals the release of intracellular Ca2+. Release of intracellular Ca2+ is followed by entry of Ca2+ into the cell across the plasma membrane. The mechanism by which Ca2+ entry is regulated is not well understood, although it is clear that (1,4,5)IP3 plays an important role. One hypothesis suggests that Ca2+ entry is triggered by the depletion of intracellular Ca2+ stores by (1,4,5)IP3, a process termed 'capacitative calcium entry'. The purpose of these studies is to gain understanding into the processes controlling capacitative calcium entry in exocrine gland cells.

Role of the cytoskeleton in calcium signaling in NIH 3T3 cells. An intact cytoskeleton is required for agonist-induced [Ca2+]i signaling, but not for capacitative calcium entry

Treatment of NIH 3T3 cells with cytochalasin D (10 microM, 1 h at 37 degrees C) disrupted the actin cytoskeleton and changed the cells from a planar, extended morphology, to a rounded shape. Calcium mobilization by ATP or by platelet-derived growth factor was abolished, while the ability of thapsigargin (2 microM) to empty calcium stores and activate calcium influx was unaffected. Similar experiments with nocodazole to depolymerize the tubulin network yielded identical results. Platelet-derived growth factor induced an increase in inositol phosphates, and this increase was undiminished in the presence of cytochalasin D. Therefore, the blockade of agonist responses by this drug does not result from decreased phospholipase C. Injection of inositol 1,4,5-trisphosphate (IP3) released calcium to the same extent in control and cytochalasin D-treated cells. Confocal microscopic studies revealed a significant rearrangement of the endoplasmic reticulum after cytochalasin D treatment. Thus, disruption of the cytoskeleton blocks agonist-elicited [Ca2+]i mobilization, but this effect does not result from a lower calcium storage capacity, impaired function of the IP3 receptor, or diminished phospholipase C activity. We suggest that cytoskeletal disruption alters the spatial relationship between phospholipase C and IP3 receptors, impairing phospholipase C-dependent calcium signaling. Capacitative calcium entry was not altered under these conditions, indicating that the coupling between depletion of intracellular calcium stores and calcium entry does not depend on a precise structural relationship between intracellular stores and plasma membrane calcium channels.

Differential effects of protein kinase C activation on calcium storage and capacitative calcium entry in NIH 3T3 cells

In NIH 3T3 cells, treatment with phorbol 12-myristate 13-acetate (PMA) reduced the release of Ca2+ by thapsigargin, but did not activate Ca2+ entry; Ca2+ influx was triggered after the residual pool was emptied by thapsigargin, and this Ca2+ influx was similar to that induced by thapsigargin in control cells. The effect of PMA was due to decreased Ca2+ storage because 1) Ca2+ release by ionomycin was similarly affected by PMA, and in both control and PMA-treated cells, ionomycin did not release Ca2+ following thapsigargin treatment; 2) PMA reduced 45Ca2+ accumulation; and 3) studies with Ca2+ indicator compartmentalized into the endoplasmic reticulum indicated that stored Ca2+ was reduced by PMA. Although PMA did not itself activate Ca2+ entry, PMA potentiated Ca2+ entry with low concentrations of cyclopiazonic acid. With a somewhat higher concentration of cyclopiazonic acid, PMA had no effect on calcium entry. Thus, protein kinase C has two apparent actions on calcium signaling in NIH 3T3 cells: 1) reduced intracellular Ca2+ storage capacity and 2) augmented calcium entry with submaximal intracellular Ca2+ pool depletion. These actions indicate a complex and potentially important role for the protein kinase C system in calcium homeostasis in this cell type.

Cell type-specific modes of feedback regulation of capacitative calcium entry

The Ca2+-ATPase inhibitor, thapsigargin, activated Ca2+ entry into pancreatic acinar cells, a process known as capacitative calcium entry. In cells loaded with the calcium chelator BAPTA, the transient Ca2+ release was blunted and the rise of [Ca2+]i on readdition of Ca2+ was slowed. However, the steady-state [Ca2+]i due to Ca2+ entry was substantially augmented compared with control cells. This indicates that [Ca2+]i exerts a negative feedback on Ca2+ entry from a compartment buffered by BAPTA and separated from the bulk of cytoplasmic Ca2+. This interaction probably occurs close to the calcium channel where [Ca2+] is higher than in the bulk of the cytoplasm. In support of this interpretation, the slower Ca2+ chelator, EGTA, also blunted the release of Ca2+ and slowed the rise of the sustained [Ca2+]i phase but failed to augment steady-state [Ca2+]i. In contrast, Ca2+ entry in NIH 3T3 cells was characterized by a transient rise of [Ca2+]i that decays to near prestimulus levels. This decay in Ca2+ entry also results from negative feedback by Ca2+ because the decrease in Ca2+ entry was reversed by incubation in a Ca2+-deficient medium. However, unlike its effects in acinar cells, BAPTA neither augmented steady-state [Ca2+]i nor prevented the inactivation of entry. Rather, in BAPTA-loaded cells, [Ca2+]i failed to increase substantially suggesting that negative regulation by Ca2+ may occur at a site distinct from the cytoplasmic compartment and inaccessible to cytoplasmic BAPTA. These two distinct types of feedback behavior may indicate subtypes of store-operated calcium channels expressed in different cells or a single type of channel which is differentially regulated in a cell type-specific manner.

[Comparative study of the names of subjects in the official curriculum with those used by nursing schools in the southeast of Brazil]

The authors compared the names of the subjects that form the official curriculum to those offered by the schools of nursing in the South East of Brazil. Forty eight schools replied to the questionnaire, a variance in the names and numbers of the subjects offered was found, indicating a difference in the way each school performs the curriculum.

Parathyroid hormone inhibits Na(+)-K(+)-ATPase through a cytochrome P-450 pathway

We have previously shown that parathyroid hormone (PTH)-(1-34) or its analogue PTH-(3-34) inhibits proximal tubule (PT) Na(+)-K(+)-adenosinetriphosphatase (Na(+)-K(+)-ATPase) activity independently of adenosine 3',5'-cyclic monophosphate generation. The present study used PT suspensions to investigate the signaling pathway responsible for this hormonal action. PTH-(1-34) and PTH-(3-34) significantly increased the release of arachidonic acid (AA) compared with control tubules, suggesting activation of phospholipase A2 (PLA2). AA, 10(-6) M, mimicked the inhibition of the pump by 10(-8) M PTH-(3-34), and together were not additive. Eicosatetraynoic acid, 3 microM, a general inhibitor of AA metabolism, blocked the PTH action. Indomethacin, 10 microM, an inhibitor of AA-dependent cyclooxygenase, did not prevent the PTH action, but 2 microM 7-ethoxyresorufin, a cytochrome P-450 inhibitor, prevented the PTH effect. 20-Hydroxyeicosatetraenoic acid (20-HETE), the main product of P-450 metabolism in PT, inhibited Na(+)-K(+)-ATPase activity to the same extent as 10(-8) M PTH-(3-34), was not additive with PTH, and was maximally inhibitory at 10(-7) M. To further investigate the signaling pathway responsible for PTH-activated PLA2, we tested the effect of PTH on cytoplasmic free Ca2+ ([Ca2+]i). PTH-(1-34), 10(-7) M, did not affect [Ca2+]i, although 10(-8) M angiotensin II promoted a Ca2+ transient. Treatment of PT with pertussis toxin (PTX) did not prevent the PTH action.(ABSTRACT TRUNCATED AT 250 WORDS)