Effects of anesthetics on nociceptive sensory evoked potentials by intraepidermal noxious electrical stimulation of A-δ fibers.

PURPOSE: Generation of nociceptive sensory evoked potentials (NEPs) by selective stimulation of nociceptive intraepidermal nerve fibers is a simple technique which could be used as intraoperative nociception monitor. We evaluated the effects of remifentanil, propofol and sevoflurane on NEPs by this technique. METHODS: Patients undergoing general anesthesia were assigned to groups in two studies. A-δ fiber selective NEPs were recorded. Study 1: NEPs were recorded at control, under anesthetics administration: remifentanil at an effect-site concentration (Ce) of 1.0 ng/mL (n = 10), propofol at Ce of 0.5 µg/mL (n = 10), or sevoflurane at 0.2 minimum alveolar concentration (MAC) (n = 10), and recovery from the anesthetics. Study 2: NEPs were recorded at control and under administration of higher dose anesthetics: propofol at Ce of 0.5 and 1.0 µg/mL (n = 10) or sevoflurane at 0.2 and 0.5 MAC (n = 10). A P-value < 0.016 was considered statistically significant in multiple analyses. RESULTS: Study 1: Remifentanil at Ce of 1.0 ng/mL significantly suppressed the amplitude of NEPs (mean amplitude (standard deviation) of control vs. remifentanil administration: 16.8 µV (3.8) vs. 10.1 µV (2.5), P < 0.001). Propofol and sevoflurane did not suppress the amplitude significantly. Study 2: Propofol at Ce of 0.5 and 1.0 µg/mL and sevoflurane at 0.2 and 0.5 MAC did not suppress the amplitude significantly. CONCLUSION: The amplitude of A-δ fiber selective NEPs was suppressed by remifentanil but not propofol or sevoflurane. NEPs with intraepidermal electrical stimulation can assess the analgesic effect of anesthetics. CLINICAL TRIAL NUMBER: UMIN000038214 REGISTRY URL: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000043328.

The Immunomodulating Effect of Phlorotannins from a Brown Alga, Eisenia nipponica, on Mice Stimulated with Ovalbumin through T Cell Regulation.

The immunomodulating effect of phlorotannin was investigated in mice stimulated by ovalbumin. When analyzing the main components of phlorotannin concentrate (PTC) from Eisenia nipponica, seven phlorotannins [eckol, 6,6'-bieckol, 6,8'-bieckol, 8,8'-bieckol, dieckol, phlorofucofuroeckol (PFF)-A, and PFF-B] were detected. These phlorotannins accounted for approximately 80% of PTC. Oral administration of PTC to mice daily for 21 days reduced serum immunoglobulin E (IgE) and total IgG1 levels attributable to Th2 cells. The production of splenic cytokines [interleukin (IL)-10 and transforming growth factor-ß1] and Treg cell-mediated expression of forkhead box protein P3 mRNA were significantly increased whereas the production of inflammatory cytokines (interferon-γ, IL-4, IL-5, and IL-17) by Th1, Th2, and Th17 cells was markedly suppressed. IL-21 production and basic leucine zipper ATF-like transcription factor mRNA expression attributable to follicular helper T (Tfh) cells were also suppressed. Flow cytometric analyses demonstrated increased number of Treg cells despite a decrease in the total T cell population. An increase in total B cells was also observed by the flow cytometric analyses in addition to increases in IL-10 production, which activates B cells. In contrast, the significantly suppressed production of inflammatory cytokines and moderate increase in Treg cell subpopulation indicated a direct impact of PTC on inflammatory lymphocytes (Th1, Th2, Th17, and Tfh). Thus, PTC may exert antiallergic effects by immunomodulation of T cells and inactivation of inflammatory lymphocyte.

Crystal structures clarify cofactor binding of plant tyrosine decarboxylase.

Plant tyrosine decarboxylase (TyrDC) is a group II pyridoxal 5'-phosphate (PLP)-dependent decarboxylase that mainly catalyzes the decarboxylation of tyrosine to tyramine. This is biologically important for diverting essential primary metabolites into secondary metabolic pathways. Intensive studies have characterized the effective of PLP-binding and the substrate specificity of mammalian 3,4-dihydroxyphenyl-l-alanine (Dopa) decarboxylases, a member of group II PLP-dependent decarboxylase. However, the characteristics of PLP binding and substrate specificity of plant TyrDCs remain unknown. In this study, we focus on the PLP binding manner, and determined the crystal structures of the apo and PLP binding form of type II TyrDC from Papaver somniferum (PsTyrDCII and PsTyrDCII-PLP). The structures showed that, unlike mammalian Dopa decarboxylase, the binding of PLP does not induce distinct conformational changes of PsTyrDCII regarding the overall structure, but the PLP binding pocket displays conformational changes at Phe124, His203 and Thr262. Combining structural comparation and the obtained biochemical findings, it is demonstrated that PsTyrDCII does not binds PLP tightly. Such characteristics of PLP binding may be required by its catalytic reaction and substrate binding. The activity of TyrDC probably regulated by the concentration of PLP in cells.

Differential effects of sevoflurane and propofol on an electroretinogram and visual evoked potentials.

The purpose of this study was to simultaneously evaluate the effects of sevoflurane and propofol on an electroretinogram (ERG) and visual evoked potentials (VEPs). Twenty-four patients scheduled for elective surgery under general anesthesia were allocated randomly to receive either sevoflurane (group S) or propofol (group P). An ERG and VEPs were recorded in an awake state and during anesthesia with three different minimum alveolar concentrations (MAC; 0.5, 1.0, and 1.5) of sevoflurane in group S or with three different effect-site concentrations (Ce) of 2, 3, and 4 µg/ml by using a target-controlled infusion technique in group P. Sevoflurane and propofol had little effect on amplitudes of the ERG b-wave. Sevoflurane significantly attenuated the amplitudes of VEP N75-P100 at 0.5, 1.0, and 1.5 MAC. Propofol did not significantly decrease the amplitude of VEPs at Ce of 2 or 3 µg/ml but significantly decreased it at Ce of 4 µg/ml. In summary, propofol and sevoflurane at clinical concentrations had little effect on the amplitude of an ERG. Sevoflurane attenuated the amplitudes of VEPs even at low concentrations. Propofol also attenuated the amplitudes of VEPs to a lesser extent compared to sevoflurane.

Systematic chemical screening identifies disulfiram as a repurposed drug that enhances sensitivity to cisplatin in bladder cancer: a summary of preclinical studies.

BACKGROUND: Since the standard gemcitabine and cisplatin (GC) chemotherapy for advanced bladder cancer yields limited therapeutic effect due to chemoresistance, it is a clinical challenge to enhance sensitivity to GC. METHODS: We performed high-throughput screening by using a library of known chemicals and repositionable drugs. A total of 2098 compounds were administered alone or with GC to human bladder cancer cells, and chemicals that enhanced GC effects were screened. RESULTS: Disulfiram (DSF), an anti-alcoholism drug, was identified as a candidate showing synergistic effects with cisplatin but not with gemcitabine in multiple cell lines. Co-administration of DSF with GC affected cellular localisation of a cisplatin efflux transporter ATP7A, increased DNA-platinum adducts and promoted apoptosis. Micellar DSF nanoparticles (DSF-NP) that stabilised DSF in vivo, enhanced the inhibitory effect of cisplatin in patient-derived and cell-based xenograft models without severe adverse effects. A drug susceptibility evaluation system by using cancer tissue-originated spheroid culture showed promise in identifying cases who would benefit from DSF with cisplatin. CONCLUSIONS: The present study highlighted the advantage of drug repurposing to enhance the efficacy of anticancer chemotherapy. Repurposing of DSF to a chemotherapy sensitiser may provide additional efficacy with less expense by using an available drug with a well-characterised safety profile.

Transcranial motor-evoked potentials of laryngeal muscles for intraoperative neuromonitoring of the vagus nerve during thyroid surgery.

PURPOSE: The aim of this study was to elucidate normative features of vagal motor-evoked potentials (MEPs) induced by transcranial electrical stimulation (TES) and to determine the influence of functional decline of the recurrent laryngeal nerve (RLN) on vagal MEPs during thyroid surgery. METHODS: A total of 54 patients undergoing elective thyroid surgery under general anesthesia were enrolled in this study. Vagal MEPs induced by TES were measured from the vocal cord using one of two types of electrodes (wire type or wide and flat type) mounted on an endotracheal tube. We investigated the effects of stimulation intensity and train pulse number on vagal MEP amplitude, the time course of vagal MEP amplitude during surgery, and the effects of functional decline of the RLN on vagal MEPs. RESULTS: The success rate of vagal MEP monitoring with wide- and flat-type electrodes was significantly higher than that with wire-type electrodes. Reliable vagal MEPs were obtained at a stimulation intensity of approximately 300 V with 3 or more pulses in 91% of the patients without preoperative RLN palsy (RLNP), and the amplitude was augmented with increasing stimulation intensity and train pulse number. Vagal MEP amplitude decreased during thyroid surgery and then partially recovered at the end of surgery. Vagal MEP amplitude recorded from the electrode ipsilateral to preoperative RLNP was significantly lower than that on the contralateral intact side. CONCLUSION: Vagal MEPs induced by TES can be obtained with a high success rate during thyroid surgery and would reflect functional status of the RLN.

Functional analyses of chitinases in the moss Physcomitrella patens: chitin oligosaccharide-induced gene expression and enzymatic characterization.

Plant chitinases play diverse roles including defense against pathogenic fungi. Using reverse-transcription quantitative PCR analysis, we found that six chitinase (PpChi) genes and two genes for chitin elicitor receptor kinases (PpCERKs) are expressed at considerable levels in the moss Physcomitrella patens subsp. patens. The expressed PpChis belonged to glycoside hydrolase family 19 (class I: PpChi-Ia and -Ib; class II: PpChi-IIa and -IIc; and class IV: PpChi-IV) and to glycoside hydrolase family 18 (class V: PpChi-Vb). Treatment with chitin tetramer or hexamer increased the expression of class I and IV PpChi genes and decreased that of class II PpChi genes. Recombinant PpChi-Ia, PpChi-IV, and PpChi-Vb were characterized. PpChi-IV exhibited higher activity against chitin tetramer and pentamer than PpChi-Ia did. PpChi-Vb showed transglycosylation activity and PpChi-Ia inhibited fungal growth. These results suggest that chitinases of different classes play different roles in defense mechanism of moss plant against fungal pathogens.

Length of the dark period affects flower opening and the expression of circadian-clock associated genes as well as xyloglucan endotransglucosylase/hydrolase genes in petals of morning glory (Ipomoea nil).

KEY MESSAGE: We isolated differentially expressed and dark-responsive genes during flower development and opening in petals of morning glory. Flower opening usually depends on petal expansion and is regulated by both genetic and environmental factors. Flower opening in morning glory (Ipomoea nil) is controlled by the dark/light regime just prior to opening. Opening was normal after 8- or 12-h dark periods but progressed very slowly after a 4-h dark period or in continuous light. Four genes (InXTH1-InXTH4) encoding xyloglucan endotransglucosylase/hydrolases (XTHs) and three genes (InEXPA1-InEXPA3) encoding alpha-expansins (EXPAs) were isolated. The expression patterns of InXTH2, InXTH3, and InXTH4 in petals were closely correlated with the rate of flower opening controlled by the length of the dark period prior to opening, but those of the EXPA genes were not. The expression pattern of InXTH1 gene was closely correlated with petal elongation. Suppression subtractive hybridization was used to isolate dark-responsive genes accompanying flower opening. The expressions of ten isolated genes were associated with the length of the dark period prior to flower opening. One gene was highly homologous to Arabidopsis pseudo-response regulator7, which is associated with the circadian clock and phytochrome signaling; another to Arabidopsis REVEILLE1, which affects the output of the circadian clock. Other genes were related to light responses, plant hormone effects and signal transduction. The possible roles of these genes in regulation of flower opening are discussed.

Second-degree atrioventricular block induced by electrical stimulation of transcranial motor-evoked potential: a case report.

BACKGROUND: Although several complications of transcranial motor-evoked potentials (Tc-MEPs) have been reported, reports of arrhythmias during Tc-MEP are very rare. CASE PRESENTATION: A 71-year-old woman underwent transforaminal lumbar interbody fusion under general anesthesia, with intraoperative Tc-MEP monitoring. Preoperative electrocardiography showed an incomplete right bundle branch block but no cardiovascular events in her life. After induction of anesthesia, Tc-MEP was recorded prior to the surgery. During the Tc-MEP monitoring, electrocardiography and arterial blood pressure showed a second-degree atrioventricular block, but it improved rapidly at the end of the stimulation, and the patient was hemodynamically stable. Tc-MEP was recorded seven times during surgery; the incidence of P waves without QRS complexes was significantly higher than before stimulation. The surgery was uneventful, and she was discharged eight days postoperatively without complications. CONCLUSIONS: Our case suggests that electrical stimulation for Tc-MEP can cause arrhythmia. Electrocardiography and blood pressure must be closely monitored during Tc-MEP monitoring.

Postoperative hyperammonemic encephalopathy due to unexpected constipation in a patient with hyperornithinemia-hyperammonemia-homocitrullinuria syndrome: a case report.

BACKGROUND: Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is a rare autosomal recessive urea cycle disorder associated with a high risk of exacerbation of hyperammonemia during the perioperative period. Here, we describe an adult patient with HHH syndrome who developed hyperammonemic encephalopathy secondary to postoperative constipation. CASE PRESENTATION: A 52-year-old patient with HHH syndrome underwent intrathecal baclofen pump insertion for lower limb spasticity under general anesthesia. The surgery was uneventful, without any increase in serum ammonia levels. However, after surgery, he was constipated, and on postoperative day (POD) 3, he fell into a coma with an exacerbation of hyperammonemia (894 µg/dL). After administering a glycerin enema, he defecated, leading to a rapid decrease in serum ammonia levels to 165 µg/dL. He regained consciousness, and serum ammonia levels remained stable as long as he defecated. CONCLUSIONS: We suggest strict management of defecation during the perioperative period to prevent hyperammonemia in patients with HHH syndrome.

The effect of six dried and UV-C-irradiated mushrooms powder on lipid oxidation and vitamin D contents of fish meat.

The effect of dried and UV-C-irradiated mushroom powder on lipid oxidation and vitamin D content in fish meat was investigated. To this end, Flammulina velutipes, Grifola frondosa, Hypsizygus marmoreus, Lentinula edodes, Pleurotus eryngii, Pleurotus ostreatus were dried by hot air and irradiated by UV-C and evaluated the effect of these treatments on the components. In general, the ergothioneine content did not change substantially, the total phenolic compound content decreased by hot-air drying, and the ergocalciferol content increased by UV-C irradiation. To the evaluate effect of mushroom powder on lipid oxidation and vitamin D content in fish meat, 5% of the hot air dried and UV-C-irradiated mushroom powder was added to fish meat and oxidized. Consequently, all six mushrooms prevented lipid oxidation, and ergocalciferol content in each mushroom powder remained between 58.2% and 69.7%. Overall, P. eryngii, L. edodes, and P. ostreatus strongly prevented the generation of lipid peroxide and aldehyde.

Successful use of differential target multiplexed spinal cord stimulation for chronic postsurgical abdominal pain.

Introduction: Recent advances in stimulation techniques have improved the efficacy and expanded the applicability of spinal cord stimulation (SCS). Among these techniques, there are no reports on the efficacy of differential target multiplexed (DTM) SCS for chronic postsurgical pain (CPSP) after abdominal surgery. Therefore, we present the successful use of DTM SCS for CPSP after distal pancreatectomy. Methods: A 49-year-old man with hypertension and severe chronic low back pain presented with neuropathic CPSP involving the left abdomen in the area of a laparotomy incision. His pain was refractory to conservative treatment and was rated 10 on a numerical rating scale (NRS). He underwent permanent implantation of a pulse generator after a 14-day trial stimulation. Results: Chronic postsurgical pain was well controlled (NRS 1-2) at a 3-month follow-up with DTM SCS. Conclusion: Differential target multiplexed SCS can be a new treatment option for neuropathic CPSP that is resistant to conservative treatment. It is important to further examine the characteristics of CPSP and identify appropriate candidates for the successful use of DTM SCS.

Differences in 5-Aminolevulinic Acid-Induced Hemodynamic Changes between Patients Undergoing Neurosurgery and Urological Surgery.

INTRODUCTION: Oral 5-aminolevulinic acid (5-ALA) is often used for photodynamic diagnosis-assisted glioma or bladder tumor surgery. 5-ALA affects blood pressure (BP). In fact, hypotension is a well-known adverse effect of 5-ALA in urology. However, information regarding 5-ALA-induced hemodynamic changes in neurosurgery remains limited. Furthermore, the duration of hypotension and how 5-ALA affects the heart rate (HR) are yet to be determined. Thus, in this study, we aimed to elucidate 5-ALA-induced perioperative hemodynamic changes in neurosurgery and urological surgery by examining real-world data. METHODS: Consecutive patients who underwent neurosurgery (neurosurgery patients; 5-ALA-pretreated vs. non-pretreated [17 vs. 16], from January 2014 to March 2021) and urological surgery (urological surgery patients; 5-ALA-pretreated vs. non-pretreated [26 vs. 101], from August 2018 to September 2020) were enrolled. Differences in hemodynamics were evaluated using the linear mixed model. BP and HR in 5-ALA-pretreated patients were compared with those in non-pretreated patients. Differences in 5-ALA-induced preoperative BP changes were compared between the neurosurgery patients and urological surgery patients. RESULTS: 5-ALA scarcely affected the hemodynamics in neurosurgery patients, whereas 5-ALA-induced hemodynamic changes were clearly observed in urological surgery patients. Hemodynamic parameters were found to be not significantly different between 5-ALA-pretreated and non-pretreated neurosurgery patients. The preoperative, intraoperative, and postoperative BP in 5-ALA-pretreated urological surgery patients were significantly lower than those in the non-pretreated patients. Preoperatively, two 5-ALA-pretreated urological surgery patients had severe postural hypotension (systolic BP <50 mmHg), and one of them did not continue with the surgery because of prolonged severe hypotension. The BP in 5-ALA-pretreated urological surgery patients tended to be persistently lower for 9 h after 5-ALA pretreatment. The preoperative and postoperative HR values were higher in 5-ALA-pretreated urological surgery patients. Cumulative incidences of BP reduction and HR elevation were significantly higher in 5-ALA-pretreated urological surgery patients. The preoperative BP reduction in 5-ALA-pretreated urological surgery patients was significantly larger than that in neurosurgery patients. CONCLUSIONS: 5-ALA-induced hemodynamics may differ between neurosurgery patients and urological surgery patients. 5-ALA may affect BP for at least 9 h.

The histamine H1 receptor antagonist hydroxyzine enhances sevoflurane and propofol anesthesia: A quantitative EEG study.

OBJECTIVE: The aim of this study was to determine the anesthesia-promoting effects of hydroxyzine on electroencephalograms during sevoflurane anesthesia and during propofol anesthesia. METHODS: We analyzed 40 patients scheduled for elective surgery under sevoflurane anesthesia (n = 20) or propofol anesthesia (n = 20). Anesthesia was adjusted at a bispectral index value of 50-60, and then 0.5 mg/kg of hydroxyzine was administered intravenously. We analyzed frontal electroencephalograms before and after hydroxyzine injection with power spectral and bicoherence analyses, which are suitable for assessing the anesthetic depth induced by γ-aminobutyric acid (GABA)ergic anesthetics. RESULTS: Hydroxyzine increased the α bicoherence peaks in both sevoflurane anesthesia (mean difference, 11.2%; 95% confidence interval (CI), 7.6 to 14.8; P < 0.001) and propofol anesthesia (mean difference, 5.6%; 95% CI, 1.7 to 9.4; P = 0.008). Hydroxyzine increased the averaged δ bicoherence values in both sevoflurane anesthesia (mean difference, 5.5%; 95% CI, 2.1 to 8.8; P = 0.003) and propofol anesthesia (mean difference, 3.9%; 95% CI, 1.0 to 6.8; P = 0.011). CONCLUSIONS: Hydroxyzine enhances both sevoflurane anesthesia and propofol anesthesia probably by facilitation of GABAergic neural circuit mechanisms. SIGNIFICANCE: The findings provide a new insight into the role of histaminergic neurons during general anesthesia in humans.

Dieckol isolated from a brown alga, Eisenia nipponica, suppresses ear swelling from allergic inflammation in mouse.

We previously found a lipophilic fraction of the methanol/chloroform extract of a brown alga, Eisenia nipponica, that had an antiallergic effect in a murine ear swelling test. In this study, we purified the active component from the lipophilic fraction using high performance liquid chromatography and analyzed the mass and nuclear magnetic resonance spectra. This uncovered the phlorotannin dieckol, which exhibited antiallergic effects in an ear swelling test using mice sensitized by arachidonic acid, 12-O-tetradecanoylphorbol-13-acetate, and oxazolone. Mechanistic investigations indicated that dieckol suppressed degranulation, chemical mediator release, and the expression of mRNA such as cyclooxygenase-2, interleukin-6, and tumor necrosis factor-α in rat basophilic leukemia-2H3 cells. In summary, we isolated dieckol from E. nipponica and demonstrated its antiallergic mechanisms. PRACTICAL APPLICATIONS: As the incidence of allergies increases worldwide, so too does the demand for food components with antiallergic and anti-inflammatory properties. Given this trend, we focused on a brown alga that displays a variety of bioactivities. Here, we have isolated dieckol from the antiallergic lipophilic fraction of E. nipponica and found that it possesses diverse physiological activities that may prevent lifestyle-related diseases. Consequently, dieckol or the alga containing this phlorotannin could be used as a health food ingredient to combat not only allergies, but also variety of disorders including the undesirable effects of aging.

Superoxide Production by the Red Tide-Producing Chattonella marina Complex (Raphidophyceae) Correlates with Toxicity to Aquacultured Fishes.

The marine raphidophyte Chattonella marina complex forms red tides, causing heavy mortalities of aquacultured fishes in temperate coastal waters worldwide. The mechanism for Chattonella fish mortality remains unresolved. Although several toxic chemicals have been proposed as responsible for fish mortality, the cause is still unclear. In this study, we performed toxicity bioassays with red sea bream and yellowtail. We also measured biological parameters potentially related to ichthyotoxicity, such as cell size, superoxide (O2•-) production, and compositions of fatty acids and sugars, in up to eight Chattonella strains to investigate possible correlations with toxicity. There were significant differences in moribundity rates of fish and in all biological parameters among strains. One strain displayed no ichthyotoxicity even at high cell densities. Strains were categorized into three groups based on cell length, but this classification did not significantly correlate with ichthyotoxicity. O2•- production differed by a factor of more than 13 between strains at the late exponential growth phase. O2•- production was significantly correlated with ichthyotoxicity. Differences in fatty acid and sugar contents were not related to ichthyotoxicity. Our study supports the hypothesis that superoxide can directly or indirectly play an important role in the Chattonella-related mortality of aquacultured fishes.

Successful Management of a Patient with Intraoperative Bleeding of More than 80,000 mL and Usefulness of QTc Monitoring for Calcium Correction.

Intraoperative massive bleeding is associated with high rates of mortality and anesthetic management of massive bleeding is challenging because it is necessary to achieve volume resuscitation and electrolyte correction simultaneously during massive transfusion. We report a case of life-threatening bleeding of more than 80,000 mL during liver transplantation in which real-time QTc monitoring was useful for an extremely large amount of calcium administration for treatment of hypocalcemia. A 47-year-old female with a giant liver due to polycystic liver disease was scheduled to undergo liver transplantation. During surgery, life-threatening massive bleeding occurred. The maximum rate of blood loss was approximately 15,000 mL/hr and the total amount of estimated blood loss was 81,600 mL. It was extremely difficult to maintain blood pressure and a risk of cardiac arrest continued due to hypotension. In addition, even though administration of insulin and calcium was performed, electrolyte disturbances of hyperkalemia and hypocalcemia with prolongation of QTc interval occurred. At that time, we visually noticed that the QT interval was shortened in response to bolus calcium administration, and we used the change of real-time QTc interval as a supportive indicator for calcium correction. This monitoring allowed for us to administer calcium at an unusually high rate, by which progression of hypocalcemia was prevented. Levels of hemoglobin and coagulation factors were preserved both by restriction of crystalloid infusion and by a massive transfusion protocol. The patient was extubated without pulmonary edema or cardiac overload and was finally discharged without any sequelae. Intensive and cooperative management for massive transfusion and electrolyte correction using QTc monitoring was considered to be a key for successful management.

Preparation of fibrin hydrogels to promote the recruitment of anti-inflammatory macrophages.

Macrophages play an important role in regulating inflammation and tissue regeneration. In the present study, uniform fibrin hydrogel scaffolds were engineered in millimeters. These scaffolds induced anti-inflammatory macrophages to digest and infiltrate the scaffold. The culture conditions of the fibrin hydrogels decreased the secretion of tumor necrosis factor-α (TNF-α), a pro-inflammatory cytokine, and increased the secretion of interleukin-10 (IL-10), an anti-inflammatory cytokine, in mouse bone marrow-derived macrophages. Similar results were also observed in human monocyte-derived macrophages (HMDMs). In addition, most of cells that infiltrated the fibrin hydrogels were macrophages expressing CD163, CD204, and CD206, which are anti-inflammatory macrophages markers, both in mice and in human cells. Therefore, to induce increased macrophage infiltration, we attempted to combine fibrin hydrogels with SEW2871, a monocyte/macrophage recruitment agent that is known to be a sphingosine-1 phosphate receptor 1 agonist, solubilized in water by micelle formation with a cholesterol-grafted gelatin. However, the fibrin hydrogels alone retained the same monocyte migration activity as the hydrogels with SEW2871-incorporated micelles in the hydrogel-bearing mouse model. These findings indicate that fibrin hydrogels have a strong promoting effect on the recruitment of anti-inflammatory macrophages. Therefore, fibrin hydrogels may be an optimal biomaterial in the design of medicines for macrophage-induced regenerative therapies. STATEMENT OF SIGNIFICANCE: The immune response to tissue injury is important for determining the speed and the result of the regeneration. Alternatively activated macrophages (M2 macrophages) resolve inflammatory response and promote tissue repair by producing anti-inflammatory factors. Promoting the recruitment of macrophages is a hopeful strategy in the design of biomaterials for tissue regeneration. In the present study, we combined the fibrin hydrogel, which promotes anti-inflammatory polarization, with a macrophage recruitment agent. We revealed that the fibrin hydrogel significantly promoted anti-inflammatory polarization in mouse in vivo and human in vitro. Moreover, macrophages significantly infiltrated into the fibrin hydrogel regardless of the agent combination. Fibrin hydrogels may become a reliable biomaterial for tissue regeneration, and the present study is believed to provide information for many researchers.

Efficacy of gelatin hydrogels incorporating triamcinolone acetonide for prevention of fibrosis in a mouse model.

INTRODUCTION: Triamcinolone acetonide (TA), a steroid, is often used clinically to prevent dysfunctions associated with fibrosis. The objective of this study was to examine whether TA can be suspended in a gelatin sheet for tissue engineering using a mouse skin wound model. METHODS: TA was suspended in biodegradable gelatin and freeze-dried in a sheet form. The sheet was analyzed for homogeneity and controlled release of TA by high-performance liquid chromatography. We made two skin wounds on the dorsal side of mice. Gelatin sheets with TA (TA sheet) and without TA (control sheet) were attached to each skin wound. To determine the efficacy of the prepared TA sheet on the skin wounds, TA-sheet versus TA-injection experiments were conducted. Hematoxylin and eosin staining was performed to assess the grade of epithelialization and alpha smooth muscle actin (α-SMA) immunohistochemical staining was conducted to evaluate myofibroblast infiltration. RESULTS: In the TA-release test in vitro, 7.7 ± 2.3% of TA was released from the sheet by 24 h. After replacing the initial phosphate-buffered saline (PBS) with collagenase PBS, the amount of released TA increased over time. The wound area/original skin wound area after 15 days with the TA sheet was significantly larger than that with the control sheet (26.9 ± 5.5% vs 10.7 ± 2.6%, p = 0.023). The α-SMA positive area/whole area with the TA sheet was significantly lower than that with the control sheet (4.65 ± 0.66% vs 7.24 ± 0.7%, p = 0.023). Furthermore, the α-SMA positive area/whole area with the TA sheet was significantly lower than that with TA injection (5.32 ± 0.45% vs 7.93 ± 0.75%, p = 0.013). CONCLUSIONS: We developed a TA sheet and confirmed both the homogeneity of the suspended TA and controlled-release of the TA in the presence of collagenase in vitro. The TA sheet caused less myofibroblast infiltration into the tissue than the control sheet or TA injection did.

Parthenosporophytes of the brown alga Ectocarpus siliculosus exhibit sex-dependent differences in thermotolerance as well as fatty acid and sterol composition.

In the filamentous brown alga Ectocarpus siliculosus, male and female sex is expressed during the haploid parthenosporophyte phase of the life cycle. Here, we found that male parthenosporophytes displayed thermotolerance whereas female specimens displayed severely reduced viability at 25 °C and 28 °C. Profiling of polyunsaturated fatty acids showed that n-3 and n-6 were the predominant species in male and female parthenosporophytes, respectively, and that the n-3/n-6 fatty acid ratio was not affected by a temperature change. Both male and female parthenosporophytes contained the sterols fucosterol, cholesterol, and ergosterol, but these were present at higher levels at 10-25 °C in female specimens than in males. Thus, these fatty acids and sterols would be expected to make the membranes more rigid in the female compared to the male, which is opposite to the paradigm that increased rigidity confers thermotolerance. Our results suggest that the sex-dependent thermotolerance in E. siliculosus parthenosporophytes is not explained by the relationship between membrane fluidity and differences in fatty acids and sterol compositions.